Getting Started with
Magic xpa 3.x and MobileSelf-Paced Tutorial

Book ID: UTGSMAM32
Edition: 1.00, September 2016
Course ID: UCGMXAM3x
Magic University Official Courseware

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Getting Started with Magic xpa 3.x and Mobile
September 2016

Copyright © 2016 by Magic Software Enterprises Ltd. All rights reserved.

Contents
Introduction................................................................................................................... 1
About Magic xpa ....................................................................................................... 1
About the Course ....................................................................................................... 2
Course Prerequisites ................................................................................................... 2
How to Use this Guide ................................................................................................ 3
Exercises ................................................................................................................... 3
Course Materials........................................................................................................ 4
Entity Relations Diagram (ERD)..................................................................................... 4
Magic xpa Studio Interface............................................................................................. 5
Creating a New Project .............................................................................................. 6
The Navigator Pane ................................................................................................... 8
The Checker Result Pane ........................................................................................... 10
The Comment Pane .................................................................................................. 10
Summary ................................................................................................................. 12Creating Your First Program.......................................................................................... 13
Opening the Getting Started Project ........................................................................... 14
The Project Source Files ............................................................................................ 14
The Application Properties......................................................................................... 15
Creating a Program.................................................................................................. 16
What Is a Task? ....................................................................................................... 19
Checking the Program .............................................................................................. 28
Running the Program ................................................................................................ 28
Executing on Your Mobile Device............................................................................... 30
About Magic xpa Attributes....................................................................................... 31
About the Magic xpa Picture ..................................................................................... 33
Exercise .................................................................................................................. 34
Summary ................................................................................................................. 35
Architecture Overview.................................................................................................. 37
Mobile Deployment .................................................................................................. 38
Summary ................................................................................................................. 40
Data Manipulation and Validation ................................................................................ 41
Numeric Data Manipulation ...................................................................................... 42
Logic Editor ............................................................................................................. 43
Alphanumeric Data Manipulation............................................................................... 51
Magic xpa Internal Data Validation ........................................................................... 55
Developer Validation ................................................................................................ 57
Data Consistency ..................................................................................................... 59
Data Consistency – Short Summary ............................................................................ 63
Parking Condition .................................................................................................... 64
Exercise .................................................................................................................. 66
Summary ................................................................................................................. 67iii

Setting Initial Values .................................................................................................... 69
Update in Task Prefix ................................................................................................ 70
Variable Initialization ............................................................................................... 71
Update in Control Prefix............................................................................................ 73
Exercise .................................................................................................................. 75
Summary ................................................................................................................. 76
Setting the Form’s Appearance ..................................................................................... 77
Adding Colors to the Color Repository........................................................................ 78
Adding Fonts to the Font Repository............................................................................ 81
Wallpaper .............................................................................................................. 85
Placement................................................................................................................ 89
Exercise .................................................................................................................. 94
Summary ................................................................................................................. 95
Viewing Data Source Content ....................................................................................... 97
Defining the Database .............................................................................................. 98
Defining a Data Source........................................................................................... 102
Automatic Program Generation................................................................................ 105
Manually Creating the Customers Program ............................................................... 107
Short Summary ...................................................................................................... 112
Viewing Several Records......................................................................................... 113
Task Mode ............................................................................................................ 113
Creating a Line Mode Program ................................................................................ 114
Exercise – Suppliers Line Mode Program ................................................................... 120
Summary ............................................................................................................... 121
Models ..................................................................................................................... 123
What Is a Model? .................................................................................................. 124
Advantages to Defining Models ............................................................................... 124
The Inheritance Mechanism ..................................................................................... 125
Field Class Models ................................................................................................. 126
Display Class Model............................................................................................... 127
Assigning Models to Objects ................................................................................... 128
Using a Field Model in a Task ................................................................................. 129
Exercises ............................................................................................................... 131
Summary ............................................................................................................... 132
The Application Engine Concept ................................................................................. 133
Event-Driven Development Concept .......................................................................... 134
The Task................................................................................................................ 134
Task Execution Stages............................................................................................. 135
The Task Execution Logic Units ................................................................................. 136
Execution Rules ...................................................................................................... 139
Summary ............................................................................................................... 143
Events and Handlers .................................................................................................. 145
Events and Handlers Concept .................................................................................. 146
Types of Events ...................................................................................................... 146
Raising Internal Events ............................................................................................ 147
iv

User-Defined Events ................................................................................................ 149
Handlers ............................................................................................................... 152
Event Checking ...................................................................................................... 154
Having More than One Handler for the Same Event ................................................... 155
Handling Internal Events ......................................................................................... 157
Exercise ................................................................................................................ 162
Summary ............................................................................................................... 163
Conditioning a Block of Operations............................................................................. 165
What Is a Block Operation? .................................................................................... 166
Block If – Conditioning Operations........................................................................... 166
Advantages of the Block Operation .......................................................................... 170
The Block While Operation ..................................................................................... 171
Exercise ................................................................................................................ 173
Summary ............................................................................................................... 174
One-to-One Data Relationships ................................................................................... 175
One-to-One vs. One-to-Many Data Relationships ........................................................ 176
Linking to Other Data Sources ................................................................................. 177
Link Header Line .................................................................................................... 177
Link Operation Usage ............................................................................................. 178
Link Types ............................................................................................................. 179
Using Link Query ................................................................................................... 180
Short Summary ...................................................................................................... 188
Link Recompute Mechanism ..................................................................................... 188
Link Success Indication............................................................................................ 188
Exercise ................................................................................................................ 191
Summary ............................................................................................................... 194
Selecting Data from a List ........................................................................................... 195
Selection List .......................................................................................................... 196
Data Control.......................................................................................................... 201
Exercises ............................................................................................................... 204
Summary ............................................................................................................... 205
One-to-Many Data Relationships ................................................................................. 207
One-to-Many Data Relationship Preface .................................................................... 208
Defining the Many Data Source ............................................................................... 211
Establishing the One-to-Many Data Relationship......................................................... 212
Subform Control ..................................................................................................... 217
More About the Subform Control ............................................................................. 223
Incremental Update ................................................................................................ 225
Exercise ................................................................................................................ 229
Summary ............................................................................................................... 230
Non-Interactive Processing .......................................................................................... 231
Data View Editor and Rich Client ............................................................................. 232
Client-Side vs. Server-Side Operations ...................................................................... 234
The Task Life Cycle ................................................................................................. 235
Identifying Client and Server Activity ........................................................................ 236v

Rich Client Operation Colors ................................................................................... 237
Batch Programming ................................................................................................ 238
Rich Client Task vs. Batch Task ................................................................................ 238
Engine Flow for a Batch Task ................................................................................... 239
Batch Task Behavior ............................................................................................... 241
Batch Delete .......................................................................................................... 242
Summary ............................................................................................................... 245
Reports ..................................................................................................................... 247
Using the Program Generator Utility ......................................................................... 248
Manually Creating a Report .................................................................................... 249
Print - Customers Form ............................................................................................ 251
Designed Report .................................................................................................... 254
The Browser Control ............................................................................................... 261
Displaying a PDF on an Android Tablet .................................................................... 264
Printing a PDF on a Mobile Device ........................................................................... 265
Complex Report Concept ........................................................................................ 265
Exercise ................................................................................................................ 273
Summary ............................................................................................................... 274
Processing Data by Groups ........................................................................................ 275
About the Group Logic Unit ..................................................................................... 276
Group Logic Unit Execution Order ........................................................................... 276
Engine Flow for a Batch Task ................................................................................... 277
Sorting the Data ..................................................................................................... 278
Exercise ................................................................................................................ 283
Summary ............................................................................................................... 284
Menus ...................................................................................................................... 285
The Menu Repository .............................................................................................. 286
Context Menu ........................................................................................................ 287
Menu Properties ..................................................................................................... 289
Application Menus ................................................................................................. 290
Summary ............................................................................................................... 292
Using the Device Functionality..................................................................................... 293
Fetching the Device Orientation ............................................................................... 294
Accessing the Camera ............................................................................................ 297
Telephone, SMS, Mail and HTTP.............................................................................. 298
Using the GPS ....................................................................................................... 299
Multiple Forms ....................................................................................................... 302
Summary ............................................................................................................... 305
Offline Implementation ............................................................................................... 307
Concept ................................................................................................................ 308
How Does It Work? ................................................................................................ 309
Local (Offline) Storage ............................................................................................ 310
Synchronization Programs ....................................................................................... 311
Offline Programs .................................................................................................... 313
Synchronization Issues ............................................................................................ 315
vi

Server Access Failure.............................................................................................. 319
Deleting a Record .................................................................................................. 322
Offline Images ....................................................................................................... 322
Exercise ................................................................................................................ 323
Summary ............................................................................................................... 323
Best Practices ............................................................................................................ 325
Models ................................................................................................................. 326
Code Reuse ........................................................................................................... 326
Logical Names....................................................................................................... 327
One-to-Many Forms ................................................................................................ 328
Defining Different Forms .......................................................................................... 328
Manager Program .................................................................................................. 328
Performance Enhancements ..................................................................................... 329
Summary ............................................................................................................... 332
Customization and Installation .................................................................................... 333
Creating a Cabinet File........................................................................................... 334
Setting Up the Server .............................................................................................. 335
Setting Up the Web Server ...................................................................................... 336
Rich Client Folders.................................................................................................. 336
Customizing the Application .................................................................................... 336
Directly Executing on an Android Device .................................................................. 342
Using Native OS Code in Mobile Apps .................................................................... 343
Fonts..................................................................................................................... 346
Summary ............................................................................................................... 349
Lesson 4 – Data Manipulation ................................................................................. 353
Lesson 5 – Initializing a Variable ............................................................................. 355
Lesson 6 – Setting the Form’s Appearance ................................................................ 357
Lesson 7 – Viewing Data Source Content .................................................................. 360
Lesson 8 – Models – Object Definition Centralization ................................................. 363
Lesson 10 – Events and Handlers ............................................................................. 367
Lesson 11 – Conditioning a Block of Operations........................................................ 371
Lesson 12 – One-to-One Data Relationships .............................................................. 373
Lesson 13 – Selecting Data from a List ...................................................................... 385
Lesson 14 – One-to-Many Data Relationships ............................................................ 390
Lesson 16 – Reports................................................................................................ 394
Lesson 17 – Processing Data by Groups ................................................................... 400
Lesson 20 – Offline Implementation .......................................................................... 404

vii

viii

IntroductionW

elcome to Magic Software University’s Getting Started with Magic xpa 3.x
and Mobile self-paced tutorial. We, at Magic Software University, hopethat you will find this tutorial informative and that it will assist you in getting
started with this exciting product.

About Magic xpa
Magic xpa provides all aspects of the application development and deployment
process within a single end-to-end platform. It features a ready-made businessapplication engine that simplifies the code-writing process and enables you to
deploy to market faster, using fewer resources.
Applications developed using Magic xpa typically have fewer coding mistakes,
undergo more thorough prototyping, benefit from greater business side input andoptimization, and can be more easily adapted to changing business needs.
Magic xpa enables you to focus more on the business logic of the application and lesson what is happening behind the scenes.

Install the Magic xpa Studio and ensure that your computer meets the
hardware requirements explained on the next page.

Introduction1About the Course
Magic University's Getting Started with Magic xpa 3.x and Mobile course is designed
to provide the student with a fundamental basic understanding of the concept behind
Magic xpa as well as tools for Magic xpa programming. The course will teach you allof the basic skills that are needed to start programming in Magic xpa.
In this course you will:
1. Learn the fundamentals of Magic xpa and how to get the best out of
Magic xpa.
2. Become familiar with the Magic xpa Studio interface.
3. Get to know the Magic xpa wizards and utilities.
4. Understand the Magic xpa concepts and standards.
5. Create a basic Magic xpa business application that:Has a full Mobile interface.
Works with an SQL database, SQLite
Exhibits one-to-one and one-to-many data source relationships.
Produces reports.

Course Prerequisites
Before you start with the course there is basic knowledge that you need to have:
Development knowledge

Familiar with databases – tables, rows, fields, indexes
and segments

Your computer must also meet some basic requirements:
Hardware

SoftwareIntroduction

Windows XP Pro and later. The course was tested on
Windows 7.
Pentium processor 1.8GHz and upwards(recommended: Dual-core, 2.66-GHz or faster)
1GB of RAM or greater
Screen resolution of at least 1024x768 pixels
IIS 7 or later.NET Framework 4 or later
For the Studio, you also need to have .NET
Framework V2.0 SP2 or V3 installed on yourmachine.

2

MobileAndroid SDK 1 installed on your desktop or laptop. Thisis needed for the lesson on customization.
Customization for iOS requires using a MacBook as well
as a valid iOS Developer Enterprise Program account.
Customizaton for windows 10 Mobile requires Visual
Studio 2015 with the Universal Windows App
Development Tools and SQLite for Universal Windows
Platform. These will not be discussed in this course.
It is strongly advised to perform the exercises using atablet.

LicenseThe course uses the MGDEMO license. This is a single
user license.

How to Use this Guide
To get the most out of this guide, follow the classroom lesson and ask any questions
that you have. You can then review the self-paced guide for that lesson and if you havefurther questions you can ask the instructor before the next lesson. The self-paced guideprovides more step-by-step instructions.
This guide also contains boxes with more information and tips. Here is what you may
find:This is a hint.

?

This is an important note.

This is a question for you.
Something to think about.

Exercises
At the end of most lessons there is an exercise. The solutions for the exercises areprovided at the end of this book. Try to do the exercise on your own before looking at
the solution.
Note that your solution may differ from the solution offered. This does not mean yoursolution is incorrect as there are many ways to solve a problem.

Introduction

3

Course Materials
The course materials contain the following:
Course data – This is data that you will need during the course exercises. This
includes the course database, images and other data files.
Classroom solutions

Entity Relations Diagram (ERD)
The diagram below shows the relationship between the SQLite tables that you will beusing in this course.

Introduction

4Lesson1

Magic xpa Studio Interface
Magic xpa has a graphical user interface that is fully compatible with current Microsoft
Windows operating systems. The interface is composed of three main parts: theNavigator pane, the work area and the status line. In this lesson you will learn about
the Studio interface and how to dynamically control the displayed items.
The Magic xpa Studio interface is composed of three main parts:
Navigator pane
Work area
Status line
The Navigator pane enables you to select one of the Magic xpa repositories to be
displayed, such as the Data or Program repository.
An important part of the Studio interface is the property sheet. Most of Magic xpa's
objects have dynamic properties, which are organized in a property sheet. The
property sheet can be displayed as a floating window, docking window, or as a tab in
the Navigator pane.
The interface enables you to view the comments of the project's objects using theComments pane and the checker results using the Checker pane.
The line at the bottom of the Studio interface is the status line, which displays different
information such as editing status and user name.
By the end of this lesson you will:
Know how to create a new project.
Be familiar with the Studio interface.
Know how to dynamically navigate between the repositories.
Know how to view an object's comments.
Know how to view the latest checker results.

Magic xpa Studio Interface

5Creating a New Project
The first step in programming in Magic xpa is creating a project. In Magic xpa, aproject is a collection of units that includes all the information related to a specificimplementation. This includes the main code, any related components, and references
to other projects. The main code is basically composed of models, data sources,
programs, and menus.
Now, you will create the Getting Started project. The models, data sources, programs,
and menus will be discussed later in this course.
1. Open the Magic xpa Studio.
2. In the Startup screen, click the New Project button.

Magic xpa Studio Interface

6

The New Project dialog box opens.

3. In the Project name entry, type Getting Started.
4. The Local Files Folder entry has a default value of:[Magic xpa path]\Projects\
Use the Browse button if you want to specify a different location.
5. Click OK.

As a result of the project creation process, the project files are created and the new
project is opened.

Magic xpa Studio Interface

7

The Navigator Pane
The Navigator pane lets you navigate between the project's objects in the Studioenvironment.
Displaying the Navigator pane as part of the Studio interface is optional.
The Navigator pane is usually located on the left side of the Studio.
1. From the View menu, select Navigator (Alt+F1) to open or close the Navigatorpane.

The first entry in the Navigator pane is a selection box, which enables you to display
one of five categories.
2. Open the drop-down list to view the categories.
3. Select the Repositories option.

Magic xpa Studio Interface

8

The Repositories View
The Repositories view displays a list of
Magic xpa's main repositories and a number thatindicates the number of items in each repository.
Selecting a repository (by clicking the option in the
Repositories view), displays it in the work area.
For example, by selecting the Programs option, theproject's Program repository is displayed.

The Property Sheet
The property sheet enables you to display the specific properties for a selected object.
To display the property sheet, you select the Property Sheet option from the View
menu.
The image displayed below is an example from an existing program. Later in thiscourse, you will be able to access similar property sheets in your own program.
Property sheets are available for the following objects:
ModelsVariables and Columns
Forms
Controls
Help Screens
The displayed property sheet dynamicallychanges according to the selected object.
You can sort the displayed properties
alphabetically or by category by clicking theAlphabetic or Categorized tab.
The modified properties are displayed in adifferent color (blue or bold).

Magic xpa Studio Interface

9The Checker Result Pane
Magic xpa enables you to check an object. The latest check results are displayed in the
Checker Result pane.
To display the latest checker result you select the Checker Result option from the View menu.
The image displayed below is an example from an existing program. Later in this course, youwill be able to access similar Checker Result panes in your own program.
The Checker Result pane is displayed (by default) under the work area.
The results are displayed in a data tree format. The levels of the tree can be sorted by theobject, message type, or by both the object and the message type.

The Comment Pane
Magic xpa enables you to attach a comment to an object in your project.
You can attach a comment to each of the following object types: models, columns, variables,
data sources, indexes, foreign keys, tasks, components, Direct SQL, events, handlers, helps,
ranges, rights, and I/O devices.

Attaching a Comment to an Object
To attach a comment to an object, such as a program:
1. Open the Program repository.
2. Park on the Main Program.
3. From the Options menu, select Comment (F12).
4. Type a comment in the displayed box.
5. Click OK to close the Comment box.

Magic xpa Studio Interface

10Viewing Comments in the Comment Pane
The Comment pane displays the comments for a selected object.

To display an object's comments:
1. From the View menu, select Comments (Alt+F12).
2. Park on the Main Program (from the example above).

Magic xpa Studio Interface

11SummaryIn this lesson you were introduced to the Magic xpa Studio interface.
You learned about the Navigator pane options and how to navigate between the main
repositories.
You learned how to open the property sheet for a selected object.
You also learned how to display an object's comments using the Comment pane.
In addition, you learned how to view the latest checker results.

Magic xpa Studio Interface

12Lesson2

Creating Your First Program
Magic xpa supports project-based development. In this lesson you will learn more
about the project concept and you will create your first program.
By the end of this lesson you will be:
Familiar with the project concept.
Able to create simple programs.
Able to define Virtual variables.
Able to add variables to a form.
Able to execute a program.

A program is the fundamental part of creating a project. Writing a program is thebasis for any development tool or language.
In this lesson you will create your first program. Then, you will execute the program toview the results on your device.

Creating Your First Program

13

Opening the Getting Started ProjectIn the previous lesson you created the Getting Started project. Now you will open the
project and create a program in it.
In the Startup screen, click the Open button.

The Project Source Files
When you create a new project, the Magic xpa Studio engine creates a new directorywith the name of the project, in the location that you specify in the New Project dialog
box. All of the project files are saved in the new directory.
The project files include:
A main project file, which has the same name as the project name and an .edp
suffix.
A Source subdirectory, which contains all of the project’s source files.
An Exports subdirectory for future export files.

Viewing the Project Source Files
Go to the [Magic xpa path]\Projects\Getting Started directory and see that the new
project file, Getting Started.edp, and the Source and Exports subdirectories werecreated.

Creating Your First Program

14

The Application Properties
Each project has its own properties. You can set the properties for the currently open
project. The set properties are saved as part of the project source files.
1. From the File menu, select Application Properties (Ctrl+Shift+P).
The properties are organized according to three main subjects:
StartUp
External Files
Security
The StartUp and Security properties will not be discussed in this course. For more
information, see the Magic xpa Help.

External FilesIn Magic xpa, you can define general settings for all of the projects and you candefine specific settings for each project. You can do this from the Options menu.
2. From the Options menu, select Settings to open its submenu.

Each of the options in the Settings submenu enables you to change the default setting
definitions for all of the projects.
For example, you can select the Colors option and add new entries to the Colorrepository. You will learn about this in a later lesson.

Creating Your First Program15However, some options can be set specifically for each project:
Colors
Fonts
Keyboard Mapping
HTML Styles
Print Attributes
The options above are external files and you can override the general files by clicking
the External Files tab in the Application Properties dialog box.
The idea is to enable you to provide unique settings for each project.

Creating a Program
In this section you will learn how to create a program in Magic xpa.
The program creation process consists of the following steps:
Creating an entry in the Program repository
Defining the task properties
Defining the task data view
Defining the task logic
Defining the task form

After the program creation is completed, the next step will be to execute the programand view the results.

The Program Repository
The Program repository contains an entry for each program within the project, startingwith the Main Program.
The image below is an example of a Program repository that contains four programs.

Creating Your First Program

16

The following table describes each column in the Program repository.

ColumnDescription#

A program identifier number that is generated automatically by
Magic xpa.
When you edit the Program repository by adding, deleting rows ormoving a program from one place to another, Magic xpa automaticallyrecalculates the number of the programs and updates their identifier
numbers.
You cannot directly change the program number.

Name

In this column, type in a descriptive name for the program. The program
name does not have to be unique and can consist of Alpha andNumeric characters.

FolderYou can group some programs under the same folder. From this entry
you can select a folder where you want to place the program entry.
Note: This column is only accessible when you have created a folder.

PublicName

This column defines the public name of the program. This name must be
unique in the project file, and it can be used for calling remote programs
or using the program in components.

ExternalThis column allows the program to be exposed for external calls.
Note: This column is only available when a public name has been
defined. This is important for your program to be exposed to calls frommobile devices.

OfflineThis property indicates whether the program can run on the server (notconnected to the server).

Last Update
Date andTime

These columns are automatically updated by Magic xpa when any
change to the program is saved. You cannot change the date and time.

Creating Your First Program17Adding a Program in the Program Repository
1. From the Project menu, select Programs (Shift+F3).

2. Park on the first row (Main Program).
3. From the Edit menu, select Create Line (F4). In Magic xpa, F4 is a shortcut for
creating a new line.
4. In the Name column of the new row, type: My First Program.
In order for this program to run on a mobile device, you need to add an external
name. You will learn more about this at a later stage.
5. In the Public Name column, type: RunMe. It is important to type this exactly as
it appears here.
6. Check the External check box.

Creating Your First Program

18

What Is a Task?
Both of the terms program and task are used to describe an application task in
Magic xpa.
There is a difference between a program and task in Magic xpa. A task is the basic
unit for constructing a program. A program can be constructed of a main task andsubtasks.
Actually, if a program consists of one main task only, like in the program you justcreated, it is equivalent to a task.
1. Park on My First Program.
2. Zoom to the program by pressing F5.
The Navigator pane displays the task tree.
In this case, the new program is constructed of only one main task.

In the image to the right, you can see an example of another task tree:
The Example task is the main task.
Sub Task A and Sub Task B are subtasks of the Example task.
The A1 task and A2 task are subtasks of the Sub Task A task.

Creating Your First Program

19

The Task Properties
Each task has its own property definitions.
The task properties include a collection of properties that let you define the task's type,
behavior, data, interface, and more advanced features.
3. When you zoom into a task, the Task Properties dialog box opens. If it is notopen, go to the Task menu and select Task Properties (Ctrl+P).

The Task name property is a descriptive name of the task.
The Task type property defines the task type. The task type can be:
Online (default), which means that the task requires user interaction, such as adata entry task.
Batch, which means that the task is an automatic task, not requiring any userinteraction.
Browser, which means that the task runs on a Web browser, using the Browser
Client methodology.
Rich Client, which means that the task runs as a Rich Client task and will run on
mobile devices.

4. Change the Task Type to Rich Client. This is what makes the program run as aRich Client program.
The Initial mode property defines the mode of operation in which execution of the task
starts.
The Source file name property is the name of the program's source file as it exists on
the disk. Each program is saved in a different file.
5. Click OK to close the Task Properties dialog box.

Creating Your First Program

20

The Task Interface
When you zoom to a task, the task interface is displayed.
The Task interface is composed of three editors:
Data View
Logic
Forms

Press the Ctrl+Tab keys to switch between the editors.
Press the Ctrl+1 keys or click the Data View tab to switch to the Data
View Editor.
Press the Ctrl+2 keys or click the Logic tab to switch to the Logic Editor.
Press the Ctrl+3 keys or click the Forms tab to switch to the Form Editor.

The Data View Editor
The Data View Editor enables you to:
Define the task's Main data source or Direct SQL statement.
Link to other data sources.
Define data source columns, Virtual variables, and parameters.
Declare additional data sources.

The Data View Lines
In the Data View Editor, you can create two types of lines:
Header line – The header line defines the task's data source types and properties.
The first header line defines whether the task has a Main data source or a Direct
SQL statement.
Detail line – The detail line defines the task's variables. The variables can be data
source columns, parameters, or Virtual variables.

Creating Your First Program21

In this lesson you will learn how to define Virtual variables only.
Later on in this course, you will learn how to define other sources inthe data view.

Defining the Task Data View
Now you will define the new program data view, which is composed of Virtualvariables.
A Virtual variable is a local variable that is used for computation and temporarystorage. The Virtual variable exists only for the program duration, so its value is not
saved after the program execution is terminated. This means that in each execution,
the values of the variables return to their default values.
There are two other kinds of variables in Magic xpa:
Parameter – Variables which receive values from a different program
Column – Data object columns defined within a database table
You will learn more about these other variables later in this course.

Creating Virtual Variables
6. Verify that you are parked on the Data View Editor.
7. Create a line (either by selecting from the Edit menu or pressing the F4
shortcut).
8. Set the first line as shown in the table below.
9. Create another line and set the information as per the second line of the tablebelow.

Variable Type

Variable Name

AttributePictureVirtualCustomer_Code

Numeric

9

VirtualCustomer_Name

Alpha

20

Creating Your First Program22

Although it might seem like it, the Virtual variables are not childrenof the Main Source header line. Later in this course, you will learn
how to select a Main Source and Main Source columns.

The Task Forms
Most projects allow for user interaction. A screen is one way to enable interaction. A
screen is a form that is displayed during the task's execution. Other types of forms areused to output reports, files, and so on.
A form displays information to the end user. Magic xpa supports various types offorms. This lesson will focus on the main form, the Rich Client Display screen.
Each task has a main form as the default and you can add additional forms.
For interactive tasks such as Online and Rich Client tasks, you use the form to display
the task's data view and to allow end-user interaction.
For non-interactive tasks such as Batch and Browser tasks, you can use the form todisplay data regarding the task progress while it is executed.
The Form Editor contains form definitions for a task. Each entry represents a form.
When you define a new task, Magic xpa automatically creates an entry in the Form
Editor, which is the task's main window. The name of the form is taken from the nameof the task. You can edit its name.
The task’s main form cannot be deleted or moved to another position in the repository.

Mobile Design Mode
When the Mobile Design mode is enabled and controls are added to the form, someof the properties will be set with different default values, which better support themobile platforms.
10. Enable this feature by clicking the Mobile Design Mode button

from thetoolbar or by opening the Options menu and selecting the Mobile Design
Mode option.

Creating Your First Program23

Main Form
Now you will define the task's main form.
11. Park on the Form Editor. Because this is a Rich Client task, the main form will
default to Rich Client Display. This is the form type used for Rich Client
programs.
In the Form Editor you can see all of the forms that are hierarchicallyabove the task that you are in. This is why the Main Program form isdisplayed.

12. Park on the My First Program form entry and zoom (F5) or double click.

By default, the Mobile Design Mode prepares a small screen to fit the dimensions of amobile phone screen. During this course, you will be developing for a tablet.
13. Therefore, increase the size of the screen by dragging it, so that it looks similar
to the one below.

14. Now, switch off the Mobile Design Mode.

Creating Your First Program

24

The Form Designer

The Form Designer includes:
A toolbar with the control commands – You can use the commands to align thecontrols’ location, size, and so on.
The controls’ Toolbox pane – This shows you the controls that you can add to theform.
The Document Outline pane – This shows you the controls that exist on the form.
You can use it to easily move controls from one container to the other.
The Variables pane and Models pane. This shows you all of the variables andmodels in your data view.
You will use these panes while editing forms in Magic xpa. The same options are alsoavailable on the overhead menu and via shortcut keys. It is good to get familiar withthe options and the shortcut keys.
If for some reason the panes are not showing in the workspace, select View menu (alsoavailable as an overhead icon).

Creating Your First Program25

Adding Variables to the Form
Now you will add the Customer_Code and Customer_Name variables to the task's
main form using the Form Designer panes.
15. From the Variables
pane, drag theCustomer_Codevariable, and drop it
onto the form), as shownin the image on theright.
16. Repeat the last step (2)for the Customer_Namevariable.

When you drag and drop a variable from the Variables pane,
Magic xpa automatically adds a Label control, which displays thevariable name next to the variable's Edit control.

Mobile Form Preview
When developing for mobile platforms, you can preview the Display forms that you
are developing by using the Mobile Form Preview pane.
17. Clicking the mobile button

from the toolbar to open this pane. You canalso access it from the Form menu.

This lets you play around with the placement andsize of the controls and see how the controls willappear on various mobile devices.
From the drop-down list at the top of the pane you
can select which mobile device you want topreview, such as iPhone 6. Next to the name of thedevice, you will see the dimensions of the device.
You can also change the orientation of the preview
and the zooming.
Note that the Mobile Form Preview pane is not
currently supported for Windows 10 Mobile devices.

Creating Your First Program26

Saving the Program
You have created a new program and defined its data view and form.
Now you will save and exit your first program:
18. From the File menu, select the Save option or click the Save button to save thechanges.

19. Close the form by clicking thepressing the Esc button.

icon at the top right of the screen or by

If you try to exit the program (by pressing the ESC key), a confirmation box isdisplayed to let you confirm or cancel the changes.
Click the Yes button to confirm the changes and exit
the program.
Click the No button to reject the changes and exit the
program.
Click the Cancel button to stay in the program.

Alternative Ways to Save
When the Form Designer is closed, from the Options menu, you can select the Save
Program option (Ctrl+S) to save the changes up to that point without leaving the
program.

Creating Your First Program27Changes to the Data View, Logic, or Form editors are regarded aschanges to the program itself. When you save or cancel
modifications from within one of the editors, changes in the othereditors will also be saved or cancelled.

Checking the Program
1. Park on the My First Program program in the Program repository.
2. From the Options menu, select the Check Syntax option or press F8.
If there are no syntax mistakes in your program, the message Program is OK willappear in the status bar.
If there are mistakes, the errors are listed in the Checker Result pane.
After completing any program it is advisable to press F8 to check for errors.

Running the Program
Now you will execute the program from the Studio environment.
1. Park on the My First Program program in the Program repository.
2. From the Debug menu, select Run (F7).

The Magic xpa Runtime window is opened and the executed program's main form isdisplayed.
To execute a program, you can press F7 or select the Run icon from the toolbar:

Creating Your First Program

28

The Studio engine automatically loads the Runtime engine when it
initially loads. However, this process is not visible to the end user untila request is made from the Studio to run something, such as pressing
F7 to execute a program. Then, the Runtime engine is visible andactive.

The Virtual variables that you created will be displayed and the task is now available
for end-user input.
1. In the Customer_Code variable, type the number 111.
2. Press the Tab key to move to the Customer_Name variable.
3. In the Customer_Name variable, type Fred.

You have just typed in values in the Customer_Code and Customer_Name Virtualvariables. Since Virtual variables exist only for the duration of the program, when you
exit the program the Virtual variable values are cleared.
4. Close the program and execute it again to see that the Virtual variable values
have been cleared.

Built-in Task Behavior
This section provides you with two examples that highlight Magic xpa's built-in task
behavior. Later on in this course, you will learn more about this internal behavior.

Internal Data Validation – Numeric Variable Example
Magic xpa handles data entry validation internally, according to the variable attribute.
In this example, the Customer_Code is a Numeric variable. Magic xpa verifies that
only numbers (and the negative/positive sign) are typed in this variable.

Creating Your First Program29

Picture Limitation Example
Magic xpa provides internal handling for Picture limitation validation, which is done
according to the variable picture.
In this example, the Customer_Code variable picture is limited to 9 characters. Magic
xpa will verify that only 9 numeric characters (and the negative/positive sign) are
accepted in this variable.
The Customer_Name variable picture is limited to 20 characters. Magic xpa will verify
that only 20 characters are accepted in this variable.
For example:
1. Type a 10-digit number in the Customer_Code variable.
Magic xpa will accept the first 9 digits and ignore the rest.
2. Type more than 20 characters in the Customer_Name variable.
Magic xpa will accept the first 20 characters and ignore the rest.

Executing on Your Mobile Device
To execute the application on your mobile device, you need to first install the Magicclient app on your device. We will use a generic client. This is for development
purposes only. In a later lesson, you will learn how to customize your own client.
For Android devices, you can install the MagicDev.APK application, which isavailable in the RIAModules\Android folder.
For iOS devices, download the Magic xpa client from the Apple App Store.
Before you run the Magic xpa client on your device, your Magic xpa applicationneeds to be running:
1. Open the Magic xpa Studio.
2. From the Options menu, select Settings and then Environment.
3. In the System tab, set the Deployment Mode environment setting to
Background.
4. Open the application.
5. Execute the Magic xpa application by pressing CTRL+F7 or by selecting the
Executes the project icon on the toolbar.

You also need to define the connection details for this server:

6. Copy the DevProps.txt file from the RIAModules\Android, RIAModules\iOS or
RIAModules\Windows 10 Mobile folder to the scripts folder.
7. Open the file in a text editor and set all of the details, such as the server IP,
program name and the application name.

Creating Your First Program30

When you run the Magic xpa client on your device, a dialog box will open asking you
to provide the path to the execution properties file. You will learn more about theexecution properties file in a later lesson.
8. Run the Magic xpa client on your device.
9. Type http://<your ip address>/MagicScripts/DevProps.txt.
MagicScripts is the default alias created during the installation. If you changed
the alias in the installation, then you should also change it here.
You will then see your program running on your mobile device.
Throughout this course you will see a number of side-by-side comparison
images for Android and iOS devices. Windows 10 Mobile is also available
as of Magic xpa 3.2.

The program will look similar to the images below:
Android:iOS:

The same program was executed on your desktop computer as well as on your mobile
device with no changes to the program. As you can see, the same program has adifferent look and feel on different operating systems. It also has the native look andfeel of each specific device.
When you park on the Customer_Code control, the device will automatically display anumeric keyboard. You will not be able to type any text even if you access the ABC
keyboard.
When developing for Android devices, you can connect your Android
device to your computer and then click the Android toggle button on
the toolbar . You can then run the project or the program and it will
be displayed automatically on your device. For information on how tosetup this up, please look at the appendix.

Creating Your First Program31

About Magic xpa Attributes
In the last example, you created two variables. You specified various properties that
help Magic xpa define the variable. One of these properties is the variable attribute (insome databases it is referred to as type). The attribute defines the characteristics of thevariable. The following table describes some of the attributes that Magic xpa supports:

Attribute
Type

Description

Alpha

Alpha is an attribute that allows the storing of alphanumericcharacters. In the Alpha attribute, Numeric characters are stored as astring. The Alpha attribute is the default attribute.

UnicodeUnicode is an attribute that allows the storing of alphanumericcharacters in Unicode format.

Numeric

Numeric is an attribute that allows the storing of an integer or adecimal number. You can store numeric values with up to 18 digits.
When you define a Numeric type, your device will initially open anumeric keyboard for your user to enter digits.

Logical

Logical is an attribute that Magic xpa stores internally as a single byte
with the 0 value (False) or the 1 value (True).
Use the Logical attribute when you are storing Boolean values, such as:
True or False and Yes or No.

Date

When you park on a Date control, your device will automaticallydisplay a Date Picker for you to select the date from a list. Each device
displays a different date picker control. Date is an attribute that isstored by Magic xpa internally as Numeric or as a String. The numeric
Date attribute is a counter of days since 01/01/01 or since
01/01/1901, depending on its storage field model. The fact that a
Date attribute is stored as a Numeric value lets Magic xpa perform
calculations to create new date values. A Date attribute is translated toits visible value only when it is displayed in Magic xpa.

Time

When you park on a Time control, your device will automaticallydisplay a Time Picker for you to select the time from a list. Each device
displays a different Time picker control.
Time is an attribute that Magic xpa stores internally as a counter of
seconds, starting from midnight. You can use a Time attribute torepresent either a duration of time or an absolute time value. Just as
with Date attributes, Time attributes can be subtracted from one
another, and values can be added to them or subtracted from them. A
Time attribute is translated to its visible value only when it is displayedin Magic xpa.

Creating Your First Program32

About the Magic xpa Picture
The picture properties can be set using a number that specifies how many charactersthe specific variable will accept.
Magic xpa provides even more functionality for the picture properties, enabling you todetermine more than just the number of characters.
In Magic xpa, the Picture property is a string that defines the variable length format.
The variable length is set using a number or mask (specific characters that function as
directives).
For example:
To configure a variable that will hold only 6 digits, you can specify its
Picture in one of the following methods:
The number six (6)The number sign (#) repeated six times: ######The number sign only once and the number six (the 6 means that the number will
have six digits): #6
To set a picture with a mask, zoom from the Picture property to a Picture dialog box,
which is different for each attribute.
Magic xpa will translate the settings in the Picture dialog box to directives in thevariable picture.
Each Magic xpa attribute has its own set of picture directives.

Creating Your First Program

33

Exercise
Now that you are familiar with additional Magic xpa attributes, you will add morevariables to the program.
1. Add the following variables in My First Program and display them on the form:

Variable Type

Variable
Description

AttributePictureVirtualCountry

Alpha

20

Virtual

City

Alpha

20

VirtualAddress

Alpha

20

VirtualGold Membership

Logical5

VirtualMembership_Date

Date##/##/####

VirtualMembership_TimeTime

HH:MM:SS

VirtualSalary_Amount

Numeric

12.2C

VirtualCredit_Amount

Numeric

12.2C

2.
3.
4.
5.

Execute the program.
Set the Gold Membership to True.
Park on the Membership_Date control and select the date 15th March, 1997.
Park on the Membership_Time control and select the time 3:15PM.

Note: You will learn more about the picture in the next lesson.

Creating Your First Program34

SummaryIn this lesson you created your first program in Magic xpa.
You learned about the project concept.
You also learned about the Program repository and how to create a program in therepository.
You learned how to define a program and some of its properties.
In addition, you learned how to define a task data view that includes local variables.
You were introduced to Magic xpa attributes and pictures.
Now, you are familiar with the program concept and you are ready to move on to thenext lesson.

Creating Your First Program

35

Creating Your First Program36

Lesson3

Architecture Overview
During the previous lesson you created a simple Rich Client program in Magic xpa andexecuted it and you saw it running both on your desktop machine and your mobile device.
Developing applications in this manner is known as developing Rich Internet Applications,
RIA.
Working with Rich Client programs means that you are working with distributed applicationarchitecture. It can be helpful to understand what is happening behind the scenes, so that you
can learn how to get the best performance.
This lesson covers:
The RIA architecture
Automatic logic partitioning
Transparent context management
Execution details

Architecture Overview

37

Mobile Deployment
Magic xpa Application Platform provides the tools to build core business applications that aresuited to the mobile environment, providing device-independent enterprise mobility in a single
unified interface.
Magic xpa applications can run natively on ssmartphones by using a native client module toimplement a single unified business logic repository that supports both Apple iOS and Google
Android.

The RIA Architecture
In the previous lesson you executed the application on your desktop machine and then ran theclient on your smartphone. The program was then displayed on your smartphone. Part of yourapplication runs on your desktop machine and part of it runs on the smartphone. This RIA
architecture consists of the following modules:
Magic xpa Server – The core process that serves the remote clients. This is a Magic xpa
Runtime engine (MgxpaRuntime.exe) functioning as an enterprise server.
Web Server – A standard Web server used to handle the remote requests.
Magic Internet Requester – An extension of the Web server that is used to connect theclient modules to the Magic xpa server and vice versa.
Magic Requests Broker – The middleware governing the flow of communication between
the Magic Internet Requester and the Magic xpa Server. The broker is in charge of theload balancing by which each request is directed to the most suitable Magic xpa server
process. The broker is also responsible for executing the fault tolerance policy and thecapacity surge policy.
GigaSpaces Middleware – GigaSpaces’ XAP in-memory computing technology is the
middleware that implements Magic xpa’s functionality on the In Memory Data Grid. The
GigaSpaces middleware is used in the deployment environment instead of the Broker.
Magic xpa RIA Client Module – A module that runs on your smart device and serves as
the front-end of the application.
In this course we will use the Broker as the middleware.

Architecture Overview

38

The image below displays Magic xpa's distributed application architecture when using the
Magic Requests Broker:

Mobile Device

Magic Internet
Requester

A client, such as a mobile client makes a request to theenterprise server, the Magic xpa Server. It does this via
the Magic Internet Requester.

Magic Requests
Broker

Magic xpa Server

The requester uses the Magic Requests Broker tocommunicate with the Magic xpa enterprise servers. The
broker receives the request and assigns a request ID tothe client's request.

Database

The request is then sent to the Magic xpa Server. The
Magic Internet Requester now works directly with the
Magic xpa Server.

Automatic Logic Partitioning
Once a Rich Internet Application is deployed, the Magic xpa platform automatically partitions
the logic of the application according to the nature of each operation that the platform isabout to execute. While running on the client, the client will automatically turn to the serverwhenever it encounters a server-side only operation. And while on the server side, theapplication will turn to the client whenever a client-side only operation is encountered orwhenever the server-side activity is completed. The automatic partitioning is the fundamental
feature of the platform, which enables the defining of logic without breaking the logic intoclient/server/communication modules. You will learn more about this in a later lesson.

Transparent Context Management
A Magic xpa RIA developer does not need to define or maintain user sessions or user
contexts. The Magic xpa platform automatically identifies the context of each request andimplicitly maintains the context to follow the current session of the end user.
The developer can define and utilize context specific information and further enhance thepersonalization of the execution with a set of functions.

Architecture Overview

39

Execution Details
In previous lessons you were asked to create the application with the name Getting Started
and to define a program with a Public name of RunMe. These are defined in a text file under
the server's Scripts alias. This file is known as the execution properties file. This file contains
properties that assist the communication between the client and the server, such as which
program the client wants to run. You will learn more about this file in a later lesson and you
will learn how to customize it.

Summary
The Rich Client architecture or Rich Internet Application involves a distributed architecture inwhich part of the code runs on the client, the smartphone, and part of it runs on the server.
Magic xpa takes care of the connection between the various modules including the context
management. As a developer you only need to define the programming logic.

Architecture Overview

40Lesson4

Data Manipulation and Validation
One of the objectives of any program is the ability to transform data from one format
to another. This includes working with numeric calculations and string manipulations.
First you will learn how to use Magic xpa arithmetic operators to perform simple
arithmetic operations on your data.
You will learn more about the Logic Editor and how to use operations.
You will then learn how to set a condition on an operation and you will be introduced
to the Magic xpa IF function. You will learn how to concatenate strings and how to trim
spaces from strings.
As in any interactive program, there is a need to validate the end-user data entry inyour program. You will also learn how you, as a developer, can validate end-user
data entry and how you can maintain data consistency.
This lesson covers various topics including:
Logic units
Operations
Calculations and conditions
Variable Change logic unit
Allow Parking property

Data Manipulation and Validation

41

Numeric Data Manipulation
Magic xpa enables you to manipulate numeric data and display the results. You can
use the simple arithmetic operators, such as addition and subtraction, and you canalso use the various Magic xpa internal Numeric functions. You will learn about someof these functions later on in the course. The following is a list of basic arithmetic
operators that you can use for numeric values:

Operator

Description+

Addition operator-

Subtraction operator*

Multiplication operator/

Division operator^

Exponentiation operator (A^B returns A to the power of B)

MOD

Modulus operator
Modulus returns the remainder of an integer division.
For example: 17 MOD 10 returns 7

In this section you will learn how to update a variable with the result of a simple
arithmetic calculation.

Data Manipulation and Validation

42

Logic Editor
You added variables in the Data View Editor and created the form in the Form Editor.
Now you will add logic to the program using the Logic Editor.
The Logic Editor enables you to define all of the task’s logical segments within a single
editor, where:
The header line represents a logic unit or a handler. You will learn more about
events and handlers in later lessons.
The detail line represents an operation.

From the Edit menu, you can create a header line by clicking Create Header Line(CTRL+H) or a detail line by clicking Create Line (F4).
Magic xpa internal logic units, for example the Control Suffix, enable you to enter asection or unit of logic pertaining to that logic unit. In this case, you will add a series ofoperations that will occur during the Control Suffix stage. This means that they will
occur when you leave or exit the control. You will have a better understanding of thisby the end of this lesson.
The logic that you want to add is that the credit for this person (Credit_Amount) is
double their salary (Salary_Amount). So if you modify the salary amount, you want toautomatically modify the credit.

Operations
You create a Header line to define events within the Logic Editor. Within each header,
you have Detail lines that make up that specific logic unit.
The Detail lines are made up of internal Magic xpa operations. There are nine
high-level operations that you can use in the Logic Editor. You can customize these
operations by adding expressions and using Magic xpa's functions, internal events,and so on. You can select an operation by selecting the operation from the combo box
or by entering the operation accelerator key (as seen in the combo box). The
operations are listed below:
Remark (default) – Enables you to enter a description of the section of code.
Update – Enables you to modify or set the value of a variable.
Call – Enables you to call a secondary program or other entities. You will learn
more about this later in this course.
Invoke – Enables you to call an external object, such as an operating systemcommand or a Web Service.
Raise Event – Enables you to raise an event. This will be discussed in a later lesson.

Data Manipulation and Validation

43

Evaluate – Enables you to enter an expression where the return value is True orFalse, but you do not need to know whether the function succeeded.
Block – Enables you to enter a set of operations with a single condition. There are
two types: Block If-Else and Block While.
Verify – Enables you to set a warning or an error as a result of a certain
expression.
Form – Enables you to either export data (to a printer or to a text file) or to importdata.

All operations defined for a single Header line are part of that logic unit. The Detaillines are indented under the Header line, as an indication that the operation is part ofthe designated logic unit.
In this example, you want to update the credit for a person where the Credit_Amountwill be double their salary (Salary_Amount). So you will use the Update operation
within the Control Suffix logic unit.
The following steps will guide you through calculating the Credit_Amount variable
based on the Salary_Amount.
1. From the Program repository, zoom into My First
Program.
2. Switch to the Logic Editor.
3. Create a Header line. You can do this by selecting theCreate Header Line option from the Edit menu or bypressing Ctrl+H.
4. Define a Control Suffix operation.
5. Zoom from the of: field and the Control list opens. This is known as a selection
list. In Magic xpa, you can zoom to the internal selection lists. Within the list,
you park on the item you want to use in your program and either click the
Select button or double-click the entry.
6. Park on the Salary_Amount control.
7. Click the Select button.

Data Manipulation and Validation

44

Expression Editor
Now you need to create the following expression: Salary_Amount * 2. For this you
will use the integrated Expression Editor.
The Expression Editor enables you to enter and display expressions.
An expression can be:
A constant, such as a specific number, a word, or a specific variable taken fromthe data view.
A formula for computing a value that consists of a sequence of operators indicating
the action to be performed and operands on which the operation is performed.
You can enter any arithmetic expression that follows conventional algebraic rules, astring, or a logical expression.
Each entry in the Expression Editor evaluates to any of the attributes that werediscussed in the previous lesson such as a numeric value, an Alpha string, BLOB, or alogical value (TRUE or FALSE), depending on the type of variable and functions used. If
an invalid combination of data types is used, Magic xpa will display an error
message.
When you right-click in the Expression Editor, an extensive context menu will appear,
where you can access the various Expression lists.
Magic xpa has many useful internal functions. You will use some of them during thiscourse.
You will now use the Expression Editor to add the functionality.
1

Park on the Control Suffix logic unit line and add a line.

2. Define an Update Variable operation.
3. Zoom to select the Credit_Amount variable from the Variable list.
4

Zoom from the With property to the Expression Editor.

5. Create an expression line by pressing F4.
6. Use zoom (or click on the list) to move to the variable selection list on the righthand side, so that you can select a variable.
7

Select the Salary_Amount variable.

8. In the expression line type: *2
The expression should be: I*2

Data Manipulation and Validation

45

9. Click OK to select the expression and exit the Expression Editor.
Note that the With column displays the expression number from the Expression Editor
as well as the expression value.

10. Save and close the program.
Now you will execute the program so that you can see the results.
11. Execute the project by pressing CTRL+F7 and then open the Magic xpa clienton your device.
12. Tap the Salary_Amount control. (You do not have to fill in all of the details thatare shown in the image below.)
13. In the Salary_Amount control, type 1000 and then tap the next control.

As you can see in the images below, when you leave the Salary_Amount control, theCredit_Amount value is updated by the Salary_Amount value, multiplied by 2.

Data Manipulation and Validation46

AndroidiOS

Explaining the Results
The Control Suffix logic unit is defined for a specific control. In this example it was
defined for the Salary_Amount control.
The Control Suffix logic unit is executed immediately when the end user leaves thecontrol.
Within the logic unit, you used the Update operation, which enabled you to update avariable value with an expression.
You created an expression in the Expression Editor and used the arithmetic operator(*) to multiply the Salary_Amount value by 2.
In the same way, you can use all of the other arithmetic operators that were mentioned
in the beginning of this lesson.

Conditional Calculations
Magic xpa allows you to condition the execution of an operation. The condition is alogic expression, which returns True or False.
Now you will add a condition to the Update operation, so that the Credit_Amountvariable will be updated by the Salary_Amount*2, but only when the Salary_Amountvalue is greater than the Credit_Amount value.
1. Zoom to My First Program.
2. Switch to the Logic Editor.

Data Manipulation and Validation

47

3.
4.
5.
6.

Park on the Update operation line.
From the Cnd column, zoom to the Expression Editor.
Create an expression line.
Enter the following expression Salary_Amount > Credit_Amount (theexpression will be I>J).
Note: You can zoom to select a variable from the Variable list to be usedwithin the expression.

7. Save and close the program.
8. Execute the project by pressing CTRL+F7 and then open the Magic xpa clienton your device.
9. In the Salary_Amount control, type: 100.
10. Tap any other control.
You will see that the Credit_Amount value was updated to 200, since the condition
evaluated to True. The Salary_Amount value (100) was greater than theCredit_Amount value (0).
Now, try a scenario in which the condition is not met.
11. In the Salary_Amount control, type 150. Remember that the amount in theCredit_Amount control is set to 200.
12. Tap any other control.
You will see that the Credit_Amount value was not updated, since the condition
evaluated to False.
The Salary_Amount value (150) was less than the Credit_Amount value (200).

Data Manipulation and Validation48

In the previous section you learned how to set a condition for an operation. In somecases you need to control the returned value as well as the operation execution. In
these cases, you need to condition the result.

The Internal "IF" Function
When you need to condition an operation, you can use the IF function. This function
evaluates a Boolean expression and returns one value if True and another value if
False. In the following example you will use the IF function to control the multiplication
factor (from the last example), so that if the customer has a gold membership, thecustomer receives better credit (the multiplication factor will be 3 instead of 2).
1. Zoom to My First Program.
2. Switch to the Logic Editor.
3. Park on the Update operation line.
4. From the With column, zoom to the Expression Editor.
5. Change the expression as follows: IF(F,I*3,I*2)
Where:F is the Gold_Membership variable and
I is the Salary_Amount variable.
This expression evaluates to:
IF (Gold Membership is True, then multiply Salary_Amount by 3, else multiply
Salary_Amount by 2).

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49

When using a Logical variable, it is not necessary to use theexpression F=True meaning Gold Membership=True. It is adequate tosimply use the variable. In this case, you could write F (instead of
F=True), which is the variable Gold Membership.

6. Save and close the program.
7. Execute the project by pressing CTRL+F7 and then open the Magic xpa clienton your device.
8. In the Gold_Membership control, type: True.
Once you type the first letter of the words True or False (T/F) in
Logical variables, Magic xpa will automatically complete the rest of
the word once you move off the field.
9. In the Salary_Amount control, type 100 and press the TAB key.
As you can see in the images below, the Credit_Amount value was updated with 300,
since the customer has a Gold_Membership.
AndroidiOS

Now you will try a different scenario in which the customer does not have a gold
membership.
10. In the Gold_Membership control, type False.
11. In the Salary_Amount control, type 2000 and press the TAB key.

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50

The Credit_Amount value was updated with 4000, since the customer does not have aGold_Membership.

Don't forget that the Update operation condition (Salary Amount >Credit Amount) still exists. Make sure that the Salary Amount islarger than the Credit Amount.

Alphanumeric Data Manipulation
Up until now you have learned and practiced Numeric value manipulations.
Magic xpa also allows you to manipulate alphanumeric data.
In this section you will learn how to use the string concatenation operator toconcatenate several strings.
The ampersand (&) operator is used in Magic xpa to concatenate Alpha strings.
In this section you will learn about the string concatenation operator and the Trim
function. You will learn additional information about these functions later on in thecourse.
In this example you will display a customer's complete address, which includes aconcatenation of the customer's address, city, and country.
1. Zoom to My First Program.
2. Switch to the Form Editor and zoom to the My First Program form.

Now you will add an Edit control to the form to display the complete address string.
3. Increase the size of the form by dragging the bottom of the form.
4. Drag the Edit control icon from the Toolbox and place it on the form as shownin the image below.

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Park on the new Edit control and open the Control Properties sheet (Alt+Enter) if it’s notalready open. In Magic xpa, the keyboard combination of Alt+Enter will access aproperty sheet. You can also access the same sheet by selecting the Properties option
in the context menu for that specific item.
5. Expand the Data property and zoom from the Expression line to assign anexpression for the control.

The Edit control can be assigned to a variable or to an expression. In
previous sections you added Edit controls that were assigned tovariables. Now, you will be adding an Edit control that will beassigned to an expression.

Data Manipulation and Validation52

6. The Expression Editor opens.
You will now use the Trim function. This function removes trailing or preceding blanks
from a string.
SyntaxParameters

Trim (string)

string: An Alpha string to be trimmed. You can type a string between
single straight quotation marks (') or type the letter of an Alphavariable.

Returns

The function returns the string without the leading and trailing blanks.

ExampleTrim(' hello ') returns the string: 'hello' without leading and trailingspaces.

Note

The apostrophes will not appear in the result.

7. Create an expression line.
8. Type the following expression: Trim(E)&', '&Trim(D)&', '&Trim(C)Where:
E is the Address variable.
D is the City variable.
C is the Country variable.
The string ', ' adds a comma separator.
In this example you are concatenating various strings together while at the same time
you are removing the extra blanks.

9. Click OK to select the expression for the Data property.

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The Edit control that you placed on the form should contain information from threevariables. Each variable may contain up to 20 characters. To display all of theinformation, including the three variables' content, and the spaces and commas
between the variables, you need to change the Edit control format to 70.
10. In the Edit Control properties’ Format property, type 70.

11. Close the program and save the changes.
12. Execute the project by pressing CTRL+F7 and then open the Magic xpa clienton your device.
13. Type in the same customer details, as you did before.
As you can see, the new Edit control displays the complete customer address, whichcontains the address, city, and country separated by commas.
Android

Data Manipulation and Validation

iOS

54

Magic xpa Internal Data Validation
In a previous lesson you were introduced to two examples that presented part of
Magic xpa's internal data validation mechanism. For example, you saw that an end
user cannot type Alpha characters into a Numeric variable. In Magic xpa, the variable
attribute, in this case the Numeric variable, prevents the end user from entering
unacceptable data.
The variable picture is a more specific way to define the data type and format of thevariable. For example, a variable with an Alpha attribute can contain Alpha andNumeric characters. Using the Picture property, you can specify the exact positions
within the variable that can contain Alpha characters and the ones that can contain
Numeric characters. The following table lists examples of variable definitions and theallowed values that can be used.

Attribute Picture

Description

Numeric

N5

A 5-digit number between -99999 to +99999.
The N directive allows the number to be negative.

##UXX

A 5-character string where the first two positions must be
Numeric characters, the next position an upper casecharacter and the last two positions can be any
character.
The # directive within the picture means that the data inthat position can only be Numeric.
The U directive within the picture means that Magic xpa
will automatically change the value to an upper casevalue.

Alpha

Note: In Android systems, auto capitalization is a settingon each keyboard. Some keyboards may have thisproperty set to off.
Example: 78Mag###-#######

A common way to define phone number variables. The
variable contains three numbers, which are the area
code, a separation character (-), and then the phone
number.

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55

Attribute Picture

Description

Date##/##/####

This format is the default format for a date.
You can also use DD/MM/YYYY.
The DD directives mean that the first two positions canonly be a number from 01 to the number of the days inthe specified month.
The MM directives mean that the end user can only entera number between 01 to 12, representing the month.
The YYYY directives mean that the end user can only
enter 4-digit numbers, representing the year in full format.

Logical5

A 5-character string that can only be True or False. Thisvariable format means that the end user can only enter
True or False. Other values will not be accepted.

Time

HH:MM:SS

This is the default picture for defining a time variable.

This section provides you with a number of examples that demonstrate the Magic xpa
internal data validation mechanism.

Numeric Attribute Validation
As you learned in a previous lesson, when you have a Numeric field, the numerickeyboard is displayed. When you try to enter a character in a Numeric field, the input
is rejected. As an example:
1. Execute the project and in the Customer_Code field, type a character, such as:a.
In a later lesson you will learn how to add a status bar so that you can pass
information to the end user. The end user will then receive an “Invalid number” error
message.

Alpha Attribute Validation
Magic xpa lets you enter any character in an Alpha variable.
The variable picture also defines the length of the variable. In this case, the name cancontain only 20 characters, since Magic xpa constrains the length of the string to 20
characters.
2. In the Customer_Name field, type: Sherlock lives in 221A Baker Street.
You will see that you will not be able to enter the entire text.

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56

Logical Attribute Validation
Magic xpa does not allow you to enter anything but True or False in Logical variables.
If you enter anything else, you will not be able to continue and you will receive anerror message.
3. In the Gold_Membership field, type: aaa.
4. Tap another field. You will receive an error and in the text of the error you will
see the valid values that you can enter in this field.

Developer Validation
Up until now the Magic xpa internal validation mechanism was discussed. This section
will explain how you as a developer can validate end-user data entry.
In this example you will ensure that the end user only enters dates that are not later
than the current date.
1. Zoom to My First Program.
2. Switch to the Logic Editor.
3. From the Edit menu, select Create Header Line (Ctrl+H) to create a Header line
for the Control Suffix logic unit. Define this Header line for theMembership_Date control.
For this example you will use the Verify operation. The Verify operation displays an
Error or Warning message whenever Magic xpa executes the operation and its
condition evaluates to True. The message will be displayed in an error box.
The Verify operation’s Mode property provides the following options:
Warning (default) – Magic xpa beeps and warns the end user by
displaying the specified message, but does not stop the program
execution. The user can ignore the message, click the OK buttonin the message box, and continue.
Error – Magic xpa beeps and alerts the end user by displaying thespecified message. The end user cannot ignore the message. The
end user must correct the input according to the constraints inorder to continue the program.
Revert (for advanced usage) – An error message is displayed. The
cursor returns to the handled control by executing the operations
that precede the Verify operation in reverse order back to the first
operation in the logic unit.

4. Park on the Control Suffix logic unit line and create a Detail line.
5. Define a Verify Error operation.

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57

6. In the property sheet, go to the Text property and type: The date is later
than the current date.
The Display property enables you to display the error message in anerror box or in the form's status line. On a mobile device, Magic xpa
does not display a status line and therefore the error message will
always be displayed in a message box.

7. Park on the Cnd property and zoom to the Expression Editor by pressing F5.
8. Create a line in the Expression Editor by pressing F4. The order that
expressions appear in the editor have no relevance to the program.
9. Select the Membership_Datevariable. This should be thevariable G assuming that you
have not added any of yourown variables.
10. Complete the expression as
follows:
G> Date().
11. Click OK.
Now you will execute the program to view the results.
12. Execute the project by pressing CTRL+F7 and then open the Magic xpa clienton your device.
13. In the Membership_Date field, select a later day than the current date, such as
15/09/2029.
14. Move to a different field.
As you can see, when the condition of the Verify operation is met (the typed date islater than the current date), an error message is displayed. After you confirm the error
message, by tapping OK, Magic xpa parks on the Membership_Date field, enabling
you to set a different value.

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Android:iOS:

You must enter a date that meets the condition you entered tocontinue, or exit the program.

Data Consistency
During project development, there are common scenarios in which you need tomaintain data consistency rules.
In this example, you need to maintain the data consistency while the end user types in
the address details. For example, take a scenario where the end user types a country
and then a certain city that belongs to the country. If the end user then changes thecountry, the city content should be cleared since the typed city most probably does notbelong to the new country. So you need to handle the change of the value. For this you
will use a logic unit called Variable Change.

Variable Change Logic Unit
The Variable Change logic unit handles the change of a variable's value. In
Magic xpa there are two ways that a variable value can be changed:
Interactively by the user – The change is a result of editing a value of the control on
the form.
Non-interactively – The change is a result of a non-interactive change, such as theUpdate operation.

The Variable Change logic unit is triggered whenever the variable value is changed in
one of the above ways.

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Parameters
When you create a Variable Change logic unit, you are prompted to approve thecreation of the following parameters. You will learn more about parameters later in thecourse.

Parameter

Description

CHG_REASON_
parameterThis parameter stores a number (0 or 1) that represents thereason the variable was changed.
0 – indicates an interactive change, such as editing the control
1 – indicates a non-interactive change, such as from an Update
commandThis parameter must be a Numeric attribute.

CHG_PRV_
parameterThis parameter stores the variable's value before the change.
This parameter must be of the same attribute as the variablechosen in the variable change.

This section will show you how to maintain the data consistency of the address details,
using the Variable Change logic unit.
1. Zoom to My First Program and switch to the Logic Editor.
2. Create a Header line (Ctrl+H) and define a Variable Change logic unit for theCountry variable.
A confirmation box is displayed, like theimage on the right, asking you if you
want to create parameters to hold theprevious value.
3. Click the Yes button in the
Confirmation box.

If you use the Country variable's value within this logic unit, the value
will contain the updated value. The previous value is passed in the
CHG_PRV_ parameter. As an example, if you changed the data in theCountry variable from England to Canada, then in the Variable
Change logic unit, Country will be Canada and CHG_PRV_Country
will be England.
It is useful to use this within the Variable Change logic unit; forexample, to compare the variable's current and previous values.

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Your program should now look similar to the image below.

The letter C to the right of lines 3-4 is an indication that these
operations are occurring on the client. This will be discussed in detailin a later lesson.

4. In the Variable Change logic unit, create a Detail line (F4).
Note: For usability and readability, it is recommended to define new
operations below the Parameters.
5. Create an Update operation for the City variable.
6. Update the City variable with the value ' ' (apostrophe, space, apostrophe).
This is equivalent to resetting an Alpha variable. You are updating the City witha blank value.
7. You need to update this variable when the previous value had an actual value;
in other words, it did not have a blank value. This means that the expression
should be CHG_PRV_Country <>' '8. Repeat the above steps for the Address variable. However, this time instead ofentering new expressions, select the existing ones.
Now you will add a Verify operation to alert the end user that the values of the city
and address were cleared.

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9. In the Variable Change logic unit line, create a line and add a Verify Warning
operation.
The warning will be: Note: The City and Address values were cleared!
10. The condition for the operation should be the same condition as the Update
operations: CHG_PRV_Country <>' '11. Close the program and save the changes.
The program should look similar to this:Now you will run the program to view the results.
12. Execute the project and then open the Magic xpa client on your device.
13. Type the same customer details as you did earlier in this lesson.
AndroidiOS

14. Change the Country value to: Spain.
15. Tap the Customer_Name control.

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AndroidiOS

As you can see, when you changed the Country value and left the control, the valuesof the City and Address were cleared and a Warning box appeared to alert the end
user of the changes.

Data Consistency – Short Summary
In the previous sections, you learned how to maintain data consistency.
You used the Variable Change logic unit to handle the change of the Country value.
Within the logic unit you defined Update operations to clear the City and Address
values, and a Verify operation to alert the end user when the values were cleared.
You set a condition for the operations within the Variable Change logic unit: Country
Previous value <>''.
This condition is necessary to make sure that the alert to the end user appears only if
the Country value is changed from one value to another, and not when the Country
value is empty and the end user enters a value for the first time.
You also saw three operations based on the same condition. This is inefficient coding
as the condition is evaluated for each operation separately. In a later lesson you willlearn about the Block operation and how to condition sections of code to make thisexample more efficient.

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Parking Condition
In the previous sections you learned one way to maintain data consistency; youhandled the content of a variable as a result of a change to another variable’s data.
Now you will learn another way to maintain data consistency. In this section, you willcontrol the parking ability of a control as a result of another variable’s content.
In this example, the City control will be parkable only if the Country variable has avalue, meaning that the variable is not empty. In addition, the Address control will beparkable only if both the Country and the City variables have values.
1. Zoom to the My First Program form of My First
Program.
Now you will set a parking condition for the City Edit
control, so that the control will be parkable only if theCountry variable has a value.
2. Park on the City Edit control and open theControl Properties sheet (Alt+Enter).
3. Park on the Allow Parking property and set it
to True.

The Allow Parking property enables you to define whether the user
can park on a certain control. On a mobile device this means that theproperty controls whether you can tap that field and enter data.
When this property is set to False, you cannot tap on the field or moveto it by any other means.
The Allow Parking property is enabled only when a variable isassigned to the control in the Data property.

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64

Define an expression in the Expression Editor (zoom from the Expression line).
4. Enter the expression: Country <>''
5. Repeat this by setting a parking condition for the Address Edit control, so thatthe control will be parkable only if both the Country and City variables havevalues. Use the following expression: Country <>'' AND City <>''The AND operator enables you to define a Boolean expression inwhich both expressions need to be evaluated to True in order for it tobe valid.

6. Run the project.
7. Type a value for the Customer_Code and the Customer_Name values as
before.
8. Tap the City control or the Address control.
You will notice that focus passed to different controls.
9. Type in a value for the Country field, and tap the City field. You will now seethat you can enter a value. You will still not be able to enter a value in the
Address field.
10. Type in a value for the City variable, and tap the Address field. The Address
field is now parkable.

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65

Exercise
1. The USA banks decided to give their clients a benefit. Each USA client will
receive an additional credit amount, which is 10 percent of the client's salary.
This calculation will be done after the end user types in the salary amount(in the Control Suffix of the Salary_Amount that you already defined).
In the Update operation of the Credit_Amount use the IF function to checkif the customer's Country=USA.

2. To make your project friendlier, add a personal welcome announcement to theform.
After the Customer_Name field, add
a Hello customer message, such as
Hello George.
Move the Customer Addressconcatenated field that you added
during this lesson to below theAddress Edit control.
You can see an example in theimage on the right.

Now you will practice what you learned about validation.
3. Add a validation to My First Program so that the end user will have to type in a
Customer_Code before tapping a different control.
4. Maintain the data consistency of the Membership_Date and Membership_Timevariables, so that if the date is changed, the time is cleared.
5. Do not allow the cursor to park on the Membership_Time field if theMembership_Date is empty. In Magic xpa, an empty date value is initially set
to '01/01/1901'Date.
Date is a literal and you will learn more about literals later in this course.

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SummaryIn this lesson you practiced some of the routine Magic xpa actions, such as zooming toprograms and using the Expression Editor.
You learned about:
Magic xpa arithmetic operators and how to use them to make calculations.
The internal logic units and you used the Verify operation and the Update Variable
operation. You were introduced to the Variable Change logic unit and learned
how to use it within your project.
The IF function and how to use it within expressions.
Ways to manipulate alphanumeric data. You learned about the Magic xpa
alphanumeric concatenation operator and how to use it to concatenate several
strings.
The Trim function, which removes spaces within strings.
Magic xpa's internal data validation mechanism and its benefits.
Validating the end-user data entry and how to maintain data consistency using the
Verify operation.

Data Manipulation and Validation

67

Data Manipulation and Validation

68

Lesson5

Setting Initial Values
Initializing variables with a default value is commonly used by developers during
project development to save the end user the trouble of entering constant values, suchas the current date.
Magic xpa enables you to set initial values for variables in different levels of the task.
Magic xpa provides you with a number of ways to initialize a variable value, such as
the Update operation and the Init property.
This lesson covers various topics including:
Init property
Task Prefix logic unit
Task Suffix logic unit
Control logic unit

Setting Initial Values

69

Update in Task Prefix
One of the ways to initialize variables with a value is by using the Update operation.
You can use the Update operation in each Task logic unit.
In Magic xpa you can define two task logic units:
Task Prefix – In this logic unit, you can specify operations that Magic xpa executes
at the beginning of the task execution.
The operations stored in this logic unit are used as initialization procedures, suchas initializing local variable values.
Task Suffix – In this logic unit, you can specify operations that Magic xpa executes
at the end of the task execution.
The operations stored in this logic unit are used as task completion procedures,such as updating parameters.
In this section, you will use the Update operation in the Task Prefix logic unit to set
variable values.

System Date and Time
Here you will update the Membership_Date variable with the Date function, which
returns the system date (the current date), and update the Membership_Time variablewith the Time function, which returns the system time (the current time).
You will use the Update operation in the Task Prefix logic unit so that the updatingprocess will be executed at the beginning of the task execution.
1. In My First Program create a Task Prefix logic unit.
2. In this logic unit, update the Membership_Date variable with the Date ()function and the Membership_Time variable with the Time () function.
3. Execute the project and run the Magic xpa client.
When you run the program, you will see that the Membership_Date field is updatedwith the current date value and the Membership_Time field is updated with the current
time value.

Setting Initial Values

70Variable Initialization
In the last section, you learned how to set a value for a variable using the Update
operation.
In some cases, there is a need to initialize a variable with a certain value.
There are some differences between the Update operation and variable initialization.
The Update operation is a procedural operation that is executed each time Magic xpa
reaches the Update command.
The variable initialization is divided into two major phases:
The procedural phase is executed when a record is created. The behavior depends
on whether you have Virtual variables or columns:
Virtual variable values are initialized in Create and Modify mode.
Column values are initialized in Create mode.
The non-procedural phase is executed when the Init expression includes othervariables within it.
The value of the Virtual variables and the columns with an Init expression
will be recomputed immediately after one (or more) of the expression’svariables have been changed.
You will learn about the table columns and task modes later in thiscourse.
The recompute mechanism is active only when a variable, which was
defined prior to the current variable in the data view, was changed.
This means that changes in variable A will affect variable B only if
variable A is defined before variable B in the data view.

During the previous lessons, you probably found it tedious to type in the same
information for every example. To handle this you can use the Init property to initialize
the Virtual variable values.
The execution side of the Init value can affect performance. This will
be discussed further in a later lesson.

Setting Initial Values

71

In this example, you will initialize the Customer_Code variable with a value of 1 andthe Customer_Name variable with the John Doe value. You will use the Init property toinitialize the variable value, so that the variable value will be updated before thevariable is displayed on the form.
1. In My First Program, go to the Data View Editor and park on the
Customer_Code variable definition line.
2. Zoom from the Init property and enter an expression for the value: 1

The Customer_Code Init expression displays the expression number
and the expression value is displayed to the right of it.
3. Park on the Customer_Name variable and enter the following expression for
the Init property: 'John Doe'For an Alpha expression, you must use single straight quotation
marks at the beginning and the end of the string expression (' ').

4. Execute the project and run the Magic xpa client.
As you can see, when you run the program, the customer code and name values are
initialized with the expressions that you set.
Android

Setting Initial Values

iOS

72

Update in Control Prefix
Up until now, you updated the variable value in the Task Prefix logic unit and in theControl Suffix logic unit. You can also update a variable in the Control Prefix logic
unit.
The Control logic unit enables you to handle the behavior of a specific control. You
can use the Control logic unit for various purposes, such as setting values for variables,
and checking input before leaving the control.
When you tap a control, the Control Prefix logic unit operations for that control are
executed before the focus is moved to the control.
Control Suffix logic unit operations are executed before the focus is moved from theparticular control to a different control. This logic unit was discussed in a previous
lesson.
If you set the Update operation within the Control Prefix logic unit, the operation will
be executed just before the cursor is moved to the control.
In this example, you will update the Country variable with the value: 'Australia' and
the City variable with the 'Melbourne' value.
You will use the Update operation in the Control Prefix logic unit.
1.
2.
3.
4.
5.
6.

Add a Control Prefix logic unit for the Country variable.
The condition for this logic unit is: Country variable is blank (Country='').
In this logic unit, update the Country variable with: 'Australia'
Add a Control Prefix logic unit for the City variable.
The condition for this logic unit is: City variable is blank (City='').
In this logic unit, update the City variable with: 'Melbourne'

Setting Initial Values737. Execute the project.
8. Tap the Country field.
9. Tap the City field.
As you can see:
The Membership Date and Time values are updated when the program begins.
The Customer Code and Name values are initialized when the program begins.
The Country value is updated only when you park on the Country field.
The City value is updated only when you park on the City field.

Note that if you change the country name and then tap another field, the Variable
Change logic unit will be active and you will get a message that the City and Address
fields were cleared. However, if you tap the City field, Magic xpa will invoke theControl Prefix logic unit and update the City with "Melbourne".

Setting Initial Values

74

Exercise
1. Update the City variable to Melbourne only if the country is Australia.
2. If the country is Tartarus, then the initial credit will be zero. Use the Init property
for this.
3. The Country variable is an Alpha field. Are the values Tartarus, tartarus or
TARTARUS all the same? If not, how can you check what the user entered sothat you can use it in an expression? How would you change the expression
you set in question 2?
4. If the country is Xanadu and the customer has a gold membership, then set theinitial credit to 1000.

Setting Initial Values

75SummaryIn this lesson you learned how to initialize values for variables in several ways.
You set variable values using:
The Update operation in different logic units. You used the Update operation in thislesson and previous lessons.
The variable’s Init property.
You learned about the behavior of each of the above options.
This lesson introduced you to the Task logic unit and the Control Prefix logic unit.

Setting Initial Values

76Lesson6

Setting the Form’s Appearance
In previous lessons you were introduced to the Form Designer. You learned about themain form and designed a basic form to display the task variables.
Magic xpa provides you with various tools to set the form’s appearance, such as theform’s background color and wallpaper as well as the controls’ color, font, style, size,and location.
This lesson covers various topics including:Color, font, and style
Wallpaper

In the Appendix of this course, you can find a best practices guide about form designfor mobile devices.

Setting the Form’s Appearance77Adding Colors to the Color Repository
Adding a Text Caption Color
Magic xpa provides you with a specific color file for each environment:
Application – The default Application color file is clr_rnt.eng. You can add, delete,and modify any entry in these files.
Internal – The default Internal color file is clr_int.eng. This includes colors that areused at runtime to display built-in screens, such as the environment setting dialog
boxes and the Range/Locate dialog boxes. You cannot add new colors and you
cannot rename existing colors. However, the entries’ color settings can be
modified.
Studio – The default Studio color file is clr_std.eng. This includes only the colors that
affect the Studio screens. You cannot add new colors and you cannot rename
existing colors. However, the entries’ color settings can be modified.
Each file contains a list of color definitions, which include a foreground color (FG) anda background color (BG).
It is good practice not to delete entries in the Magic xpa files, but only in theapplication file.
Now you will add two color definitions to the Color repository.
1. From the Options menu, select Settings and then Colors.
2. Click the Application tab.
a. Park on the last color line.
b. Create a line by pressing F4.
3. In the Name column, type: Text Caption.
4. Zoom from the FG column.
5. Select the first (empty) entry from the System drop-down list.
6. Set the following RGB
colors:Red = 68
Green = 68
Blue = 138
7. Click OK.
8. Zoom from the BG column.
9. Select the first (empty) entry
from the System drop-down list.
10. Check the Transparent check box.
11. Click OK.

Setting the Form’s Appearance

78You gave the color a meaningful name, Text Caption. This will help
you maintain consistency in your project if you assign this color to all
the Text controls that are used as captions.

Adding a Text Color
In a similar manner you will add a color that will be used for the text.
1.
2.
3.
4.

Create a line.
In the Name column, type: Text
Zoom from the BG column.
In the Text: BG window, select the first (empty) entry from the System dropdown list.
5. Check the Transparent check box.
6. Click OK.

7. Click OK to close the Color repository.
A Save As dialog box will appear.
8. From the Effective immediately parameter, select Yes.
9. Click OK.

Setting the Form’s Appearance79Changing a Control’s Color
Magic xpa enables you to set the appearance of each control placed on the form.
In this section, you will learn how to change the color of a control.
In the Color repository, you defined two colors: Text Caption (color # 4) and Text
(color # 5). Now, you will change the color of the Label controls to the Text Caption
color.
1. Zoom to the My First Program form of My First Program.
2. Select the Customer_Code Label control by clicking on it.
3. If the Label control’s Control Properties sheet is not open, right-click on thecontrol and select Properties (Alt+Enter).
4. From the Color property, zoom to the Color repository and select the entry Text
Caption (# 4).
As you can see, the color of the Customer_Code Label control has changed to blue.

5. Repeat stages 2-4 for all of the Label controls to change their color to the Text
Caption color.
6. Close the program and save the changes.

Setting the Form’s Appearance80

It is possible to select a number of controls at the same time and thento set the same color for all of the select controls. You do this using
one of the following methods:
Press the Ctrl key and then click each control.
Click above the first control, keep the left mouse button pressed
down, and move the mouse down until all of the controls aremarked.

Adding Fonts to the Font Repository
Adding a Text Caption Font
Similar to the colors, Magic xpa provides you with a specific Font file for eachenvironment:
Aplication – fnt_rnt.eng is the default Application font file, which contains a list of
10 default font definitions. You can add an unlimited number of application fontdefinitions to the list, which you can then use to design your task forms andcontrols.
Internal – fnt_int.eng is the default Internal font file, which contains a list of 100
fixed font definitions.
Studio – fnt_std.eng is the default Studio font file, which contains a list of 100 fixed
font definitions.
The list contains font definitions that are used within the tool (for windows, operations,expressions, and so on).

Setting the Form’s Appearance81Now you will add two font definitions to the Font repository.
1.
2.
3.
4.
5.

From the Options menu, select Settings and then Fonts.
Click the Application tab.
Create a line and in the Name column, type: Text Caption.
Zoom from the Font column.
From the Font Style list, select Bold.
The default font in the Studio is MS Sans Serif. This font may not be avalid font in the device that you are using. The device will reset thefont type to its own default setting. It will use the Font Style that you
defined. In a later lesson, you will learn how to use device specificfonts.

6. Add a new Magic xpa font named Text, using the default values.

7. Click OK to close the Font repository.
The Save As dialog box will appear.
8. From the Effective immediately parameter, select Yes.
9. Click OK.

Setting the Form’s Appearance82Changing a Control’s Font
Magic xpa enables you to control the appearance of each control placed on the form.
In this section, you will learn how to change the control’s font.
You previously added two new font definitions to the Font repository, Text Caption(font # 11) and Text (font # 12). You will now change the font of the Label controls to
the Text Caption font.
10. Zoom to the My First Program form (of My First Program).
11. Select the Customer_Code Label control by clicking on it and open the Control
Properties sheet.
12. From the Font property, zoom to the Font repository and select the entry named
Text Caption.
13. In the same way that you changed the Customer_Code Label control, change
the font of all the Label controls on the form to the Text Caption font.

Remember: You can select multiple controls by pressing Ctrl and clicking on thecontrols.

Move a Control
You may need to move controls to make the form look the way you want. You canmove controls using the mouse or the keyboard as follows:
By mouse: Click on the middle of the control and drag the control on the form to
the requested position.
By keyboard: Select the control and then move the control using the arrow keys.
The following instructions show you how to move the Customer_Code Edit control to
the right, in order to uncover the Customer_Code Label control’s content.

Setting the Form’s Appearance83

Using the Mouse
Click on the Customer_Code Edit control and drag it to the right.
Position it so that the entire Customer_Code Label control is displayed.

Using the Keyboard
Click on the Customer_Code Edit control.
Press the right arrow key to move the Edit control to the right.
Position it so that the entire Customer_Code Label control is displayed.

Reset the Control Size
The font you have chosen is bigger than the existing font. Therefore, you can see only
part of the text for some of the Label controls. You can manually resize the control by
dragging it to the right. Or, you can use Magic xpa’s Fit Control Size tool to adjust thecontrol’s size to the control’s picture size.
14. Select the Customer_Name Label control by clicking on it.
15. In the toolbar, click the Fit Control Size icon.
16. Change the positions of the rest of the Edit controls so that the Label controls
are displayed in their entirety.

Setting the Form’s Appearance84Wallpaper
Magic xpa enables you to set wallpaper for a form. The wallpaper is a file that serves
as the background of the window. The wallpaper is one of a form’s appearance
properties, which enable you to control the form’s appearance. In this section, you will
set a wallpaper file to be used as the form background and you will be introduced tosome of the form properties.

Copying Files
There are several directories and files that were prepared for you to use during thecourse.
Please copy the following folders from the CourseData directory into your project(Getting Started) directory.
data
env
imagesproducts
Text

Setting a Wallpaper File in the Form Properties
1.
2.
3.
4.

Zoom to the My First Program form.
Open the Form Properties.
From the Wallpaper property, click the Zoom
button to browse for a file.
Select the Wallpaper.jpg file (located in: [Magic xpa
installation]\Projects\Getting Started\env) and click the Open button.

Setting the Form’s Appearance85Dynamic Variable
You have just set a file name and path as the form’s wallpaper.
Using a specific file name and its path within a project may have some disadvantages
later on. For example, if you use the Wallpaper.jpg file within several programs as its
form’s wallpaper, and then you change the directory name or just move the file toanother location, you need to change the file name in every program that uses it aswallpaper. This may be very complicated in multi-program projects. Moreover, thesame project can be executed on different computers with different file locations, sothat the file references must be adapted to each computer environment.
To solve this problem, Magic xpa provides you with Logical Names. You will learn
more about these special variables in a later lesson. For now you will learn about auseful internal Logical Name:%WorkingDir% – This logical name contains the value of the path of the working
directory. In the current example that means:<Magic xpa installation path>\projects\Getting Started.

5. Park on the Wallpaper property.
6. Edit the property to: %WorkingDir%env\Wallpaper.jpg.

You can open the Form Designer and see that the wallpaper image is still there.

Setting the Form’s Appearance86Transparent Color for a Control
When setting wallpaper, sometimes you want the controls to have a transparent color
so that they fit in with the background.
To make a control transparent on its background, the control needs a color that has atransparent background.
In the following example you will set the full address Edit control as a transparent
control.
1. In the Form Designer, park on the full address Edit control and open the control
properties.
2. Set the Border property to False.
3. From the Color property, select the Text entry.
In the image below you can see that an image is set for the form as a result of thewallpaper setting and the full address control appears as a transparent control on thewallpaper background.

4. Close the program and save the changes.

Setting the Form’s Appearance

87Running the Program
You completed the form design. The program is ready for execution. Now, you will run
the program to view the results.
1. Run My First Program.
2. Type the customer details as shown in the image below.

AndroidiOS

As you can see in the images above, the use of wallpaper provides a more enhanced
look than the original black background. The program running on the Android device
and the iOS device have a similar look. As you can see from the image on the left (theAndroid image), the Android system’s edit control default color does not look good on
the wallpaper image. You will change this in the exercise.

Setting the Form’s Appearance88Placement
Placement is a very important issue when executing your program on a mobile device.
You will see the reason with a small example.
1. Open your program, My First Program, and add a new Virtual variable named
Address Label.
2. Make this an Alpha variable with a length of 200.
In an address label, you would have the name of the person on one line and then theaddress on another and so forth. You need to have a way of moving the text to a newline.
ASCIIChr (numeric)SyntaxParameters

Numeric: A number from 0 to 255 which represents an ASCII
character.

Returns

A character representing the ASCII value.

Note

ASCII 10 represents a line feed.

3. Set the Init property of the Address Label to the following expression:
Trim (B)&','& ASCIIChr (10)&Trim(E)&','&ASCIIChr (10)&Trim(D)&','&ASCIIChr (10)&Trim(C)where B is Customer Name, E is Address, D is City and C is Country.
4. Zoom into the form and move all the controls from Gold_Membership onwards
to further down on the form.
5. Park on the customer address concatenated Edit control that you added on theform.
a. Zoom into the Data property and change the value to the Address Labelvariable.
b. Right-click on the the Format property and re-inherit the value by rightclicking on the selecting Inherit. The value should now show 200 and not
70.
c. In the Appearance section, set the Vertical Alignment property to Top.
d. Reset the Border property to True.
e. In the Input section, set the Multiline Edit property to True.
f. In the Navigation section, set the Height to 2.5.

Setting the Form’s Appearance

89

g. Make sure that the height does not overlap the Gold Membership Edit
control. If it does, move the Gold_Membership control downwards.
Now you can execute the program and see the result.
AndroidiOS

As you can see in the image above, the Address Label shows only part of the data, yetat the bottom of the form there is more than enough room to display the data. This istrue when holding the tablet in Portrait mode. Is it true when you hold it in Landscapemode? What happens when you run the same program on a smartphone or a tablet
with a smaller screen? This is where placement comes in.
Placement is a property that determines whether or not controls are resized when theform is resized. When a control’s Placement property equals zero, the relative size ofthe control does not change when the size of the form is changed in runtime.
When the Placement property is larger than zero, the relative size changes
proportionally when the size of the form changes in runtime.

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90

The placement of a control is defined by four values.

In the Placement property, the Width and Height values determine how the control
resizes itself when the form is resized. The value is in percentages. When you set thevalue as zero, you are defining that the control is not resized. When you set a value of100, you are saying that the control resizes itself with the form.
As an example, you will increase the height and width of the Address Label when theform is increased. To do this:
1.
2.
3.
4.
5.
6.

Zoom into My First Program and zoom into the Form Designer.
Park on the Address Label control and open the control property sheet.
Click on the Placement property and then click the Zoom button.
Set the Width property to 100 in and the Height property to 100.
Click OK. The Placement property will show: 0,100,0,100.
Execute the program.

Setting the Form’s Appearance

91You can see from the image below that the Address Label’s size increased bothhorizontally and vertically. The problem is that the controls below the Address Labelare distorted because the controls are displayed one on top of the other. The othercontrols need to be moved.
AndroidiOS

The X and Y values of the placement solve theproblem. They determine how a control moves when
the form is resized. The value is also in percentages.
When you set the value as zero, you are definingthat the control stays in place. When you set a valueof 100, you are saying that the control moves withthe form for its full placement.

Setting the Form’s Appearance

92You will define that the Gold Membership control moves according to the placement.
This means that it will always appear after the Address Label, no matter how much that
control’s height grows. To do this:
1.
2.
3.
4.
5.

Zoom into My First Program and zoom into the Form Designer.
Park on the Gold Membership control and open the control property sheet.
Click on the Placement property and then click the Zoom button.
Set the Y property to 100.
Click OK. The Placement property will show: 0,0,100, 0.

Remember that if you change the Edit control, its label must move with it:
6. Park on the Gold Membership Label control and open the control property
sheet.
7. Click on the Placement property and then click the Zoom button.
8. Set the Y property to 100.
9. Click OK. The Placement property will show: 0,0,100, 0.
Execute the program.
AndroidiOS

As you can see from the image above, the Address Label increased in both width andheight and the Gold Membership control moved accordingly.

Setting the Form’s Appearance

93

Exercise
Now you will practice what you learned during this lesson.
1. Define a new color, Edit controls (Green = 90, Blue = 146). This text is an
example of what it will look like. Remember that the background must betransparent.
2. Change the color of all the Edit controls to Edit control.
3. Change the font of all the Edit controls to Text.
4. Define the placement of Membership_Date, Membership_Time,
Salary_Amount, Credit_Amount so that they move together with the Gold
Membership.
5. Define Customer_Name, welcome customer and Address controls so that theirwidth increases as the form increases but they remain in place.
Make the color and font files specific for this project.
6. Copy the color and font file to your project directory under the folder named
Env and set the color and font files in the Application properties using the%WorkingDir% logical name.
You will not see any changes in your project. However, from now on, all changes thatyou make to the color or the font files will apply to the files belonging to your projectand not to the generic files in the Support directory.

Setting the Form’s Appearance94Summary
This lesson introduced you to some of Magic xpa’s form design options.
You learned how to define colors and fonts to be used within your project.
You also learned how to change a control's color, font, size, location, and style.
You then learned about setting wallpaper for a form and about additional form
appearance properties.
You were introduced to the Logical Names option and used the %WorkingDir%logical name.
You learned about placement. Remember that when resizing the form:
Defining values of X=100 and Y=100 will keep the control in the bottom rightposition.
Defining values of Width=100 will resize the control horizontally. This is mostly
used when the control size is smaller than its content.
Defining values of X=100 will move the control horizontally. This is mostly used
when this control is displayed after a control that has a Width placement of 100%.

Setting the Form’s Appearance95

Setting the Form’s Appearance96Lesson7

Viewing Data Source Content
Saving data is a fundamental requirement for a data-related application. Magic xpa
supports the saving of data to various databases, such as: Oracle, DB2, Microsoft SQL(MSSQL), Pervasive, and ODBC.

This course uses SQLite as the database. To work with other SQL
databases, refer to the Magic xpa documentation.

Up until now you created programs with Virtual variables. Virtual variables exist as
long as the program is running. This means that data has to be entered every time theprogram is executed. There is no stage where you can save Virtual variables.
In this lesson you will learn how to create an entry (a data source) in the Datarepository.
This lesson covers various topics including:
Data sources
Program Generator utility
Screen mode and Line mode display
Table controls

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97

Defining the Database
About the Database Repository
The first step in defining a data source is to define the database in which the data
source is located.
Magic xpa enables you to connect to multiple database management systems(DBMSs), such as Btrieve, MSSQL, and Oracle.
The Database repository contains details about all of the physical databases that canbe accessed in the current installation of Magic xpa.
In the Database repository you can define multiple entries that point to different
databases or to the same database. Each entry in the Database repository contains
information regarding the DBMS, including the database name, user and password,
and additional details, which provide Magic xpa sufficient information to connect tothis database later on.
By default, there are some predefined databases that are created automatically in the
Database repository.

As you can see from the image above, additional databases exist for sample
applications. These are installed optionally by the Magic xpa installation.

Defining the GettingStarted Database
The course is provided with a GettingStarted SQLite database and course-related
tables and data. This database is located in the data folder. In the previous lesson, you

Viewing Data Source Content

98were asked to copy folders, including the data folder, from the CourseData directory
into the Getting Started directory.
To access those tables, you need to define a connection to the SQLite entry in the
Database repository.
To open the Database repository:
1. Verify that no projects are open.
2. If your project is open, select Close Project from the File menu.
3. From the Options menu, select Settings and then Databases.
In the Database repository:
4. Park on any line, such as the last line, and create (F4) a database entry.
5. In the Name column, type Getting Started.
6. In the Data Source Type column, make sure that DBMS is selected.
7. The default for the Database Name is MAGIC. Clear this entry. There is no
Database name in SQLite.
8. Zoom from the DBMS column to open the DBMS List, park on the SQLite entry,
and click the Select button (or press Enter).
Note: This may already have been selected.
9. The Location column shows the exact path to the database data. In the previous
lesson you learned about the %WorkingDir% logical name. Set the Location to:%WorkingDir%data\GettingStarted.dat

Viewing Data Source Content

99Setting Database Properties
The Database Properties dialog box contains three tabs:
Login tab – details regarding the login procedure (such as user name andpassword)
Options tab – information regarding the connection between Magic xpa and theunderlying database
SQL tab – data regarding the SQL connectivity
For the SQLite database, you do not need these properties. The image below shows anexample when using an MSSQL database.

Check Existence
When you execute a program that displays table content, Magic xpa sends a request
to the DBMS (where the table is located) specifying the required information. If thetable does not exist in the database (this is not referring to an empty table), an error
message will be returned from the underlying DBMS. In most cases when this happens,
the developer wants Magic xpa to create the required table (according to the tablestructure in the Data repository).

Viewing Data Source Content

100Magic xpa can check for the table's existence and create the table in the underlying
database when necessary. (The checking of the table's existence and creating thetable occurs once per program.) A specific property located in the SQL tab of the
Database Properties dialog box, supports this behavior, the Check Existence property.
1.
2.
3.
4.

Open the Getting Started Database Properties dialog box (Alt+Enter).
Click the SQL tab.
Select the Check Existence check box.
Click OK to close the Database Properties dialog box.

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101

Defining a Data Source
The next step is to define the data source. Defining a data source is divided into thefollowing main steps:
Defining the data source header
Defining columns
Defining indexes
Defining foreign keys. This is not in the scope of this course.
The Data repository is divided into two sections:
The upper pane contains basic properties of the data source, including its name,data source name, database, folder, and public name.
The lower pane displays three repositories: columns, indexes, and foreign keys.
The displayed content in the lower pane changes according to the selected data
source in the upper pane.

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102

Defining the Customers Data Source
Now, you will define the Customers data source.
1. From the Project menu, select Data (Shift+F2) to open the Data repository.
2. Create a line.
3. In the Name column, type Customers.
4. In the Data source name column, type Customers.
5. From the Database column, zoom to the Database List, and select the Getting
Started entry.

Defining Columns
The Column repository contains the column definitions of the data source. Each data
source has its own Column repository. You define columns for a data source in thesame way you defined Virtual variables in the data view of the program. For eachcolumn you can set a name, model, attribute, and picture.
6. Park on the Customers data source in the upper pane.
7. Click the Columns tab in the lower pane.
8. Define column entries for the items exactly as shown in the image below:

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103

Defining an Index
Now you will define a unique index for the Customers data source.
9. Click the Indexes tab in the lower pane.
10. Create a line and define an index as shown in the image below:

A Unique Index is an index where only one record with a specific value in the index
can be present in the table. Note: Primary keys will not be discussed in this course.
Now, you will define the index segment.
11. From the Customer_Code Index name, zoom to the Segments repository.
12. Create a line in the Segments repository.
13. Zoom from the Column column. The cursor will move to the Column list (righthand pane).
14. Park on the Customer_Code entry and press Enter to select the Customer_Codecolumn. The Customer_Code will appear as the index segment in the Segments
repository.

15. Click the upper pane to return to the Data Source definition.
16. In the Confirmation dialog box, select Yes to save your work.
You have just finished defining the Customers data source.

Viewing Data Source Content

104Automatic Program Generation
Displaying the table content is performed in a program similar to the one you recently
created. Up until now you created programs that display and handle Virtual variables.
You will now use a handy tool known as the Generate Program utility to create a
program that displays the Customers data source’s content.
1. In the Data repository, park on the Customers data source.
2. From the Options menu, select Generate Program (Ctrl+G).

3. In the Program Generator dialog box, from the Mode property, selectGenerate.
The Mode property defines whether the result program will be temporary or
permanent. The options are:Execute – Generates andexecutes a temporary program
for the selected data sources.
Generate – Generates
programs for selected data
sources, and adds the
programs to the Program
repository. The programs are
not automatically executed.
4. From the Option property, select Rich Client. This property sets the program’sfunctionality.
5. Set the Program name property to Customers.

Viewing Data Source Content

1056. Click the Style tab.
7. From the Display property, select Screen.
8. Click OK.

The Program Generator added a program based on the Customers data source to theProgram repository.
9. Open the Program repository (Shift+F3).
10. Verify that the new program was added.

Rich Client programs need to have a Public name so that they can be executed
externally. At this stage of the course, the Public name is defined as RunMe. In a later
lesson, you will learn how to customize this:
11. Park on the My First Program entry and clear the Public Name definition.
12. Park on the Customers entry and set the Public Name property to RunMe.
13. Check the External box.

Viewing Data Source Content

106Running the Customers Program
You now have a program that can display the data from the Customers data source.
14. Execute the project and display it on your mobile device.
AndroidiOS

As you can see from the image above, you are provided with a basic program that
may or may not suit your needs. You may need to make some changes to the program
to make the program more readable. In iOS, the Label controls need to be increased.
The Generate Program utility is useful when you need to create a simple program.

Manually Creating the Customers Program
In the previous section you used the Program Generator to create a Screen mode
program. In this section you will manually create the same program.
A Magic xpa program is created using three main steps:
Defining the data view.
Adding logic.
Designing the form.

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107

In Magic xpa you only need to define the data view and design the form. Magic xpa
will provide all of the basic logic that you need to browse the content of a data source.
1.
2.
3.
4.

Open the Program repository (Shift+F3).
Create a line and name the program: Customers - Screen Mode.
As before, park on the Customers entry and clear the Public Name definition.
Park on the Customers - Screen Mode entry and set the Public Name property
to RunMe.
5. Check the External box.

Defining a Main Source
6. Zoom into the Customers - Screen Mode program.
7. Define the Task Type as Rich Client.
8. Click OK.
9. In the Data View Editor, park on the Main Source definition.
10. In the Data Source Number column (the field to the right of the words Main
Source), zoom to the Data Source list and select the first entry, the Customers
data source.
Note: The first index is automatically selected in the Index column.

Viewing Data Source Content

108You will now learn how to select columns for the Customers data source.
11. Create a line and from the column number (circled in red below), zoom to the
Column Selection window.

12. In the Column Selection window, select all of the columns using one of thefollowing methods:
Park on the first line, hold down the Shift key, and click on the # columnof the last line.
Park on the first line, hold down the Shift key, and press the Down Arrowkey until all 10 rows are marked.

13. Click the Select button or press Enter.
All of the Customers columns should now appear as shown in the image below.

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109

Designing the Form
Now that you have completed defining the data view, you now need to design thetask form. First, you will set wallpaper for the form.
1. Open the Form Editor.
2. Verify that you are parked on the form for this task.
Note: The first entry in the list is the form from the Main Program.
3. Open the Form Properties sheet and in the Wallpaper property, type:%WorkingDir%env\Wallpaper.jpg
4. Zoom into the Form Designer.
5. From the Task Variables pane, drag the Customer_Code variable and drop iton the form.
6. Repeat step 5 for the rest of the variables.
7. Change the Font of all the Label controls to Text Caption.
8. Change the Color of all the Label controls to Text Caption.
9. Fit the size of all the Caption controls to the displayed text.
10. Move the Field controls, so that the entire value of the Label controls will be
displayed.

Viewing Data Source Content

11011. Change the Color of all of the field controls to Edit control.

12. Close the program and save the changes.
13. Execute the project and display it on your mobile device.
AndroidiOS

As you can see, only one record is visible.

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111

Short Summary
Up until now you created a data source (table) in the Data repository and created two
programs that browse the table content. The first program was created using theProgram Generator; the second one was manually created.
During the data source creation, you were introduced to the Data repository, which is
divided into two panes:
Upper pane: where you define the data source name and its underlying database
information.
Lower pane: which is divided into three repositories:
Columns: where you define the Data Source columns and its properties,
such as type and picture.
Indexes: where you define the Data Source indexes and their segments.
Foreign keys: where you define external (other tables’) indexes that are
related to specific columns in the current table. This feature is used tomaintain data integrity and it will not be discussed in this course.
You learned how to create a program that browses the content of a table. You saw
that development is very similar to the use of Virtual variables.
In the next section you will learn how to display more than one record on the form.

Viewing Data Source Content

112Viewing Several Records
The manner in which you display the information on the form serves a purpose.
Screen mode – In this mode, only one record is displayed on the screen at a time.
Screen mode is usually used to display detailed information when the end userneeds to focus on a specific object and needs the maximum amount of informationon the screen.
Line mode – In this mode, several records are displayed on the screen at a time.
Line mode is usually used to display key information when the end user needs tosearch within a collection of records and needs minimum information for a quickview.

Task Mode
During this course you used a screen mode form, which enabled you to enter data
directly into a field. When you tapped the field, you were immediately able to edit thefield. This is known as a modify mode. However, when you display multiple records
such as a customer list you may not want your user to edit the data but simply browse
it. In Magic xpa tasks, there is a mode of operation known as Task Mode. The task’smode of operation determines which data manipulations are allowed on the data.
Magic xpa allows four modes of operation:

Mode of
Operation

Allowed Operations

CreateThis mode allows the end user to create new records.
When you are in Create mode you can only see the records that you
have added in the current session. To view all of the records, you needto switch to Query or Modify mode.

ModifyThis mode allows the end user to edit existing records and delete
records.
When you are in Modify mode, you can also create records. This is a
specific mode in Magic xpa called Create in Modify.

QueryThis mode allows the end user to scan through records, without updating
the records or deleting them.

DeleteThis mode is part of the Modify mode. This mode deletes the current
record.

The developer can specify the task’s initial mode as well as the allowed modes.

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Creating a Line Mode Program
You will now create a Line Mode program.
1. Open the Program repository and create a program called: Customers - LineMode.
2. As before, park on the Customers - Screen Mode entry and clear the Public
Name definition.
3. Park on the Customers - Line Mode entry and set the Public Name property to
RunMe.
4. Check the External box.

Defining the Task Mode
Set the Task Mode as follows:
5. Zoom into the Customers - Line Mode program.
6. In the Task type property, select Rich
Client.
7. Set the Initial mode property to
Query. Users will only be allowed toscroll through the data without being
able to edit it.

Defining a Main Source
Create the data view as you did in the previous section. In the Data View Editor:
8. Park on the Main Source definition and select the Customers data source andthe first index.
9. Select all of the Customers columns.

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Designing the Form
Now that you have completed defining the data view, you now need to design thetask form.
Set the wallpaper for the form as you did before:
10. Open the Form Properties sheet and in the Wallpaper property, type:%WorkingDir%env\Wallpaper.jpg
11. Zoom into the Form Designer.

Placing a Table control on the form
In the Form Designer:
12. Zoom to the Customers - Line Mode form.
13. From the Toolbox, click on the Table control.
14. Drop the Table control on the form as shown in the image below.

Only one Table control is allowed on a form. Therefore, you will not beable to drag more than one onto the form.

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Attaching variables to the Table control
15. From the Task Variables pane, drag anddrop the Customer_Code variable onto theTable control.
16. In the control properties, set the color to the
Edit control color. This will provide a similarcolor to the screen mode form.
Now you will add two more variables to the table:
17. Place the following variables on the table:
Customer_Name
Gold_Membership

18. In the control properties of all three Edit controls, set the color to the Edit control
color.

Expanding the table size
When attaching controls to the table, the table does not automatically resize.
Moreover, the table height determines the number of the displayed rows.
19. Select the Table control and increase the table width and the table height.
20. Close the program and save the changes.
21. Execute the project and display it on your mobile device.

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116AndroidiOS

As you can see, the customers are displayed in table format and more than one record
is visible. You can move to a different record by tapping the relevant record. You can
see that in the different mobile devices, there are some differences. In the Android
device, the system default for the table color is Black and on the iOS device, column
titles are truncated so that you are unable to read the full text.
The use of colors for your program depends on your own form design.
You may decide that the defaults provided by the operating system
suit your needs or you may decide that you want to provide a
consistent look and feel for your application across all platforms. It isyour choice. During this course you will be developing a similar lookand feel for all the devices.

Changing the Table’s Look and Feel
To change the table to provide a more unified look among all operating systems you
will do the following:
Change the color of the table.
Change the color of the row highlighting line. You will add a color to support this.
Change the text of the column header.
The first step will be to add a new color. All of the other actions are defined in the
program’s Form Editor.
1. From the Options menu, select Settings and then Colors.
2. Create a line.
3. In the Name column, type: Row Highlight.

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4. Zoom from the FG column. Select the first (empty) entry from the System dropdown list. Define the color as Blue (Blue=255).
5. Zoom from the BG column. Select the first (empty) entry from the System dropdown list. Define the color as Blue (Red=160, Green=190, Blue=230).
6. In the Text: BG window, select the first (empty) entry from the System dropdown list.
7. Click OK to close the Color repository. A Save As dialog box will appear.
From the Effective immediately property, select Yes.
Now you will change the table properties on the form:
8. Zoom into the Customers - Line Mode program.
9. Zoom into the Form Designer and park on the Table control.
10. Open the control properties sheet.
11. In the Appearance section, set the Set Table
Color property to Table. You will see that the
Color property above it is now accessible.
12. Zoom from the Color property and select the Text
color.
13. Zoom from the Row Highlight Color property andselect the color you defined previously, Row
Highlight.
You have now defined a uniform look across theplatforms. The next stage is to change the text for thecolumn headings:
14. Return to the Table control.
15. In the Customer_code column, click on the column header. This will select the
Column control.
16. Zoom into the control properties sheet for the Column control.
17. Park on the Column title property and change the name to Code.
18. Park on the Color property and select the Text Caption color.
19. Park on the Font property and select the Text Caption font.
You will now do the same for the Customer_Name and Gold_Membership columns:
20. In the Customer_Name column, press click on the column header.
21. Open the control properties sheet for the Column control.
22. Park on the Column title property and change the name to Name.
23. Park on the Color property and select the Text Caption color.
24. Park on the Font property and select the Text Caption font.
25. In the Gold_Membership column, pressclick on the column header.

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26. Open the control properties sheet for the Column control.
27. Park on the Column title property and change the name to Gold.
28. Park on the Color property and select the Text Caption color.
29. Park on the Font property and select the Text Caption font.
30. Set the Width property to 11. This will decrease the size of the column but notaffect the size of the Gold_Membership Edit control, which is part of thiscolumn.
31. Close the program and save the changes.
32. Execute the project and display it on your mobile device.
Android

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Exercise – Suppliers Line Mode Program
Now you will practice some of what you have learned:
1. Define the table in the Customers - Line Mode program so that when the size ofthe form increases so will the table.
Now you will practice working with data sources:
2. Define a Suppliers data source in the Data repository. Base it on the Getting
Started database.
3. Define the following columns:

Name

Model

AttributePictureSupplier_Code0

Numeric9

Supplier_Name

0

Alpha

20

Phone_Number

0

Alpha

###-#######

Address

0

Alpha

20

Years_Since_Start_Working

0

Numeric

2

Bonus

0

Numeric

3.2

4. Define a unique index called Supplier_Code with a segment for the
Supplier_Code column.
5. Create a program and name it: Suppliers - Line Mode.
6. Use the Suppliers data source as the program's Main Source.
7. Select all of the Suppliers data source columns.
Define the Suppliers - Line Mode form as follows:
8. Provide wallpaper for the form.
9. Display the Supplier_Code and the Supplier_Name in a table.
10. Change the heading of the Supplier_Code column to Code.
11. Use colors and fonts as you did during the lesson.

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120SummaryIn this lesson, you learned about data sources, including defining data sources as well
as viewing and manipulating the data source content.
You learned about the Database repository, where you defined a database based on
the SQLite DBMS.
You defined the Customers and Suppliers data source in the Data repository.
You learned how to use the Generate Program utility to create a Screen mode
programs. You can use the same tool to create a Line mode program.
You manually created Screen mode and Line mode programs.
You learned how to use a Table control within your programs.
You also learned about some other properties to improve the look and feel of yourtable.

Viewing Data Source Content

121Viewing Data Source Content

122Lesson8

ModelsA Magic xpa model is a set of properties that can be used to define a class of objects.
The use of models is optional, but using them will benefit you throughout thedevelopment and maintenance of the project.
The advantages of using models include saving development time, ensuringconsistency throughout the project, and making project maintenance easier.
Up until now, you created the project without taking into account the issues mentioned
above.
In this lesson you will learn about the Magic xpa Model repository, how to create amodel, and how to attach a model to an object.
The knowledge and tools you will learn about in this lesson will help you create a more
efficient and organized project.
This lesson covers various topics including:Model repository
Model types
Field models
Rich Client Display models
Model associations
Inheritance mechanism

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What Is a Model?
A model is a set of properties that can be inherited by an object.
When an object is associated with a model, the value of each object property that has
not been defined, inherits the value of the model.
When a property value is defined for an individual object, the inheritance for thatvalue is considered “broken”. The defined value overrides the model’s property value.
When properties of a model are updated, the change is automatically reflected in allof the associated object’s properties.

Advantages to Defining Models
When you plan the object items required for a specific project, consider whether they
can be grouped together based on common attributes.
In the Model repository, Magic xpa allows you to define these groups of objects bydefining a model for each group; that is, a prototype class having all of the group’scommon qualifiers.
The use of model definitions is optional, but using them will benefit you throughout thedevelopment and maintenance of your projects.
Some advantages to using the Model repository are:Time savings for project development. Once you have created an object model,
you no longer have to set the same property values for other objects.
Ease of maintenance. Once you have defined the properties associated with a
specific model, any modification to the model is automatically inherited by all of its
associated objects.
Ensure matching of columns in different data sources for Field models. Whencolumns are compared for link purposes, or passed as parameters, their attributes
must match exactly. A good way to ensure that they will match is to define themwith the same model.

ExamplesField Model
Assume a Customer_Code object is used widely in the project. You can set the object
properties such as Attribute property (Numeric) and Picture property (9 digits) once in
the Model repository and then use this model throughout the project. In addition, if you
need to modify the object’s picture, for example from 9 digits to 10 digits, you only
have to do it once in the Model repository. Magic xpa will update all of thecorresponding objects. You could also define the color and font of this object.

Models124Form Model
Assume that in your project all of the forms are uniform and have a wallpaper image
in the background. It is time consuming to repeatedly set these properties for each newform. Using a model, you can inherit all of these properties without the need to set
them, and without having to remember what you want the form to look like or how to
set it. In addition, if you need to change one or more properties, the change will takeeffect immediately in all of the forms that use that model.

The Inheritance Mechanism
This section explains Magic xpa’s inheritance mechanism.
When assigning a model to a new object, the object properties are inherited from themodel.
Selecting or typing a new value in the properties will break the inheritance mechanism
for the specific property.
When assigning a model to an existing object, only the properties that have not been
set individually (modified) are inherited from the model.
When changing an object’s model to another model, the associated object inherits theproperties of the new model.
When removing a model from an object, the object’s properties are set as the object’s
default values.
For properties in the Form Designer, to control the inheritance mechanism, you rightclick on the property and select Inherit, As Data or Break.
A modified property (a disinherited property) is displayed in bold. A property set As
Data will appear with the following marking:

The As Data option only appears for some properties and only when there is a value
set in the Data property. When this option is selected, the property inherits its value
from the Data property and not from the model.

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For properties not in the Form Designer, you can control the inheritance mechanism foreach property using the following toggle button. This button displays the opposite of
the current property’s inheritance status. So, if the property is broken, the inheritanceicon is displayed.
Break InheritanceUse this button to break the inheritance of the property.

Inherit Property

Use this button to inherit the property from the model.

A modified property (is displayed in blue and bold.

Field Class Models
You will now learn how to define a Field class model. You will define a Model for
Code, which can be used for both the Customer_Code and the Supplier_Code.
1.
2.
3.
4.
5.
6.
7.

From the Project menu, select Models (Shift+F1).
Create a line.
In the Name column, type: Code.
From the Class column, select Field.
From the Attribute column, select Numeric.
Open the Code model properties.
In the Picture property, type: 9.

You have just defined your first model in the Modelrepository.
In a similar manner you can define a model for Name, which can be used for both theCustomer_Name and the Supplier_Name.
1. Create a line.
2. In the Name column, type: Name.
3. From the Class column, select Field.
4. From the Attribute column, select Alpha.

5. Open the Code model properties and in the Picture property, type: 20.
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Display Class Model
Previously in this course, you created several programs with tables. For each program,
you set the Wallpaper property. Now you will set a consistent form appearance forthese programs using a Rich Client Display class model.
1. Create a line in the Model repository.
2. In the Name column, type: Table Display Form.
3. From the Class column, select Rich Client Display.
4. From the Attribute column, select Form.

5. Set the Wallpaper property to: %WorkingDir%env\Wallpaper.jpg.
6. Set the Wallpaper Style to Distorted Scaling.

When creating the programs, you changed the font and color of each of the static
texts. In this section you will define a Rich Client class model for a static control. The
most commonly used static control in your project is a text control that is used as alabel. You will now create a Label control model and set its font, color, and style.
Later, you can assign this model to all of the Text Caption controls in the forms.
7. Create a model.
8. In the Name column, type: Text Caption.
9. From the Class column, select Rich Client Display.
10. From the Attribute column, select Label.
11. Define the following properties:
Font – Text caption
Color – Text caption
Style – No Border

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In this section you will define a Rich Client class model for the Edit control. Later, you
can assign this model to all of the controls in the forms.
12. Create a model line.
13. In the Name column, type: Edit Control.
14. From the Class column, select Rich Client Display.
15. From the Attribute column, select Edit.
16. Set the Color property to the Edit Control color.

Assigning Models to Objects
Usually, you create the model prior to the object creation (a column in a data source,
or a variable in a task). Then, when you create the object, you only need to set themodel that the object should use and that’s it; all of the object’s properties will beinherited from the model.
Up until this stage in the course, the data sources were already created and you simply
created a definition for it in Magic xpa. Therefore, you need to assign the model to an
existing object. Then, you need to change the broken properties so that they inherit thevalue from the model.
In the following examples you will assign different types of models to objects.

Assigning a Field Model to a Column
In this example, you will assign the Code model to the Customer_Code column in the
Customers data source.
1.
2.
3.
4.

Open the Data repository and park on the Customers data source.
Zoom to the Column repository.
Park on the Customer_Code column.
From the Model column, zoom to the Model selection list.
Note: The Model list displays only the available models for the object. In thisexample, only Field class models are displayed.

5. Select the Code model.
6. Repeat steps 3-4 for the Customer_Name column and select the Name model.

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Inheriting the Model Properties
Assigning a model to an object is only part of the process.
When assigning a model to an object, Magic xpa sets all modified properties as
broken. You want the object to inherit its properties from the model; therefore, youneed to change the status of the broken properties to the inherit status. This is very
useful if you decide you want to change the picture of the field. You would then only
make the change in the model and not everywhere that it is used.
You want the object to inherit the Picture properties from the model.
7. Park on the Customer_Code column and open the Column properties.
8. From the Picture property, click the Inherit
button.
9. Verify that the button displays
after you click the button.
Note: Notice that the Code model is set in the Model property.
10. Repeat the above steps for the Customer_Name column.
When you exit the Customers data source’s Column repository, you will receive a
confirmation window asking you if you want to save the changes.
11. Click Yes.

Using a Field Model in a Task
You can also use models within tasks.
1. Open the Program repository and open the first program you wrote, My First
Program.
2. Open the Data View Editor and park on the Customer_Code Virtual variable’s
Model column (to the right of the word Customer_Code).
3. Zoom to the Model list and select the Code model.
Inheriting the model’s properties:
4. Park on the Customer_Code column and open the Column properties.
5. From the Picture property, click the Inherit
button.
Verify that the button displays

after you click the button.

Note: Notice that the Code model is set in the Model property.
6. Repeat for Customer_Name.

Assigning a Model to a Control
1. Open the Customers - Screen Mode program.
2. Open the task form.
3. Open the Customer_Code Label properties.

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4. Park on the Model property and zoom to the Model list by pressing the
button or by pressing F5.
5. Select the Text Caption model.
6. From the Font property, right-click and select Inherit.
Verify that the value does not appear bolded after you select Inherit.
7. From the Color property, right-click and select Inherit.
8. From the Style property, right-click and select Inherit.
9. Repeat steps 4-8 for all captions. (Remember that you can mark more than one
control at a time.)

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Exercises
Now you will practice working with models:
1. Create the following models for the Customers and Suppliers data sources:

Name

Class

Attribute

Model Properties

Country

Field

Alpha

Picture: 20

City

Field

Alpha

Picture: 20

Address

Field

Alpha

Picture: 20

Gold_Membership

Field

LogicalPicture: 5

Amount

Field

Numeric

Picture: 12.2C

Phone_Number

Field

Alpha

Picture: ###-#######

Years_Since_Start_Working

Field

Numeric

Picture: 2

Bonus

Field

Numeric

Picture:3.2

2. Assign models to all of the Customers and Suppliers data source columns.
3. Don’t forget to inherit the model’s properties.
4. Assign a model to all of the Edit controls in the Customers - Screen mode task’sform.
5. Define a model for an Edit control named Display Only that has:a. A color based on the Text color.
b. No border.
6. Define a model for a Rich Client table that has:a. A color based on the Text color.
b. Row highlighting that is based on the Row Highlighting color.
c. Placement so that the length of the table increases along with the form.
7. Define a model for a table column that has the Text Caption font and color.
This is a bit more challenging:
8. Make it so that when the code and name are placed in a Rich Client table,
they will always have a Color property of Edit control and no border.
Hint: Look at the properties of the model.
9. Implement the models defined in 5 through 7 on the Customers - Line Mode
program.

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SummaryIn this lesson you learned about Magic xpa models.
A model is a collection of object properties.
The use of models is optional, but using them will benefit you throughout thedevelopment and maintenance of the project.
Some of the advantages are:
Saving development time
Ensuring consistency throughout the project
Ease of maintenance
You learned how to create models, and how to assign models to columns, variables,
controls, and forms.

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Lesson9

The Application Engine Concept
The Magic xpa engine is the driving force behind Magic xpa’s ability to perform data
manipulations that are largely transparent to the developer and to the end user.
The Magic xpa engine automatically manages actions, such as opening files, reading
records from database sources, sorting records, and additional actions that are notusually part of other development tools. The Magic xpa engine saves the developerconsiderable amounts of development time by supplying these built-in operations.
Magic xpa enables you to define execution steps, called logic units, and to define a
set of operations within those logic units. You can select which operations are executed
and when, but the Magic xpa engine dictates which steps should be taken toaccomplish these operations. These steps are mostly pre-defined and carried out by theengine with no input from the developer or the end user. It is important for you tounderstand these steps, so that you can then develop your tasks with this information inmind.
This lesson covers various topics including:
The Magic xpa engine
Event-driven methodology
Task execution logic units
Task execution rules

Application Engine Concept133Event-Driven Development Concept
The Magic xpa engine is event-driven. This means that the engine responds to events
that occur during the task execution. The developer does not know which part of thecode will be executed next. The event-driven methodology consists of three parts: theevent, the trigger of the event, and the handler of the event.

Event
An event is a logical definition of an occurrence. The event is a flag that tells Magic
xpa that something should be handled. The event can be a built-in Magic xpa event or
it can be an event that was defined by the user.

Triggering an Event
An event needs a trigger that will determine when the event occurs. An event can betriggered internally by Magic xpa, by the developer, or according to an end-user
action.

Handling an Event
Magic xpa takes care of an event using handlers. Each event should have a handlerthat handles the event when it is triggered. The handler usually consists of a set ofoperations. The handler can be internal in Magic xpa or defined by the developer.
You will learn more about events and handlers in the next lessons.

The Task
Magic xpa’s basic object is the task. A program contains one or more tasks.
A task is a data-handling procedure with a defined beginning and end, which carries
out a set of operations with or without end-user interaction. The task execution process
is mainly defined by the task’s main data source and the task type. Therefore, the firststep in programming is defining the task’s Main Source and the task type.

Main Source
Most of the time, the engine executes a task by looping through the Main Source of thetask.

Task Type
There are four types of tasks: Online, Batch, Browser and Rich Client. Rich Client tasks
can be marked as interactive and non-interactive. During this course you have only
worked with interactive Rich Client tasks.

Application Engine Concept134Online, Browser and interactive Rich Client tasks enable end-user interaction throughthe task execution. When a Main Source is defined, the end user browses the Main
Source by navigating through the records. Only the records, which are browsed by theend user, are processed by the engine.
Batch and non-interactive Rich Client tasks are used to perform automatic procedures,such as producing reports and scanning a data source for calculations. In these tasks,
when a Main Source is defined, Magic xpa loops automatically through the task’s
Main Source, starting from the first record until the last record within a given range.

In all types of tasks, you can define a range. Magic xpa loops
through the records within the range.

Task Execution Stages
Once the Main Source and the task type are set, the next step is to customize the task
to accomplish a specific implementation. This is done by selecting the operations to be
performed, conditioning the operations’ execution, and defining in which stages of thetask execution the operations will be executed.
A standard task execution process follows several stages. These stages change
according to the task type and according to the set logic units.
For example, in a simple Online or interactive Rich Client task, the following stages
occur:
1. The database data sources that are defined in the task data view are opened(including the Main Source and linked data sources). You will learn more about
this later on.
2. Magic xpa starts the task, performing actions such as initializing Virtualvariables with values.
3. The first record of the Main Source is fetched for processing.
4. Manipulations are performed on the record, according to the set operations.
These may include displaying the record on the screen, accepting the end-user
selections and updates, and writing the record back to the database.
5. The engine checks whether another record should be fetched for manipulationor whether to end the task execution (the end-user requests to leave the task or
the End Task Condition evaluated to True).
If the next record should be fetched, Magic xpa returns to stage 3.
6. Magic xpa terminates the task, performing actions such as closing databasedata sources.

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135

The Task Execution Logic Units
Most Magic xpa logic units are pre-defined for specific events that occur during thelifecycle of the task.
Within the logic unit, you define a set of operations to be performed. Consequently,
these operations will be performed when the event is triggered.
Magic xpa logic units are designed to handle different task levels, as shown below.
The Task level, which occurs when the task starts or when it ends, is handled by thetask’s logic units.
The Record level, which occurs when Main Source records are manipulated, ishandled by the record’s logic units.
The Control level, which occurs when a specific control is accessed by the end
user, is handled by the control’s logic units.
The Variable level, which occurs when a variable value is changed, is handled by
the variable’s logic unit.
The Event level, which can occur at any point where the event is triggered, ishandled by the Event logic unit.
Operations within the logic units described above can be defined by the developer.
Magic xpa has additional code that is internally executed according to Magic xpa’s
internal rules and cannot be seen or accessed by the developer. On the next pages,
you will learn about the various logic units.

Task Prefix and Task Suffix
The Task logic unit is one of Magic xpa’s basic logic units. In the Task logic unit you
can specify operations that should be executed at the beginning and at the end of thetask. It is divided into two logic units:

Task Prefix
The Task Prefix logic unit is executed once when the task begins. Its trigger is the task
execution. Within this logic unit, you define operations that will be executed during theinitialization stage. (Data source information is not available in this stage.)

Task Suffix
The Task Suffix logic unit is executed once when the task terminates. Its trigger is thetask termination. Within this logic unit, you define operations that should be done once
as a termination stage. (Data source information should not be manipulated in thisstage.)

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136

Record Prefix and Record Suffix
The Record logic unit is one of Magic xpa’s basic logic units that occur during thetask’s lifecycle. In the Record logic unit you can specify operations that should beexecuted in the Record level, for every record, when it is fetched and when its
manipulation ends. It is divided into two logic units:

Record Prefix
The Record Prefix logic unit is executed for every record immediately after the record is
fetched and before the end user sees the record’s content. Its trigger is when the record
is fetched. In the Record Prefix logic unit, you define operations that should be done
once per record, as the record’s initialization stage.

Record Suffix
The Record Suffix logic unit is executed as follows:
Batch and non-interactive Rich Client tasks – will be executed for each record
Online, interactive Rich Client or Browser tasks – will be executed only if the user
modified the current record. You can force this mode by using the Force Record
Suffix property.
In the Record Suffix logic unit, you define operations that will be executed once perrecord during the record’s termination stage and before the record is saved to the
database.
The Record Suffix logic unit may be executed 0, 1, or 2 times per record, dependingon the end user’s interaction with the record. In Delete mode, the Record Suffix is
executed twice.
The Record logic unit is cyclical and may be executed several times during the task
execution.

Control Prefix, Control Verification, and Control Suffix
The Control logic unit is one of Magic xpa’s basic logic units. The Control logic unit isavailable for Online, Rich Client, and Browser tasks.
In the Control logic unit you can specify operations that should be executed whenevera certain control on the form is accessed.

Control Prefix
The Control Prefix logic unit is executed before the insertion point is moved to thecontrol. Its trigger is when the end user takes an action to park on the control.
In the Control Prefix logic unit, you define operations that are done before the end user
can manipulate the control’s content.

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137

Control Verification
The Control Verification logic unit is executed whenever the insertion point is taken
away from the control, before the Control Suffix logic unit is executed.
This logic unit is also executed when the insertion point passes through the control
without parking on it. (This is a special mode, called Fast mode, in Magic xpa.)
In the Control Verification logic unit, you define operations that validate the control
content, regardless of whether or not the end user edits the control.

Control Suffix
The Control Suffix logic unit is executed whenever the insertion point is taken awayfrom the control. Its trigger is exiting the control.
In the Control Suffix logic unit, you define operations that validate the control content,
or define actions that result from editing the control.
The Control logic unit can be executed several times depending on the number of enduser interactions.

Variable Change
The Variable logic unit is one of Magic xpa’s basic logic units. In the Variable logic
unit you can specify operations that will be executed as a result of a change to thevariable value.
The Variable Change logic unit is executed whenever the variable value is changed by
the end user (editing the control) or internally (such as using the Update operation). Its
trigger is the variable change.
The Variable Change logic unit can be executed several times for each change to thevariable value.

Application Engine Concept138

Short Summary
The following table describes Magic xpa’s basic logic units and their triggers.

Logic Unit Name

Logic Unit Trigger

Number of Executions

Task Prefix

A task execution starts

Once

Task Suffix

A task execution ends

Once

Record Prefix

A record is fetched

1 per record

Record Suffix

A record manipulation ends

0 - 2 per record

Control Prefix

An end user parks on a control-

Control Verification

An end user leaves a control, before
Control Suffix

Control Suffix

An end user leaves a control-

Variable Change

A variable value is changed-

Execution Rules
This section will provide you with the details about the processes that are executedduring the task’s lifecycle.

Task Initialization
The Data View Preparation
All of the data sources defined in the Data View Editor are opened.
Magic xpa examines the task data view operations, and the task’s logical record iscreated based on:
Column definitions from the Main Source and linked data sources.
Virtual variables and parameters.
Parameter values are received from a calling task.
Virtual variables are initialized with values that match the variable attribute(numeric variables are initialized with zero, alpha with blanks, etc.).
The task range is defined according to the range criteria in the Range Window.
The engine sorts the data view according to the specified Sort Indicators (ifspecified in the Sort Indicator window).

Application Engine Concept139Additional Preparations
The next steps include operations that initialize the task.
I/O devices are opened (if I/O devices are specified in the I/O Device
repository).
The operations in the Task Prefix logic unit are executed.

At this stage, no data from the Main Source or linked sources isavailable.

Record Processing
After the Task Prefix is executed, the data view records are processed as follows:

Record Prefix
The first record in the data view is located and fetched.
In Online and interactive Rich Client tasks, if there are no records in the data view,the task can either terminate or go into Create mode. It can also display a screen
without input.
This behavior is governed by the task properties called Allow Empty Dataview andAllow Create.
The Init expression is evaluated for all of the Virtual variables. The Init expressions
for columns are evaluated only if the task is in Create mode.
All of the links to data sources are executed for all records displayed on the screen.
If the Evaluate condition option in the Task Properties is set to Before entering
record, Magic xpa evaluates the End Task condition.
The Record Loop begins here. Therefore, from here on you can manipulate data
source columns.
The Record Prefix logic unit operations are executed.

Processing Controls
For each record, in interactive tasks, the accessed controls’ logic units are executed.
Control Prefix – For each control which is accessed by the end user, the Control
Prefix logic unit operations are executed.
Control Verification – The Control Verification operations are executed whenever
the end user moves from the control that the Control Verification logic unit is set for,or the control is skipped over (Fast mode). A control is skipped over in Fast mode
when the end user skips over this control to get to a different control.
Control Suffix – The Control Suffix is performed whenever the insertion point istaken away from the control. This occurs when the end user moves to a different
control, exits the record, or exits the task.

Application Engine Concept140Processing Variables
In Online and Rich Client tasks, the Variable Change logic units are executed
whenever a variable value is changed.

Record Suffix
In Online, Rich Client and Browser tasks, the Record Suffix logic unit is executed forrecords that were modified.
In Batch tasks, the Record Suffix is always executed.
In Online, Rich Client and Browser tasks, the Record Suffix logic unit is executed whenthe end-user interaction with a record is terminated. This happens when:
The end user moves to another record.
The end user changes the Task mode (Modify, Create, Query).
The end user deletes the record.
The task execution is terminated, such as a result of end-user interaction or if an
End Task condition evaluates to True.
When Magic xpa terminates the task, the Record Loop must be terminated first.

Task Termination
There are several ways to terminate the task execution, such as the end user leaves thetask, the End task condition evaluates to True, or the Exit event is raised.
Before the task is terminated, the following happens:
The Task Suffix logic unit operations are executed.
I/O devices are closed.
The task’s data sources are closed.

The Task Suffix logic unit is executed after the termination of theRecord Loop. Therefore, there are no data values that are reliable
during this stage of execution.

Application Engine Concept141

Brief Overview
The following table summarizes the Magic xpa logic unit triggers, execution rules, andthe order in which the logic units are executed.

Logic Unit

Logic Unit Trigger

Next Logic
Unit

The Next Logic
Unit Executes If:

Else,
ExecuteTask Prefix

A task is executed

There is at least one
Record Prefix record in the data
view

Task
SuffixRecord Prefix A record is fetched

ControlPrefixThis is an Online orRich Client task

RecordSuffixControlPrefixThe cursor parks on acontrol

Control
Verification

No restrictions

Control
Verification

Control editing isterminated or the
cursor skips over thecontrol

ControlSuffixNo restrictions

ControlSuffixControl editing isterminatedVariable
ChangeThe variable value is RecordchangedSuffix

Variable
ChangeA variable value ischanged

The record is about
to be saved in an
Task
Record Suffix
Online or Rich Client Suffix
task

Record Suffix

A record is about tobe saved

Task Suffix

Task Suffix

A task is about to beterminatedNo restrictions

The above table demonstrates only one execution cycle for each logic unit.
If the record or the control cycle is not terminated, that cycle will be
repeated (from its Prefix logic unit to its Suffix logic unit).
A Control logic unit can only be executed inside a Record logic unit cycle,
and a Record logic unit can only be executed inside a Task logic unit.
A parent logic unit cannot be terminated unless its sub-logic unit isterminated.

Application Engine Concept142SummaryIn this lesson you learned about the Magic xpa engine concept.
You were introduced to the event-driven methodology, which consists of three basic
elements: the event, trigger, and handler.
You learned about the task execution process, including the task type and the task’s
Main Source.
The task’s main levels include: the Task level, Record level, Control level, and Variablelevel. Each level is handled by different logic units. You learned about the task
execution logic units, as well as the logic units’ triggers and roles.
As you can see, Magic xpa has a lot of internal processes that are performed
according to various scenarios. For example, when you select main data sourcecolumns in a Rich Client task, Magic xpa internally opens the data source, selects thecolumns from the data source, handles the displayed data, and saves the data to thedata source after the end user chooses to leave the record. All of these processes weredone by Magic xpa automatically.
Now that you know about most of the Magic xpa engine’s behavior, you will be able
to create more efficient programs that take advantage of the task execution engine’s
behavior rules.

Application Engine Concept143Application Engine Concept144Lesson10

Events and Handlers
Event-driven programming is the writing of code for a logical unit that handles acertain scenario and will be executed on demand.
Procedural programming is the writing of code so that the operations are executed one
after another, according to a predefined scenario.
To implement event-driven programming, it is important to know about triggers, events,and handlers.
You need to know how to set events in Magic xpa and how to trigger them. You mustalso know how to create handlers that will handle the events.
This lesson will introduce you to the Events and Handlers concept in Magic xpa. Thislesson covers various topics including:
Magic xpa triggers
Magic xpa events
Defining an event
Invoking an event
Event-driven logic
Handling events
Checking events
Propagate mechanism
Overwriting internal event handling

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Events and Handlers Concept
As you learned in the previous lesson, event-driven programming consists of threeelements:
An event is a logical definition of an occurrence.
A trigger is an action that triggers the event. Triggers can be external (by the enduser) or internal (Magic xpa internal code or programmer code).
A handler is a logic unit of code that is activated as a response to the event
triggering.
An event can have more than one trigger and more than one handler. Each trigger
can raise the event in a different scenario. One or more handlers can handle the eventfor each scenario.
Magic xpa events can be project-related events, which are defined in the Main
program and are applied to the whole project. These events can be triggered during
the execution of any of the project’s programs. The events can also be task-related
events, which are defined in a specific task and are applied to the task in which they
are defined or to the task and its subtasks.

Types of Events
There are different types of events in Magic xpa. The first two events will be covered in
the scope of this course.
Internal events – These are pre-defined internal Magic xpa events. These events are
generally invoked as a result of a user’s action. For example, when you tapped afield, you raised a Control Prefix event.
User events – These are events that are created by you, the developer, for use
within the application.
Timer events – These events are raised at the end of a defined time interval.
Expression events – These events are invoked when a certain expression evaluates
to True.
Error events – These events are invoked when a database-related error occurs.
.NET events – This is only available in Rich Client tasks on desktop machines.

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Raising Internal Events
In a previous lesson you created a program that displayed a single record in screenmode and when you displayed the same data source in table mode, you discoveredthat there were more records. You will now create a button that will enable you tomove between the records.
1. Zoom into the Customers - Screen Mode program.
2. Zoom into the Form Designer.
3.
4.
5.
6.
7.

Place a Button
control at the bottom of the form.
Zoom into the control properties.
Park on the Format property and remove the text, which is initially set to Button.
Park on the Button style property and select Image button from the combo box.
Park on the Image List file name property and type
%WorkingDir%\images\Next.png.
8. From he Event Type property, select Internal.
9. From the Event property, select Next Row.
10. Set the Color to Text Caption. This will make the button transparent for images
that have a transparent color.
11. From the toolbar, click the Fit Control Size

icon.

You have just defined a button that when tapped, the next record will be displayed on
the form.
Android

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iOS

147

How Does It Work?
You defined a button that when tapped, the next record was displayed. You did thisby raising the Magic xpa internal event called Next Row. You learned previously thatan event has three elements:
The event, which in this case is the Next Row event.
The trigger that triggers the event, which in this case was invoked by tapping thepush button.
The handler, which is code that is activated as a response to the event triggering.
In this case it was the Magic xpa internal mechanism that handled this event foryou.
Using the same method you can define a button that will move to the previous record:
1. Place a Button
control at the bottom of the form, to the left of the otherbutton.
2. Zoom into the control properties.
3. Park on the Format property and remove the text, which is initially set to Button.
4. Park on the Button style property and select Image Button from the combo box.
5. Park on the Image List file name property and type
%WorkingDir%\images\Previous.png.
6. From the Event Type property, select Internal.
7. From the Event property, select Previous Row.
8. Set the Color to Text Caption.
9. From the toolbar, click the Fit Control Size
icon.

Button Control
While working in the Studio you used push buttons often without knowing what actions
they performed when you clicked on them. You can use your own push buttons on yourform to perform actions that you define. A Button control is used when you want totrigger an action when the end user clicks it or in the case of smartphone applications,taps it. As an example, you can have a push button that when you tap it, the program
ends.
There are different types of buttons, depending on the Button Style:
Image Button – You used this type in this lesson. An image button is an image filecontaining four or six images that correspond to the four or six different states of apush button. You can read more about this in the Magic xpa Help. In this course
you are using six-state image buttons that were designed for this course, such as
the Next and Previous images.
Hyperlink – This displays a hyperlink in the same way as a Browser would.

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Push Button – The actual look and feel of this button depends on the device thatyou are using. You need to provide the text that is displayed on the button and theoperating system is then responsible for the look and feel.

User-Defined Events
In this section you will define and use User events. As User events are events definedfor the application, it is good practice to provide them with a meaningful name.
You will now create two User events:
Set Gold Membership – This event will not have a defined trigger. At a later stage
you will use the Raise Event operation to invoke the event.
Set Date and Time – This event will be triggered by pressing a button. On a
desktop machine, you could raise this event using a keyboard combination, suchas Ctrl+T, but with smartphones and tablets you do not have that functionality.
1.
2.
3.
4.
5.
6.
7.

In the Program repository, zoom to the Customers - Screen Mode program.
From the Task menu, select User Events (Ctrl+U).
Create a line and in the Description column, type: Set Gold Membership.
In the Trigger type column, select None.
Create another line and in the Description column, type: Set Data and Time.
In the Trigger type column, select None.
In the Force Exit column, select Control. This instructs the task to exit the current
control before executing a corresponding Event logic unit.

Invoking Events
In the Event repository, Magic xpa enables you to define the trigger type and valuethat will raise the event.
In some cases, you want to raise the event according to the application logic,
regardless of whether the trigger is specified in the Event repository.
In those cases, you can use the Raise Event operation to trigger the event.

Raise Event Operation
In this example, you want the Gold_Membership variable to have a True value
whenever the Salary_Amount is changed to a value greater than 50,000.
The basic way to perform this is to have an Update operation that updates theGold_Membership variable with the True value.

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The example image below depicts what was described above. (Please do not create
this operation.)

Changing the customer status to Gold may involve more than just updating the
Gold_Membership variable to True. (This will not be demonstrated in the current
example.)In addition, the customer status may be changed for reasons other than the customer’ssalary. (This will also not be demonstrated in the current example.)
When using the event-driven methodology, the upgrading of the customer status isdone in one location (the handler), and the reasons (triggers) for upgrading thecustomer status can be done in many locations.
You will now create the logic unit that will raise the Set Gold Membership event when
the Salary_Amount value is changed.
8. In the Customers - Screen Mode program, open the Logic Editor and create a
Header line (Ctrl+H).
9. Set a Variable Change logic unit for the Salary_Amount variable. Answer"No" to the question about creating parameters. The reason for doing this isthat you will not need the parameters within the scope of the handler.
10. Create a line and select the Raise Event operation from the drop-down list.
11. In the Event dialog box, from the Event Type drop-down list, select User.
12. From the Event field, select the Set Gold Membership event and click OK.
13. Set the Wait property to Yes.
14. In the Cnd field (or in the Condition property), create an expression for when
the Salary_Amount is greater than 50000, for example: I>50000.
15. Click OK.
The Gold_Membership event will be invoked when the Salary_Amount value ischanged and its value is greater than 50,000.
You have just used the Raise Event operation to invoke an event according to the task
logic.

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The Raise Event operation’s Wait property indicates whether the event
should be invoked immediately (Yes) or placed at the end of the event
queue (No).
The Arguments property defines the arguments that will be sent to theevent handler once the event is invoked. The property displays thenumber of arguments passed from the raised event.

Note that by raising the event, Magic xpa does not handle the event at this stage. (Ifthe event is raised, nothing happens since the event has not been handled.)

Invoking a User Event Using a Button Control
Like with the Raise Event operation, you can invoke a User event using a Push Button
control on the task form.
Unlike the Raise Event operation, the Push Button control cannot force the task
execution to wait until the event is done.
The Raise Event operation and the Push Button control can be set to invoke thefollowing event types:
User – Any of the events that are defined in the Event repository.
Internal – Magic xpa internal events.
System – Magic xpa internal events that are mapped to a specific keystroke
combination. This is unavailable in smartphones and tablets.
In this lesson, you will invoke a user-defined event from a push button.
1. Zoom into the Customers - Screen Mode program.
2. Open the Form Designer.
3. Add a Button control. Zoom into the control properties.
4. Park on the Format property and type in: Set Date and Time.
5. From the Event type property, select User.
6. From the Event property, select Set Date and Time.
7. From the toolbar, click the Fit Control Size

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icon.

AndroidiOS

Handlers
In the previous section, when you tapped the Set Date and Time button, nothing visible
happened. In essence what happened was that the button raised the Set Date andTime event but there was no mechanism in place to deal with the event. This is known
as a handler.
You use the Event logic unit to handle user-defined events. A Magic xpa handler is aset of operations to be performed when a specified event is invoked. Magic xpa has
the following handlers:
Handlers for internal events – These are Magic xpa engine handlers that handle
internal events. For example, to handle the Next Row internal event, Magic xpa
will leave the current record and park on the next one.
Handlers for built-in events – These handlers perform the engine execution rules forthe different task levels. In previous lessons, you created a handler for one of thebuilt-in events, the Variable Change logic unit.
Handlers for user-defined events – You create these handlers using the Event logic
unit.

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Event Logic Unit
The Event logic unit enables you to handle events. Using the Event logic unit, you canassign a handler to an event. The Event logic unit is executed only when the assigned
event is invoked during runtime. The Event Logic unit properties include:

Parameter
Name

Description

Event Name

Displays the handled event name.
From this parameter, you can:Zoom to the Event dialog box to select the handled event.
Select the Event type from the Event Type drop-down list.
Zoom from the Event field to select an event from the Event list.

on:Enables you to assign an event to a control (one of the current task’s
controls). This column displays the assigned control name. You can typea control name or zoom to select a control name from the Control list.

Scope

Enables you to define the event scope. The options are:Task – The handler will be executed if the event is invoked from thattask only.
SubTree – The handler will be executed if the event is invoked fromthat task or its subtasks.
Global – The handler is executed if the event is raised from thecurrent task, its subtasks or any other projects (host or components).
This option appears in the Main program.

Cnd

You can condition the execution of the handler by setting an
expression.

Handling the Set Date and Time Event
Previously you created the Set Date and Time event, which was triggered when theuser tapped a push button. When this event occurs, the Membership_Date and theMembership_Time variables need to be updated with the current date and time values.
Now, you will create the handler for the event.
1. In the Logic Editor, create a Header line and select Event. The Event dialog box
appears.
2. In the Event type combo box, select User.
3. Zoom into the Event list and select Set Date and Time.
4. Create a Details line and update Membership Date with Date().

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5. Update Membership Time with Time().

You have just created the Set Date and Time event handler. If you execute the program
and then click the Set Date and Time button, you will see that the date and time are
updated accordingly. Remember that this is not updated to the database until you
move to a different record.

Event Checking
Magic xpa inspects the task events at different times, depending on the task type.

Online, Interactive Rich Client and Browser Tasks
In general, in this course you will only use the Rich Client task. Events are checkedwhen:
The end user taps something in a Rich Client task or for other tasks when they press
a key.
The task is idle. This occurs when the task is waiting for end-user input and theKeyboard Idle Seconds environment setting timeout occurs.

Batch and Non-Interactive Rich Client Tasks
You will learn more about this type of task in a later lesson:
The time interval for a Batch task depends on when the Batch Event Interval
environment setting timeout occurs.
The number of processed records set in the Record Event Interval environment
setting is reached.

Using the Raise Event Operation
This explanation is valid for any task type. The Magic xpa engine checks the Raise
Event operation’s execution condition. If you use the Raise Event operation with the
Wait property set to Yes, Magic xpa will find and execute the related event handler
immediately. This is known as synchronous. If the Wait property is set to No, the event
will be added to an event queue and will be inspected according to the task type as
described above. This is known as asynchronous.

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Having More than One Handler for the Same Event
In some cases you have more than one handler for the same event. For example, takea scenario where you have two handlers for a user-defined event named Print, one thatprints the customer’s details meaning the customer card and one that prints an invoice
for the order.
Magic xpa’s default behavior is that each raised event is handled by the first handler(according to Magic xpa’s rules) and after that the event is cleared. So, no otherhandler (if one exists) will handle this event. Therefore, according to Magic xpa’s rules,
only one handler will handle the Print event.

Which Handler Will Handle the Event?
According to Magic xpa’s rules the lowest handler in the execution tree will handle theevent.
In the example above, this means that if you create the Customer Card printing
handler after the Invoice printing handler, meaning physically lower in the Logic Editor,
Magic xpa will handle the Customer card print handler as shown in the image below.

The Propagate Property
You can overcome the behavior described above using the Propagate property. The
Propagate property has two options:
Yes – Magic xpa searches for a higher level handler to handle the event. (If nohandler is found, nothing will happen.)
No – Magic xpa does not search for a higher level handler to handle the event.
Setting this property to Yes is useful when you have a handler for the event in a parent
task as well as in the current task. You will learn about this scenario later in this lesson.

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Example
To understand the event checking mechanism, you will now add another Event handler
for the Set Date and Time event.
1. In the Customer - Screen Mode program, create another handler for the Set
Date and Time event.
2. In the details logic, set a Verify Warning operation with the text: "Set Date andTime".
You have just created an additional handler for the Set Date and Time event handler.

3. Execute the program on your mobile device and tap the Set Date and Timebutton.
You will receive the Warning message box with the text, "Set Date and Time". When
you tap the OK button, focus returns to the form but the date and time variables are not
updated.
4. Zoom into the Customer - Screen Mode program
5. Park on the new Set Date and Time handler and in the properties set the
Propagate property to Yes.
6. Execute the program again.
You will notice that the date and time were changed to the current values.

Explaining the results
For each event that is invoked, Magic xpa searches for a handler that is defined for it.
Whenever a handler for this event is found, Magic xpa executes the handler.
Upon completion of the handler execution, Magic xpa searches for another handler forthe event, only if the Propagate property of the last executed event handler is set toYes. (If there are several handlers for the same event in the same task, the bottom-mosthandler is executed first.) If the Propagate property is set to No, the search process is
terminated.

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In the previous example, you defined two handlers for the same event, Set Date andTime. When the event was invoked, the first event handler was executed. You werethen notified that the date and time were set. Since the Propagate property of thishandler was set to Yes, the next matching handler for this event was executed. Then,the Membership_Date and Membership_Time variables were updated with the current
date and time values.

Handling Internal Events
Earlier in this lesson you added buttons to the form that raised internal Magic xpa
events, such as Next Row and Previous Row. When these events were raised you
allowed the Magic xpa engine to handle these events. As with other events you can
add your own code to handle these events, basically overriding the Magic xpa default
behavior.
As an example you will add an Edit button to the customer list so that you can edit thecustomer’s details.
1. Zoom into the Customers - Line Mode program and zoom into the Form
Designer.
2. Place a Button control at the top of the form.
3. Zoom into the control properties.
4. Park on the Format property and remove the text, which is initially set to Button.
5. Park on the Button style property and select Image Button from the combo box.
6. Park on the Image List file name property and type
%WorkingDir%\images\Edit.png.
7. From the Event type property, select Internal.
8. From the Event property, select Modify Records.
9. Set the Color to Text Caption. This will make the button transparent for images
which have a transparent color.
10. From the toolbar, click the Fit Control Size

icon.

Now execute the application. Park on any line and tap the Edit button.
You are now able to edit the information displayed in the table.

?

When developing mobile applications, only part of the information isdisplayed in the list. Look at the contacts application on yoursmartphone and edit a contact.
How would you perform something similar in Magic xpa? Where is
all of the information for a single customer displayed in a single form?

Events and Handlers157

As you remember, the Customers - Screen Mode program displays all of theinformation for a customer. What you need to do is that when you press the Edit
button, Magic xpa will display the Customers - Screen Mode program.
11. Zoom into the Customers - Line Mode program and zoom into the Logic Editor.
12. Add a Header line and select the Modify Records internal event.
13. Create a details line for the Call Program operation. This operation enables
you to call a program and pass parameters to the new program.
14. Select the Customers - Screen Mode program from the list.
If you now execute the application and park on the first customer and tap the Edit
button, Magic xpa will display the Customers - Screen Mode program and display the
first customer. However, if you park on a different customer and tap the Edit button,
you want that customer’s details to be displayed in the called program. You can
implement this by using a parameter.

Parameters
A parameter is a local variable that holds the received values from a calling program.
It is a channel between the called program and the calling program to pass
information from one to the other. The parameter can be used like any other variable.
However, you should remember that an update of a parameter variable will result in
the parent program’s variable also being updated.
1. Zoom into the Customers - Screen Mode program and zoom into the Data View
Editor.
In the Customers - Screen Mode program you will set a parameter for the Customer
Code. This will allow you to only display a specific customer according to its code.
2. Park on the first line, the Main Source definition, and create a line.
3. From the drop-drown list, select Parameter.
4. You are now parked in a field displaying ??. Type in P.Customer code. You do
not need to add the P. before the name you provided. However, when looking
at a selection list of variables you will see that it is good practise to make a
distinction between different types of variables.
5. To the right of that, zoom and select the Code model.

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Parameters are passed according to the order they appear in the data
view. Magic xpa does not make a distinction as to where theparameters are placed within the data view. It is possible to disperse
parameters throughout the data view. However, for both readability
and maintenance, it is better to group these variables together.
Parameters are normally defined at the beginning of the data view.

Range Criteria
When you pass the customer code to the Customers - Screen Mode program, you
expect the program to only display the customer that you are parked on.
Range criteria enable you to display only those records that fall between two values,
from-to. You will now set the P.Customer Code parameter as the Range from criteria
and the Range to criteria.
6. Park on the Customer_Code column.
7. Zoom into the Range from property and zoom into the Expression Editor.
8. Create an expression for the P.Customer Code parameter. As you can see, theparameter is not only visible due to a different color but also due to the name.
9. Zoom into the Range to property and zoom into the Expression Editor. Selectthe same expression as the Range from property.
The next stage is to pass the relevant customer code to this program. This is performed
from the calling program.
10. Zoom into the Customers - Line Mode program and zoom into the Modify
Records logic unit.
11. Park on the Call Program operation.
12. From the Arguments field, zoom to the Arguments repository.
13. Create a line, zoom and select the Customer_Code variable.
Now execute the application. Park on any line and tap the Edit button.
The Customers - Screen Mode program will be displayed showing the customer you
wanted to edit. You can now edit the data. As an example, edit the date and timedetails.
When you close the Customers - Screen Mode program, you return to the Customers Line Mode program with the focus still on the same line that you originally wereparked on. The data in the table was updated.

Events and Handlers

159

If you edited data that was displayed in the Customers - Line Modetable, such as the customer name, you need to inform Magic xpa torefresh the view and display the updated data.

Magic xpa has an internal event appropriately called View Refresh and is responsible
for refreshing the view. In the lesson scenario, there are two ways of refreshing theview:
In the called task, meaning Customers - Screen Mode. If one of the controls on theform was modified, the task will pass through the Record Suffix logic unit. You canraise the View Refresh event from the Record Suffix logic unit.
In the calling task, meaning Customers - Line Mode. You can raise the View Refresh
event from the Modify Records handler.
For the purpose of this course, you will raise it from the calling task:
14. Zoom into the Customers - Line Mode program and zoom into the Modify
Records logic unit.
15. Add a detail line after the Call Program operation.
16. Select the Raise Event operation from the drop-down list.
17. In the Event dialog box, from the Event Type drop-down list, select Internal.
18. From the Event field, select the View Refresh event and click OK.
Now execute the application. Park on any line and tap the Edit button.
You can now edit the data. Try editing the name and then returning to the table andsee the result. The View Refresh event is very useful. You can read more about it in the
Magic xpa Help.

?

You modified the Customers - Screen Mode program so that it
displayed the record corresponding to the parameter that was
passed. What happens if you now execute the Customers - Screen
Mode program on its own to scroll through the customers?
You are faced with an empty screen because the parameter value iszero.
How can you overcome this situation and display all of the records?

When you execute the Customers - Screen Mode program on its own, the parameter iszero, meaning that in the Range from value you have zero and in the Range to value
you have zero. What you would like to be able to do is to range from the lowest value
to the highest value. The lowest value is zero; therefore you only need to handle thehighest value, which is 999999999.

Events and Handlers

16019. Zoom into Customers - Screen Mode program.
20. Zoom into the Range to property.
21. Add an expression in the Expression Editor:
IF (P.Customer Code > 0, P.Customer_Code, 999999999).
Now execute the Customers - Screen Mode program and you will be able to scroll
through the records.
Another method of handling the expression is to use the CndRange function. Thisfunction enables you to provide a conditional expression in the minimum andmaximum properties of the range and locate expressions.
SyntaxParameters

CndRange (condition, value)

Condition: A condition that will be evaluated during runtime. A

condition returns either True or False.
Value: A value that will be returned if the condition evaluates to True.

You can use this function instead of the expression you defined above.
22. Set the expression to: CndRange (P.Customer Code > 0, P.Customer_Code)If a Customer Code is passed as a parameter, the condition is evaluated to True andthe value will be used in the range. If a code is not passed, the expression will beignored and behave as if no expression exists.
It is useful to use this expression in the from and to properties.

Events and Handlers

161

ExerciseDuring the lesson you raised the Set Gold Membership event but there was no handler
for it:
1. Update Gold_Membership with a True value whenever the Salary_Amount islarger than 50,000.
2. As before, when the Salary_Amount is larger than 50,000, increase theCredit_Amount by 20%.
In the Customers - Screen Mode program:
3. Add a button that enables the user to delete a customer. There is a readyprepared image, Delete.png, in the images folder for you.
Note: The user can run this program both directly and indirectly, meaning that
it is called from the Customers - Line Mode program. If the program is calledfrom the Customers - Line Mode program, then once the customer is deleted,the program must be closed and focus will be returned to the calling program.
The next exercise is slightly more challenging:
4. Add a button that enables the user to add a customer. There is a readyprepared image, Add.png, in the images folder for you.
Hint: What task mode should you be in? How do you change the task mode?
Initial Mode can be an expression.
If you want to further your knowledge, look at Literals in the Magic xpa Helpand then look at the MODE literal.

Events and Handlers

162Summary
The event-driven methodology allows you to combine non-procedural operations in atask.
The event-driven programming is based on three elements: the event, its trigger, andthe event handler.
An event can be invoked by the following types of triggers:
SystemInternal
Timer
Expression
Another way to invoke an event is by using the Raise Event operation or by using
the Push Button control.
User events are located in the task’s Event repository.
The event handler is defined using the Event logic unit in the task’s Logic Editor and it
contains operations to be executed when the event is invoked.
You can define several handlers for the same event and determine which of them will
be executed, by using the Propagate property.
You can also define a handler for Magic xpa internal events.
In interactive tasks, Magic xpa checks the event’s execution condition whenever thetask is idle or the end user triggers the event execution.
Using the Raise Event operation (Wait = Yes/No), the developer can decide whether
the event will be synchronous or non-synchronous.

Events and Handlers

163Events and Handlers

164

11

LessonConditioning a Block of Operations
In some instances, you need to condition part of the code execution. In most cases,
conditioning each operation will do the job. To create a more structured and efficientcode it is recommended to use the Block operation. This allows you to group several
operations with one execution condition.
This lesson covers various topics including:
Block If, Block Else, Block End and Block While operations
Grouping the execution of several operations within one condition

Conditioning a Block of Operations 165

What Is a Block Operation?
Assume you have three operations, such as:
Update Gold_Membership with True
Update Salary_Amount with Salary_Amount * 1.1
Update Credit_Amount with Credit_Amount * 1.2
Each of these operations will be executed if the Membership_Date is before
1/1/2000. You can add the same condition to each of the operations but that meansthat the same expression is evaluated each time, making the code inefficient.
The Block operation encloses a group of procedural operations within a logical block.
The execution of all operations in the block depends on the condition of the Block
operation.

Block If – Conditioning Operations
The Block If operation is used to enclose several operations within a certain condition.
This type of Block operation consists of three parts:
Block If
Block ElseBlock End
When Magic xpa reaches the Block If operation, it checks the Block If condition.
If it is True, the operations within the Block If operation are executed one by one.
If it is False, Magic xpa skips the operations within the Block If operation.

Block Else
The Block Else operation is an extension of the Block If operation. It enables you tocheck several conditions within a single block unit.
You can define several Block Else operations within the same Block If operation. The
Block Else operation is defined within the logical block of the Block If operation(between the Block If and the Block End operations).
When the condition of the Block If operation is not met, Magic xpa skips to the BlockElse operation. If the Block Else condition is met, the operations within the Block Else
operation (until the next Block Else operation or the Block End operation) are executed.
Then, Magic xpa skips to the next Block Else operation and so on, until it gets to theBlock End operation.
If the Block Else condition is not met, Magic xpa skips to the next Block Else operation,
if it exists, or to the Block End operation.

Conditioning a Block of Operations 166

Take into account that Magic xpa checks each Block Else condition. You may find that
more than one Block Else condition may result in True. In this case, the operations
within each of the Block Else sections will be executed.
A Block operation can be nested.

The Structure of the Block Operation
The following examples demonstrate various ways to use the Block operation.
Example 1

Block If
Operation
Operation
Block End

This is mainly used to condition a group of
operations with one condition. In a previous lesson,
you had three operations with the same condition.
You could have grouped these operations in thesame Block operation. In that way, the condition
would have only been checked once.

Example 2

Block If
Operation
Operation
Block ElseOperation
Operation
Block End

This is mainly used to perform a scenario in a
specific case. If the condition is not met, the Elsesection (the default) will be performed.

Example 3

Block If
Operation
Operation
Block ElseOperation
Operation
Block ElseOperation
Block End

This is the aame as Example 2, but here there ismore than one special scenario. (The Else section
can also be conditioned.)

Example 4

Block If
Operation
Operation
Block If
Operation
Block End
Operation
Block End

This shows an example of a nested block.

Conditioning a Block of Operations 167

Using the Block If Operation
In this section, you will practice using the Block operation. In Lesson 4, in My First
Program, you added a Variable Change logic unit and within the Variable Change
logic unit you performed three operations, each with the same expression.
In the Customers - Screen Mode program you will clear the value from the City andAddress variables if the Country variable has a value and the value was changed.
1. Zoom into the Customers - Screen Mode program and open the Logic Editor.
2. Create a Variable Change logic unit for the Country variable.
3. Click Yes to automatically create the parameters.
4. In the Variable Change logic unit, add a Block If operation with the condition:
CHG_PRV_Country <> ''The Block End operation is created automatically when you create a
Block If operation.

5. Park on the Block If line and create a line under it.
6. Update City with '' – remember this is the way to reset an Alpha value.
7. Update Address with ''.
The two Update operations will only execute if the condition of the Block If operation
evaluates to True.
If you now execute the application and run the Customers - Screen Mode program andchange the Country variable, you will see that both the City and Address values werecleared when you tapped another field.
As an example of a nested Block, if the value of the Country variable was changed toEngland, then update the City with London.
8. Zoom into the Customers - Screen Mode program, open the Logic Editor andzoom into the Variable Change logic unit for the Country variable.
9. Park on the Block If line and create a line under it.
10. Add a Block If operation with the condition: Upper (Country) = 'ENGLAND'.
The reason for using the expression Upper is because expressions are case sensitive.
Here you are changing the value to uppercase. You will also notice that you wereasked to check against the Country variable and not its previous value.

Conditioning a Block of Operations 168

11. Park on the new Block If line and create a line under it.
12. Update City with 'London' – remember this is the way to reset an Alpha value.

As you can see from the image above, there are two Block If operations, one directly
after the other. The second Block If operation is a nested block. The second Block
operation is displayed by the Logic Editor as nested. The nested block encompasses
operations from the Block If to the Block End.
As you may already have understood from the task logic above, after exiting the inner
block, the City variable will be cleared even though the nested block may haveupdated the value with London.
13. Park on the Update Variable line where you updated the City with 'London'and create a line.
14. Add a Block operation and select Else.
15. Create a line beneath the Block Else operation.
16. Update City with ''.
17. Park on the line after the first Block End operation where you first updated City
with '' and delete the line by pressing F3. In a later lesson you will learn how
to copy lines.

There are many ways of doing what you just did. A nested Block If scenario was used
as an example.

Conditioning a Block of Operations 169

Advantages of the Block Operation
The Block operation encloses a group of procedural operations into a logical block, sothat all the operations within the block are dependent on the same condition, which is
the Block operation condition.
Using the Block operation has several advantages:
As a developer, it saves you time since you can set a condition for several
operations, instead of setting the condition for each of the operations separately. In
addition, it makes the maintenance of the program easier. If you need to change
the condition, you only need to change it once, in the Block operation.
For the engine, it saves multiple checks when several operations depend on thesame condition. When you use the Block operation, the engine checks thecondition once, when it gets to the Block operation and not every time it gets toeach of the operations.
Using the Block operation enables you as a developer to simplify the expressions.
You can divide complex expressions into several logical sections and set each ofthem as the condition of a Block operation.
For example, if you want to set a Verify Warning operation when the country is
Italy and the city is Rome, you can use:
Block If (Cnd: Country='ITALY')Block If (Cnd: City='ROME')
VerifyBlock End
Block End
The Block operation enables you to nest operations. If you need to execute several
operations under a certain condition and then, some of the operations need to be
executed under another condition, you can use a Block operation with a condition
and within it use another Block operation with another condition. In this case, all
the operations within the embedded Block will be executed only if both of the Blockconditions are met.
In the above example, the Verify operation will be executed only if:
Country='ITALY' and City='ROME'.

Conditioning a Block of Operations 170

The Block While Operation
The Block While operation instructs Magic xpa to repeatedly execute the operations
within the block for as long as the Block condition is evaluated to TRUE.
Magic xpa evaluates the Block While condition. If the condition is met, the operations
within the block are executed one by one until the Block End operation is reached.
Then, the condition is evaluated again and if it is met, the operations are executed
again, and so on. This creates a loop effect.
Once the condition is not met, Magic xpa skips to the Block End operation andcontinues the task flow.
LoopCounter() is a special function that returns the number of times the loop has
iterated. This means that you do not have to create a special counter for each loop.
As an example you are going to check the value of the address entered by the user tosee if the user entered the at sign (@). If @ exists in the string, you will give a warning.
In this example, you will do this be checking each letter in the address to check
whether it is an @ or not. To do this you will use two new functions: Len, which returns
the length of an Alpha string, and Mid, which extracts a specified number ofcharacters from an Alpha string.

SyntaxLen (string)Parameters

string: An Alpha string.

Returns

The length of the string.

Note

If you are using an Alpha variable of size 20, then Len (A) will return
20 regardless of what is in the string. It is advisable to use this
together with the Trim function to remove trailing blanks.

SyntaxMID (string,start,length)

Parameters

string: An Alpha string.
start: A number representing the starting position of the substring
length: A number representing the number of characters to fetch

Returns

A substring of the other string.

Conditioning a Block of Operations 171

Now you will see how to use these functions:
1. Zoom into the Customers - Screen Mode program.
2. Open the Logic Editor and add a Variable Change header line for Address.
3. In the dialog box that pops up about adding parameters, click No. You do notneed the parameters for this example.
4. Create a Detail line.
5. Add a Block While operation and set the condition to:
LoopCounter () <= Len (Trim (Address))
If Address contains the value 'Magic xpa', then Len (Trim (Address)) will return
9 and the block logic unit will execute 9 times. Remember that the LoopCounterfunction returns the current iteration of the block.
6. Create a Detail line after the Block While operation.
7. Add a Verify Warning operation and set the warning text to:"The address contains the invalid @ character."
8. Zoom from the condition and set the following expression:
MID (G, LoopCounter(),1) = '@'The MID function returns a substring of the address starting from the value
returned by the LoopCounter function.

Magic xpa has a function named Instr, which you can use instead ofthe loop. Read more about this function in the Magic xpa Help.

Conditioning a Block of Operations 172

Exercise
When adding a new customer, update the Credit_Amount value according to thefollowing logic:
For all customers whose Salary_Amount is more than 8000:
For customers who do not have a Gold Membership, the Credit_Amountvalue will be updated with the Salary_Amount*2.
For customers who have a Gold Membership, the Credit_Amount value
will be updated with the Salary_Amount*3.
If the Salary_Amount is more than a 1000, but less than 8000, update theCredit_Amount with the Salary_Amount.
If the Salary_Amount is less than a 1000, update the Credit_Amount with 50% of
the Salary_Amount.
Hint: Use the Stat function to determine whether or not the program is in Create mode.
Remember that you can only add a new customer from the Customers - Line Mode
program.

Conditioning a Block of Operations 173

Summary
Block operations help you simplify your expressions, save you the time of setting thesame expression in several places, reduce the program maintenance, shorten theengine execution time, and provide you with a logical way to nest operations undercertain conditions. The Block operation is used for two reasons:Conditioning a group of operations using Block If and Block Else.
Performing a group of operations in a loop, as long as the condition is met using
Block While.
You learned about some new functions, including Len, MID and LoopCounter.

Conditioning a Block of Operations 174

Lesson12

One-to-One Data Relationships
This lesson introduces you to one-to-one data relationships and describes how they are
implemented in Magic xpa.
Data sources are designed to contain data for specific subjects, such as:
The Customers data source, which contains customer information, such as Name,
Address, and Phone Number.
The Items data source, which contains item information, such as Name, Price,
Quantity, and Supplier/Manufacturer.
The Orders data source, which contains order information, such as Customer,
Order Data, Total Price, and Discount Percent.
In many cases there are relations between the data sources. For example, in theOrders data source there is a customer field that specifies who is the customer in thisorder.
To validate the customer’s existence in the system, or to display more information
about the customer, you connect to the Customers data source and search for theorder’s customer in the Customers data source.
In Magic xpa, when you need to process a specific record for each record in the Main
Source it is called a one-to-one data relationship and it is done using the Link operationin the task’s Data View Editor. This lesson describes how to use the Link operation tocreate a one-to-one data relationship.
This lesson covers various topics including:
Link types
The Recompute mechanism
The Link Success Indication property

One-to-One Data Relationships

175One-to-One vs. One-to-Many Data Relationships
Magic xpa enables you to establish the following two relationships between data
sources:
One-to-one data relationships
One-to-many data relationships (You will learn about the one-to-many data
relationships in a later lesson.)
The following table compares the one-to-one and the one-to-many data relationships:

One-to-One Data Relationship

One-to-Many Data RelationshipCommon variables are used to maintainthe connection.

Common variables are used to maintain theconnection.

The Main Source and the linked data
source are defined in the same task.

Each data source is defined as the Main
Source in a different task.

Only one record is returned from thelinked data source.

Several records can be returned for eachrecord.

The Magic xpa Recompute mechanism is
responsible for maintaining theconnection.

The task’s range is responsible formaintaining the connection, according to apassed parameter.
In addition, the Magic xpa Subform control
mechanism is also responsible formaintaining the connection.
You will learn about the Subform control ina later lesson.

One-to-One Data Relationships

176

Linking to Other Data Sources
Magic xpa enables you to connect between data sources to establish the one-to-one
data relationship by defining the Link header line in the Data View Editor.
To connect between two data sources, both data sources need to contain a common
variable. Usually the common variable is an index segment in the secondary data
source.
During task execution, Magic xpa fetches a single record from the linked data sourcefor every record of the Main Source. Magic xpa fetches the first record that meets thecondition. Remember that there may be more than one.

Link Header Line
Linking to other data sources is part of the data view definition in Magic xpa.
Therefore, the Link operation is defined in the Data View Editor.
The Link definition consists of the following elements:
The Link header line definition, which includes:
The linked data source
The Link typeThe index by which the data sources are linked
Within the Link section, detail lines are added that define the linked data sourcecolumns.
Locate criteria, which are defined for the common variables in the linked data
source.
An End Link operation, which closes the Link operation.
All of the columns between the Link operation and the End Link operation. Thesecolumns are all part of the same data source.

One-to-One Data Relationships

177

Link Operation Usage
The Link operation is used to:Extend the record’s data view.
Check the existence of a particular record in linked data sources (used to perform
validity checks).

OrdersCustomers

Order Number
Order Date
Customer Code
Order Amount
Method of Payment

Customer Code
Customer NameCountryCity
Address

Extending the Record’s Data View
In some cases, you need to extend the information you have from the Main Source byretrieving additional information from other data sources. This feature is enabled using
the Link operation.
Suppose that you have the following data sources in your project:
Orders – includes order number, order date, customer code, order amount, andmethod of payment
Customers – includes customer code, name, country, city, and address
You can create a program that displays the Orders data source records. The program
displays a customer code for each order. To display the customer name in the same
program, you need to extend the program’s data view. You need to link to theCustomers data source by locating the customer according to the customer code anddisplaying the customer name.

One-to-One Data Relationships

178Perform Validity Checks
Another usage of the Link operation is to check the existence of a value in a data
source (validity checks).
Using the previous example, the Orders data source contains a customer code, while
the Customers data source contains all of the customers’ details.
When adding a new order, the end user will be asked to enter a customer code aspart of the order details.
The information that the end user enters should be verified according to the information
already existing in the system. You can use the Link operation to verify the customer
code that the end user entered against the Customers data source.

Link Types
Magic xpa has five types of Link operations; each with a different behavior. The
following are the Link operation types:
Link Query – This operation is used to establish a connection to a record in thelinked data source. If the link fails (because the record does not exist in the linked
data source), no record is displayed.
Link Write – This operation is similar to the Link Query operation. However, in the
Link Write operation, if the linked record does not exist, Magic xpa will attempt tocreate a record in the linked data source.
Link Create – Magic xpa creates a new record in the linked data source. If theindexed record exists, you will receive errors if the indexes are unique.
The following two Link types are used for SQL databases. They are not covered in thiscourse:Link Inner Join – The program’s data view includes only records that have an
existing linked record in the linked data source.
Link Left Outer Join – This operation behaves the same as the Link Query operation;
however, the preparation of the data view is different. The program’s data view
includes all of the Main Source records, regardless if a linked record exists in thelinked data source.

One-to-One Data Relationships

179

Using Link QueryIn this section you will create an Orders program that will display the Orders data
source with additional information from the Customers data source (using the Link
operation).
This example involves three main steps:
Defining the Orders data source
Creating the Orders program
Extending the Orders program data view by linking to the Customers data source

Defining the Orders Data Source
1.
2.
3.
4.

In the Data repository, create a data source and name it Orders.
In the Data source name column, type: Orders.
In the Database column, select Getting Started.
Create the following columns:

Name

Model

AttributePictureOrder Number

0

Numeric

6

Date##/##/####

Order Date
Customer Code

Code

Numeric

9

Amount0

Numeric

8.2

Method Of Payment

0

Alpha

15

Setting a Rich Client Display Control
As you know, Magic xpa enables you to set the default appearance for each column.
This is performed in each column’s Style properties.
Multiple choice controls allow the user to see all of the possible choices, and preventthe user from accidentally entering any incorrect or invalid values.
A combo box, also known as a drop-down box, is a choice control that only displays
one value, rather than all of the possibilities, until the user opens up the box. Typing
the first character selects the first item matching that character.

One-to-One Data Relationships

180

In the Orders program, you want the Method Of Payment column to be displayedusing a Combo Box control every time you place the column on a GUI form.
1. Park on the Method Of Payment column.
2. Open the Column Properties.
3. From the Rich Client style property, select Combo box.

About the Items List and Display List Properties
The Items List property lets you set a string that defines the options that can be selectedfrom the choice control. The various options are delimited by commas.
The Display List property lets you display values that are different from the ones in theItems List property. The Display List string must contain an identical number of items to
the Items List string. For example, if you enter "1,2,3" in the Items List and"Red,Green,Blue" in the Display List, the user will see the options Red, Green, and Bluein the combo box, but internally the variable will have the values 1, 2, or 3 according
to the selected color.
When setting the Rich Client property to Combo box, the Items List is sometimes a set
list (such as a combo box for Gender). In these cases, the list can be set during thecreation of the column in the data source.
Moreover, Magic xpa enables you to differentiate between the value that the end user
sees and selects (Display List) and the one that will be stored in the column (Items List).
In this course you will only use the Items List.

One-to-One Data Relationships181

In this example, you will display the following options in the Method of Payment
column: Cash, Check, Credit Card, and Coupons.
1. From the Rich Client entry, click the Zoom button ( ) to open the Combo box
control property sheet.
2. In the Items List property, type: Cash, Check, Credit Card, Coupons.
3. Set the Color property to Edit Control color.
4. Close the Combo box control property sheet.

Defining the Order Number Index
You will now define two indexes for the Orders data source.
1. Create a Unique index called Order Number.
2. Select Order Number as the first segment.
3. Create a Unique index called Customer with the following segments:
Customer Code
Order Date
Order Number
You have now finished creating the data source.

Creating the Orders Program
An order usually has two parts, the order details and the order lines. In this lesson you
will display the details and in another lesson, you will complete the program. The
order details can be displayed in a screen mode form.
1. Create a program and name it Orders. Remember to set the Public name to
RunMe and to check the External box.
2. Zoom to the Orders program.
3. From the Task Properties dialog box, set the Task type to Rich Client.
4. Set the Initial Mode to Query.
5. Open the Data View Editor of the Orders program.
6. Create a Main Source definition for the Orders data source and use the Order
Number index.
7. Add all of the Orders data source columns to this program.

One-to-One Data Relationships

182Linking to the Customers Data Source
1. Park on the last line in the Data View Editor.
2. Add a Remark line.
Note: A Remark line is not needed for the program to work; however, it makes
the program more readable.
Enter the following remark: Fetching the customer's details
3. Create a Header line and from the combo box, select Link Query.
4. Select the Customers data source.
5. Zoom from the Index property and select the first index. You will see that theCustomer Code was added automatically.

The End Link operation was created automatically when you added
the Link operation.
When you create a Link operation, the Index Segments areautomatically added as columns within the Link section.

The S to the left of the link is an indication that this is a Server
operation. This will be discussed in a later lesson.

One-to-One Data Relationships

183

6. Park on the Customer Code column definition.
7. Create a line.
8. Add the Customer Name and the City columns from the Customers data
source.
You can add any column from the Customers data source. The ones you wereasked to add were selected simply to show the power of the link mechanism.

Defining Locate Parameters
In this example, the Customer Code column is the common variable between the twodata sources. To set the Orders data source’s Customer Code as the Locate parameterin the Customers data source’s Customer Code column:
1. Park on the Customers data source’s Customer Code column definition.
2. From the Locate entry, zoom to the Expression Editor.
3. Create an expression for the Customer Code variable from the Orders data
source. You will see that in this program there are two Customer Codevariables. You are defining a link between the two variables.
4. In the To entry, enter the same expression number.

In the Locate and To columns, it is important not to select the Linked
data source’s common variable. This is why you selected theCustomer Code form the Orders data source and not the Customers
data source.
The variable used in the Locate and To expressions must be declared
above the Link section in the Data View Editor.

One-to-One Data Relationships

184

Designing the FormIn this section, you will design the Orders program form. The form will display theorder details and some of the customer details.
1. Open the Form Editor.
2. Park on the Orders form and zoom to the Form Designer.
3. Open the Form Properties sheet (Alt+Enter).
4. Select Table Display Form as the model.
You will now place controls on the form. See the image below as an example of therequired layout. Please adhere to this layout as you will need it in a later lesson.
5. From the Task Variables pane, drag the Order_Number variable and drop iton the top left area of the form.
6. Place all of the variables on the form except for the Customer_Code from theCustomers data source.
Note that when you place the Method_Of_Payment variable, only a Combo
Box control will appear.
7. Place the Customer_Name variable to the right of the Customer_Code
8. Delete the Customer_Name caption control.
9. Place the City variable to the right of the Customer_name. Delete the City
caption control.
There are two Customer_Code variables, one from the Orders data source and one
from the Customers data source. You only placed the variable from the Orders data
source. The reason for this is:If the Link operation was successful, these columns will have the same value. Thereis no need to display the value twice.
The Orders data source is the Main Source and is used for editing. The Customers
data source is used to expand the Main Source and in this case, is used to display
extra information. In essence, it is used here only for display purposes.
For the Method_Of_Payment combo box:
10. From the Toolbox, select a Label (Text) control and add it to the left of the
Method_Of_Payment combo box.
11. Open the Label control properties and in the Text property, type:
Payment Method.

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Handling the Edit control captions
12. Select all of the Static controls (by holding down the Control key and selecting
all of the Static controls, one at a time).
13. Open the property sheet for the selected controls.
14. Attach the controls to the Text Caption model.
15. Inherit the Font property for all of the controls.
16. While all the Text controls are selected, click the Fit Control Size icon (the toolbar.
17. Click on the form to de-select all of the controls.

) fromHandling the Dynamic controls
Controls belonging to the Orders data source are editable controls and those fetchedfrom the Customers data source are for display. You will connect the Edit controls todifferent models.
In a previous lesson, you created two models: Display only and Editable field.
18. Attach the controls to the models as follows:

Model

Controls to Attach

Editable field

Order_Number, Order_Date, Customer_Code and Amount edit
controls

Display only

Customer_Name and City edit controls

19. Move the Edit controls so that the entire value of the Label controls are
displayed. Your form will look similar to the image below.

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When you execute the application, you will find that all of the fields are empty andyou cannot tap any control. This is because your program is in Query mode and there
are no orders in the data source.
As you know from this course, the best practice for designing anapplication for a mobile device is to have a list of orders where you
have buttons enabling you to add, edit and view an order.
You will practice this during the exercise.
Often the option to modify or delete a specific item will not be in thetable but in the details screen. This depends on your own application
design.
For the purpose of this example:
1. Zoom to the Orders program.
2. From the Task Properties dialog box, set the Initial Mode to Create.
When the program runs, it will immediately go into Create mode.
Execute the application.
3.
4.
5.
6.

In the Order_Number field, type: 1.
In the Order_Date field, type the current date (such as 26/10/2013).
In the Customer_Code field, type: 2.
Tap the Amount field.

The customer details are displayed for the customer code that you entered. You willprobably see the details for Antony Perot who lives in Rome.
7. Change the customer code to 4 and see how the customer details are changed
accordingly.
AndroidiOS

8. Change the customer code to 25. You will see that when the customer does notexist, the customer details are cleared.

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9. Set the customer code to: 2 (Antony Perot).

If you tap the Payment Method, the device will open a drop-down box enabling you toselect the type. The display depends on each operating system.

Short Summary
The data view of the Orders program that you created consists of:Orders data source columns
Customers data source columns
Both data sources share a common column, the Customer_Code column. The data
relationship between both data sources is one-to-one, since each order has a
Customer_Code value that appears only once in the Customers data source.
You used the Link Query operation to retrieve the customers’ details (if the linked
customer exists).
The Orders form displays both the order details and some of the customer details.

Link Recompute Mechanism
In the previous section, where you executed the Orders program, you were asked tochange the Customer Code value and view the result.
Each time the Customer Code was changed, the customer’s details were also changed.
Magic xpa re-evaluates the Link condition and attempts to locate the appropriate
customer record in the Customers data source for the new Customer Code value.
This behavior is referred to in Magic xpa as Link Recompute.
The Link operation is only recomputed when all of the following occur:
A variable is part of the Locate From and To expressions.
The variable used in the Locate From and To expressions is declared above the
Link section in the Data View Editor.
The variable data has changed.

Link Success Indication
When you set the Customer Code value to 25, you saw that the Customer details werecleared (nothing was displayed). This happened because the Customer Code number
25 does not exist.

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The end user does not know if the customer details are empty because:
The customer does not exist, or
The customer does exist, but the information for the customer is cleared.
Since the end user does not have a clear indication of the customer’s existence, youmust provide one.
One of the Link operation properties is Success indication. This property returns alogical value.
To retrieve the Link Success indication value, you need to set a Logical variable in theproperty.
You can use the Success indication value to alert the end user when the link fails.
This is another method of validation; validating that the input is correct. Without using
this method, you could add a non-existing customer code to the order, but this would
create a data-integrity problem.
In this example, you will improve the Orders program by adding a failure notification
when a customer cannot be found in the Customers data source.
1. Open the Data View Editor of the Orders
program.
2. Add a Customer Exists Logical Virtual variable
before the Link Query operation.
3. Park on the Link Query line and open its
properties.
4. From the Success indication property, zoom to the
Variable list and select the Customer Exists
variable.
5. Open the Logic Editor and create a Control Suffix
logic unit for the Customer_Code control.
6. Create a Verify Error operation with the text: "Customer does not exist.".
7. Set the condition to NOT Customer Exists.
Now execute the application again.
8. In the Order_Number field, enter 2.
9. In the Customer_Code field, type the number 25.
10. Tap another field. An error message appears.
To leave the screen you must enter a valid customer code.
11. In the Customer_Code field, type the number 5.
You have now actually added two orders, order #1 and order #2.

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Short Summary
In the last section, you used the Link operation to validate data entry. For this purpose
you used the Success indication property.
First, you defined a Virtual variable to store the Success indication property value.
Then, you defined a Control Suffix for the Customer_Code variable, which raised anerror when the Link operation failed.
During the program execution, when an end user enters a non-existing customer code,
Magic xpa alerts the end user that the customer code does not exist in the Customers
data source and forces the end user to enter an existing customer code value.

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ExerciseComplete the order scenario so that its behavior reflects the correct method of creating
applications on a mobile device. This means:
1. Add parameters to the Orders program so that according to the parameter theuser will be able to view a specific order, update a specific order or add a
new order.
a. When a new order is created, set the current date as the initial date.
b. As an extra example, add a push button that deletes the current order.
This is only visible when the program is in Modify mode.
Hint: The visibility condition will be Stat (0,'M'MODE).
2. Add a program named List of Orders, which displays a list of all of the orders.
a. Display only the order number, order date and the customer’s name.
b. Add a push button that when pressed will add a new order.
c. Add a push button that when pressed will enable the user to modify thecurrent order.
d. When the user taps a specific order in the table, the details of the order
will be displayed.
Hint: The mobile tap action raises the Magic xpa internal event named
Click. What happens when you handle the Click event and call theOrders program?
You will now define the products for the course. You will:
3. Define the Products data source in the same way that you previously createddata sources.
4. Create the Products List program to display all of the products.
5. Create the Products program to display a single product.
a. Also display the supplier’s details.
b. If a user enters an invalid supplier code, then display an error.
c. Add a button enabling the user to modify the current product.

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6. The Products data source has the following fields:

Name

Model

AttributePictureProduct Code

Code

Numeric

9

Product Name

0

Alpha

60

Description

0

Alpha

100

Supplier Code

Code

Numeric

9

Product Price0

Numeric

6.2

Stock Quantity

0

Numeric

6

7. Define two unique indexes:
a. ProductCode with the Product_Code index segmentb. SupplierCode with the Supplier_Code and Product_Code index segments
You need to add data to the Products data source. You can do this by using
Magic xpa’s internal Import mechanism to import data. This imports a text file into thetable.
8. Park on the Products data source.
9. From the Options menu, select Generate Program.
10. In the Option parameter, select Import.
11. In the Text file parameter, select the Products.TXT text file. This text file islocated under the Text folder of the Getting Started project directory. In Lesson
6 you were asked to copy this directory. You can zoom to browse for the file.
12. The program will be added to the Program repository. Execute the program toimport the data.

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13. Add a new program that browses the Products data source.
14. Set up the form as shown in the image below.

15. Define placement on the Product Name and Description so that:a. When the form increases, the width and height of the product name and thedescription increases.
b. All of the controls below the description must move so that they always appear
below the description.
As with all programs, the product only displays a single product. Therefore:
16. Define a program named All Products, which displays a table with only the
product name. When the user taps a product, the Products program will becalled displaying that product. Both All Products and Products are display only
programs.

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193Summary
This lesson introduced you to the Link operation, which is used to implement one-to-one
data relationships.
The main use of this type of relationship is to connect a record of the program’s Main
Source to a specific record of another data source.
The Link operation is used to:Extend the record data view by adding variables of linked data sources.
Perform validity checks for the entered data and check the existence of a particular
record in linked data sources.
Modify or create records in the linked data source, according to the link criteria.
You were introduced to the various Link types:
Link Query
Link Write
Link Create
Link Inner Join
Link Left Outer Join
In this lesson, you used the Link Query operation to extend the Orders program’s data
view and perform validity checks for the Customer_Code value using the Successindication property.
In the exercise, you created the Products program, which displays the product details
and some of the supplier details, using the Link Query operation. You also added avalidity check for the Supplier Code value using the Success indication Link property.

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13

LessonSelecting Data from a List
In this lesson you will learn how to create and call a program that allows the end user
to select a value from a list. You will also learn about the Data control, which allows
you to select data from a data source using a Combo Box control, and how todetermine when to use a Data control instead of a selection list.
This lesson covers various topics including:Selection tables
Defining a Data control

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Selection List
In the Orders program from the previous lesson, the end user had to type in the
Customer Code and only then the customer details appeared.
Having the end user type in the Customer Code without knowing the Customer Name
is not a good idea. This means that the end user needs to memorize the customer
codes. In addition, in most cases the Customer Code has no real meaning to the end
user, but the Customer Name usually does have meaning.
The proper solution for the above is to let the end user select a value from a list.
By showing the end user all of the available information such as the customer’s name,they can then select an entry without the frustration of having to guess the appropriate
value.
A selection list is an interactive program that displays its data view as a list andenables the end user to select a value from the list.
Using a selection list involves two parts:
Creating a Selection List program.
Calling the selection list from the host program.
In this example you will create a program that displays the Customers data source
content (Customer Code and Customer Name) as a selection list.
1. Create a program named Select Customers.
2. From the Task type property, select Rich Client.
3. From the Initial mode property, select Query. A selection list is used to selectvalues from a list. Other operations, such as modifying or creating newrecords, should not be used here. Therefore, it is better to set the task’s Initialmode to Query.
4. From the Selection table property, select Yes.
By setting the Selection table property to Yes, Magic xpa executes the Record Suffix
logic unit and exits the program as soon as the Select event is raised. This special task
engine behavior includes the following stages:
Updating the selected value as a return parameter
Closing the current program
Returning to the calling program

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1.
2.
3.
4.
5.
6.

Open the Data View Editor.
Set the Main Source to Customers and use the Customer_Code index.
Add the Customer_Code and Customer_Name columns to the program.
Park on the first line, the Main Source definition, and create a line.
From the drop-drown list, select Parameter.
Set the name to P.Customer code and select the Code model.

Setting Locate Criteria
The Locate criteria enable you to locate a specific record and have the cursor park on
the matching record when the program starts. You will now set the Customer Codeparameter as the Locate from criteria, so that if the calling program sends a parameter,
Magic xpa will search for this customer and the cursor will park on that record when
the selection list opens.
1. Park on the Customer_Code column.
2. Open the Column Properties and zoom fromthe Locate from property to the Expression
Editor.
3. Create the following expression:
P.Customer Code.

Returning the Selected ValueAs was mentioned before, when you set a program’s Selection table property to Yes,
Magic xpa executes the Record Suffix logic unit as soon as the end user selects a value
by raising the Select event.
Now you will use this unique behavior to update the parameter with the selected
Customer Code.
1. In the Logic Editor, create a Record Suffix logic unit.
2. Create an Update Variable operation.
3. Update the Customer code parameter with the Customer_Code column.

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The Selection List Form
Most of the Selection List program’s forms are similar: a Table control with two columns(the Code column and the Description or Name column), and two push buttons: Selectand Exit. Now you will create the Customers selection list’s form according to theabove description.
1. Open the Form Editor.
2. Park on the Select Customers form.
3. Attach the form to the Table Display Form model.
4. Zoom to the Form Designer.
5. Drag the Table control onto the form. Set the Model property to Table.
6. Select the Customer_Code variable and place it on the table. This is alreadylinked to the Edit control model.
7. Select the Customer_Name variable and place it on the table. This is also
already linked to the Edit control model.
8. From the Customer_Code column’s Column Title property, change the name toCode.
9. Select the Column Heading model.
10. Set the Customer_Name column’s model to the Column Heading model.
11. Increase the width and the height of the table to display some records.

Adding a Select Button
As was mentioned before, the unique behavior of a Selection List program is achieved
when the Select internal event is raised.
12. Place a Button control at the top of the form.
13. Zoom into the control properties.
14. Park on the Format style and remove the text, which is initially Button.
15. Park on the Button style property and select Image Button from the combo box.
16. Park on the Image List file name property and type
%WorkingDir%\images\OK.png.
17. From the Event Type property, select Internal.
18. From the Event property, select Select.
19. Set the Color to Text Caption. This will make the button transparent for images
that have a transparent color.
20. From the toolbar, click the Fit Control Size

Adding the Exit Button
You can also add an exit button.
21. Place a Button control at the top of the form.
22. Zoom into the control properties.

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198

icon.

23. Park on the Format style and remove the text, which is initially Button.
24. Park on the Button style property and select Image Button from the combo box.
25. Park on the Image List file name property and type:%WorkingDir%\images\Exit.png.
26. From the Event Type property, select Internal.
27. From the Event property, select Exit.
28. Set the Color to Text Caption. This will make the button transparent for images
that have a transparent color.
29. From the toolbar, click the Fit Control Size
icon.
The form will look similar to the image below.

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Calling the Selection List
Creating the selection list is only part of the process of using a selection list. You needto call this list from a different program.
You will now set an event that will be raised in the Orders program. The event handler
will call the Select Customers program and pass the order’s Customer Code value as aparameter.
1. Zoom to the Orders program and select User Events
2. Create an event named Select Customers and from the Force Exit column,
select Editing.

The Force Exit column is set to Editing so that the new selected value
will be displayed in the Customer Code control after the selection list
is closed.

Now you will create an Event logic unit that will call the Select Customers programand send the Customer Code value as an argument.
3. In the Logic Editor, create a Header line for the User event, Select Customers.
4. Create a line for the Call Program operation. This operation enables you to calla program and pass parameters to the new program.
5. Call the Select Customers program.
6. From the Arguments field, zoom to the Arguments repository.
7. Create a line, zoom and select the Customer_Code variable from the Orders
data source.
8. Zoom into the Form Designer.
9. Add a push button to the right of Customer_Code.
10. Zoom into the control properties.
11. Park on the Format style and type … (three dots).
12. From the Event Type property, select User
13. From the Event property, select the Select Customer event.
14. Set the Visible property to NOT (Stat ('Q'Mode)). This means that it will not be
visible when the program is in Query mode.
15. Set the Width property to 3.5.
16. Set the Height property to 1.5.

You will now run the Orders program and learn how to use the selection list that you
just created.

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1.
2.
3.
4.
5.

Remember to give the List of Orders program the public name RunMe.
Execute the application.
Park on any order and tap the Edit button.
The Orders program will appear.
Tap the browse button that you defined to the right of Customer_Code.

The Select Customers window opens, enabling you to select a customer from the list.
Note that the customer number that appeared in the order is highlighted. This isbecause you have located the customer according to the argument from the Orders
program.
5. Tap on a different customer and tap the Select button.
You can see that the Customer_Code value was updated with the selected Customer
Code value.

Data Control
A selection list is an all inclusive solution for selecting data from a list. However, insome cases, when the list to select from is short, it is more efficient to use a Data
control. Like a Selection List program, a Data control enables the end user to select avalue from a list.
A Data control is a Combo Box control that displays one column from a data source.
Magic xpa builds the control’s list of options during runtime, according to theproperties specified in the Control Properties.
Unlike a Selection List program, a Data control is a control within the central programand not a separate program.
By using the Data control:
You do not need to create a separate Selection program and you do not need tocall the Selection program.
You do not need to validate the end-user selection.
The user can select a value from a list, instead of typing a value.
You do not expose internal codes in your programs; the user will only see thedescription or name.
Like a selection list, you can type the value in the Data control to perform an
Incremental Locate.

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201

Using a Data control has some restrictions, such as:
The list should be short.
You can only display one column from the data source.
As an example, you will display the suppliers’ list in the Products program as a Data
control. In most cases, selecting a supplier using a Data control is not reasonable,
since you have many suppliers. However, in this course, the Suppliers data source only
has a few records; so for practice purposes only, you will use this data source with a
Data control.
1. Zoom into the Products program.
2. Zoom into the Form Editor.
3.
4.
5.
6.
7.
8.

Zoom from the Orders form into the From Designer.
Select the Supplier_Code Label control.
Open the Control Properties.
Park on the Text property and change it to: Supplier.
Delete the Supplier_Code Edit control.
Delete the Supplier_Name Edit control.

Adding the Data Control
9. From the Toolbox, drag a Combo Box control () and drop it to the right of
the Supplier Label control (where the Supplier Code Edit control was).
10. Open the Combo Box control properties.
11. From the Data property, select the Supplier_Code variable (from the Products
data source). This was previously used as an Edit control.
12. From the Data Source number property, zoom and select the Suppliers data
source.
13. From the Display field property, zoom and select the Supplier_Name.
14. From the Linked field property, zoom and select the Supplier_Code.
15. From the Index property, zoom and select the Supplier_Code index.
16. Increase the Width of the control to 30 so that all of the data will be visible.
You may need to increase this even further according to your device.
Remember that you set placement for other controls, so you need to set placement forthis control as well. You only need to move the control if the height of the form
increases.
17. Zoom into the Placement property and enter 100 in the Y property. The
placement will look like this: {0,0,100,0}.
18. Remember to give the All Products program the public name RunMe.
19. Select a product from the list.
20. In the Products program, tap the Edit button.

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202

You can see that the Data control displays the supplier name value since you set theSupplier_Name as the displayed field.
21. Park on the Supplier combo box and select a different supplier. The look andfeel of the Data control is governed by the operating system.
Android

iOS

Remember that Magic xpa will internally save the Supplier_Code variable and not the
supplier’s name that is displayed.

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203

Exercises
As you will be using push buttons more and more, it is good practice to define models
for them.
1. Create a model named Browse button, for the Browse button with the same
properties as the button you defined during this lesson. You can use the Internal
event, Zoom, as the initial Raise event.
2.

Create a model named Image button, for the image button with the same
properties as the button you defined during this lesson. You can use theEdit.png image as the default image and the Internal event, Zoom, as the initial
Raise event.

You will now practice creating a selection list. In a previous lesson, you copied the
products folder to your project directory. This folder contains image files for the
products. Each image file name has the same name as the product name but with ajpg extension, such as Apple 2 GB iPod Nano.jpg.
3. In the Products program, add the display of the product’s image.
4. For use in the later lessons, create a selection list for the Products data source.
5. This selection list will be similar to the other selection lists that you created, but
it will display the image as a thumbnail and the product name in the table.
6. As an extra example, if the user taps a row in the table, it will display the
Products program so that they can see more details.

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204

SummaryIn this lesson you learned about the selection list and the Data control.

Selection Lists
A selection list is a Magic xpa interactive program that is used to enable the end user
to select a value from a list. The main steps in creating a Selection List program are:Setting the program as a Query only program.
Setting the Selection table property to Yes.
Defining a Main Source.
Defining a parameter to return the selected value.
Setting the Locate criteria.
Creating the program form, including Select and Exit buttons.
When the end user selects a value from the Selection List program, Magic xpa’s
behavior is:
Magic xpa executes the Record Suffix logic unit and the Task Suffix logic unit.
The program execution is terminated.
The parameter is returned to the calling program.

Data Control
A Data control is a Choice control that is used to enable the end user to select a value
from a list. The Data control displays a list of values, which are records of a data
source.
A Data control saves development time as well as making the end user’s interaction
easier.
A Data control, as opposed to a selection list, has some limitations, such as being
limited to one column in a data source and only being useful when there are only a
few options to select from.

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205

Selecting Data from a List

206

14

LessonOne-to-Many Data Relationships
In a previous lesson, you learned about the one-to-one data relationship. Anothercommon type of data relationship is the one-to-many data relationship. In this lesson
you will learn about one-to-many data relationships, and how to implement them in
Magic xpa.
A one-to-many data relationship exists when one record from one data source isrelated to several records from another data source. In Magic xpa, a one-to-many
relationship is implemented by using two tasks or programs.
In this way, the first task (usually called the parent task) displays the main record andthe second task (usually called a subtask) displays the "many" or multiple records. This
relationship is often displayed to the end user using two different display formats, theparent program displaying the single record in screen mode and the child program
displaying the multiple records in a table. This is not always the case, since you may
decide that the parent program will also be a table. During this course you will only
use the method of displaying the parent in screen mode.
Magic xpa uses a Subform control to display the child task’s form within the parenttask’s form and refreshes the subtask each time the common variable is changed in theparent ask.
This lesson covers various topics including:Writing a program that handles two data sources with a one-to-many data
relationship
Creating a subtask
The Subform control

One-to-Many Data Relationships

207One-to-Many Data Relationship Preface
A one-to-many data relationship is established between a primary data source and asecondary data source in such a way that each record in the primary data source has
several related records in the secondary data source.
The one-to-many data relationship will be explained using the Orders and Order Lines
data sources.

Primary Data Source
In the following example, the Orders data source is the primary data source.
An order record usually contains basic details regarding the order, for example:
Order Number
Order Date
Customer CodeTotal Amount
Method of Payment
The Order Number will be the Unique index of the data source, since each record hasa unique order number.

Secondary Data Source
The Order Lines data source is the secondary data source. It contains several data
items:
Order Number
Order Line
Product
QuantityPrice
The Order Number and the Order Line will be the Unique index of the data source.
The same order number can repeat several times with different order line numbers. The
linkage between the Orders data source and the Order Lines data source is the Order
Number.

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208

The Relationship Between the Data Sources
For each record in the Orders data source there are several records in the Order Lines
data source. This is the exact definition of a one-to-many data relationship.
Here’s an example of an order:

Orders data source with sample data
Order Number

Order Date

Customer
CodeTotal Amount Method of
Payment

1

20/11/2012

1111

100

Cash

Order Lines data source with sample data
Order Number

Order Line

Product

Quantity

Price

1

1

Logitech G5 Laser Mouse

3

15

1

2

Key Chain with LED Light

4

10

1

3

Infrared Thermometer Gun

1

15

The Order Number variable appears in both data sources; this is the common elementof the two data sources that establishes the connection.
In the above example, there is one record with Order Number = 1 in the Orders data
source and three records in the Order Lines data source with Order Number = 1.

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209

Advantages of the One-to-Many Data RelationshipIf someone is not familiar with one-to-many data relationships, they would just create
one data source for orders. Using the same example from the last page, the data
source would look as follows:

Order
NumberOrder Customer
Date
Code

Total
MethodAmount ofPayment

Line

Product Qty

Price

1

20/11 1111
/2012

100

Cash

1

Logitech 3
G5
Laser
Mouse

15

1

20/11 1111
/2012

100

Cash

2

Key
4
Chain
with LED
Light

10

1

20/11 1111
/2012

100

Cash

3

Infrared
Thermo
meter
Gun

15

1

You can see that the first five columns are repeated for each line in the order.
This will cause problems, such as the end user having to repeatedly type the same
information, and large records because of the repeated data. The result would be alarge data source, which takes up more disk space and slows down the engine’s
performance.
The solution to this problem is to define two data sources according to the following
rules:All of the repeating data columns should be defined in the primary data source.
All of the unique data columns should be defined in the secondary data source.
Both data sources should be connected using a common column.
The common column is the only column that will be repeated in the secondary data
source.
Separating data into two data sources saves the end user from having to type the samedata several times and it also reduces the size of the records.

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Defining the Many Data Source
In previous lessons, you added a data source by creating the table in the Datarepository. When working with most SQL databases, the DBA creates the table in SQL.
Magic xpa enables you to import the definition of that table thereby saving you from
redefining the table. This is known as Get Definition.
You will use this to retrieve the definition of the Order_Lines data source.
1. Open the Data repository.
2. Create a data source named Order_Lines.
3. Use the same name for the Data source name column.
4. Select the Getting Started database.
5. From the Options menu, select Get Definition or press F9.
The table definition is now a part of the Data repository. All that is left to do is toattach the entries to the models you have already created:
6. Attach Product_Code to the Code model.
7. Make sure to inherit the Picture.

The Order_Number of the new table must be the same as the Order_Number in theOrder_Lines data source. In a previous lesson, you defined this as Numeric with a sizeof 6. If you had defined a model, you could simply attach the model here and it would
inherit all of the attributes.
Make the following changes to the column pictures:
8. Set the Order_Number to 6.
9. Set the Line_Number to 3.
10. Set the Product_Price to 6.2.
11. Set the Product_Quantity to 3.

The Get Definition functionality is only valid for SQL databases.

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Establishing the One-to-Many Data Relationship
When viewing an order that has the order heading and the order lines, you often want
to display both the heading and the lines on the same form. When you use a tablet,
there is a difference in what can be displayed when the table is in portrait orlandscape mode. There is also a difference between what is displayed on a tablet andwhat is displayed on a smartphone. You need to know where your program will be
executed and set up the program accordingly. In a later lesson you will learn how tofind out if the program is in landscape or portrait mode. If your program is running ona smartphone, you may decide that to show a one:many scenario, you would add apush button in the Orders program to call another program that displays the lines forthat program. This method is suitable for all of the mobile environments. In thisexample, you will be displaying the order and its lines on a single form. You candecide which method suits your purpose for your own application.
To establish the one-to-many data relationship, you will use two tasks in the same
program. The first task will be a parent task and the second task will be a child task.
This is known as a subtask.
1. Zoom to the Orders program.
2. In the Navigator pane, click the Orders entry.
(If required: Select Navigator from the View menu to open the Navigatorpane.) If the Properties pane is displayed, click the Navigator tab which isvisible at the bottom of the pane.
3. Create a line. A new entry (task) will be created in the Task tree, as you cansee in the image below.

The Task Properties dialog box (of the new task) opens.
4. In the Task name property, type: Order Lines.
This is automatically defined as a Rich Client task
because the parent task is a Rich Client task.
5. Set the Initial mode to Query.

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6. Open the Data View Editor of the Order Lines program.
7. Set the Main Source to Order_Lines and the index to OrderLine.
8. Add all of the Order_Lines columns.
The Order_Lines data source has a column that has a one-to-one data relationship with
the Products data source. The connection is the Product_Code column. To increase theinformation about the selected product, you will add a link to the Products data source.
9. Create a Header line and select Link Query.
10. Select the Products data source with the ProductCode index.
11. Add the following columns from the Products data source: Product_Name,
Product_Price, Stock_Quantity.
12. In the Product_Code (of the Products data source), define an expression for the
Locate properties, which uses the Product_Code from the Order_Lines data
source.

Maintaining Data Integrity
The Orders data source has a one-to-many data relationship with the Order_Lines data
source.
To ensure that the Order_Lines subtask will only manipulate records that are related tothe parent task’s order record, you need to do the following:
Set a Range criteria according to the common variable (Order_Number). This
ensures that only records relating to a certain order will be displayed.
Initiate the subtask’s common variable (Order_Number) with the parent task’scommon variable (Order_Number). This ensures that when a new record is added,
the Order_Number will be added automatically.
Prevent the end user from seeing or updating the subtask’s common variable(Order_Number).

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In addition, the subtask content should be displayed within the parent task’s form,
using a Subform control.
The Subform control enables automatic displaying and refreshing of the subtask
content according to a parameter that was passed from the parent task.
To use the Subform control’s automatic behavior, a parameter should be defined in thesubtask.

Defining the Task Range
In the Order_Lines subtask’s Data View Editor:
13. Create a line below the Main Source row.
14. Add a parameter: P.Order_Number parameter with Attribute = Numeric andPicture = 6.
Now you will add the task range:
15. Park on the Order_Number column from the Main Source.
16. From the Range from property, zoom to the Expression Editor and create an
expression for the Order_Number parameter.
17. From the Range to property, select the same expression number that you set in
the Range from property.

Initializing the Order Number ValueThe Order_Number is the connection between the two tables. This should be added
automatically to each new record in the child task. This is performed using the Init
property.
18. From the Order_Number column, tab to the Init property.
19. Zoom to the Expression Editor.
20. Select the expression that you created for the P.Order_Number parameter.
Each time a new record is created in the subtask, Magic xpa will initialize theOrder_Number in the subtask with the Order_Number value passed from the parenttask.

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214Designing the Order Lines Form
The form is a similar form to the forms you have created during this course.
1. Open the Form Editor.
2. Open the Order Lines Form Properties.
3. Attach the form to the Table Display Form model.
4. Set the Height property to 12.750.
5. Zoom to the Order Lines form.
6. Place a Table control on the left corner of the form. Use the model named
Table.
Remember that in runtime, adding an order line to the table will be performed bycalling a program. Therefore you need to leave space for the push button.
7. Drop the Line_Number variable on the table. Select the Edit control model.
8. Click on the Line_Number column’s header area.
9. Zoom into the Column Properties and select the Column Header model.
10. In the Column Title property, type: Line.
11. Set the Width property to 7.
You will now add the Product_Name Edit control. This field is large and therefore youneed to reduce the size of the field initially. The Placement properties will increase thewidth wherever possible.
12. Increase the size of the table so that it fills the form.
13. Drop the Product_Name variable on the table. Select the Edit control model.
14. Open the Product_Name Edit Control Properties.
15. Set the Width property to 40. Note that the Allow Parking property is set to
False.
16. Click on the Product_Name column.
17. Open the Column Properties and select the Column Header model.
18. In the Column Title property, type: Product.
19. Set the Width property to 40.

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In a similar manner, you will add the quantity and the price, both taken from theOrder_Lines data source:
1.
2.
3.
4.
5.
6.
7.

Drop the Product_Quantity variable on the table. Select the Edit control model.
Open the Product_Quantity Control Properties.
Click on the Product_Quantity column.
Open the Column Properties and select the Column Header model.
In the Column Title property, type: Qty.
Set the Width property to 7.
Drop the Product_Price variable on the table. Select the Edit control model.

8. Open the Product_Price control Properties.
9. Click on the Product_Price column.
10. Open the Column Properties and select the Column Header model.
11. In the Column Title property, type: Price.
12. Set the Width property to 13.5.
Your form should look similar to the image below:

Adding a Line Total Column
In each line, the product price and the product quantity are displayed. It makes sensethen to add a Line Total for each line. You will now add an Edit control that will
display the Line Total.
1. Drag an Edit control onto the table, on the header of the Price column.
2. Open the Edit Control Properties and set the model to Edit control.
3. Expand the Data property and zoom from the Expression line
4. Set the expression: Product_Price*Product_Quantity, both from the Order_Lines
data source.
5. Set the Format property to 6.2.
6. Set the Width property to 12.
7. Set the Horizontal alignment property to Right.
You will now change the Table Column Properties:
8. Select the new Edit Control column.

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9. Open the Edit Control Column Properties and select the Column Header model.
10. In the Column Title property, type: Total.
11. Set the Width property to 13.5.
You have almost finished creating the program. What is left is to be able to add a row
and to change a row. You will do this soon. By this stage you should know how to do
this.

Subform Control
Now that the subtask creation is completed, it should be called and displayed within
its parent task, the Orders task.
Magic xpa uses a Subform control to display, call, and refresh a subtask’s content.
The Magic xpa Subform control provides an easy way to integrate another task’s form
within a given form.
A parent-child relationship between two tasks, which you are learning about in thislesson, is an example for the usage of the Subform control.
The task that is called from the Subform control is independent of the parent task, interms of record cycle and logic, and is a dependent unit in terms of the parent task’svalues.
Using the Subform control has the following advantages:
The navigation from the parent task to the called task is handled automatically by
Magic xpa.
The data view of the subform can be refreshed automatically (by Magic xpa)
according to the parent task’s passed arguments.
When the end user re-enters the subform’s task, Magic xpa retains the last positionin the subform’s data view.
Magic xpa provides a tab cycle for the Subform control, and therefore for thecalling task.
The Subform control permits event activation from a parent task.

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217You will now add a Subform control to the Orders form.
1. From the Navigator pane, click the Orders task.
2. Zoom to the Orders form.
3. Place a Subform control ( )on the form (under the controls that are alreadythere).
4. Open the Subform Control Properties.
5. From the Connect to property, select SubTask.
6. From the PRG/TSK num property, zoom to the Subtask list.
7. Select the Order Lines subtask.
8. From the Arguments property, zoom to the Argument repository.
9. Create a line and zoom from the Var column to select the Order_Number
column.
10. You want the subform to increase when the size of the form increases so thatyou can see more information. Therefore, enter 100 in the Width and theHeight properties: {0,100,0,100}.
11. Increase the width and height of the subform to fill the bottom of the Ordersform.
You have finished creating the Order Lines subtask and displaying its form within theOrders form. This means that you have created your first one-to-many data relationshipprogram.

In this lesson, you used a Subform control that called a subtask and a different task
was executed within that subtask.
The Subform control is navigated just like any other Magic xpa control. To move to any
entry in the subform, you just tap it.

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If you run the application by cutting and pasting the RunMe public name to the List ofOrders program and then viewing an order, you will not see any order lines, since you
have not added any. You need to create the program that adds a specific line.
You can add the Add Lines program as a subtask of the Order_Lines program:
1. Zoom to the Orders program.
2. In the Navigator pane, click the Order Lines entry and press F4 to create a new
subtask.
3. The Task Properties dialog box (of the new task) opens. In the Task nameproperty, type: Add / Edit Line. This is automatically defined as a Rich Client
task because the parent task is a Rich Client task. This task will be called when
you edit a line and when you add a line
4. In the Data View Editor, add a Parameter and name it P.Initial Mode. It will be
Alpha with a size of 1.
5. Set the Main Source to Order_Lines and the index to Lines.
6. Add all of the Order_Lines columns.
7. Zoom into the Range from property of the Order_Number column and set therange to the Order_Number column of the Order_Lines subtask that appears in
the Order Lines task, not the current task.
Since this is a subtask, the variables from the parent task are visible and you
can use them directly. There is no need to use a parameter.
8. Set the same expression in the Range To property and in the Init expression.
Remember that the Init expression is evaluated when the task is in Createmode.
If the subtask is called in modify mode, you also need to range according to theLine_Number column, but in create mode, you set the value of the Line_Number
column:9. Zoom into the Range from property of the Line_Number column and set theexpression to:
CndRange (U='M', N)
where U is P.Initial Mode and N is Line_Number from the Order Lines subtask
10. Set the same expression in the Range to expression.
As you might remember, the Order_Lines data source has a column that has a one-toone data relationship with the Products data source. The connection is the
Product_Code column. You will be adding a link to the Products data source. As theuser needs to select the product, you need to also add a Link Success variable.
11. Add a Virtual variable with a Logical attribute named Product exists.
12. Create a Header line and select Link Query.
13. Select the Products data source with the ProductCode index.

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14. Add the following columns from the Products data source: Product_Name,
Product_Price, Stock_Quantity.
15. In the Product_Code (of the Products data source), define an expression for the
Locate properties, which uses the Product_Code from the Order_Lines data
source, of the current task. Remember that the variables from the parent task
are visible.
16. Zoom into the Task Properties and set the Initial mode property to By Exp.
Zoom into the Exp. property and set an expression:
If (P.Initial Mode = 'C', 'C'Mode,'M'Mode)
This means that if C is passed, the subtask will be in create mode and if not itwill be in modify mode.
17. From the Task menu, select User Events.
18. Create an event named Select Product and from the Force Exit column, selectEditing.
19. In the Logic Editor, create a Header line for the User event, Select Product.
20. Create a line for the Call Program operation.
21. Call the Select Products program.
22. From the Arguments field, zoom to the Arguments repository.
23. Create a line, zoom and select the Product_Code variable from theOrder_Lines data source in the current task.

Now you need to define the form:
1. Zoom into the Form Editor and set the model to Table Display Form.
2. Drop the Line_Number and Product_Code variables from the Order_Lines data
source on the form. Do not forget to use the models.
To the right of the Product_Code you are going to add the select button:
3. Drag the Browse button model from the Models pane
onto the form. Magic xpa will automatically create therequired control for you and attach the model to thecontrol.
4. Zoom into the control properties and from the Event Typeproperty, select User.
5. From the Event property, change the event so that it raises the Select Products
User event.
6. Add the Product_Name variable to the form.
7. Add the Product_Price and the Product_Quantity.
8. You can add the product’s picture as well.

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220Each product has a default price, which is fetched from the Product_Price column of the
Products data source. When creating a new order line, the default product priceshould be presented to the end user. This is what is known as the list price or catalog
price. In your scenario, the end user should be able to change the price of the productfor the specific order. Therefore, there is a Product_Price column in the Order_Lines
data source.
In the following section you will implement the above logic, using the Variable Change
logic unit and the Update operation.
1. Open the Logic Editor and create a Header line.
2. Set a Variable Change logic unit for the Product_Code variable (from theOrder_Lines data source).
3. Create the parameters by clicking Yes in the Confirmation dialog box. The twoparameters will be created in the Variable Change Logic Unit section.
4. Create an Update Variable operation.
5. Update the Product_Price (from the Order_Lines data source) with theProduct_Price (from the Products data source).
If the user changes the Product_Code number in the order, a new price will be fetchedfrom the database.
The parent task that displays the order’s lines needs to know that there are changes
and therefore the view needs to be refreshed.
6. Create a Record Suffix logic unit.
7. Raise the View Refresh event.
Now you need to call this subtask from the parent subtask.
1.
2.
3.
4.
5.
6.

Zoom into the Order Lines subtask.
Select User Events.
Create an event named Add order line.
Create another event named Change order line.
In the Logic Editor, create a Header line for the User event, Add order line.
Create a line for the Call Program operation. Park on the Program combo box
and select Subtask. Select the Add / Edit line subtask.

7. From the Arguments field, zoom to the Argument repository.
8. Create a line and create an expression: 'C'.
9. Create a Header line for the User event, Change order line.
10. Create a line for the Call Program operation. Park on the Program combo box
and select Subtask. Select the Add / Edit line subtask.
11. From the Arguments field, zoom to the Argument repository.
12. Create a line and create an expression: 'M'.

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Now you need to add the push buttons to the form that will raise the events.
13. Zoom into the Form Editor and zoom into the Order Lines form.
14. From the Models pane, drag and drop the Image button model at the top of theform.
15. Zoom into the Control Properties.
16. Park on the Image List file name property and modify the image name to
Add.png.
17. From the Event Type property, select User.
18. From the Event property, select Add order line.
19. Click the Fit Control Size icon.
The edit line icon can be displayed on the table:
20. Drag and drop the Image button model on the table, on the Line Total column.
21. Zoom into the Control Properties. Since the default image is the Edit.png, there
is no need to update the image.
22. From the Event Type property, select User.
23. From the Event property, select Change order line.
24. Click the Fit Control Size icon.
Your form will look similar to the image below:

Remember that you run the Orders program from the List of Orders program.
1. Execute the application. The List of Orders program is displayed.
2. If there is an order, such as order #1, click the Edit icon. If no order exists, click
the Add icon.
3. The order will open but no lines will be displayed.
4. Click the Add icon and add the following line:

Order

Line

Product_Name

Price

QuantityLine Total

1

1

Logitech G5 Laser Mouse

69

3

207

One-to-Many Data Relationships222

5. Add another line:

Order

Line

Product_Name

Price

QuantityLine Total

1

2Sony PSP console

500

3

1500

The Sony PSP console price is: 527.14. You have to manually change
the price to 500.

AndroidiOS

6. On the Orders form, tap on the Amount control.
7. Type the value: 1707.00.
8. Select Credit Card as the Method Of Payment.

More About the Subform Control
Subform View Refresh
The subform view is refreshed whenever the end user executes its task, such as clicking
the Subform area or tabbing into it.
The subform view is also refreshed automatically by Magic xpa. This occurs when thevalue of one of the passed parameters is changed and the Automatic Refresh property
is set to Yes.

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Note: This is why you sent the Order_Number as a parameter to the subtask. In thisway, whenever the end user navigates between the orders (even without entering the
Subform area), the Subform view is automatically refreshed.
Magic xpa also supplies an internal Subform Refresh event.

Subform Task Execution
The Subform task is executed:
For the first time, after the first Record Prefix of the parent task. (This mode of
execution is referred to as: executing the first Record Prefix.)
When the end user tabs into the Subform control.
When the end user clicks the Subform area (either when clicking on a specificcontrol or any location in the Subform area).
You can control when a subform is loaded with the Refresh When
Hidden property. This property is useful when the subform is notinitially visible, which may be when it is a part of a Tab control orwhen there is an expression on its Visible property.

Subform Task Termination
The Subform task is terminated when:
The outside of the Subform area is clicked.
The Close (internal) event is raised.
The End Task condition of the Subform task evaluates to True.
The parent task is closed.
When the Subform task is terminated, the following occurs:
The Control Suffix logic unit (of the parked control in the subform) is executed.
The Record Suffix logic unit (of the connected task) is executed.
The Task Suffix logic unit (of the connected task) is executed.
The focus returns to the next control in the parent task as determined by the parenttask’s tabbing order and tabbing direction.

Subtask Form Transparency
Look at the Orders program while it is executing.
Can you see that there are actually two wallpapers: one for the Orders task and one
for the Order_Lines subtask?

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224AndroidiOS

If you would have used plain wallpaper you would not be able to tell the difference;but since you are using wallpaper, the difference is observable. To overcome this, youneed to set the Subtask form with a transparent color and remove the Subtask form’s
wallpaper.
1.
2.
3.
4.

Zoom to the Orders program and select the Order_Lines task.
In the Form Editor, park on the Order_Lines form.
Clear the Wallpaper property.
In the Color property, select the color: Text Caption.

Incremental Update
While creating the first order you were asked to manually fill in the Amount value.
As you may have already figured out, this is not the right way to calculate the order’samount.
Magic xpa has a specific mechanism that performs such calculations; this mechanism
is called Incremental Update.
This section will introduce you to Magic xpa’s incremental updating.
Magic xpa enables you to incrementally update a variable, meaning that the update
expression value is evaluated and added or subtracted from the updated value
according to the following rules:
If a new record is added, the value is added to the updated value.
If a record is deleted, the value is subtracted from the updated value.
If a record is modified, the old value is subtracted and the new value is added tothe updated value.
You will now automatically calculate the order’s Amount and disable the ability to parkon the Amount control, so that the end user will not be able to manually change its

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value. For each order line, you have a total for the line that is based on a calculationof the product price and the quantity. You used an Edit control containing an
expression. In this section, you will update the Amount variable with the same
expression. You are going to update the Amount variable when the Product_Price *Product_Quantity value changes. To implement this, you will add a Line Total variable
and use that on the Form Editor instead of the Edit control. You will update the Amountvariable from the Record Suffix logic unit.
To add the Line Total variable:
1. Zoom to the Orders program and zoom to the Order_Lines task.
2. Open the Data View Editor.
3. Add a line, preferably as the last line in the editor.
4. Create a Virtual variable and name it: Line Total.
5. Set the Attribute to Numeric and the Picture to 6.2.
The Line_Total Edit control that you placed on the form was a calculation of the productprice and the quantity. You will use Magic xpa’s internal recompute mechanism byusing this expression in the Init property of the Virtual variable that you added.
6. Park on the Line Total variable and tab to the Init property.
7. Zoom to the Expression Editor.
8. Select the expression Product_Price * Product_Quantity that you previously
created.
The Line Total variable is automatically calculated every time a change is made toeither the Product_Price variable or the Product_Quantity variable. Since the value is
automatically calculated, there is no need to park on the variable. You need to makethe variable non-parkable on the form. This will be the same behavior as using an Edit
control. There are two methods of doing this:
Placing the variable on the table and making the control non-parkable. You haveused this method throughout this course.
Defining the non-parkable property at the level of the variable.
For this example, you will use the second method:
1. Park on the Line Total variable.
2. Open the variable property sheet.
3. In the Style node, park on the Rich Client table property. This is the property
that governs the look and feel of this variable when it is dropped on a table.
4. Click the Zoom
button. This opens a control property sheet.
5. In the Parking section, set the Allow Parking property to No.
6. Set the Model to Edit Control.

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Adding the Line Total variable to the form:
1. Zoom to the Order_Lines form.
2. Park on the Total Edit control and delete it.
3. From the Task Variables pane, drag the Line Total variable and drop it on thetable on the Price column.
4. Open the control property sheet. Check that the Allow Parking property is set toNo.
5. Open the Column Control Properties.
6. Set the model to Column Header.
7. Set the Column title property to Total.
To update the Amount variable you need to perform this where you update the lines
and this is in the Add / Edit Line subtask.
1. Zoom into the Add / Edit Line subtask.
2. Open the Logic Editor.
3. Zoom into the Record Suffix logic unit.
4. Before the Raise Event of the View Refresh event, create a line for the Update
operation.
5. Update the Amount variable (from the Orders data source) with theProduct_Price * Product_Quantity variables, both from Order_Lines data
source.
6. From the Update operation’s properties (Alt+Enter), set the Incremental property
to Yes.
Now when the Amount variable is automatically calculated by Magic xpa, the end
user should not be able to manually change its value. Therefore, you will now set theAmount control’s Allow Parking property to False.
1.
2.
3.
4.

In the Navigator pane, click the Orders task.
Open the Form Editor and zoom to the Orders form.
Select the Amount Edit control.
From the Amount Control Properties, set the Allow Parking property to False.

You can now execute the application.
1. Edit the first order, order number 1.
2. Tap the Add button to add an order line.
3. In the Line column, type: 3.
4. Zoom from the Product Code column and select: HealthCare Foldable Full Body
Massage Lounger (product number 30).
5. In the Quantity column, type: 1

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Close the task and you will be returned to the list of order lines. The new line is there.
Check the Amount value; it should display: 1906.95. This is the sum of the existing
Amount value plus the value of line number 3 (199.95).
1. Click the edit button on order line number 3.
2. Change the Product Price from 199.95 to 340.
3. Close the task and check the Amount value; it should display: 2047.00.
This is the sum of the existing Amount value plus the difference in line 3 (340 199.95 = 140.05).

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228

ExerciseCountries and cities have a one-to-many data relationship. Each country can have
many cities.
Now you will practice what you learned so far, by creating a program that displays alist of countries and their related cities.
1. Create a model named Country&City Code with a Numeric attribute and a
Picture of 6. Set the Color to Edit control.
2. Create Getting Started data sources for Countries and Cities and import thedefinition using the Get Definition utility.
3. Attach the Country&City Code model to the Country_Code and City_Codecolumns and re-inherit the Picture property.
4. Define a Countries program that displays the country and its cities.

One-to-Many Data Relationships229

Summary
This lesson introduced you to the one-to-many data relationship.
You learned how a one-to-many data relationship can help save space and reduce
maintenance, when compared to having all of the data in one data source.
You practiced creating a parent task and child task in order to implement a one-tomany data relationship using Magic xpa.
The example included:
Defining a parent task and a subtask.
Using the Range and Init properties to prevent data integrity violation.
Using a Subform control to display the subtask’s form within the parent task’s form.
Determining the refresh trigger by passing an argument to the child task in the
Subform control.

One-to-Many Data Relationships

230Lesson15

Non-Interactive Processing
Throughout this course you learned about Rich Client programs. Until now, theassumption when developing a program was that the programs ran on the samemachine, but this is not a real life scenario. There is often a client machine and aserver machine. The server holds the main part of the application installation, including
images, files and the database. The client is a thin client and provides the front-end
interface.
In every interactive program, there is a part of the program that executes on the server
and a part that executes on the client. There is constant traffic of information along the
network between the client and the server. The communication between the two isdone by sending a compressed XML file. It is this traffic that may prevent a smooth user
experience by creating a bottleneck. It is good practice to try and minimize this traffic.
In the next few pages you will learn about client interaction with the server. Then, youwill learn about the Magic xpa Batch task.
This lesson covers various topics including:
How the Rich Client interacts with the server
How the Magic xpa engine works in Batch tasks
The differences between Rich Client tasks and Batch tasks
When to use Batch tasks
How the Magic xpa engine processes Batch tasks
Maintaining data integrity using a Batch task

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231Data View Editor and Rich Client
The interaction between the client and the server is via XML files. The data view isassembled on the server. The actual records and fields that are used are included in
the XML that is sent to the client.

Variables
Variables are usually neutral. However, for some variables, every time the variablechanges on the client, server access is immediately required. Such variables are called
server-side variables. These variables have an “S” next to them, and are shown in acontrasting color. You have seen this while developing programs during this course.
This can happen if the variables are used in the Range/Locate of a link. Each changeof the variable value will execute the link again; hence there will be access to theserver.

BLOBs
In a Rich Client program, if the data view contains BLOB variables with lots of content,
the BLOBs will be passed between the server and clients (like other variables), and thismight slow down the program. It is advised not to define the BLOBs in the data view ifthey are not used, or you should create a new Batch task that handles them if they are
to be used on the server side.

Functions
Functions are the smallest building-block of an expression, and the side of theexpression will depend on the functions (and variables) in it. Each Magic xpa function
is client-side, server-side, or neutral. You can find a list of these in the Magic xpa Help.
When you select a function, you can see its execution side in the Function List. It will
say Server, Client, or Client & Server (meaning neutral).

Non-Interactive Processing232Expressions
Expressions are built from one or more functions and variables. The side of theexpression is determined by the side of the functions and variables.
Every expression can be categorized as being Client-side, Server-side, Neutral, or
Mixed.
Client-side expressions can only execute on the client.
Server-side expressions can only execute on the server.
Neutral expressions, however, can execute in either place. They will execute on theserver if the operation is being executed on the server or on the client if theoperation is being executed on the client.
Mixed expressions contain elements from the server and from the client.
It is important to know what kind of expression is being used. Expressions are used inmany different places within a task. If the expression is a server-side expression, but isbeing used in a place that would require it to be evaluated on the client, the client has
to stop and send a request back to the server before processing can continue. In somecases, the syntax checker will disallow the process; in other cases, it is allowed, but it
will be slow.
Every expression is marked as to where it will
be executed:
S = Server-side
C = Client-side
M = Mixed
blank = Neutral
This is important to know, because theexpression will be used in an operation, a property, or an Init value. You want to makesure that the side of the expression matches where it is used.

Range and Locate Expressions
Range and Locate expressions are sometimes evaluated on the client, and at othertimes on the server. Therefore, the expressions used in Range and Locate need to be
neutral.

Init Property
Client-side expressions cannot be used in the Init property. If you need to use client-side
expressions in an Init property, use an Update Variable operation in the Record Prefix
logic unit.

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233

Client-Side vs. Server-Side Operations
As was discussed before, there is a part of the program that executes on the server
and a part that executes on the client. Some of the internal Magic xpa operations areclient-side operations and some are server-side operations.

Operation

Where executed

VerifyClientCall

UpdateInvokeMixed: A Call to a Rich Client task using the Destination property.
There is immediate access to the client to close the task that currently
runs in that subform.
Server – Other Calls (to Rich Client tasks or Batch tasks) areconsidered as Server, since there is access to the server to initiate thetask that has been called. After the focus returns to the client, the task
is drawn there. You will learn more about Batch programming later inthis lesson.
This depends on the variable being updated and the expression used forthe update.
Server – UDP, Web S, Web S Lite
Client and Server – OS Cmd (depends on the Execute on property)
COM – Not supported for Rich Client tasks

Raise Event

The Raise event execution side is determined by the handler's execution
side of that event.

Evaluate

This can be executed either on the client or the server depending on theoperation.

BlockThis can be executed either on the client or the server depending on the
Block expression.

Form

Not supported for Rich Client tasks. You can run reports on the server anddisplay the results on the client.

Link Query

Server. It is recommended that you limit the use of Link operations because
they are costly in terms of server interaction. Many times, you can use a
Data control or Inner Join instead.

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234

Operations are also affected by the expressions used in theirproperties, such as the Condition property.

The Task Life Cycle
You learned about the application engine in a previous lesson. You were also
introduced to the program life cycle and the various internal logic units.
When developing a Rich Client program, some of these logic units are executed on theclient and some on the server:

Operation

Where executed

Task Prefix

Server. No client-side operations or functions can be used here.

Task Suffix

This can be client or server, depending on the operations within.

RecordThis can be client or server. It is recommended not to use Server-sidefunctions and operations here in order to diminish accessing theserver when browsing through the record.

ControlThis can be client or server. It is recommended not to use Server-sidefunctions and operations here in order to diminish accessing theserver when tabbing through the controls.

Variable
ChangeThis can be client or server. It is recommended not to use Server-sidefunctions and operations here in order to diminish accessing theserver during the recompute mechanism or when changing acontrol’s value.

Error

Server.

These are recommendations; however, it is not always possible torefrain from accessing the server to perform the task logic.
It is good practice to group client operations and server operations
together to decrease network activity.

Non-Interactive Processing235

Identifying Client and Server Activity
As some of the operations are client and some are server, when you develop a
program, it is important to know where the program may have a performance problem
due to running back and forth between the client and the server.
Magic xpa provides a visual aide and displays the handling mode of each handler,
operation, and function. A character appears on the left side of the line number
column representing the handling modes below:
C – Client-side handling: The operation will be performed on the client.
S – Server-side handling: The operation will be performed on the server.
M – Mixed mode handling: The operation will be performed on both the client andthe server.
U – Unknown: This is for operations that the development Studio does not know
where they will be evaluated. For example, when you use the Raise Event
operation but the handler is not found.
E – Error: The operation is not supported, such as the Form Output operation.
If a character does not appear, the entry can be executed on either the client or theserver.
This is shown in the following image:

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236

Rich Client Operation Colors
The background color of the operations in the Task Editor indicates whether theoperation is server-side, client-side, neutral, or unknown. The colors are provided by
Magic xpa but you can change them in the Studio Color repository.
The table below describes the various colors:

Color Name
White

ServerUnknown

Description••••

Client-side operations that must be executed on the client side
Handlers’ headers that contain client-side operations
Neutral operations that appear after a client-side operation
Unsupported operations, such as mixed operations•••

Server-side operations that must be executed on the server side
Handlers’ headers that contain server-side operations
Neutral operations that appear after a server-side operation•

Unknown-side operations. These are operations which the Studiocannot know if they will be executed on the server side or clientside.

Neutral lines will have the same colors as the line above them, since they will be
executed on whichever side is currently doing the processing. The flow itself can vary,since some of the operations may have a condition that will evaluate to FALSE, so they
will not be processed.

For more information about working with Rich Client applications, see
the Developing Rich Client Applications concept paper in the
Magic xpa Help.

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237

Batch Programming
Up until now you learned about Rich Client programs. Sometimes it is necessary tohave a program that performs a process without user interaction. In Magic xpa, thesetypes of programs are called Batch programs.
In this and the next lessons you will be introduced to the concept and behavior of
Batch programs. You will then be shown how to create a program that performs aprocess without user interaction.
Batch tasks are used to perform a process on a set of records from a data source. They
can also perform processes with no data source. Batch tasks are used for processes,
such as reports, record updates or deletion, and calculations.
Although a Batch task has a form, most Batch tasks are executed without displaying
anything to the end user.

Rich Client Task vs. Batch Task
Rich Client Task

Batch Task

Enables end-user interaction.

Does not allow end-user interaction.

Enables the end user to navigate
through the Main Source records.
Only the records that are scrolled
are scanned.

The task scans all of the Main Source records
within the range criteria. If no Main Source isdefined, or the task is in Create mode, the task
loops until the End Task condition is met.

The Control logic unit is available.
The engine handles logic related to
end-user navigation.

The Control logic unit is not available, since
there is no end-user interaction and the engine
does not park on controls.

The Group logic unit is notavailable.

The Group logic unit is available and enables
you to handle groups of data. You will learn
about this logic unit in a later lesson.

The Task Form is an essential part of
the task creation and execution.

The Task Form is optional and most of the time is
not in use.

If the data is changed, the Record
Suffix logic unit is executed and thedata is saved.

The Record Suffix logic unit is always executed.
A record is always saved to the database, even
if it was not changed.

Events are handled when the task is
idle.

Events are handled every set period of time or
every number of processed records.

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Engine Flow for a Batch Task
The engine execution rules work differently in Batch tasks than in Interactive tasks.

Interactive task engine cycle

Batch task engine cycle

Task Prefix
Record Prefix
Control Prefix
Control Verification
Control Suffix
Variable Change
Record Suffix
Task Suffix

Task Prefix
Group Prefix
Record Prefix
Record Suffix
Group Suffix
Task Suffix

As you can see, in the Batch task there are no Control-related logic units, but there are
logic units that allow you to handle groups of records.
Note: You will learn about the Group Prefix and Group Suffix logic units in a later
lesson.

Batch Task’s Life Cycle
This section explains the processes that are executed during a Batch task’s life cycle.

Task Initialization
The Task Initialization operations are similar to the operations in the Online task.

Group Processing
The Group logic unit creates breaks during the data view processing. You can use
the Group logic unit to calculate sums at certain levels, to display data by groups,
or to print breaks in a report. You will learn more about this logic unit in a later
lesson.
The Group Prefix logic unit operations are executed for the first task cycle andwhenever the Group logic unit’s variable value is different from the previous record
value.

Record Processing
The Record Prefix logic unit operations are executed.
The Record Suffix logic unit operations are executed.
The record is saved with the new values. If the Task mode is set to Delete, therecord is deleted.

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239

End Group Processing
When a new record is fetched and the Group logic unit’s variable value is different
from the previous record value, the Group Suffix logic unit operations are executed forthe previous record and the Group Prefix logic unit operations are executed for thecurrent record.

Batch Task Termination
The Task Termination operations are similar to the operations in a Rich Client task.
Unlike in Rich Client tasks, where the end user terminates the task, in Batch tasks thetermination occurs according to the following properties or actions.
The End Task Condition Property
This property enables the developer to determine the task termination. The options are
Yes, No, and setting an expression.
The Evaluate Condition Property
This property determines when Magic xpa evaluates the End Task condition. The
options are:
Before Entering Record – The End Task condition is evaluated before entering therecord.
After Updating Record – The End Task condition is evaluated after the record is
updated.
Immediately when condition is changed – The End Task condition is evaluated
immediately when the condition is changed (without completing the current logic
unit execution).

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240

Batch Task Behavior
In this section you will learn about different characteristics that determine the Batch task
behavior.

Batch Task with a Main Source
A Batch task loops through the Main Source records (within a Range criteria). The task
repeats the Record Prefix and Suffix logic unit operations for each scanned record.
The task execution is terminated if one of the following conditions is met:
The End Task condition (in the Task Properties) evaluates to True (as explained on
the previous page).
The engine reaches the last record in the range of records.

Batch Task with No Main Source
If no Main Source is defined, the Batch task is executed as long as the End Task
condition is not met.
This type of task is called a Zero Main Source Batch task.
For example, if you create a program that cycles through Virtual variables, the record
loop will be endless, until the End Task condition is met.

Batch Task with a Main Source and in Create Mode
When defining a Batch task with a Main Source and the Initial Mode property is set toCreate mode, the task behaves like a Zero Main Source Batch task.
For example, if you create a program that only adds records to the data source, therecord loop will be endless (no range can apply here), until the End Task condition ismet.

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241Batch Task Usages
The Batch task has many usages. In many cases there is a clear connection between
the Batch task mode and its usage.
The following will give you a general description about the Batch task usages
depending on the Task mode.

Task
Mode

UsagesQuery

Used to scan Main Sources and produce outputs, such as reports, or
calculation outcomes, such as number of records, maximum value andminimum value.

CreateUsed to import data from an I/O source or to copy data from one or moredata sources.

ModifyUsed to perform sequential updates in a data source or make collective
calculations for records in the data source.

DeleteUsed to perform sequential deletions in a data source according to acertain scenario, such as maintaining data integrity.

Batch Delete
Batch tasks with an initial mode set to Delete can be used to maintain data referential
integrity.
In the previous lesson you learned about one-to-many data relationships. You practiced
this concept by creating the Orders program.
The end user creates an order by creating one record in the primary data source(Orders) and several records in the secondary data source (Order_Lines).
When deleting the order record from the primary data source, the related order lines’
records in the secondary data source are left orphaned.
This will happen unless you handle this by using a Batch task that deletes all of therelated order lines’ records from the secondary data source whenever the related
record is deleted from the primary data source.
On the following pages you will improve the Orders program by adding a Batch task
to handle orphaned records.

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In a previous lesson you added a push button to the Orders program that will enable
the end user to delete an order. But what if that order also had lines? They also need
to be deleted. In this example you will add a subtask to the Orders task that will becalled every time the end user deletes a record from the Orders task. The called
subtask will be a Batch task that deletes all of the Order_Lines records that have thesame Order_Number as the Orders task’s Order_Number.
1. Zoom into the Orders program.
2. In the Navigator pane's Task tree, park on theOrders node and create a line.
In the Task Properties dialog box:
3. In the Task name entry, type: Delete OrderLines.
4. From the Task type entry, select Batch.
5. From the Initial mode entry, select Delete.
In the Data View Editor:
6. Set the Main Source with the Order_Lines data source.
7. Set the Main Source index with the OrderLines index.
8. Create a line and select the first Order_Lines column: Order_Number.
The subtask should delete only the lines that have the same Order_Number as in theparent task. Therefore, you need to set a range on the Order_Number column.
9. Park on the Range property.
10. Create an expression for the Order_Number from the parent task’s Orders
data source.
11. Set the same expression number in the Range To property.
The Delete Order Lines subtask should be called from the Orders program whenever
the end user deletes an order. This is from the Delete Line logic unit.
12. Click on the Navigator pane and in the Task tree, park on the Orders node.
13. Open the Logic Editor and zoom into the Delete Line logic unit.
14. Add a detail line immediately after the Header line.
15. Call the Delete Order Lines subtask.

Non-Interactive Processing

24316. Execute the application and display the List of Orders program.
17. Tap the Add order button and create a new order like the image below (iOSdisplay).
18. Create a new order with order lines as shown in the image below.

19. Return to the list of orders and you will see the new order.
20. Tap the Edit order button.
21. When the order loads, tap the Delete button.
22. In the Confirmation dialog box, click Yes.
Although you do not see the Batch task execution, Magic xpa executed the Batch taskthat deletes the related order lines.

Non-Interactive Processing244Summary
This lesson introduced you to the Rich Client engine’s client/server activity. You
learned which parts of the task were executed on the client and which were executedon the server. You also learned how to identify problematic operations during
development.
You then went on to learn about Batch tasks, which are server-side tasks that are
executed without any user interaction. You learned about the main differences between
Rich Client tasks and Batch tasks. You also learned about the Batch task’s engine cycle
compared to the Rich Client task’s engine cycle.
You then learned about the Batch task’s engine flow. You learned that Batch tasks
behave differently when there is a Main Source and when there is no Main Source.
In addition, you learned that Batch tasks are used mainly for:
Creating reports
Processing a group of records
Processing sequential updates
Calculations
Copying records from one data source to another
Importing data from an external file
You created a Batch subtask that deletes order lines; this maintains data integrity in theOrders program.

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245

Non-Interactive Processing

246Lesson16

Reports
Creating reports is an essential part of the application’s functionality. A report is adisplay of the application data.
You will use Magic xpa’s Program Generator utility to generate a simple report of adata source.
You will then learn how to manually create a simple report.
This lesson covers various topics including:
Using the Program Generator to create a simple report.
Manually creating a simple report.
Designing a report that includes headers and footers.
Creating the report as a PDF.
Displaying the PDF using the Browser control.
Displaying the PDF using third party applications.
Printing the PDF from a mobile device.

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247

Using the Program Generator Utility
In this section you will create a program that produces a report of the Customers data
source.
1. Open the Data repository.
2. Park on the Customers data source.
3. From the Options menu, selectGenerate Program.
4. The Program Generator dialog box
opens.
5. In the Mode field, select Generate.
6. In the Option field, select Print.
7. Park on the Columns field.
8. Zoom to the Column Selection
window.

The value in the Column column shows the position of the column on the form.
9. For the following columns, set the Column
column with the value zero (0):Gold_Membership, Membership_Date,
Membership_Time, Salary_Amount, andCredit_Amount.
10. Define the order so that the report will
display the address first, then the city andthen the country.
11. Click OK.

As was mentioned in an earlier lesson, the Column Selection window
allows you to determine which variables will be displayed in thereport and the order of the displayed variables. A value of zero in the
Column column of a variable indicates that it will not be displayed.

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12. Click the Style tab.
13. Select the Caption check box.

The Print - Customers program was added to the end of the Program repository.
You can zoom into the program and view it. Next you will learn how to create thesame program manually.

Manually Creating a Report
You have just learned about automatically generating a program that prints the
Customers data source content. You will now create the same program manually.
1. Create a program and in the Name column, type: Print - Customers 2.
2. Zoom into the program.
The Task Properties dialog box opens.
3. Set the Task type to Batch.
4. Set the Initial mode to Query.
Now you’re going to set the task’s data view.
5. In the Data View Editor, set the Main Source to Customers.
6. Set the Index to Customer_Code.
7. Add the first 5 Customers columns from the data source to the Data View
Editor.

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Defining I/O Devices
When running a report on a desktop computer, the output is printed on a printerconnected to the computer. When you are using a mobile device, this is not feasible.
The report needs to be displayed on the client machine. Although there are manycases in which you might want to print reports on the server machine, in this course
you will be printing on the client. The suggested method for printing to a clientmachine is to create a PDF and to display it.
To setup an output for a program, you need to define an I/O device. This enables you
to define an output that:
Imports data from external files.
Outputs data to a graphic printer, files, PDF, and so on.
Sends HTML files to the internet requester.
Accesses XML files.
You will define an entry in the I/O Device repository that will enable you to print thereport to a PDF through the Graphic Printer properties.
1. From the Task menu, select I/O Devices (Ctrl+I).
2. In the I/O Device repository, create a line.
3. Set the name to Print - Customers.

By default, the generated program is designed to print the output to a printer, thedefault printer of the operating system. To direct the program output to a PDF:
4. Park on the Exp/Var property and zoom to the Expression Editor.

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You need to provide a name for the file that will be created. You can provide a simple
name such as c:\Temp\CustomerList.pdf . The PDF is created on the server. You can
use the temporary folder to save the files or any other folder. Magic xpa has a logicalname, %TempDir%, which returns the temporary folder.
5. Create an expression for the file name:'%TempDir%CustomerList.pdf'
6. Open the Print - Customers I/O Properties(Alt+Enter).
7. Set the PDF property to Yes.

The PDlg column (in the I/O Device repository) and the Preview
property (in the I/O properties) are both set to No. In Rich Client
tasks, the printing is done on the server and if one of these properties
would be set to Yes, the Print dialog box would be unnecessarily
opened.

You can also define specific security options for the PDF file by clicking the Security
button.
You will learn about some of the other properties in this dialog box later on.
8. Close the dialog box.

Print - Customers Form
Up until now you have used only one type of form in the Form Editor, the Class = 0
form. In Magic xpa the forms are divided into two major classes:
Class = 0 is used for GUI display and user interaction.
Class > 0 is used for I/O operations.
Now you will use a Class > 0 form. This form will be printed to the PDF that you set in
the I/O Device repository.
1. Open the Form Editor.
2. Create a form.
3. In the Name column, type: Print - Customers.
4. In the Class column, type: 1.

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Note that the Class column value is larger than zero.
5. From the Interface Type column, select GUI Output.
The dimensions of an A4 page are 210x297mm or approximately 21x30 cm (or 8.3
x 11.7 inches). Setting the Form units property to Centimeters and the form's Widthproperty to 20 cm will ensure that the form you are designing will be presented
properly in the print-out device.
You will now set the form properties according to the explanation above.
6.
7.
8.
9.

Open the Form Properties sheet.
In the Form units property, select Centimeters.
In the Width property, type: 20. This will give the form a 1-cm margin.
In the Height property, type: 3.

In Magic xpa, when using a Table control in a Class > 0 form, the detail area isduplicated for each printed line. This is unlike Class = 0 forms (GUI Display), where
the number of lines is fixed and the end user can scroll between the records.
Now, you will add a Table control to the form to display the Customers details.
10. Zoom to the Print - Customers form.
Notice that the form area looks different. Output forms have a different form designer
than Display forms.
11. From the Control palette, select a Table control and place it on the form.
12. Change the Height property to 1.
13. Select the following variables, one by one, from the Variable palette and placethem on the Table control:
Customer_Code, Customer_Name, Address, City, and Country.
The form should look like the image below.

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14. Exit the Form Editor (ESC).

Using the Form Output Operation
A task can have many Class > 0 forms. Magic xpa does not know the order of theForm Output operations’ output or how many times the forms should be used.
The Form Output operation is used to instruct Magic xpa which form to use and when
to send it to the output device. You will now use the Form Output operation in the
Record Suffix logic unit to print all of the customers in the Customers data source.
As previously mentioned, a Table control in a Class > 0 form behaves differently thana Class=0 form; the table detail area is duplicated every time the form is printed out.
You decreased the table size on the previous page. This behavior enables you to print
data in a table format without having to deal with the table design.

1.
2.
3.
4.
5.

Open the Logic Editor and create a Header line.
Define a Record Suffix logic unit.
Create a detail line.
Select Form from the combo box and then select Output.
Zoom and select the Print - Customers Output form.

6. Close the program and save the changes.
You have just created a simple report that displays the Customers data source. You
can run the program from the Program repository and then go to your temporary
directory and open the PDF file you just created.

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Designed Report
The last section showed you how to create a very basic report; when only the mostnecessary elements are printed. Now you will learn how to improve the display of yourreport. You will start by improving the Table control that you created in the last section.
Then, you will add the following forms that will make your report look more
professional and comprehensive:
A page header
A headerA footerA page footer
To improve the look of the report, you will now add the following:
A new color
A new font

Adding a New ColorThis example includes adding a Header form to the report. The report header will betext with a specific color and font. Therefore, you will now add a new color to the
Color repository.
1. From the File menu, select Application Properties.
2. In the Application Properties dialog box, select the External Files tab.
3. Park on the Application Color Definition file property.
4. Zoom to the Application Color repository.
5. Park on the last line and create an entry.
6. In the Name column, type: Report Header.
7. Zoom to the FG column.
8. In the System entry, select the blank (first) option.
9. In the Basic Colors area, define the following shade of blue:
RGB = 0,64,128.
10. Return to the Application Color repository.
11. Zoom to the Report Header: BG dialog box.
12. Check the Transparent box.
13. Return to the Application Color repository.
14. Click OK (to return to the Application Properties dialog box).
In the Save As dialog box:
15. In the Effective immediately entry, select Yes.

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Adding a New Font
1. In the Application Properties dialog box, park on the Application Font
Definition file property.
2. Zoom to the Application Font repository.
3. Park on the last line and create a new entry.
4. In the Name column, type: Report Header
5. Zoom from the Font column.
6. In the Font section, select Book Antiqua. Magic xpa supports only True or OpenType fonts for display. For printing purposes you can use any font that yourprinter driver supports.
7. In the Font Style section, select Bold Italic.
8. In the Size section, select 18.
9. Return to the Application Font repository.
10. Return to the Application Properties dialog box.
In the Save As dialog box:
11. In the Effective immediately entry, select Yes.

Modifying the output
You will now update the color and font for the table’s column titles.
1. Open the Program repository and zoom into the Print - Customers 2 program.
2. Park on the Print - Customers form and zoom to the Form Editor.
3. For each column:
a. Press Alt+Click on the column.
b. In the Column properties (Alt+Enter), from the Font property, zoom andselect the Text Caption font.
c. For the Customer_Code column, change the title to Code.
d. In the Color property, zoom and select the Text Caption color.
4. Close, save, and return to the Form Editor.

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Page Header
In the Form Editor:
1. Create a line BELOW the Print - Customers 2 GUI Display form and name it
Page Header.
2. Park on the Area column and select Page Header from the combo box.

The physical placement of Header, Detail, and Footer forms in the Form Editor isimportant. Each header form must be followed by its matching footer form. All headerfooter pairs must precede the detail lines. Therefore, the new Page Header form shouldbe placed before the Detail line. This form should also use centimeters as the form unit
and have a width of 20. Additional forms in this course will also have these settings.
Instead of manually changing this for each form, a better way to do this is to create amodel with these dimensions. You will now create a model.
1.
2.
3.
4.
5.
6.

Open the Model repository and create a line.
Name the model GUI Print Form.
From the Class column, select GUI Output.
From the Attribute column, select Form.
Set the Form Units property to Centimeters.
Set the Width property to 20.

Return to the Print - Customers 2 program and:7. Zoom into the Form Editor. Park on the Page Header form and select the GUI
Print Form model.
8. Set the Height property to 3.5.
A page header, or simply a header, is separated from the main body of text andappears at the top of a printed page. The course data includes the images folder,which contains header and footer image files for the report’s page header and pagefooter.
9. Zoom to the Page Header form.
10. Place an Image control on the form.
11. Open the Image control properties.

Reports25612. In the Default image file property, type: %WorkingDir%images\Print_Logo.jpg.
13. Set the Image Style to Scaled to Fit.
14. Set the Width property to 17.4.
15. Set the Height property to 3.
16. In the Command palette, click the Horizontal center of form
command icon.
17. In the Command palette, click the Vertical center of form
command icon. This will center the Logo image on the form.

Adding a Report Header
A report header is used to provide a descriptive caption for the report. The Header
form is automatically outputted for the second and subsequent pages, whenever a newpage of the same class is about to be printed. The Header form will not be printed forthe first page. You will now add a Header form to your report.
1.
2.
3.
4.
5.
6.

7.
8.
9.

Return to the Form Editor.
Park on the new Page Header form and create a line.
In the Name column, type: Header.
From the Area column, select Header.
Open the Form Properties sheet and select the GUI Print Form model.
Set the Height property to 1.
Zoom to the Header form.
From the Control palette, select a Text control and place it on the form.
Open the Text control properties and set the following properties:
a. In the Text property, type: Customer List.
b. From the Font property, select Report Header.
c. From the Color property, select Report Header.

10. In the Command palette, click the Fit Size (11. Click the Horizontal center of form (horizontally on the form.

Reports257) command icon.

) command icon. This will center the text

12. Click the Vertical center of form (vertically on the form.

) command icon. This will center the text

Adding a Footer
The Footer area is usually used for a report summary.
1.
2.
3.
4.
5.
6.

Return to the Form Editor.
Park on the Print - Customers GUI Output form.
Create a line and in the Name column, type: Footer.
From the Area column, select Footer.
Open the Form Properties sheet and select the GUI Print Form model.
Set the Height property to 1.

In this example, you will display the total number of printed customers in this report.
The Counter (0) function returns the number of records processed in the current task.
You will use the Counter (0) function to return the number of customers printed in thereport. The Counter function is only relevant for Batch tasks and non-interactive Rich
Client tasks. You will also use the Str function to convert the number to a string.
7. Zoom to the Footer form.
8. From the Control palette, select an Edit control and place it on the form.
9. Open the Edit control properties and from the Data property, enter a new
expression: 'Total Number of Customers: '&Trim(Str(Counter(0),'6'))
10. In the Format property, type: 40.
11. In the Font and Color properties, select Text Caption.
12. Park on the Edit control and move the control to the left.
13. In the Command palette, click the Fit Size ( ) command icon.
14. Click the Vertical center of form ( ) command icon. This will center the Edit
control on the form.

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Page Footer
A page footer is usually used for company-related information. In this example you will
use an image from the Images folder. As with the header forms, the placement of thepage footers is important.
1. Return to the Form Editor and park on the Footer form and create a line.
2. In the Name column, type: Page Footer.
3. From the Area column, select Page Footer.
4. Open the Form Properties sheet and select the GUI Print Form model.
5. Set the Height property to 2.

6.
7.
8.
9.

Zoom to the Page Footer form.
From the Control palette, select an Image control. Close the dialog box.
Open the Image control properties.
In the Default image file property, type:%WorkingDir%images\Print_Footer.jpg.
10. Set the Image Style to Scale to Fit.
11. Set the Width property to 18.76.
12. Set the Height property to 1.67.
13. Close the Image control properties.
14. In the Command palette, click the Horizontal center of form command icon.
15. In the Command palette, click the Vertical center of form command icon. This
will center the Logo image on the form.
16. Close the Form Editor.

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Printing the Header and Footer Forms
You have designed the report the way you want it to look. Now you need to print it.
A Header form (a form with the Area column set to Header) has a unique behavior.
The Header form is automatically outputted for the second and subsequent pages,
whenever a new page of the same class is about to be printed. The Header form will
not be printed for the first page. Therefore, there is a need to manually print it for the
first time.
The Task Prefix logic unit is used to perform processes that should be executed once,
when starting the program. You will now add a Form Output operation to print the
Header form.
1.
2.
3.
4.

Open the Logic Editor.
Create a Header line.
Create a Task Prefix logic unit.
Create a detail line and set the Form Output operation to print the Headerform.

The Footer form is the report footer and it should be printed once on the last page ofthe report. Therefore, it should be printed from the Task Suffix logic unit, which is
executed only once when the program ends.
5. Create a Task Suffix logic unit.
6. Create a detail line and set the Form Output operation to print the Footer form.

Setting the Page Header and Footer
A page header and page footer should be printed on every page regardless of thepage content. Therefore, the Page Header and the Page Footer forms are defined in
the I/O properties. This way Magic xpa will always include these forms on the printed
pages.
1. From the Task menu, select I/O
Devices (Ctrl+I).
2. Park on the Print - Customers entry.
3. Open the I/O Properties dialog box.
4. Zoom from the Page header form
property to the Form list and select the
Print Header form.
5. Zoom from the Page footer form andselect the Page Footer form.
6. Click OK. Close the program and savethe changes.

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The Browser Control
Printing to a PDF is useful. You can decide when you want to print it or display it.
However, you are often in a situation when you need to view the document on yourmobile device. One way to handle this is to use the Browser control.

The Browser control is an internal Magic xpa control similar to other controls discussed
during this course. The control enables you to display HTML files and any other files
that your Internet browser can display.
The Browser control simulates the work of the internet browser. Once this control has
been dropped on the form, you have an embedded browser and can use the control tosuit your needs. This means that you can use JavaScript with your HTML files.

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In the next few pages you will create and call a Rich Client program to display the PDF. To
create the Display PDF program:
1. Create a new program and name it: Display PDF.
2. In the Task Properties dialog box, set the Task type entry to Rich Client.
When you created the PDF, it was created on a location on the server. If the PDF is left
on the server then you have a few issues that you need to solve, such as:
Naming the PDF – Remember that you may have a number of clients running thesame report and to call it CustomerList.pdf may not show the same result foranother client running the same report. Also what if you are trying to display thereport and at the same time another client machine is overwriting?
Security – Since the directory will be exposed to the web, other clients can see thesame report. If you are offering a huge discount to one client, would you wantanother client to see that? What about if the report is sales figures before reportingthem to the stock market?
As a result, the report needs to be copied to the client. Magic xpa provides theServerFileToClient function, which copies a file from the server to the client. The
function returns the location of the file on the client. You will now see how to use this:
3. Create a Parameter variable named P.PDF to display with an attribute of Alphaand a size of 255.
In the Form Editor:
4. Open the Display PDF form properties. Use the Table Display Form model.
5. Zoom into the Form Designer.
6. Drop a Button control on the form and select theImage Button model.
7. Change the name of the Image file to Exit.png.
8. Change the name of the Internal event to Exit.
9. Zoom into the Placement property and set the X
property to 100. That way when the form
increases horizontally, it will move together withthe form.
10. Click the Fit Control Size icon.
11. Drop the Browser control ( )on the form.
12. Increase the height and width of the control to fill the form as shown in theimage above.
13. In the Placement property, set the Width and Height to 100.
14. Zoom from the Data property and create the following expression:'file:/'&Trim(P.PDF to display)

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This will work on a desktop client as well as an iOS client. It will not work on mostAndroid devices. To view this on an Android device you will need a third party
reader.

Displaying the PDF
To display the PDF, you will:
Create a Print push button in the Customers - Line Mode program.
In the Print handler:
Call the Print - Customers 2 program.
Call the Display PDF program.
In this course you will be defining reports for a few programs each with its own Print
handler. Instead of defining the handler in each program, you can define it in theMain Program. The definition will then be available for all of the programs.
1. Zoom to the Main Program. The Main Program is a parent program for all of
the programs. Any object defined here is visible to other programs in the
project.
2.
3.
4.
5.
6.
7.

Open the Event repository and create a new event:In the Description parameter, type: Print.
From the Trigger type parameter select None.
Close the Main Program.
Zoom to the Customers - Line Mode program.
Add a Virtual variable named PDF Name with an attribute of Alpha and alength of 255.
8. Open the Form Editor and zoom to the form.
9. Drop a Button control on the form. Select the Image button model.
10. Open the control property sheet and change the image file name to Print.png.
11. From the Event Type property, select User.
12. From the Event property, select the Print User event that you defined in the Main
Program.
13. Use the Fit Control Size icon.
14. Zoom into the Logic Editor.
15. Add a header line for the Print User event.
16. Add a detail line and call the Print - Customers 2 program.
17. Add a detail line and update the PDF Name variable with the expression:ServerFileToClient('%TempDir%CustomerList.pdf')
18. Add a detail line and call the Display PDF program.
19. Zoom into the Arguments and add a line. Zoom into the Var column and selectthe PDF Name variable.
You can now run the application and view the results.

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Displaying a PDF on an Android Tablet
You can view a PDF on an Anroid machine using a third-party PDF viewer application,such as Adobe Acrobat Reader. You do this by using the Invoke OS command with thecommand of pdf:filename, where filename is a path to a local file that is stored on a
public folder on the device, such as the /SDCARD folder.
The ServerFileToClient function copies the file to a local folder that only the current
client has access to, in this case the Magic xpa client. To be able to view the file in athird party application, you need to copy it to a public folder. You do this by using the
ClientFileCopy function.
In the Print User event logical unit, you used the ServerFileToClient function to return thelocation of the file on the client to a variable named PDF Name. For example, thefollowing commands will copy the ReleaseNotes.pdf file from the C:\Magic\ folder on
the server to the /SDCAD folder on the client and will open a PDF viewer to show thisfile:
1. Add a detail line and create an Evaluate Expression operation.
2. Set the expression to:
ClientFileCopy( Trim (PDF Name),'/sdcard/CustomerList.pdf')
3. Add a detail line and create an Invoke OS Cmd operation.
4. Set the expression to: 'pdf:/sdcard/CustomerList.pdf'
5. Set the Execute On property to Client.
When dealing with an Android client, calling the Display PDF program will give anerror message to the user.
If you are developing an application for both Android and iOS devices
you can use an expression to define whether the Display PDF program
will be called or the Android section. You will learn how to do this in alater lesson.

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Printing a PDF on a Mobile Device
Very often you need to actually print the report. You can do this on your iOS device toprinters that support the AirPrint protocol and on your Android device to printers that
support the Google Cloud Print protocol. When you display the PDF in the Bowser
control, you have the print option. Here you can select the printers in your wirelessnetwork that support the AirPrint protocol or Google Cloud Print protocol. If you wantto print the report without displaying it first, you can do this by using the Invoke OS
Cmd operation with the syntax of: "Print:filename" where filename is either:A path to a local file, as received from the ServerFileToClient function
A URL to a file on a Web server, such as'http://example.com/PublishedAplications/CustomerList.pdf' (This option is only
available for iOS devices)
One property of the Invoke OS Cmd operation is Execute on. You can select either
Client or Server. For printing, you need to select Client.

Complex Report Concept
When you look at a report, it often seems one-dimensional; but if you look carefully
you can see that the data can be arranged in various formats. Moreover, in one report
you can have several formats (layers). For example, in an invoice you can see:
General information, such as the customer name and address, at the top of thepage
A list of the items that were ordered, in the middle of the page
Summary information, such as the total amount, at the bottom of the page.
The layers can be arranged so that they present the best visualization of theinformation. The information can be retrieved from one or more data sources, and canbe processed in one or more tasks.
There are a number of points to remember when creating complex reports:
I/O devices should be defined in the parent task only, and shared between theparent and the child tasks.
Parent task forms can be accessed from the subtask’s Form Editor.
Parent-child forms that share the same class (Class>0) should have the same width
and the same interface type.

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In this lesson you will create an Invoice printout using the Orders, Order Lines,
Customers, Products, and Suppliers data sources.
1.
2.
3.
4.
5.

Open the Program repository and create a program named: Invoice.
Zoom into the program and the Task Properties dialog box will open.
From the Task type property, select Batch.
Set the Initial mode to Query.
Open the Data View Editor and set the Orders data source as the Main
Source.
6. Set Index number 1 as the Main Source’s Index.
7. Add all of the Orders data source’s columns to the data view.
8. Park on the last line in the Data View Editor.
9. Select Create Header Line (Ctrl+H) and select a Link Query to the Customers
data source.
10. From the Index entry, select the first index.
The Customer_Code column will be selected automatically within the Link Query
operation.
1. Add the following columns to the Link section: Customer_Name, Address, City
and Country.
2. Within the Link Query, park on the Customer_Code column’s Locate From
entry.
3. Zoom to the Expression Editor and create an expression for the
Customer_Code from the Orders data source.
4. Enter the same expression for the Locate To entry.

Forms
Now you will create the Page Header and Page Footer forms for the report. These arevery similar to other reports you created in this lesson.
5. Open the Form Editor.
6. Create a line and in the Name entry, type: Page Header.
7. Create the Page Header as you learned in a previous lesson. Use the GUI Print
Form model.
8. Create a line and in the Name entry, type: Page Footer.
9. Create the Page Footer as you learned in a previous lesson. Use the GUI Print
Form model.

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Now you will create the Header form. This form will contain the report name as well as
the order title information.
1.
2.
3.
4.
5.
6.
7.

Park on the Page Header form line and create a line.
In the Name column, type: Header.
From the Area column, select Header.
Open the Form Properties and select the GUI Print Form model.
Set the Height property to 2.67.
Zoom to the Header form.
From the Control palette, select the Edit control and place it on the form.

8. Open the Edit Control property sheet and from the Data property, zoom to theExpression Editor and create the following expression:'Order Number: '&Trim(Str(Order_Number,'6'))
9. The Format has a default of 30.
You can change this to 21 since this is the maximum size of the data in theexpression.
10. From the Font property, select the Report Header font.
11. From the Color property, select the Report Header color.
12. From the Command palette, select the Fit to Size command icon. This will fit thecontrol to its defined measurements.
13. From the Command palette, click the Horizontal center of form command icon.
This will center the Edit control on the form.
The Header form will include more information than just the report name. You will now
add customer details to the Header form.
1. From the Variable palette, select the Customer_Code variable (from the Orders
data source) and place it on the form (see the image on the next page).
2. From the Variable palette, select the Customer_Name variable and place it to
the right of the Customer_Code control. Delete the Customer_Name caption(The static control only).
3. Open the Customer_Code static control properties.
4. In the Text property, type: Customer:
5. From the Font property, select the Text Caption font.
6. From the Color property, select the Text Caption color.
7. From the Control palette, select the Text control and place it on the form
8. In the Text property, type: Address:
9. From the Font property, select the Text Caption font.
10. From the Color property, select the Text Caption color.
11. From the Control palette, select the Edit control and place it on the form.
12. From the Edit Control property sheet, go to the Data property, zoom to theExpression Editor and create a line.

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13. Type the following expression:
Trim(Address)&', '&Trim(City)&', '&Trim(Country)
14. In the Format property, type the value 70.
15. From the Font property, select the Text font.
16. From the Color property, select the Text color.

The Footer form will include information about the order amount and payment terms.
You will now add the order amounts and the payment terms to the Footer form.
1.
2.
3.
4.

Return to the Form Editor.
Park on the Header form and create a line.
In the Name column, type: Footer.
From the Area column, select Footer.

5. Open the Form Properties and select the GUI Print Form model.
6. Set the Height property to 1.
7. Zoom to the Footer form.
8. From the Variable palette, select the Amount variable and place it on the form.
9. Zoom into the control properties of the Amount Edit control anda. From the Font property, select the Text font.
b. From the Color property, select the Text color.
10. Zoom into the control properties of the Amount Text control andc. In the Text property, type: Amount:d. From the Font property, select the Text Caption font.
e. From the Color property, select the Text Caption color.
11. Use the Fit to Size icon for both controls.

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Defining the I/O Device
1. From the Task menu, select I/O Devices (Ctrl+I).
2. Add a line and set the name to Print Invoice.
3. From the Exp/Var column, zoom and set the following expression:'%TempDir%Invoice.pdf'
4. Open the I/O Properties dialog box.
5. From the Page header form property, zoom and select the Page Header form.
6. From the Page footer form property, zoom and select the Page Footer form.
7. From the PDF property, select Yes.
8. Exit the I/O Device repository.

Print Invoice Lines Subtask
The information for the Details form needs to be retrieved from the Order_Lines data
source. Therefore, you now need to create a subtask that will scan and print the Order
details.
1.
2.
3.
4.
5.

In the Navigator pane, park on the Invoice entry and create an entry.
In the Task name property, type Print Invoice Lines.
From the Task type property, select Batch.
Set the Initial Mode to Query.
Open the Data View Editor.

6. Set the Order_Lines data source as the Main Source.
7. Select the first index as the Main Source index.
8. Add all of the main source’s columns to the data view.
9. Park on the Order_Number row.
10. From the Range property, zoom to the Expression Editor and create a line.
11. Add an expression for the Order_Number column from the Orders data source,from the parent program.
12. Enter the same expression in the Range To property.
You will now link to the Products data source to retrieve the Product Name and theSupplier Code. You will use this Supplier Code to get the Supplier Name.
13. Park on the last line in the Data View Editor and create a Header line.
14. Set a Link Query to the Products data source.
15. From the Index property, zoom and select the first index.
16. Add the following columns to the Link operation: Product_Name andSupplier_Code.
17. In the Link Query operation, park on the Product_Code column’s Locate From
property.

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18. Zoom to the Expression Editor and create an expression for the Product_Codecolumn from the Order_Lines data source.
19. Enter the same expression for the Locate To entry.
The next section is added so that you can see how to use multiple links in a program.
1.
2.
3.
4.
5.

Park on the last line in the Data View Editor and create a Header line.
Set a Link Query to the Suppliers data source.
From the Index property, zoom and select the first index.
Create a line and add the Supplier_Name column to the Link operation.
Park on the Supplier_Code column’s Locate From entry.

6. Zoom to the Expression Editor and add an expression for the Supplier_Codefrom the Products data source.
7. Enter the same expression in the Locate To entry.
Now you will create the details form:
8. Open the Form Editor and create a form.
9. In the Name column, type: Print Invoice Lines.
10. Open the Form Properties and select the GUI Print Form model.
11. Set the Height property to 2.2.

Magic xpa enables you to view the parent task’s forms from thesubtask’s Form Editor in order to make the development processeasier.

12. Zoom to the Print Invoices Lines Output form.
13. Place a Table control on the form.
14. Attach the following variables to the Table control:Line Number (Alt+Click on one of the empty lines and change the nameof the column header to Line. Change the width of the column to 0.8.)
Product_Name (from the Products data source)
Supplier Name (from the Supplier data source)
Product_Quantity (Change the name of the column header to Quantity.
Change the width of the column to 1.4.)
Product_Price (Change the name of the column header to Price. Change
the width of the column to 1.6.)
15. In the Product_Name column, mark the Edit control and decrease its Widthproperty to 9.5.
16. Mark the Column control and decrease its Width property to 9.75.
17. Change the name of the column header to Product.

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18. Attach an Edit control to the table and mark it.
19. Open the Edit control properties and from the Data property, zoom to theExpression Editor.
20. Create the following expression: Product_Price * Product_Quantity.
21. In the Format property, type: 8.2
22. In the Width property, type: 2.
23. Mark the column where you placed the Edit control and open the Column
properties.
24. In the Column title property, type: Line Amount.
25. In the Width property, type: 2.2.
26. Mark all of the columns in the Table control.
27. Open the Multi Selection Properties sheet (Alt+Enter).
28. From the Font property, select the Text Caption font.
29. From the Color property, select the Text Caption color.
Now you will output the Print Invoice Lines form.
1. Open the Logic Editor.
2. Create a Record Suffix logic unit.
3. Add a Form Output operation and print the Print Invoice Lines form.
Now you need to output the Header and Footer forms:
4. In the Navigator pane, click the Print Order parent task.
5. In the Print Order task, open the Logic Editor and create a Record Suffix logic
unit.
6. Add a Form Output operation and print the Header form.
7. Add a Call Subtask operation and call the Print Invoice Lines form.
8. Add a Form Output operation and print the Footer form.

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Short Summary
The example showed you how to create a complex report.
In this example, the report header and report footer were created in one task (parenttask) and the report details were created in another task (child task). Both tasks output
the forms to the same I/O device that was set in the parent task.
Unlike the previous example, where the Report Header form was output in the Task
Prefix logic unit and the Report Footer form was output in the Task Suffix logic unit, in
this example both the Header and Footer forms were output in the parent task’s Record
Suffix logic unit. This is because, in this example, the Header information and theFooter information are processed from the Orders data source. The information fromthe Details form is handled in the subtask; therefore, you called the subtask after the
Header form output and before the Footer form output.
In the subtask, you extended the data view by linking to the Products data source andto the Suppliers data source. As you may have noticed, you can link to a data source(Suppliers in this example) based on information retrieved from another linked data
source (Products in this example).
The result is a complex report, which displays all of the orders in the data source andthe order lines for each order.

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Exercise
1. The correct way to print an invoice would be to print a specific invoice. Print an
invoice for a specific order from the List of Orders program.
2. Using what you learned so far in this course, create a Suppliers List report.
3. You should create the report in the same way that you created the Customers
List report. Invoke the Suppliers list report from the Suppliers - Line Mode
program.
When you are finished, the Suppliers List report should look similar to the image
below.

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SummaryIn this lesson you learned how to create a basic report.
You started the lesson by generating a report program using the Generate Program
utility.
You learned about the Browser control and how to use the control to display a PDF
Then, you manually created the same report.
You learned about the I/O Device repository.
You learned about forms with the Area column bigger than zero, which are used for
I/O devices.
You learned about the Form Output operation.
Then, you learned how to enhance your report by adding the:Page header
HeaderFooterPage footer
You learned about the role of each form on the page.
You learned that Header forms are printed automatically for every new page from thesame area, beginning with the second page and onwards.
You learned where to print the Header form and the Footer form.
You learned where to set a page header and a page footer so that they will be printed
on every page for the same I/O device.
You learned how to display the PDF on your device by first copying the PDF to theclient and then displaying it using the Browser control for iOS devices..

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Lesson17

Processing Data by Groups
In some cases, several records stored in a data source can have a common
denominator. For example, in the Order_Lines data source, records that belong to thesame order can be referred to as one group. Another example is cities and countries;
all of the cities for the same country can be referred to as one group.
Magic xpa enables you to process data segmented as groups, using the Group logic
unit. The Group logic unit can be defined in Batch tasks only.
You can define the following Group logic units:Group Prefix
Group Suffix
This lesson covers various topics including:Grouping data in Batch programs
Using the Group logic unit
Group logic unit operations in the Task execution process
The correlation between the Sort criteria and the Group logic units
Defining a Sort for a task

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About the Group Logic Unit
The Group logic unit creates breaks during the data view processing.
You can use the Group logic unit to calculate sums at certain levels, to display data bygroups, or to print breaks in a report.
You define a Group logic unit for a variable. The Group logic unit is executed whenthe variable value changes.
You can define several Group logic units for different variables in the same task.
The order of the Group logic units needs to match the order of the segments in thetask’s sort criteria. For example, if the task’s Main Source index segments are
Country_Code and then City_Code, the Group logic unit should be defined in thesame order; first the Group logic unit for the Country_Code variable and then theGroup logic unit for the City_Code variable.
Grouping data according to part of the segments in the sort criteria is allowed, as longas the segments are used from top to bottom. Grouping data starting from the middleof the sort criteria segments may give an undesirable result.

Group Logic Unit Execution Order
Before you begin using the Group logic unit, it is important that you understand how
the Magic xpa engine behaves when a Group logic unit is defined in a task.
The Magic xpa engine scans the Main Source records according to the sort criteria (aspecified index or the specified task sort).
The Group Prefix operations are executed before the first record in the group isprocessed.
The Group Prefix operations are executed before the Record Prefix operations.
The Group Suffix operations are executed after the last record in the group isprocessed.
The Group Suffix operations are executed after the Record Suffix operations are
executed.
When the value of the variable defined in the Group logic unit is changed, the Group
logic units are executed accordingly.

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The following displays the execution of the logic units:
Task Prefix
Group Prefix (for the first record or when the group’s variable value ischanged)o Record Prefix
o Record Suffix
Group Suffix
Task Suffix

Engine Flow for a Batch Task
Previously you learned about the engine flow in a Batch task. This section explains theprocesses that are executed during a Batch task’s life cycle when a Group logic unit
exists.

Task Initialization
The Task Initialization operations are similar to the operations in an interactive task.

Group Processing
The first record is fetched into memory.
If the Evaluate condition task property is set to Before entering record, the End Task
condition is checked.
The Exit action is checked, whether or not the user has pressed ESC.
The Group Prefix logic unit operations are executed for the first task cycle andwhenever the Group logic unit’s variable value is different from the previous record
value.

Record Processing
The Record Prefix logic unit operations are executed.
The Record Suffix logic unit operations are executed.
The record is saved with the new values. If the Task mode is set to Delete, therecord is deleted.

End Group Processing
When a new record is fetched and the Group logic unit’s variable value is different
from the previous record value, the Group Suffix logic unit operations are executedfor the previous record and the Group Prefix logic unit operations are executed forthe current record.

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Sorting the Data
The data view can be sorted in two ways:
Using the Main Source index – In this case, the order of the index segments mustmatch the order of the Group logic units.
Using the task’s Sort Indicator repository – This option can be used when you do
not have an index that matches the order of the Group logic units.
Group logic units must follow two basic rules:
The order of the index segments should match the order of the Group logic units.
The higher segment in the index should be the higher Group logic unit.
The Group Suffix should follow the Group Prefix. You should not open a newGroup logic unit between them.
You do not have to create a Group Prefix logic unit or Group Suffix logic unit if you do
not have any operations to define in them.
The following example will help clarify the above.
Assume you have a data source that contains a list of customers with address details,
including the country, city, and street name. You want to print the list of customers
according to the country and the city that they live in.
You need to define two Group logic units. The first Group logic unit will be for theCountry variable and it should be the topmost Group logic unit in the Logic Editor. The
second Group logic unit will be for the City variable and it should be defined after the
first Group logic unit in the Logic Editor.
The index should have the following segments and in the following order: Country andthen City.
Using the Sort option with large data sources may slow the task’s
performance since Magic xpa builds a temporary index to sort thedata source records.

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278You will now create a program that prints the countries and their cities.
1.
2.
3.
4.
5.
6.

Create a program named Print Countries and Cities.
In the Task Properties dialog box, set the Task type property to Batch.
Set the Initial mode property to Query.
In the Data View Editor, set the Cities data source as the Main Source.
Select the second index as the Main Source index.
Create a line and add all of the columns of the Cities data source to the dataview.

To be able to show the country name, you need to link to the Countries data source.
1. Park on the last line in the Data View Editor.
2. Create a Header line (Ctrl+H) and create a Link Query to the Countries data
source.
3. Select the first index.
4. In the Link Query operation, create another line and add the Country_Namecolumn.
5. Set the link’s Locate properties of the Country_Code column to theCountry_Code variable from the Cities data source.
You need a Virtual variable to hold the number of cities for each country.
1. Park on the last line in the Data View Editor.
2. Create a Virtual variable named Number of Cities with an Attribute of Numericand a Size of 6.
Now you will prepare the form as you did in the previous lesson:
1. Open the Form Editor and create a line. In the Name entry, type: Page
Header. Set the Model to GUI Print Form.
2. Create the form as you did in the previous lesson.
3. Create a line and in the Name entry, type: Page Footer. Set the Model to GUI
Print Form.
4. Create the form as you did in the previous lesson.

Processing Data by Groups279

5. Park on the Page Header form and create a line.
6. Create a Header form and name it Country Header. Set the Model to GUI Print
Form.
7. In the Height property, type: 1.
8. Zoom to the Country Header form.
9. From the Control palette, select the Edit control and place it on the form.
10. Open the Edit Control Properties.
11. From the Data property, create an expression:'List of cities for: '&Trim(Country_Name)(select the Country_Name variable from the list).
12. In the Format property, type 43.
13. In the Font property, select the Report Header font.
14. In the Color property, select the Report Header color.
15. From the Command palette:
a. Click the Fit to Size command icon.
b. Click the Horizontal center of form command icon.
c. Click the Vertical center of form command icon.

Creating the City Detail Form
1. Return to the Form Editor.
2. Park on the Country Header form and create a line.
3. Create a Detail form and name it City List. Open the Form Properties andattach the GUI Print Form model.
4. In the Height property, type: 2.2.
5. Zoom to the Cities List form.
6. From the Control palette, select a Table control and place it on the form.
7. Select City_Code and City_Name variables and place them on the Table
control.
8. Mark the City_Code column and set the Color to Text Caption and the Font to
Text.
9. Set the Column Title property to Code.
10. Mark the City_Name column and set the Color to Text Caption and the Font to
Text Caption.

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Creating the Country Footer Form
1. Park on the City List form and create a line.
2. Create a Footer form and name it Country Footer. Attach the GUI Print Formmodel.
3.
4.
5.
6.

In the Height property, type: 1.
Zoom to the Country Footer form.
From the Control palette, select the Edit control and place it on the form.
Open the Edit control’s property sheet and in the Data property, enter thefollowing expression:'Total number of cities in '&Trim(Country_Name)&': '&Trim(Str(Number ofCities,'6'))
Select the Country_Name and Number of Cities from the Variable list.
7. Set the Format to 60 and the Font and Color to Text Caption.
8. Click the Fit to Size command icon.

Defining the I/O Devices
1. From the Task menu, select I/O Devices.
2. Create a line and set the Name to Countries and Cities.
3. From the Exp/Var column, zoom and set the following expression:'%TempDir%CountryCityList.pdf'
4. Open the I/O Properties dialog box.
5. From the Page header form property, zoom to the Form list and select the Page
Header form.
6. From the Page footer form property, zoom to the Form list and select the Page
Footer form.
7. Set the PDF property to Yes.

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Defining the Group Logic Units
Each group of cities should have both a header and a footer. To print the groupheader, you will use the Group logic unit for the Country_Code variable. This way,
every time the Country_Code variable value is changed, a new group Header form
will be printed.
1. Open the Logic Editor and create a Header line.
2. Set a Group Prefix logic unit for the Country_Code variable (from the Cities
data source).
3. Add a Form Output detail operation and print the Country Header form.
4. Add an Update Variable detail operation and update the Number of Cities
variable with zero. You are resetting the counter every time the Country_Codechanges.

Now you will print out the Detail form for each city in the group. In addition, you needto increase the Cities Counter variable value by one, for each city in the group. This isperformed in the Record Suffix logic unit.
1. Create a Record Suffix logic unit.
2. Add a Form Output detail operation and print the City List form.
3. Add an Update Variable detail operation and update the Number of Cities
variable with Number of Cities+1. This increases the counter of the number ofcities.
Now you need to print the footer showing how many cities there are for that country.
This is performed in the Group Suffix logic unit.
1. Create a Group Suffix logic unit for the Country_Code variable.
2. Add a Form Output detail operation and print the Country Footer form
You can now run the program. You can also execute the program using the same
methods that you used in the previous lesson, such as adding a Print icon to theCountries program.

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ExerciseCreate a report that displays each supplier and a list of its products. At the end ofeach supplier, add the number of products for the supplier.
The image below displays a sample of the result report.
As a small challenge, print each new supplier on a new page.

Processing Data by Groups283

SummaryIn this lesson you were introduced to the Group logic unit.
You learned when and how to use the Group logic unit.
You learned how to define a Group logic unit.
You used the Group logic unit in a Batch task in order to group data and print a reportwith breaks.
The following information is important to keep in mind when defining a Group logic
unit:
The Group variables must match the Main Source index segments or the Sort
segments.
You can define several Group logic units for different variables.
The order of the Group logic units within the Logic Editor defines the groupingorder (the topmost Group logic unit is the highest Group level and the bottommostGroup logic unit is the lowest Group level).
The Group Prefix logic unit is executed before the first record is processed andeach time its variable value changes.
The Group Suffix logic unit is executed after the last record is processed from thesame group.

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Lesson18

Menus
Pulldown menus are the type of menus commonly used in menu bars (usually near the
top of a window or screen), which are most often used for performing actions. This
type of menu is not used in mobile devices.
Context menus are accessed by right-clicking. The choices presented in the context
menu are automatically modified according to the current context.
Magic xpa enables you to define menus in your project. The project menus serve as aninterface for the end user to run the project programs during runtime.
This lesson will introduce you to the following Magic xpa menu options:Default Pulldown menu – Magic xpa provides a default pulldown menu whencreating a project. This menu contains all of the basic options that are needed
during runtime.
Toolbar menu – A set of buttons displayed below the pulldown menu, which serveas shortcuts to pulldown menus.
Additional menu structures – These can be created as required. These menus canbe used from the project as context menus.
This lesson covers various topics including:What menus are used forDefining pulldown menus
Defining SDI forms
Defining context menus
Attaching a context menu to a control or a form
Raising an event from a Menu entry
Adding a menu to the toolbar menu
Defining MDI forms

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The Menu Repository
The Menu repository contains the Default Pulldown menu and enables you to define
additional menus.
1. From the Project menu, select Menus (Shift+F6).

Property

Description

Menu
Name

This column displays the logical name of the menu structure.

Entry
Name

This column is used by various Magic xpa menu-related functions tocontrol the menu’s display.
This column should have a unique value for each menu entry.
The use of the backslash character (\) is not allowed in this column.

The Default Pulldown Menu
Every new project is generated with a Default Pulldown menu. The Default Pulldown
menu includes all of the basic options that are needed during runtime. For example,
the File menu contains all of the file options, such as: Open Application, Close
Application, and Exit.
The Default Pulldown menu is only used in desktop applications. For mobile
applications this needs to be removed since it is still processed by the engine.
2. Park on the Default Pulldown menu.
3. Delete the entry so that you now have an empty repository.
A pulldown menu is not used in a mobile environment. Later in this lesson you willlearn how to implement a pulldown menu for a regular Rich Client task.

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Context Menu
In a smart device, context menus are used to perform actions that are usuallyconsidered to be general actions. In some cases there is a need to have additional
options in a specific program or part of a program. Context menus are used to provide
the additional options. On a desktop computer, context menus are invoked by clicking
the right mouse button. On smart devices, they are activated differently. You will see
how after seeing an example.
For mobile devices it is only possible to define a context menu for forms andnot for controls.

In the List of Orders program, you added buttons for adding an order, printing an
invoice and so on. To print an invoice, the screen design displays the print icon.
However, it is not clear that the print button will print an invoice and the end user may
think that it’s for printing out the list of orders. A context menu will avoid this issue.

On iOS devices, if the form has a context menu, a button is added to
the right corner of the form.

As an example you will first see how to print an invoice from the context menu.
1. Open the Menu repository.
2. Add a line and in the Menu Name column, type Orders context menu.
3. Zoom to the Menu Definition repository and add a line.
You can define a menu entry to call a specific program or to raise an event. It is goodpractice to use events.
4. From the Entry Type column, select Event.
5. In the Entry Text column, type Print Invoice.
6. From the Menu Params column, zoom to the Event dialog box.
7. From the Event type field, select User.
8. From the Event field, zoom to the Event list.
9. Select the Print event.
10. Click OK.
11. Close the Menu Definition repository and the Menu repository.

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Attaching a Context Menu to a Form
Now you will attach the Orders context menu context menu to the List of Orders form.
This will make the context menu available anywhere in the List of Orders program.
1. Open the Program repository.
2. Zoom to the List of Orders program.
3. Open the Form Editor and park on the List of Orders form.
4. Open the form properties.
5. From the Context Menu entry, zoom to the Menu list.
6. Select the Print Invoice menu.

Handling the Print Event
Now you will create the logic unit that handles the Print event as you have done inearlier lessons.
1.
2.
3.
4.
5.
6.

Open the Logic Editor and create an Event logic unit.
From the Event entry, zoom to the Event dialog box.
From the Event type field, select User.
From the Event field, zoom and select the Print event.
From within the Event logic unit, create a line.
Add a Virtual variable named PDF Name with an attribute of Alpha and alength of 255.

During this course you have not created a variable within a logic unit but, as you cansee, it is possible. The definition and value within the logic unit are only valid within
the scope of the logic unit itself.
7. Add a detail line and call the Invoices program.
a. Zoom into the Arguments and add a line.
b. Zoom into the Var column and select the Order_Number variable.
8. Add a detail line and update the PDF Name variable with the expression:ServerFileToClient('%TempDir%Invoice.pdf')
9. Add a detail line and call the Display PDF program.
a. Zoom into the Arguments and add a line.
b. Zoom into the Var column and select the PDF Name variable.
You can now run the application and see how to use the context menu.

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Android

iOS

Context menu buttons

Menu Properties
The menu properties are divided into three tabs:
Properties – General settings, such as assigning a right or a help screen to a menu
Toolbox – Image and toolbar related settings
States – Initial state of the menu entry (Checked, Visible, and Enabled)
As an example, you will provide an image for the Print Invoice context menu.
1. From the Project menu, select Menus.
2. Park on the Orders context menu menu and zoom to the Menu Definition
repository. Park on the Print Invoice menu entry.
3. Open the Menu Properties dialog box by pressing Alt+Enter.

4. Click the Toolbox tab.

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5. From the Image for property, select Menu. In mobile applications there are no
toolbars, so there is no need to set an image for the bar.
6. In the Tool images property, type: %WorkingDir%images\PrintInvoice.png.
7. Click OK. Close the Menu repository and save the changes.

Not every operating system currently supports images in mobile devices.

Application Menus
The application menu appears at the top of the screen and it is how end users run the
programs in your application. As an example, in the Magic xpa Studio you have
Project, Options, Debug, Tools and so on. The menu options change when you enter a
program and you have a different set of menus. During runtime execution, you may
have, for example, a menu for Orders, Reports, Tools and so on. This is how your user
navigates through your application.
In the smart device world, application menus are no longer displayed, at least in theformat you were used to. A lot of thought needs to be given to the application menu
since this is the first item that the end user will see when loading your application. You
need to think about the methodology of what you display. Remember that in the smart
device environment, what you knew as application menus are now no longer visible
throughout the application.

Button-Driven
One option is to have a set of push buttons, each loading a different program. In thiscase you could have a program called MyMenu that is the program initially executedand this program displays buttons such as Orders, Products, Reports and Tools.
This is simple to implement and provides you with a simple solution. Once the user
taps a button, the program is loaded and when it is closed, it returns to the initialprogram.

Context Menu
You already know how to add a context menu. Instead of having buttons or in addition
to buttons, you could provide a context menu and display that context menu on each
form.

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Content-Driven
Many applications prefer to have their initial pages displaying content with little or nonavigation. For example, you can open your email client. If you have not configured
more than one email, it immediately shows you your emails. This is content. If you havemore than one mailbox, in iOS you will see a list of the mailboxes with the number of
unread emails listed. This is a page with statistics.
In iOS, the Notes application shows you the last place you were currently parked on; if
it was in the middle of a note, it will show you that note, if not, it will display the list ofnotes.
For example, when you view the eBay application, as you
can see in the image on the right, they show you a pageof statistics, such as what you are watching, buying or
selling in one row and in a list format, they show
reminders, messages and saved items. At the bottom, they
display the navigation functions. A lot of thought wasprovided to preparing the correct methodology for the
initial program.

Course Menu
There is no correct way as to what to display in the course scenario; it depends on
your company’s methodology. You could use any one of the scenarios discussed. If
you want to display content, you could show a list of orders or you could show
statistics.

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Summary
Menus are useful when you want to enable the end user to load other programs fromthe current program. You can use push buttons to perform similar actions, but that often
takes up screen real estate that on smaller devices is important.
The context menu provides you with a useful way of providing more options without
taking up place on the screen.
You learned about the initial program and that special thought needs to be given towhat to display when your end users load your application. When this course wasbeing written, the trend of smartphone applications was to display minimal navigation
options and display content instead. Content can be a list of orders, a list of people
who are currently in the club or statistics, or any other option.

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19

LessonUsing the Device Functionality
The advantage of working with a mobile device is that you are able to use the device’s special
features such as the GPS and camera. You also can change between mobile phones andtablets and between Portrait and Landscape modes, thereby increasing what is viewed on theform.
This lesson covers various topics including:Querying device characteristics
Using the GPS and camera
Mail, SMS, HTTP and other apps

Using the Device Functionality293

Fetching the Device Orientation
During this course you used your tablet in Portrait mode. Turning it sideways turns it into
Landscape mode and you immediately have more screen real-estate to be able to display
more data.

Landscape Mode
When you rotate your device to Landscape mode, you are able to view more information oneach line. When you use placement on the table you are able to view more of the text. For
example, have a look at the email list below.

You also have the option of displaying more information on the table. Remember that you can
use the ClientOSEnvGet ('device_orientation') to know whether you are currently in Portrait orLandscape mode.
In this exercise, you will modify the Customers - Line mode program so that if the device is in
Landscape mode, it will also display the full address of the customer since there is more roomfor display.
1. Zoom into the Customers - Line mode program.
2. Zoom into the Form Editor.
What you are going to do in this example is to provide an expression for the Data property of
the Customer Name Edit control such that when the device is in Portrait mode, only the namewill be displayed, but when it is in Landscape mode, the name and full address will be

Using the Device Functionality294displayed. So you need to retrieve the device’s orientation. Magic xpa provides a functionthat returns the specific environment setting: ClientOSEnvGet. Now you will see how to use it.
3. Select the Customer Name Edit control and enter the following expression in the Data
property:
If (ClientOSEnvGet ('device_orientation') = 'Portrait', Customer Name, Trim (CustomerName)&','&Trim (Address)&','&Trim(City)&','&Trim (Country))
4. Set the Format to 100. You do not need to increase the table or the actual column.
Placement will do this for you.

When the device’s orientation is changed, Magic xpa raises the Window
Resize internal event. You can add your own code in the logic unit to
update variables as a result of the current orientation.

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Here are some of the keywords that can be used within the ClientOSEnvGet function.

Keyword

Description

device_os

Returns the device’s operating system

device_screen-width

Returns the device’s screen width in Portrait mode in pixels

device_screen-height

Returns the device’s screen height in Portrait mode in pixels

device_physical-width

Returns the device’s physical screen width in portrait mode in
inchesdevice_physical-height

Returns the device’s physical screen height in portrait mode in
inchesdevice_orientation

Returns the device’s screen orientation

device_os-version

Returns the device’s OS version number

device_model

Returns the device’s model number or namedevice_touch

Returns “1” if the device has a touch screen

temp

Returns the local cache folder on the device

device_location

Returns the current device’s location

device_magic-version

Returns the RIA client version number

device_udf|getargs

Returns the query parameters when the application was launchedfrom another application

device_udf|getpushid

Returns the device ID, which can be used for sending push
notifications to the device

device_udf|my_string

Calls a user defined function

device_resource-folder

Returns the value of the resource folder

As an example of the use, you might decide that one feature is not available on iOS orWindows 10 Mobile and so you can use the ClientOSEnvGet ('device_os') = 'Android'
expression.
Note that on Android devices, you can also use Java predefined keys (for example:
ClientOSEnvGet (‘java.io.tmpdir’)) to get additional information.

Using the Device Functionality296Sometimes there are scenarios where you want to lock the orientation of thedevice such that when you run a certain program it always displays in
Landscape mode. To do this, you can set the Lock orientation form property
to Landscape.

Accessing the Camera
One of the useful features of a smartphone is the ability to take pictures and then to store
them. As an example you will use the camera to take a picture of whatever you want anddisplay the picture.
1. Zoom into the Customers - Line mode program.
2. Zoom into the Data View Editor and add a Virtual variable named Picture Location
with an attribute of Alpha and a size of 250.
3. Create a User event named Take Photo.
4. Zoom into the Form Editor.
5. At the top of the form, to the left, add a push button.
6. In the Format property, type Take Photo and raise the User event, Take Photo.
Now you need to handle the Take Photo event and initiate the camera. It is possible to initiate
a camera from the device using the ClientFileOpenDlg function. This will enable the user totake a picture and select it.
1. Zoom into the Logic Editor
2. Add a logic unit for the Take Photo User event.
3. Create an Update operation with the Picture Location variable and enter the following
expression: ClientFileOpenDlg('','camera','','FALSE'LOG,'FALSE'LOG).
The full path name of the picture will be returned from the function.
Now you need to display the image. There are many ways to do this and, here, one method
is described. You will display the image in a subtask.
1. Create a subtask named Display Photo.
2. Add a Parameter named P.Image Location with an Alpha attribute and a size of 255.
3. Zoom into the Form Editor.
4. Drop an Image control on the form.
5. Zoom from the Data property and select the P.Image Location parameter.
6. Set the Load image from property to Client.
7. Set the Image Style property to Scaled to Fit.
8. Return to the parent task and zoom into the Take Photo User event.
9. Add a line after the Update operation of the Picture Location variable.
10. Call the Display Photo subtask and pass the Picture Location variable as an argument.

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297

You can now run the application.
In your program, you should upload this picture to the server using the
ClientFileToServer function.
Displaying the image as a full screen is not always necessary. Sometimes you simply want todisplay it as a popup. You can do this by using additional information:
1. Zoom into the Display Photo subtask and then zoom into the Form Designer.
2. Set the Pop Up form property to True.

Instead of using the camera value in the ClientFileOpenDlg function, you can use the images
value and the operating system will display the photo gallery for you to select an image.

Telephone, SMS, Mail and HTTP
Sometimes you want to be able to call the number listed in your database or send an SMS(text message) or an email. This is simple to do. You will now see an example using the dialer.
1.
2.
3.
4.
5.

Zoom into the Customers – Line mode program.
Create a User event named Dial Out.
Zoom into the Form Designer.
At the top of the form, add a push button.
In the Format property, type Dial Out and raise the User event, Dial Out.

Now you need to handle the Dial Out event and initiate the device caller.
6.
7.
8.
9.

Zoom into the Logic Editor
Add a logic unit for the Dial Out User event.
Add an Invoke operation and select OS Cmd from the combo box.
Set the expression to: 'tel:###-#######' meaning a phone number, such as'tel:+1-949-250-1718'.

10. Set the Execute on property to Client.

Using the Device Functionality298When you run the application and tap the Dial Out button, the device will invoke the dialer ofthat device. Remember that each device and each operating system is different.

To send an SMS, meaning a text message, you would simply change the tel to sms.
Sending an email is simple. It uses the mailto functionality of HTML. The syntax is:
mailto: email_address?subject=Comments&body=text
The only mandatory part is the email address. Here are some examples:
mailto:mui@magicsoftware.com
mailto:mui@magicsoftware.com&subject=Getting Started with Magic xpa 3.x for
Mobile&body=We want to take this course

Accessing a website
You can also access a website using the Invoke OS Cmd operation by providing a full URL
such as http://www.magicsoftware.com. In runtime, the website will be opened in the default
browser of the device.

Using the GPS
The GPS or Global Positioning System has been around for longer than mobile devices havebeen with us, but today your mobile device uses GPS to be able to locate your device andoffer you services in your vicinity, such as places to see, restaurants, or even how to get to adifferent location. It is up to you how to use the GPS options of your local device. Bear in mind
that GPS applications often drain the device’s battery life.
To get the device location, you use the ClientOSEnvGet function to query the current device
location. This fetches the location using the internal or connected GPS device. ClientOSEnvGet('device_location') returns the current device location, using any of the available location
options, such as GPS, Network, and so on. The result is a string in the following format:
OK|Latitude|Longitude, where OK is a fixed part for testing to see if a result was returned,
and Latitude and Longitude are the coordinates of the current location. If a location could not
be obtained, for any reason, an error message will be returned.

Using the Device Functionality299

1. Zoom into the Customers – Line mode program.
2. Zoom into the Data View Editor and add a Virtual variable named GPS Location withan attribute of Alpha and a size of 50.
3. Create a User event named Use GPS.
4. Zoom into the Form Designer.
5. At the top of the form, to the left, add a push button.
6. In the Format property, type Use GPS and raise the User event, Use GPS.
Now you need to handle the Use GPS event and initiate the internal GPS.
7. Zoom into the Logic Editor
8. Add a logic unit for the Use GPS User event.
9. Create an Update operation with the GPS Location variable and enter the following
expression: ClientOSEnvGet ('device_location').
Assume that the operation returned a value similar to the image below. You first need to check
whether a GPS value was returned:
10. Add a Block If operation and use theexpression: Left (Trim (GPS Location),2)='OK'
The Left function takes X characters from the left, in your case, 2 characters.
Within the block you know that a valid GPS position was returned. You now need to retrieve
the GPS data. Like everything in Magic xpa, there are many ways of doing this. In this case,
you will first remove the first three characters, OK| and then you will replace the second pipecharacter (|) with a comma (,).
11. Add an Update operation with the GPS Location variable and update it withMid (GPS Location, 4, 50)
Remember that you were first introduced to the Mid expression in the lesson about the
Block operation. The expression above takes the original text from the fourth character,thereby disregarding OK|.
Now you need to replace the | character with a comma. To do this you will use the RepStr
function, which replaces all occurrences of a string within text, with a different string. The
syntax is:
RepStr (Text data, String to change, string to replace)
12. Add an Update operation with the GPS Location variable and update it with
RepStr (GPS Location, '|', ',')
These are the coordinates that you can now use in Google Maps. Of course you could havebroken the string and fetched the longitude and the latitude values and carried out any
manipulation you wanted. You can now display this in a number of methods. For this example
you will use the Browser control in a subtask.

Using the Device Functionality300

13. Create a subtask named Display Location.
14. Add a Parameter named P.Current Location with an Alpha attribute and a size of 50.
15. Zoom into the Form Editor.
16. Set the Pop Up form property to True.
17. Drop a Browser control on the form.
18. Zoom from the Data property and add the following expression:'https://maps.google.com/?q='&Trim (P.Current Location).
19. Return to the parent task and zoom into the Use GPS User event.
20. Add a line before the end of the Block operation.
21. Call the Display Location subtask and pass the GPS Location variable as an argument.
You can now run the application.

After you have the GPS location, you can show a map with this location using a 3rd party
application, for example by using the Invoke OS Cmd operation with Execute On=Client withany of the following expressions:

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You can directly enter: https://maps.google.com/?q='&Trim (GPS Location). If the Google
Maps application is installed on the device, you will be asked todecide in which application to display the location.
You can use 'geo:'&Trim (GPS Location). This will display eachapplication that can display a geographical address.
You can load a specific application directly by using its name, such as:'waze://?q=London' to open the Waze GPS application and navigate to London.

Location queries can sometimes take time to respond, because
the GPS device is searching for satellites. During this time, theclient is blocked, waiting for a response. You should make proper
indications for the user that this is the situation. As an example,
before invoking the GPS service, you can display a form such as“Searching for GPS location…”
Location queries have a built-in timeout of 20 seconds.

Multiple Forms
When your user uses a tablet or a smartphone, the amount of information that can bedisplayed on the device differs greatly. If all you are going to display is a list of names, thenthere is no difference in the screen design. However, if you want to display an order entry
system using subforms or you want to have a dashboard showing everything that is happening
in your office at the same time, then the size of the device matters. You also know that iOS
and Android devices have different functionalities and the look and feel is different. Therefore,
you need to decide whether you want to define different forms for different devices.
Magic xpa enables you to create different forms and then according to an expression, you
can programmatically decide which one to display. Bear in mind that the form is loaded when
the task is loaded and you are unable to change the form once the task is up and running.
Of course, the type of device does not change once you start using it and, therefore, you can
use a Main Program variable to hold the type of device:
1. Zoom into the Main Program.
2. Add a Virtual variable with a Logical attribute and name it Tablet?
Now you need to update the variable with True when you are running on a tablet. The
question is where?

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Manager Task
You will often find that you need a manager task. This task is the first task that is called andperforms some initiation functionality and then loads your program. This is the program thatwill be the initial program. You will see how to use this.
1. Add a program named Start.
2. Set the Public name to RunMe and check the External box.
3. Set the Task type to Rich Client, but uncheck the Interactive box. This will make this atype of Batch task, but it will run on the client.
4. Set the End task condition to Yes and the Evaluate end task condition to After updatingrecord. If you do not do this, the task will never end.

A Rich Client task needs at least one variable:
5. Add a Numeric variable named Screen Width with a size of 3.2.
6. Add a Record Prefix logic unit.
7. Create an Update operation with the Screen Width variable and enter the following
expression:
Val (ClientOSEnvGet ('device_physical-width'),'3.2')
This fetches the device’s physical width of the screen when the device is in Portraitmode.
How do you know whether you are using a smartphone or a tablet? There is no real way ofknowing, but tablets are generally physically larger devices than phones and so you can use
their physical dimensions. For this example assume that a smartphone has a physical width of
up to 3.5".
1. Update the Tablet? variable with Screen Width > 3.5.
2. Call the All Products program.
Now you will see how to create other forms. As an example, if the All Products program islaunched from a smartphone, the list of products will be displayed, which is the way that the
program currently behaves. However, if the same program is launched from a tablet, theproduct’s image will be displayed to the right of the table.
1.
2.
3.
4.

Zoom into the All Products program.
Zoom into the Form Editor by pressing Ctrl+3 or clicking the Forms tab.
Park on the All Products form.
Change the Form name to All Products - Smart Phone.

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You are now going to copy this entry:
1. From the pulldown menu, select Edit, thenEntries and then select Repeat Entries.
2. In the dialog box, enter 2, which is the form
that you are about to copy. This will duplicate
the current entry.
3. Park on the last form.
4. Change the Form name to All Products - Tablet.
5. Zoom into the All Products - Tablet form.
6. Increase the width of the form so that you can add an Image control.
7. Drop an Image control to the right of the table.
8. Set the Data property to '%WorkingDir%'&'products\'&Trim(Product name)&'.jpg'.
9. Set the Color to Text Caption.
10. Set the Image Style to Scaled to Fit.
Remember that the table is set to increase by 100% if the size of the device increases;
therefore, you need to adjust the image accordingly:
11. Zoom into the Placement property and set the X property to 100.
12. Exit the Form Editor.
13. Open the Task Properties dialog box by pressing Ctrl+P.
14. Click the Interface tab.
The Main Display property governs which form will be displayed. Remember that this iscalculated before the task is displayed.
15. Zoom into the Main Display property and then into the Expression Editor.
You are now going to enter an expression, so that if you are running on a tablet, the All
Products - Tablet will be displayed. If not, you will display the All Products – Smart Phone form.
Like with the Task mode property, when you use a form number inside any expression, toupdate it automatically, it is good practice to use the FORM literal. If you have an expression,
such as IF (A, 3, 2), this will work and is correct. However, if you add a new form you willneed to make changes. By using the FORM literal, it is updated automatically. You can also
select the form in the Expression Editor by clicking theicon.
16. Enter an expression, such as IF (Tablet?, '3'FORM, '2'FORM).
Now when you run the application, you will see a different form on different platforms. You
will see other uses of the manager program later in this course.

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SummaryIn this lesson you learned how to interact with the device using Magic xpa functions. The
ClientOSEnvGet function has predefined keywords that enable you to use some of the device’s
options, such as the GPS and camera.
The built-in keywords enable you to fetch details about the device and display different
information. For example, you may decide that a certain program is only available if you areusing an iPhone.

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Using the Device Functionality

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20

LessonOffline Implementation
Magic xpa mobile applications work in a client server mode in which the client, the mobile
device, is the interface that the user sees and contains part of the code. However, the server is
at a remote location, has the database and handles any heavy workload. There is constantcommunication between the client and the server depending on the type of work involved. As
you already know, when you call a new task, this process involves accessing the server tofetch the task details and then to display the task on the client.
What happens when you do not have internet communication? That is where offline
programming is necessary. Magic xpa enables you to develop offline tasks. Offline programs
allow users to continue to be productive in areas with intermittent, limited or unavailable
internet connectivity. While working offline, data is stored locally on a local database, andperiodically, when internet connectivity resumes, you can synchronize it back to the server.
This lesson covers various topics including:
The Offline concept
Local data sources
Offline programs
Synchronization of data
Synchronization issues

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Concept
When planning an offline implementation, it is important to understand the challenges andconstraints that you need to overcome to enable applications to work completely offline
without a server connection. Unlike a connected application, server connectivity is either
non-existent or intermittent, and applications need to be adjusted to handle this scenario
properly, without compromising usability and data integrity. As a programmer, you need totake into account the technical aspect of being disconnected, and the data consistency aspect,
as follows:
You can store a subset of relevant server data or client-only data on the client. You need tounderstand what data is constant data, such as a list of countries and which is not updated
often, such as suppliers and items that are updated often, such as stock. However, evenwhen dealing with stock, you may not need all of the data on the client. For example, asalesperson who deals with orders involving computer hardware only needs the products
dealing with computers, while a salesperson who handles cleaning products only needs
that subset. You can also have a scenario where the salespeople have access to the entire
catalog but only current stock quantities is kept on the server and needs to besynchronized.
On systems that require user authentication, consider storing user credentials securely on
the client.
Allow data entry on the client and update client data with server data for data consistency.
Working under intermittent network connectivity (network disconnects, slow connections)while allowing uninterrupted operation and data consistency.
Keeping application resources such as application metadata, image resources and so on,
locally on the client, while allowing updates during connectivity periods.
The above challenges define an offline pattern that is different from patterns used when
network connectivity is guaranteed, and require the developer to handle additional usage
scenarios. Magic xpa provides tools and features that allow developers to tackle thesechallenges and provide a complete offline experience.
Some programs are totally client programs and some are server-based and others are both.
An example of a client program can be something like a university student’s lesson timetable.
This timetable is only updated every semester and, therefore, the data can be kept on theclient. An auction-based client depends entirely on server data and, therefore, you need aninternet connection for this. A customer order can have elements of both server and client
data. You will learn more about this later.

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How Does It Work?
Unlike connected applications, offline applications are designed to work without (or withintermittent) network connectivity. This limitation defines a different execution flow for offline
applications. Typical offline applications will work as follows:
On first invocation, offline applications must download and synchronize all necessary
resources required for the offline operation. These include application metadata, images,client-side data and so on. This requires an offline application to be connected at least
once before it can work offline. If there was no initial connection, the programs will notwork.
For applications that require user authentication, user credentials should be securely stored
on the client to allow for operation without server authentication. To ensure validity, such
credentials should be re-checked when connected.
Following initial invocation, all user interactions must be done using local resources only
(local data, local images and so on). By using local resources exclusively, the application
is guaranteed to work, regardless of the internet connectivity state and without requiring
server access. All data updates should be stored locally on the local database.
Periodically, at an application-dependent timing, the application must synchronize
modified local data back to the server and download server data that was modified since
the last synchronization. Remember that data objects can be updated by multiple clientsand by the server simultaneously and therefore two clients may update the same data at
the same time. You need to take this scenario into account.
Since Magic xpa automatically synchronizes metadata objects while connected, anapplication that runs offline must be allowed to periodically synchronize changes to its
metadata objects. Typically, if an internet connection is available on startup, metadata
objects will be synchronized automatically. The developer should plan for allowing
metadata updates to happen when the application changes.
The following sections describe, in more detail, how to implement each of the above, and the
supporting Magic xpa features that enable each capability.

Terminology and Definitions
The following terminology is used:
Offline program – A program that runs only on the client. This program will not access theserver and cannot use server resources.
Local data source – A data source pointing to a database that is stored locally on theclient.

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Local (Offline) Storage
The RIA client supports local data sources. Using a local data source, you can save data on
the client and use it later on, mainly in Offline programs that do not access the server. Using
local storage can also improve performance by locally caching data. The local database isdefined by setting the DBMS column in the Database repository to Local in the same way thatyou defined one in Lesson 7, Viewing Data Source Content. A local DBMS database’s data
source is a client data source, and will be stored locally in the client cache.
To open the Database repository:
1.
2.
3.
4.
5.
6.

Verify that no projects are open.
From the Options menu, select Settings and then Databases.
Park on any line, such as the last line, and create (F4) a database entry.
In the Name column, type Country Data.
In the Data Source Type column, make sure that DBMS is selected.
Zoom from the DBMS column to open the DBMS List, park on the Local entry, and click
the Select button (or press Enter).
7. The Location column shows the exact path to the database data. Set the Location to:Countries.dat.
The country and cities data do not change often and therefore there is little synchronizationneeded. To support the Countries and the Cities data sources on the client, you need to
duplicate their entries in the Data repository:
8. Zoom into the Getting Started project.
9. Zoom into the Data repository.
10. Park on the last line and from the pulldown menu select the EditEntriesRepeat
Entries option.
11. Zoom from the From option and select the Countries data source and then zoom fromthe To option and select the Cities data source.
You will see that the two entries are duplicated.
12. Park on the new Countries data source and change the name to Local Countries.
13. Zoom from the Database column and select Country Data.
14. Park on the new Cities data source and change the name to Local Cities.
15. Zoom from the Database column and select Country Data.
In this example the structure of the data sources is identical. Now you need to setup the
program that synchronizes the data from the server to the client.

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Synchronization Programs
You need to define programs for each data source that you want to synchronize. The
following two programs need to be created for each data source:
Server to Local synchronization – Update the local data source with server data.
Local to Server sync synchronization – Update the server data source with local data.
Both of these programs are necessary if the update is bidirectional; meaning, the data can be
updated on both the server data source and the local data source. If the update is done only
in one location, then only one program is required. In the example that you are currently
using, Countries and Cities, you only need to synchronize from the server to the client. This
will be done by using a non-interactive, non-Offline Rich Client program with a server data
source as the Main source.
1. Zoom into the Program repository and create a program named Sync Countries from
2.
3.
4.
5.
6.
7.

server.
Set the Task type to Rich Client.
Uncheck the Interactive box to make this a non-interactive task.
Set the End task condition to Yes.
Set the Evaluate condition to Before entering record.
Zoom into the task and select Countries as the Main source.
Select all of the fields from the Countries data source. In this case there are only two
fields.

Now you need to perform the synchronization. To do this, you will use a function named
DataViewToDataSource. The DataViewToDataSource function takes the entire data view andcopies in to a data source. You will now see the use of this function:
8. Zoom into the Logic Editor and add a Task Suffix logic unit.
Now you need to use the DataViewToDataSource function. The syntax of the function is:
DataViewToDataSource (<generation>, <variable names>, destination data source number,destination data source name, destination columns names)

The variable names are the names referred to in the Data View
Editor in the Name column (Field Description property). These arecase sensitive.

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The generation will be zero since you are referring to the current task.
Variable names will be the names referred to in the Data View name column of the task,such as Country_Code, Country_Name.
The destination data source number will be the entry of the Local Countries data source inthe Data repository. In this case as with others, it is good practice to use the DSOURCE
literal. You can select the data source from within the Expression Editor by click theicon.
The destination data source name is the name of the table, if you do not use the number.
You generally do not need to specify a name.
The destination columns names are the names of the fields in the data source that thevariable names will be copied to. The first name from the Variable names argument will becopied to the first entry here. If all the names are identical to the Variable names, you can
use ''.
9. Add an Evaluate Expression operation:
DataViewToDataSource (0, 'Country_Code,Country_Name','8'DSOURCE, '','')'8'DSOURCE is the Local Countries data source
If the destination data source does not exist, it will be created.
If a record exists in the destination data source, it will be updated.
That is the scope of the synchronization program from the server to the client. Now that you
have the synchronization program, where do you call it from?
In the previous lesson you created a manager program named Start. You can use this program
to run the synchronization programs.
10. Zoom into the program named Start.
11. Zoom into the Task Suffix logic unit and after the Update operation for the Tablet?
variable, add a Call operation to the Sync Countries from server program.
If you now run the application, the Local countries data source will be created on the client,but the All Products program will be displayed. You want to be able to display the list of
countries using the local data on the client device.
In Offline tasks, as opposed to non-Offline tasks, the Task Prefix logic
unit executes on the client. Therefore, it can contain client-side logic.

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Offline Programs
For a program to work without server access, it must be specifically defined as an Offline
program. An Offline program is downloaded to the client automatically on initial connection
and kept cached at the client. Unlike non-Offline programs that are validated against theserver on each invocation, Offline programs are always loaded from the client cache and do
not require any server connectivity.
1. Zoom into the Program repository and create a program named Offline Countries.
2. Set the Task type to Rich Client.
You define a Rich Client program as offline by checking the Offline check box in the Task
Properties dialog box or the Program repository.
3. Check the Offline box to make this an Offline task. You can now only use local storage
data sources.
4. Zoom into the task and select Local Customers as the Main source.
5. Select all the fields from the Customers data source. In this case there are only two
fields.
6. Zoom into the Form Editor, add a Table control and add the Customer_Code andCustomer_Name fields. Set the look and feel of the form as you have during previous
lessons.
Now you can call this program from the Start program.
7. Zoom into the program named Start.
8. Zoom into the Record Prefix logic unit and change the Call operation to the All
Products program, to call the program named Offline Countries.
You can now run the Start program and you will see the list of countries available on the local
device.

Offline Task Limitations
The following limitations apply to Offline tasks:
You cannot use server data sources in an Offline task.
You cannot use server-side operations and expressions in an Offline task.
Only Offline programs can be used in an Offline program’s subform.
Offline programs cannot be used in a non-Offline program’s subform.
Offline tasks can only have Offline Rich Client subtasks.
When testing offline capabilities in the Studio, the server needs to run in Background
deployment mode. If the application was started on the client without server access, andthe access to the server then resumes, the application will not be able to access the serverwhen the server is running in Online deployment mode.
The Tree control and Frames forms are not supported in an Offline task.

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Main Program Flow
Applications with Offline programs have a slightly modified startup and execution sequence
for allowing offline startup while also supporting a connected startup.
On startup:
If the client can connect to the server, the Main Program will run both on theserver and on the client, so a context will be opened on the server ready to serve
future requests.
If the client cannot connect to the server, the Main Program will run only on theclient, without opening a context on the server. In future server access, the client
will try again to connect to the server as detailed below.
When closing the application:
If the application was connected to the server, it accesses the server to close thecontext.
If there is no connection to the server, but there is no server logic in the Main
Program’s Task Suffix logic unit, then the application will be closed on the client
without showing an error. In this case, the context on the server will remain open
until the context inactivity timeout is reached.

Have you noticed some issues that arose with this small example?

?

Every time you run the application, the synchronization program
will run and all country data will be copied from the server to theclient. The Countries data source does not change much. How
can you change this so that synchronization is only performed
when needed?
If you do make a change to the country data, such as adding a
new country or renaming one, how do you update the server
about only that change?
In actuality, both issues are the same issue but from different aspects.

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Synchronization Issues
When dealing with a static data source such as the Countries data source, you very often
want to simply copy the data source over once and then forget about it. In essence, all you
need to do is to check whether there are records in the local data source and if there arerecords, then there is no need to copy the data source. A simple solution to handle this would
be to perform a Link Query operation and if there are records in the local file, then you do notneed to perform data synchronization. Actually, country names can change, such as in 2012
the Somali Republic changed its name to The Federal Republic of Somalia. Sometimes, newcountries are created such as South Sudan in 2011. You still need a mechanism to be able toupdate records when needed.
Data synchronization between a server data source and a local (client-side) data source
depends on identifying the modified records. Being able to properly keep track of changes
requires making changes to both data structures and to the logic that displays and updates
data. You need what is commonly known as an audit trail. In this section you will learn about
one method of doing this by keeping a string in the format YYYYMMDDHHMMSS.
1. Zoom into the Model repository.
2. Add a Field model named Timestamp with an attribute of Alpha and a picture of 14.
3. Zoom into the Data repository.
4. Park on the Countries data source.
5. Zoom into the Column repository and park on the last line, the Country_Name row.
6. Add a line and name the entry Last Modified and link it to the Timestamp model.
7. Press Enter and you will return to the Data repository.
8. If you press Enter or move to a different line, you will get a new dialog box, Confirm
Convert Operation. Click Yes.
9. You do not need to create a backup, so you can ignore the next dialog box.
10. Click OK on the last dialog box, which asks you which index to use.
The operation above converts the actual data source to meet the new definition in which you
added a field. This new field is also used for when you update records in the data source.
1.
2.
3.
4.

Park on the Local Countries data source.
Zoom into the Column repository and park on the last line, the Country_Name row.
Add a line and name the entry Last Modified and link it to the Timestamp model.
Press Enter and you will return to the Data repository.

Magic xpa does not convert this data source since it exists on the client. It will automaticallybe converted once the application loads in runtime.
It is important that the names in both data sources are the same,
including upper and lower case.

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How do you use the new field?
You are going to add data to the Countries data source:
1. Zoom into the Countries program that you created in an earlier lesson.
2. Add a Rich Client subtask and name it Add Country.
3. Set the Initial mode to Create.
4. Select Countries as the Main source and select all three records.
5. Zoom into the form and display only the Country_Code and the Country_Namevariables. You can set the Pop Up form property to True.
6. Zoom into the Logic Editor and add a Record Suffix logic unit.
7. Add an Update Variable operation and update the Last Modified variable with thefollowing expression: DStr (Date (),'YYYYMMDD')&TStr (Time(),'HHMMSS')This will create a string concatenating the data and time.
8. Return to the parent program and add a User event named Add Country.
9. Zoom into the Logic Editor and add an Event logic unit for the Add Country User event.
10. In the Add Country logic unit, call the Add Country subtask.
11. Raise the View Refresh internal event.
12. Zoom into the Form Designer and place a Button control at the top of the form.
13. Zoom into the control properties. Set the Model to the Image button model.
14. Park on the Image List file name property and change the image to Add.png.
15. From the Event Type property, select User.
16. From the Event property, select Add Customer.
17. Click the Fit Control Sizeicon.
If you executed the application and ran this program (and not the Start program), you will see
the modified program. As an example, add Panama as country number 24.

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The timestamp has also been written to the Countries data source. This mechanism is valid
also for updating the data in the data source and not only adding data. The issue now is how
do you transfer only the modified record, meaning the newly added country. For this you needa new data source that will be saved locally:
1. Zoom into the Data repository and park on the last entry.
2. Add a new data source and name it Local sync table.
3. Set the Database column to Country Data. This is the local database.
4. Zoom into the Column repository and add a line.
5. Name the entry Idx with an attribute of Numeric and a picture of 2.
6. Add another line, name the entry Last Modified Country and link it to the Timestamp
model.
Now when you access the synchronization program, you need to first check this data source
to see when the last update was made.
You are now going to make some changes to the Start program and to the Sync Countries
from server program:
From the Start program, you are going to fetch the last synchronization timestamp from the
Local sync table.
You will pass this as a parameter to the Sync Countries from server program so that you
can perform a range starting from that timestamp.
From the Start program, you will update the Local sync table with the current timestamp.
This will then be the last synchronization timestamp.
1. Zoom into the Start program.
2. Add a Virtual variable named Last Country timestamp and link it to the Timestamp
model.
3.
4.
5.
6.
7.

Add a subtask named Fetch last sync data and uncheck the Interactive box.
Set the End task condition to Yes and the Evaluate condition to After updating record.
Zoom into the Data View Editor and set the Main source to the Local sync table.
Select all of the columns from this data source.
Add a Record Suffix logic unit, add an Update operation and update the Last Country
timestamp variable from the parent task with the Last Modified Country column fromthis subtask.

8. Return to the parent task.
9. Zoom into the Task Suffix logic unit and after the Update operation for the Tablet?
variable, add a Call Operation to the Fetch last sync data subtask, before the call to
the Sync Countries from server program.
Now you are going to make some changes to the program that synchronizes the data so thatit uses the timestamp information.
1. Zoom into the Sync Countries from server program.

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2. Add the Last modified column from the Countries data source to the data view.
3. Add a Parameter named P.Last Sync with a model of Timestamp.
4. Park on the Last modified column and zoom into the Range from property, and set thefollowing expression: P.Last Sync. This ranges all of the entries since the lastsynchronization.
5. Zoom into the Logic Editor and zoom into the expression you previously defined. You
previously defined the expression as:
DataViewToDataSource (0, 'Country_Code,Country_Name','8'DSOURCE, '','').
You now need to add the Last Modified variable to the list
'Country_Code,Country_Name,Last Modified' so that you have the same data on theserver and the client.
You now need to update the Local sync table with the new timestamp so that the next time you
perform synchronization it will take only the most recent changes.
1. Zoom into the Start program and zoom into the Task Suffix logic unit.
2. Park on the Call operation to the Sync Countries from server program.
3. Zoom into the Arguments property, add a line and select the Last Country timestamp
variable.
4. Add a new line, add an Update operation and update Last Country timestamp with thefollowing expression: DStr (Date (),'YYYYMMDD')&TStr (Time(),'HHMMSS').
5. Add a subtask named Update last sync data and uncheck the Interactive box.
6. Set the End task condition to Yes and the Evaluate condition to After updating record.
7. Zoom into the Data View Editor and add a Link Write operation to the Local synctable. With a Link Write operation, if no record exists, one will be added.
8. Select the Idx column and set an expression of 1 for the Locate from and Locate tocolumns. Use the same expression for the Init expression.
9. Select the Last Modified Country column, since this is the variable you want to update.
10. Add a Record Suffix logic unit, add an Update operation and update the Last
Modified Country column with the Last Country timestamp variable from the parent
task.
11. Return to the parent task.
12. Add a Call operation after the Update operation to the Last Country timestamp
variable and call the Update last sync data subtask.
You can now execute the application and call the Start program as you did in the previous
lesson. When you execute the application, all country data is synchronized from the server tothe client. You will see that the new country was added to the local database.

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Server Access Failure
When you execute the application and try to perform a task that requires server access, suchas data synchronization and there is no internet access, meaning no server, then all server
programs will crash. This is because their metadata does not exist on the client. Only the
Offline programs will be available. You will get an error message such as "Cannot access theserver" and the end user cannot do anything about that. This includes the manager program.
You defined the manager program named Start as a regular Rich Client program but if there isno server access, this program will not load and your application will not run.
1. Zoom into the Start program.
2. In the Task Properties dialog box, check the Offline box to make this an Offline
program.
You now have another problem. The Sync countries from server program is a server-side
program and you cannot call a server-side program from an Offline program.
As you know, the Main Program is the parent task for the whole application. You can use thisprogram to call server-side programs.
3. Zoom into the Main Program.
4. Add a User event named Sync countries.
The program you created was to synchronize the countries data from the server to the client.
So you could have named this event Sync countries from server. However what if you also
wanted to implement the opposite direction in which you synchronize the server with clientdata?
Spoiler: You are going to do that in the exercise. In this case, you can use the same event andpass it a parameter. Do you remember that the Sync countries from server program receives
the current timestamp as a parameter? You can solve this in two ways, either you can define
the Last Country timestamp variable as a Main Program variable or you can pass the value asa parameter to the Sync countries event. In this example, you will add it as a parameter to theevent.
5. Zoom into the Parameters column.
6. Add a new line, set the Name to P.Current Timestamp and select the Timestamp
model.
7. Add a new line, set the Name to P.Sync from Server? and set the Attribute to Logical.
You will be passing a value of True when you want to synchronize from the server tothe client and False when you synchronize from the client to the server.

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8. Zoom into the Logic Editor.
9. Create a logic unit for the Sync countries User event.
10. A dialog box appears asking: Create Parameter variables to match parameters to theevent? Click Yes. The parameters you defined will be added to the logic unit.
11. Add a line and use a Call operation to call the Sync countries from server program.
12. Zoom into the Arguments property, add a line and select the P.Current Timestamp
parameter.
13. Set the condition on the line to P.Sync from Server?.

14. Zoom into the Start program again and zoom into the Logic Editor.
15. Park on the Call Program operation to the Sync Countries from server program.
You can delete this line and add a new one or modify the line.
16. Instead of the Call Program operation, add a Raise event operation and select the
Sync countries User event.
17. Zoom into the Arguments property, add a line and select the Last country timestamp
variable to match the P.Current Timestamp parameter.

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18. Add a second line, zoom into the Exp column and create an expression of True tomatch the P.Sync from Server parameter.

Now you can run your application.

Network Unavailable Errors
When server access fails for any reason, such as when there is no network, the client device
will display an error message:
Magic xpa will display an error dialog box and the user will be prompted to retry or abort
the operation. The client will retry the operation as many times as the user requests.
All non-Offline programs running on the client will be terminated.
This means that if you try to perform data synchronization, it will also fail since these are nonOffline programs. You can decide whether or not to display the dialog box.
You can display the dialog box by using the ClientSessionSet() function, which can disable thedialog box for the entire session.
1.
2.
3.
4.

Zoom into the Start program.
Zoom into the Task Suffix logic unit.
Add a line after the Update operation for the Tablet? variable.
Add an Evaluate Expression operation and set the following expression:
ClientSessionSet ('EnableCommunicationDialogs','FALSE'LOG)
You are disabling the display of the dialog box for the entire session.

Even with this function, the server-side programs are still performed even though there is noserver access. The only difference is that there is no error message. You can solve this byusing another function that will return whether or not there is server access. The
ServerLastAccessStatus() function will return an error code of zero if the last access to theserver was successfully completed or a non-zero value if an error occurred.
1. Zoom into the Start program.
2. Zoom into the Task Suffix logic unit.
3. Add a line after the Evaluate expression operation where you used theClientSessionSet function.

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4. Add a Block If operation and set the condition to ServerLastAccessStatus()=0. Thiscondition ensures that the access to the server will be made only if the client
successfully accessed the server on the last attempt. If the client failed to connect to theserver, then by having this condition, the client will not try (and fail) to reconnect to theserver.
5. Delete the Block End operation.
6. Add a line before the Call operation to the Offline Countries program and set a Block
End operation.
All the server-side programs will now be encased within the Block If operation. This allows theuser to continue working.

Deleting a Record
In this lesson, so far, you only learned about adding or modifying records, yet often you needto delete records and synchronize those records between the client and the server. There are a
few solutions to this; however, it is good practice to use a logical delete system. This systemdoes not physically delete the record but indicates that the record has been deleted. To
implement this method you would:
Add a column to the server table named Deleted with an attribute of Logical.
Add a column to the local table named Deleted with an attribute of Logical.
When you delete a record, you do not physically delete the record but update the Deleted
column with a value of True and updated the Timestamp with the current date and time.
When you display the values of the table, you will always display only those rows where
the Deleted variable is FALSE.
These records will also be synchronized when you perform the server synchronization.
Because you are not physically deleting the records, the table will have redundant records.
You can consider periodically doing a clean-up of all deleted records.

Offline Images
Images need to be transferred to the local device. These include images needed for the Offline
programs, such as image buttons as well as data images, such as product images.
To make sure all images used in Offline programs are available when disconnected, you
should copy, on initial startup, all server images that are used in Offline programs to the client
using the ServerFileToClient() function. This function compares server and client file timestamps
and will download new or updated server files to the client cache. Files that are unchanged
will not be downloaded. This function also accepts a folder as a parameter, so you can usethat to copy all content of the folder to the client.

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Exercise
You will now practice some of the issues that you learned in this lesson.
1. Add an option in the Offline Countries program so that you are able to add a country
to the local data.
2. Add a button so that in the Add Country task, the update will immediately be updated
in the server table.
Take into account that there may be no server access, so you also need to
implement client to server synchronization in the Start program.
3. Test this by adding country #25 named Mexico.

Summary
If you decide to give offline capabilities to your application, you need to give thought as to
how to implement the programs and of course which programs are offline and which are not.
You need to think about the following issues and take into account:
Which programs are fully offline and which need to be online.
An Offline program cannot call a server program and you need to use the Main Program
to call a server program.
Your implementation of the synchronization operations and how to have the same data on
the server and the client. Remember that when you have multiple clients you may
encounter a situation where the same record is updated by two different clients.
Synchronizing data involves the following steps:
Fetch the last timestamp that a successful synchronization was performed.
Use the DataViewToDataSource function to synchronize the data according to thetimestamp.
Update the timestamp with the current date and time.

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Lesson21

Best Practices
You now have a working knowledge of developing a Magic xpa program for use on amobile device and you know how to differentiate between different operating systems.
During this lesson, you will learn about some best practices to help cut down on
programming time as well as enhance runtime performance.
This lesson covers various topics including:
Using models
Using logical names
On-demand one-to-many forms
Defining multiple main forms
Code reuse
Performance enhancements

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Models
You learned about models in this course and you used them in various lessons. The useof models is optional, but using them will benefit you throughout the development andmaintenance of your projects. Some advantages to using the Model repository are:Time savings for project development. Once you have created an object model,
you no longer have to set the same property values for other objects of that class.
Ease of maintenance. Once you have defined the properties associated to a
specific model class, any modification to the model is automatically inherited by allof its associated objects.
Ensure matching of columns in different tables for Field models. When columns arecompared for link purposes, or passed as parameters, their attributes must matchexactly. A good way to ensure that they will match is to define them with the samemodel.

Field Models
You used Field models to define a unified size and properties so that you did not needto define the same properties over and over again, such as with the Code model thatyou defined as a Numeric attribute of 9 digits. If you now decide that you want todefine this as 5 digits, you only need to make the change in one place. You can also
define the look and feel of this object on the form so that you define the colors and fontof the object when it is dropped on the form. You can easily make changes to the fontin one place and not in every place it is used throughout the application. Magic xpa
will update all of the corresponding objects.

Form Models
You defined a model for a form so that when the model is used you have a unified
look and feel for all forms without the need to remember what the location of thewallpaper is or what colors to use. It is then simple to change the name of thewallpaper.

Code Reuse
In the last lesson you synchronized data in two places, in the Start program and in the
Offline Countries > Add Country program. In essence, you duplicated the code. You
could design this better so that you can reuse the same logic. You could either use theMain Program Sync Countries event or create a Sync Countries Manager program thatwill encapsulate all of the logic in one place. This will cut down on development timeand if you need to make changes, it will cut down on maintenance, since there will
only be one section that needs to be dealt with.

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Logical Names
During the course you often referred to a reference, such as %WorkingDir%, which is
known as a logical name. For example, the form’s wallpaper was set to%WorkingDir%env\Wallpaper.jpg. The %WorkingDir%env logical name is a locationthat changes from computer to computer and device to device. If you had defined thepath of the wallpaper image as c:\Temp\Wallpaper.jpg, that may be valid on yourspecific computer but will not work on other computers and almost certainly not on amobile device.
Logical names help in writing portable applications. The Logical Names facility allows
development of applications without any explicit relation to physical storage media or
operating system naming conventions. Magic xpa achieves such portability bytranslating project logical names at runtime, according to the Logical Name repository
used as the translation repository of the installation. A logical name can be usedwhenever a file name is to be used.
When you used image buttons during the course you referred to the location%WorkingDir%images and added the \Name.png for every image. It would be amuch simpler issue to remember if you had a logical name setup named buttons thatpoints to %WorkingDir%images\ so that within the form you could simply use%buttons%Add.png. By using this method, if you decide to clean up the folders andmove the button images to a different location, you only have to make a change to the
Logical Names repository. This will make things easy if you decide to move to a Unix
facility in which the slash is in the opposite direction. Bear in mind that when you use
the ServerFileToClient () function you will now need to use
ServerFileToClient ('%buttons%').

Internal Logical Names
The working directory (the directory of the main project) and the engine's main
directory are retrievable using the following reserved internal logical names:%EngineDir% – This logical name will be translated to the path of the Magic xpa
engine.
%WorkingDir% – This logical name will be translated to the path of the working
directory.
%TempDir% – This logical name will be translated to the path of the system’s
temporary directory.

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One-to-Many Forms
You learned about using the Subform control to display a one-to-many operation, suchas a country and the cities attached to that country or an order in which you have theheader and the lines. In the example where you display the list of countries and in the
subform you displayed the list of cities, remember that when you move through the listof countries, you are displaying the cities. This invokes server access to fetch the rangeof cities and then display them.
In this case you can decide whether you need to display the list of cities immediately ina subform, or to display them on demand by clicking a push button or by handling the
Tap event. In the List of Orders program, you displayed the orders in a list but only
displayed the order number, the order date and the customer name. When you tapped
the order, you were shown the full order including the lines. In this case you weredisplaying the order details on demand. You could develop this further and display theorder lines by tapping a button. This is all part of your own screen design.
Also remember that this will depend on your device. If you have a large device, suchas an iPad, you may decide that you want to use subforms, but when you use an
iPhone, you may want to implement the on-demand system.

Defining Different Forms
Different devices have different amounts of information that can be displayed. As
previously mentioned, an iPad and an iPhone cannot display the same amount of
information and an iOS machine and an Android machine have different displays.
Therefore, what works on one device will work differently on another, or not at all.
In an earlier lesson, you learned how to differentiate between a smartphone and atablet. You may decide that you also want to differentiate between iOS and Android.
You can consider preparing different forms for different scenarios.
Remember to use the Mobile Form Preview pane to help you develop your applications
for various platforms.

Manager Program
During this course you defined a manager program, which was the first program you
executed. This program enabled you to perform certain session operations so that you
could ensure ease of use during the rest of the session. This is where, for example, you
fetched the device characteristics, such as what the operating system is or whether you
are using a smartphone or a tablet. You also used this same program forsynchronization of data between the client and the server and vice versa. You can use
the same program to transfer all of the task images from the server to the client so that

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328they are there when necessary and will not be transferred on demand. You could alsotransfer all of the product images.

Performance Enhancements
It is always a good idea to take into account the issue of performance. During thiscourse you implemented some of the issues while progressing through the various
lessons.

Remove redundant components and menu entries
When you learned about menus, you were asked to delete the Default Pulldown Menu.
This is important for mobile devices since, by default, a new application is created witha default pulldown menu. This is not used in mobile applications and should be
removed.
You did not learn about components during this course because this is an advanced
issue, but when a new application is created, Magic xpa automatically adds areference to the User Functionality component. This is invalid in a mobile device andshould be removed. To do this:
1. Access the Component Resource Repository by clicking Shift+F7 or by selecting
it from the Project menu.
2. Park on the UserFunctionality line and delete the line by pressing F3.
3. Press Enter to exit the repository.

Minimize calls to the serverGroup Server-side operations together
A logic unit can have both server-side operations and client-side operations. If you
group the server-side operations together, you can minimize the server access so thatinstead of going back and forth to the server, all operations are executed and thencontrol is returned to the client.

Avoid redundant calls to the server
In Offline programs, if you have no server access there is no point in calling the server
program. Magic xpa will attempt to access the server and will fail and while this ishappening the end user will be waiting. You can condition server access programswith the following condition: ServerLastAccessStatus()=0.
This condition will ensure that the access to the server will be made only if the client
successfully accessed the server on the last attempt.

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Therefore, if the client failed to connect to the server on the last attempt made, then byhaving this condition, the client will not waste time trying to reconnect to the server toperform the operation.

Cache application resources
To make sure that images used in Offline programs are available when disconnected,
you should copy, on initial startup, all server images that are used in Offline programs
to the client using the ServerFileToClient() function.
To improve the performance of copying the files to the client, you should download afull folder and not several separate files.
The ServerFileToClient() function supports folders and wildcard characters.
Executing the function once for a folder with several files means that there will be one
request to fetch the modification timestamp of all of the files and then consecutive
requests for each file that was changed. This means that if the files were not changed,
the second time the application is started, only one request will be made.
Executing the function once per file means that for each file there will be one request to
fetch the modification timestamp and then a consecutive request to fetch the file if it
was changed. This means that for the first time the application is started, there are
more timestamp check requests as compared to using a folder. For the second time theapplication is started, if the files were not changed, there will be a request to fetch thetimestamp for each file as compared to a single request when using a folder.
Avoid Record level transactions on non-interactive client processes
When you have a non-interactive process that updates a lot of records, it is advised touse a Task level transaction when possible.
Using a Record level transaction will open a transaction for each record, which can
reduce the performance. In addition, when the task updates a server data source, aRecord level transaction will access the server after each record in order to commit thetransaction and, therefore, will reduce the performance even more.

Copy a set of records between the server and the client
If you need to copy several records from the server to the client or from the client to theserver, it is best to do it using the DataviewToDataSource() function.
This function copies a set of records (according to range criteria) as a whole and not
one by one, which results in improved performance.

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UI Improvements•••

Avoid using a transparent color on the Table control and controls attached to thetable – Using a transparent color is not recommended since it will slow down theperformance when scrolling a table.
Avoid using an alternate color on the Table control – Using an alternate color is
not recommended since it will slow down the performance when scrolling a table.
Avoid using borders for controls placed on a Table control – On iOS devices, forcontrols on a table, the controls' border and especially the corner radius will slow
the table's performance.

Best Practices331Summary
This lesson summarized the best practices and you have used most of them throughout
this course. These ideas will aid you in creating better and more readable applications
that will be easily maintainable.

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22

LessonCustomization and Installation
In previous lessons you used the MagicDev client for your tests and you used the environmentthat the installation process provided. In this lesson you will learn how to provide your own
environment.
This lesson covers various topics including:
The execution properties fileSigning the keystore file
Creating your own Android package file
Adding your own code
Note: In this lesson you will only be practicing on an Android device. There are similar
methods for creating iOS and Windows 10 Mobile customizations. See the Magic xpa Help
for additional information.

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Creating a Cabinet FileTo execute a project in runtime, you need to create a project cabinet file.
A cabinet file is a file of a project in cabinet format, which can be used at runtime only, using
the Magic xpa Runtime engine.
You cannot open a cabinet file using the Magic xpa Studio.
Now, you will create a cabinet file for your project.
1. Open your project.
2. From the File menu, select Create Cabinet.

The Cabinet File dialog box opens. You need to specify thecabinet file name and location in this dialog box.
3. Select the directory where the cabinet file will besaved.
It is recommended to save the cabinet file (.ecf) in
the same directory as the project file.
4. In the File name entry, make sure that it shows Getting Started.
The default cabinet file name is the project name.
5. Click the Save button.

At this stage, the cabinet file is created.

If the cabinet file exists in the directory, you will be asked to confirm
the overwriting of the existing file.

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Setting Up the Server
For detailed information about deploying your applications, you’ll findin the Support folder of Magic xpa the following concept paper:•

Deploying Rich Client Applications

In addition to the Broker middleware, Magic xpa 3.x supports an InMemory Data Grid (IMDG). GigaSpaces’ XAP in-memory computing
technology is the middleware that implements Magic xpa’sfunctionality on the In Memory Data Grid. To learn more about this,see the following concept paper:•

Deploying Applications on GigaSpaces

Running the application on the same machine that you developed the project can bemisleading. The Runtime engine and the Studio engine share the same environment and thesame configuration. Therefore, you can create a cabinet file (.ecf) and execute the same
project using the Runtime engine.
Your final application is actually divided into two parts: the server and the client.
The server side runs on a remote machine, which is accessed via URLs. This is where thedeployment engine and environment will be configured. This is also where the database willreside. The client is any client machine and nothing is deployed there.
All of the settings and configurations that you set in the Magic.ini file are set on the server
computer. There are some other settings that need to be set in the Magic.ini file specifically forthe server:
1. Set the DeploymentMode property to B. This ensures that the server will run in the
background. Note that when an application runs in the background, there is no userinteraction. As you learned when discussing reports, displaying a print preview or a
print dialog box is meaningless.
2. Set the ActivateRequestsServer property to Y. This property informs the Magic xpa
engine that it will run as an enterprise server and will receive requests through theRequest broker. You will learn about this later in the lesson.
3. Set the InternetDispatcherPath property to /MobileScripts/MGrqispi.dll. This property
is the HTTP requester and is set by the installation process. It defines the name andrelative Web path to the Internet requester.

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Setting Up the Web Server
Before installing Magic xpa for Mobile, you need to ensure that you have a Web server, suchas IIS, up and running. When you install Magic xpa Deployment on the server, the installation
procedure takes care of configuring the Web server to execute RIA applications. However,there are some configuration issues that you need to take into account.
The Rich Client application modules need to be deployed so that they can be executed on thenative deployment environments.
Since the Rich Client environment is intended for use on the Internet, it is useful to understandthe technology that is being used.

Rich Client Folders
The installation procedure creates three subfolders in the Magic xpa installation folder:
Scripts – This folder holds the Internet requester files and RIA prerequisites files.
RIACache – This folder holds the cache data for tasks, images and menus.
PublishedApplications – This folder holds the application files that should be exposed, suchas the HTML, manifest and RIA modules files.
Although these are installed under the installation directory, other locations can be used. Thisis managed by the Web aliases. The following Web aliases were configured by the course
installation process and are required to deploy this course’s Rich Client application:
MobileScripts – This alias points to the Scripts directory of your Magic xpa installation.
MobilePublishedApplications – This alias points to the PublishedApplications directory of
your Magic xpa installation. You used this alias during the course.
These locations can be changed to meet your application requirements.
The Rich Client cache location may be tweaked to suit your needs. This is manipulated via a
Magic.ini setting, RIACacheFilesPath. This defines the location where the Magic xpa server
will write the Rich Client cache files.

Customizing the Application
Throughout this course, you used the icon provided by the installation, which includes the
Magic icon and wallpaper. However, the client may already have an installation of anotherapplication or you may want to provide your own icon. Creating a custom application
requires compilation using tools provided by the mobile devices.

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You can change items such as:
Icon
Startup splash screen
Execution properties – You learned about this in the previous section.
Client title
Application version
Package name
Here is an explanation about how to do this for an Android-based mobile application. For
other mobile devices, please see the Magic xpa Help.
When you execute your application on a client, you need to deploy some modules on theclient. This is the module that enables the logic that is defined on the client, such as displaying
the form and client-side logic. It is also responsible for accessing the server when more
information needs to be displayed.
Magic xpa includes a wizard to assist you in creating the deployment files.
1. To access the wizard, from the Options menu, click Interface Builder and then Rich
Client Deployment.

From the Welcome screen, click Next.
The Available Configurations screen will appear.
This is a list of all the manifest files created fromthis application. The list should be empty.
2. Click New to create a new configuration.

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Application Settings
The Application Settings screen contains information about the configuration and the projectsettings.
The following properties need to be defined:
Application Title – This field has two purposes.
The name provided here will be the name thatyou will see in the list of Available
Configurations. This will also be the name of themobile package that will be created.
Application Description – This is a simple
description of the application.
Publisher Name – This is an important property
and is part of the ClickOnce signature. It is the
publisher name that the end user will see. This isrelevant for desktop RIA deployment.
Copyright – This is not applicable for mobile
applications.
Version Code – This is the internal code for your version.
Version Name – This is the version that your user sees.

Once a Publisher Name has been entered, you will be able to progress to the next screen.

Server Information
The server settings are important and need to be valid for each installation.
The deployment of the application can be done to two separate servers:
Published server – Contains the RIA modules and the application manifest and HTML files.
Application server – Contains the Web requester for the application.

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If you move your installation to a different Web server address, you need to redefine thefollowing settings:

Publish Web Server Configuration
Server Name – The name or IP address ofthe server in which the files will be stored
and accessed by the end users. This canalso be in the format ofwww.example.com.
This field is mandatory and cannot be left
blank.
If you update this field with http:// or
https://, it will be removed.
Magic xpa Scripts – The Web alias thatpoints to the Scripts directory.
Published Applications Alias – The alias of
the Published Applications folder.

Application Web Server Configuration
Server Name – The name or IP address of the server in which the Rich Client application
will be stored. This field is mandatory and cannot be left blank. This can also be in theformat of www.example.com.
The default value is the publish server name.
Web Requester – The Web requester name to use. The default value is theInternetDispatcherPath from the Magic.ini file.
Use Secure Protocol (https) – This check box determines whether to use the https or httpprotocol when running the application.

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Execution Details
Now that you have entered all of the details about the server, you need to enter specificinformation about the application’s execution.
The following properties need to be defined:
Application Name – This is the name that the
Web requester will use.
Start Program Name – This property is
mandatory for mobile applications. There is aselection list to select the initial program. The
programs that will appear in this box have thefollowing properties:
Type set to Rich Client
Public name is not blank
External check box is checked
During the course, you were asked not to makechanges to the name of the first program andleave it as RunMe. In this dialog box, you canmake any changes that you want.
Environment Variables – A comma-delimited list of the environment variables that the Rich
Client will read from the client when it loads. These variables are not used in mobile
applications.
At the beginning of the course you were asked to point to the location where the DevProps.txt
file existed. In this dialog box you can change the name of the DevProps.txt file to a different
name, such as GettingStart.txt.
You will learn how to manually change this file during this lesson.

Generate deployment files
In this dialog box you select which environment you
are going to create files for. For this course, selectAndroid.

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Android Settings
This dialog box creates important customization settings. It writes the information to a file
named settings.properties.
The following properties need to be defined:
SDK Folder – The folder where you installed
the Android SDK.
Platform – The version in which thecompilation will be made. This will be under
the Platform folder.
Package Name – This is taken from otherinformation you have provided during thissession. The package name must be in lower
case and unique across all packages
installed on the Android system. If you use
upper case letters, the build script will convert
them to lower case. The package namecannot include numbers and some reserved
words such as ‘new’.
Resource folder – You can change icons and logos by copying them to the relevant
location.
Icon – To change the icon, replace the icons’ files in the res\drawable-XXX
subfolders. You will need to provide icon files in all of the following sizes:
36x36, 48x48 and 72x72 pixels.
Startup screen logo – To change the startup screens, replace the logo.png files
located in the res\drawable-XXX subfolders. You need to provide logo files indifferent sizes corresponding to the device’s size.

Signing
To continue with the creation of the package, you need to have a Key Store file. The keystore
file is a file that enables you to “sign” your APK file. To do this, you use your own keys andcertificates. A sample keystore file is provided in the installation. You can use this by selecting
the <installdir>\Projects\Customization\Source\test.keystore file, but leave all of the otherproperties as-is.

Uploading to Your Android Device
There are a few ways to install the APK client on the Android client:
Run the APK directly on the Android device. For example, by receiving the APK file as anemail attachment and clicking on it.
Download the APK via the mobile device’s browser.

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Download your application from the Android market.
In this course you will be using the browser method.
1. Navigate to the Android browser.
2. In the URL, enter: http://server_name/MobileScripts/GettingStarted.apk.
3. Go to the Downloads area in the emulator and your APK file will be there. Click it andfollow the instructions.
After successfully installing the APK you will see a new application icon on your device.

Directly Executing on an Android Device
As mentioned in the early lessons, you can run a program on an Android device by toggling
the Execution on Android

icon from the Debug menu and then, when this entry is toggled:

Executing a Rich Client program from the Studio (F7) will switch the engine to Runtime
mode and launch the application on the mobile device or simulator using the selected
program as the start program.
Executing the project from the Studio (Ctrl+F7) will switch the engine to Runtime mode andlaunch the application on the mobile device or simulator using the start program that isdefined in the execution.properties file.
For this to work, you need to:
1. Install the application on the mobile device or simulator. You can install the generic
MagicDev.apk, which is available in the RIAModules\Android folder.
2. Connect the device to your network so that the application will be able to connect tothe Magic xpa server to run the project.
3. From the Android settings menu, enable the USB Debugging option.
4. If you are using a device, connect the device to the PC using a USB cable. You may
need to install the generic Google USB driver (from the Android SDK Manager, install
the Google USB Driver package from the Extras folder) or the driver that came with thedevice.
5. Define the application package name in the Run.bat file located in the
RIAModules\Android folder under the installation folder. To do this, open the file using
a text editor and change the value of the PackageName variable to your package
name, as it is defined in the settings.properties file. For example, when using the
MagicDev.apk, which is available in the RIAModules\Android folder, you can set thename to com.magicsoftware.magicdev.
To check if your PC can access your device, open the command prompt, navigate to the
RIAModules\Utils\ADB folder under the installation folder and execute the following
command: adb devices.
You should see your device in the devices list.

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The execution of the application on the Android device or simulator is done using the Android
Debug Bridge (ADB) utility. For more information about this utility, please see the Magic xpa

Help.
You can change the ADB commands by altering the Run.bat file located in the
RIAModules\Android folder under the installation folder.
If the server on which Magic xpa is running is not defined in DNS, the Android
mobile client will fail to access the Magic xpa server, since the device cannot
translate the machine name to the IP address and you will get the following error:"Unable to resolve host name". If you encounter this error, you need to set the full
URL with your machine's IP address in the HTTP Requester environment setting.
For example: http://192.168.0.111/MagicScripts/MGrqispi.dll.
Usually, when using the Genymotion simulator, you can define the following
value as the IP address: http://192.168.56.1/MagicScripts/MGrqispi.dll(192.168.56.1 is the default host IP address that the Genymotion VirtualBox
supplies).

Using Native OS Code in Mobile Apps
Magic xpa provides an excellent platform for developing mobile applications, but sometimes
you need features that are not provided out-of-the-box. You can add native OS code to a
Magic xpa application. The code must be in the native language of the device such as Java
for Android devices and Objective-C for iOS.
The installation of Magic xpa includes samples of using native OS code. The image below
shows you the Android folder where you can find the samples. There is a similar folder foriOS.

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You can use native OS code in your application in two ways:
Call from your Magic xpa application to native OS code
Raise a Magic xpa user event from the native OS code

1. Call from your Magic xpa application to native OS code
You can do this in your application by evaluating the ClientNativeCodeExecute function with
the name of the native code method and parameters.
So, for example, in the image below, the ClientNativeCodeExecute() function will execute theresize method in the ImageResize class in the mobile application code and pass it thearguments of filename, ratio, width and height.

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The native code for this function looks as follows:

Android
The ImageResize.java file located in the Rich Internet Samples\Android\ImageResize-src
folder:iOS
For iOS, although you are sending several different parameters to the method, you need todefine the called method with only one parameter of NSArray type. All of the Magic xpa
parameters are automatically set into this array. Then you can retrieve the parameters from thearray
The AppDelegate.mm file located in the RIAModules\iOS\Source\MagicApp folder:

Windows 10 Mobile
The ImageResize.java file located in the Rich Internet
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2. Raise a Magic xpa user event from the native OS code
You can then raise a Magic xpa event from your code that will handled in your Magic xpa
application. You do this by adding the following lines to your native code:

Android
1. Add the declaration: import com.magicsoftware.core.CoreApplication;
2. Raise the event:
CoreApplication.getInstance().invokeUserEvent(event_name,param1,param2); where
event_name is the user event name and param1 and param2 are the values that will
be passed to the user event handler.

iOS
1. Add the declaration: #import "Magicxpa.h"
2. Add an array that will hold all of the parameters’ values, ending with a nil value:
NSArray *params = [NSArray arrayWithObjects:param1, param2, nil]; whereparam1 and param2 are the values that will be passed to the user event handler.
3. Raise the event: [Magicxpa invokeUserEvent:event_name Params:params]; where
event_name is the user event name.

Windows 10 Mobile:
Raise the event: com.magicsoftware.richclient.CoreMethodInvoker.InvokeUserEvent(event_name,param1, param2); where event_name is the user event name and param1 and param2 are thevalues that will be passed to the user event handler.

Fonts
The Magic xpa mobile RIA client uses the same font table as other interfaces. Each device has
a set of available fonts that are usually different from the fonts found on a Windows desktop
and different from one another.
Since it is not possible to select mobile fonts using the Windows fonts dialog box, to enter
these fonts into the font table, you need to directly edit the fonts table file (such as fnt_rnt.eng)
using a text editor.
Here are some example font table entries:
Android Droid Serif font: Android font,Serif,14,0,0
Android Bold Droid Serif font: Android bold font,Serif,14,0,0,Bold
iOS Helvetica font: iOS font,Helvetica,14,0,0
iOS Helvetica font: iOS bold font,Helvetica-Bold,14,0,0

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If the font defined in the font table is not found on the mobile device, the default font will be
used with the size defined in the font table.
On Android devices you need to send the font family name and the style of the font you want.
The system will find a matching font for you. For example, to use a Droid Serif font use:
"Android Serif bold,Serif,12,0,0". You can see the font list in the System/Fonts folder in thedevice file system.

Specific Font files for each operating system
You learned that you can define specific forms for the different operating systems. You canalso maintain multiple different font files for each mobile platform so that you can give it anative look and feel. If you want a different set of fonts for each platform, create a separate
font file and put it in a subfolder with the name of the platform under the folder containing thedefined font file.
For example: If the runtime font file is Support\fnt_rnt.eng, then you can:Put the Android font file under Support\Android\fnt_rnt.eng.
Put the iOS font file under Support\iOS\fnt_rnt.eng.
At runtime, if it exists, the appropriate font file will be used automatically.
If you decide to use separate font entries for each device, you need to edit the fonts tablemanually using an external text editor such as Notepad. For example, Android uses a fontknown as Sans:
1.
2.
3.
4.

Open the Android fnt_rnt.eng file in a text editor.
Add the following line: Android Edit Labels,sans,8,0,0,Bold
Save the file.
Close the Getting Started project and reopen it so that the new font list will be
reloaded.
5. Zoom into the Select Customers program.
6. Zoom into the Form Designer and for the two column headers, select the new font.
Because the font is now bold, you need to increase the width.
7. Execute the project.

You will see that the label is now bold.

Adding a font manually
When you added the font manually, you added the line:
Android Edit Labels,sans,8,0,0,Bold to the Font list.
Each entry in the list is defined in the following way:

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The attributes are the Font Style and the Effects. The dialog box above will be translated to thefollowing entry in the Font list:

If you use different fonts for different devices, you will need to use an
expression for the font of a control. You can use the ClientOSEnvGetfunction in the expression:
IF (ClientOSEnvGet ('device_os')='android', '1','4')
You may decide that working with the CASE function will better suit
your application.

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SummaryIn this lesson you learned how to customize the environment to suit your own needs.
Remember that the steps to prepare your application are:
1. Create a cabinet file.
2. Prepare the icons and splash images.
3. Define the settings.properties file and the execution.properties file by using the builder
or by modifying them manually.
4. Define the DevProps.txt file to suit your environment.
5. Get a keystore file. Check this link for more details:
http://developer.android.com/tools/publishing/app-signing.html
6. Create the APK file.
7. Move the file to an IIS alias exposed folder, such as the scripts alias.
8. On your Android device, navigate to your browser and upload using the following
path: http://server_name/magic_scripts_alias/apkname.

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Customization and Installation

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Solutions

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Lesson 4 – Data Manipulation
The USA banks decided to give their clients a benefit. Each USA client will receive anadditional credit amount, which is 10 percent of the client’s salary.
1. In the Logic Editor, go to the Update Variable line and zoom into the With
column.
2. Find the line with the IF function,
which should look something like
this: IF(F,I*3,I*2).
3. To this IF function add thefollowing:+ IF(Trim(C)='USA',0.1*I,0)
Where C = Country and I =Salary_AmountYour expression should now look
like this:IF(F,I*3,I*2) + IF(Trim(C)='USA',0.1*I,0)To make your project friendlier, add a personal welcome announcement to the form.
4. Park on the form and press Ctrl+A. All of the controls on the form should now
be marked.
5. Unmark the controls above the Country field, by pressing the Ctrl button andclicking on each control.
6. Move the other controls down.Play around with the dragging until theplacement looks right to you.
7. From the Toolbox, drag an Edit control onto the form and place it beneath theCustomer_Name Edit control.

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You will now assign an expression to the Edit control that displays a concatenation of
the word 'Hello' and a trimmed Customer_Name.
1. Expand the new Edit control’s Data property zoom from the Expression line andopen a new line.
2. Enter the following expression. Make sure that there is one space between theword Hello and the customer name: 'Hello '&Trim(B)where B is the Customer_Name variable.
You will now move the Customer Address concatenated control that you added in the
Customer Address example during the lesson to below the Address Edit control.
3. Move the controls around to make room below the Address Edit control.
4. Drag the Customer Address concatenated control from the bottom of the form
and move it into place.
Add a validation to My First Program so that the end user will have to type in a
Customer_Code before continuing to the next control.
5. Add a Control Suffix logic unit to the Customer_Code control.
6. Add a Verify operation in Error mode that will check if the Customer_Code=0
and alert the end user.
Maintain the data consistency of the Membership_Date and Membership_Timevariables, so that if the date is changed, the time is cleared.
7. Add a Variable Change logic unit to the Membership_Date.
8. Within the Variable Change logic unit, add an Update operation that updates
the Membership_Time with 0.
Do not allow the cursor to park on the Membership_Time Edit control if theMembership_Date is empty. In Magic xpa, the default value of a date variable is'01/01/1901'Date, therefore:
9. In the Membership_Time Edit control’s Allow Parking property, set the following
expression: (Membership_Date<>'01/01/1901'Date).

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Lesson 5 – Initializing a Variable
You were asked to update the City variable to Melbourne only if the Country isAustralia.
1. In the Logic Editor, go to the Control Prefix logic unit for the City variable.
2. Add a condition for the Update where Country='Australia'.
If the country is Tartarus, then set the initial credit to zero.
3. Zoom into the Data View Editor.
4. Park on the Credit_Amount variable.
5. Zoom into the Init property and set the following expression:
IF (Country='Tartarus',0, Credit_Amount)

The Country variable is an Alpha field. This is case sensitive. This means that thevalues Tartarus, tartarus and TARTARUS are not the same.
You can check what the user entered by changing the value of the input to either all
upper case letters or all lower case letters. The Upper function changes all charactersto upper case.
6. Park on the expression you just entered,
IF (Country='Tartarus',0, Credit_Amount) and change it to:
IF (Upper (Country) ='TARTARUS',0, Credit_Amount)
This only changes the value within the IF function and does not affect the actual value.

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If the country is Xanadu and the customer has a gold membership, then you need to set
the initial credit to 1000. To do this you need to make some changes to the previous
expression:
7. Park on the expression you just entered,
IF (Upper (Country) ='TARTARUS',0, Credit_Amount)
The IF function’s syntax is IF (expression, THEN, ELSE). In the example you asked "If
the country is Tartarus then set the credit to zero." You did not take into account otherpossibilities, such as if the country is another specific value.
8. In the expression above, replace Credit_Amount with:
IF (Upper (Country) ='XANADU' AND Gold Membership,1000, Credit_Amount)

The expression will be more complex and will look like this:IF (Upper (Country) ='TARTARUS',0,IF (Upper (Country) ='XANADU' AND Gold Membership,1000, Credit_Amount))

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Lesson 6 – Setting the Form’s Appearance
Defining a new color for the Edit controls and name it Editable control:
1. From the Options menu, select Settings and then Colors.
2. Click the Application tab.
3. Park on the last color line. Create a line by pressing F4.
4. In the Name column, type: Editable control.
5. Zoom from the FG column.
6. Select the first (empty) entry from the System drop-down list.
7. Set the following RGB colors:a. Red = 0
b. Green = 90
c. Blue = 146.
8. Click OK.
9. Zoom from the BG column.
10. Select the first (empty) entry from the System drop-down list.
11. Check the Transparent check box.
12. Click OK.

Changing the Color and Font of all Edit controls:
1. Select all of the Edit controls on the form.
2. Change the Color of the controls to Editable control.
3. Change the Font of the controls to Text.
In order for the color and font files to be specific for this project, you will now copy thecolor and font file to your project directory and set the color and font files in the
Application properties using a logical name.

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Making the Color and Font Files Application SpecificUsing the Windows Explorer navigator:
1. In your Project (Getting Started) directory, make sure that you have the env
folder. This should be where the Wallpaper.jpg image is found.
2. From the Support directory (located in the Magic xpa installation directory),
copy the clr_rnt.eng and the fnt_rnt.eng files to the Env directory that you justcreated.
Setting the Color and Font Files in the Application Properties
3. Open the Getting Started project.
4. From the File menu, selectApplication Properties(Ctrl+Shift+P).
5. Click on the External Files tab.
6. In the Application Color Definition
file property, type:%WorkingDir%env\clr_rnt.eng
7. In the Application Font Definition
file property, type:%WorkingDir%env\fnt_rnt.eng
8. Zoom into each definition to check
whether it displays the font and color file that you created.

You will not see any changes in your project. However, from now on, all changes thatyou make to the color or the font files, will apply to the files belonging to your projectand not to the generic files in the Support directory.

Placement
Defining the placement of Membership_Date, Membership_Time, Salary_Amount, andCredit_Amount so that they move together with the Gold_Membership:
1. Select all the Edit controls of Membership_Date, Membership_Time,
Salary_Amount and Credit_Amount together with the Label controls.
2. Zoom into the control property sheet.
3. In the Navigation section, zoom into the Placement property.
4. Set only the Y property (the one at the top). The property will be set to
0,0,100,0.

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Defining the Customer_Name, welcome customer and Address controls so that theirwidth increases as the form increases but they remain in place:
5. Select the Edit controls of Customer_Name, Address and the Hello Customer
control, but not their Label controls.
6. Zoom into the control property sheet.
7. In the Navigation section, zoom into the Placement property.
8. Set only the Width property (the one at the bottom). The property will be set to
0,100, 0,0.
9. Execute the program.
AndroidiOS

As you can see, you now have a similar look and feel for both environments.

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Lesson 7 – Viewing Data Source Content
Increasing the table size as the form increases:
1. Zoom into Customers - Line Mode program and zoom into the Form Designer.
2. Park on the Table control and open the control property sheet.
3. Click on the Placement property and then click the Zoom button.
4. Set the value of 100 in the Height property. Click OK.
5. The Placement property will show: 0, 0,0,100.
When you run the program, you will now see all of the records:

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Suppliers Program
Now, you will define the Suppliers data source.
1. From the Project menu, select Data (Shift+F2) to open the Data repository.
2. Create a line.
3. In the Name column, type Suppliers.
4. In the Data source name column, type Suppliers.
5. From the Database column, zoom to the Database list, and select the Getting
Started entry.
Defining columns:
6. Click the Columns tab in the lower pane.
7. Define column entries for the items exactly as shown in the image below:

8. Define a unique index called Supplier_Code with a segment for the
Supplier_Code column.

Defining the Program
Now you will define the program that will display the suppliers in a table:
1. Create a program and name it: Suppliers - Line Mode.
2. Use the Suppliers data source as the program’s Main Source.
3. Select all of the Suppliers data source columns.

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Define the Suppliers - Line Mode form as follows:
4. Provide wallpaper for the form. Set the Wallpaper property to:%WorkingDir%env\Wallpaper.jpg.
5. Add a Table control to the form. Set the following properties for the table:
a. Set the Set Table Color property to Table.
b. Set the Color property to Text color.
c. Set the Row Highlight Color property to the Row Highlight color.
6. Attach the Supplier_Code and Supplier_Name variables to the Table control.
7. Set the Color property to Edit control.
8. Click on the column header of the Supplier_Code column and zoom into thecontrol property sheet.
9. Set the Column title property to Code.
10. Park on the Color property and select the Text Caption color.
11. Park on the Font property and select the Text Caption font.
12. Click on the column header of the Supplier_Name column and zoom into thecontrol property sheet.
13. Park on the Color property and select the Text Caption color.
14. Park on the Font property and select the Text Caption font.
When you run the program, it will look similar to the image below:

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Lesson 8 – Models – Object Definition Centralization
Defining Models
Now you will create models for the Customers and Suppliers data sources.
Add the following models for the data sources and set the parameters as shown in
the table below.

Name

Class Attribute Model Properties

Country

Field

Alpha

Picture: 20

City

Field

Alpha

Picture: 20

Address

Field

Alpha

Picture: 20

Gold_Membership

Field

Logical

A Logical field attribute has adefault picture (5 digits).

Amount

Field

Numeric

Picture: 12.2C

Phone_Number

Field

Alpha

Picture: ###-#######

Years_Since_Start_Working

Field

Numeric

Picture: 2

Bonus

Field

Numeric

Picture:3.2

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Assigning a Field Model to a Column
1. Review the Assigning a Field Model to a Column section in this lesson.
2. Assign models to all of the remaining Customers and Suppliers data sourcecolumns.
3. Park on a column and open its properties (Alt+Enter).
4. From the Model property, zoom and select the model shown in the image
below.
5. From the Picture property, click the Inherit
button.
6. Verify that the button displays
after you click the button.
Customers data source:

Suppliers data source:

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Assigning a Model to a Control
Follow the example from the Assigning a Model to a Control section.
1. Open the Customers - Screen Mode task’s form.
2. Assign the Edit control model to all of the Edit controls.
3. Park on the Color property for each of the Edit controls and inherit the model’s
properties.

Defining the Display Only Model
You will now define the model for a Display Only Edit control:
1. From the Project menu, select Models (Shift+F1).
2. Create a line.
3.
4.
5.
6.
7.
8.

In the Name column, type: Display Only.
From the Class column, select Rich Client Display.
From the Attribute column, select Edit.
Open the control properties sheet.
In the Appearance section, set the Border property to No.
Zoom from the Color property and set the color to Text Caption.

Defining Models for Tables
You will now define the models for the various sections of a table:
1. From the Project menu, select Models (Shift+F1).
2.
3.
4.
5.
6.
7.

Create a line.
In the Name column, type: Table.
From the Class column, select Rich Client Display.
From the Attribute column, select Table.
Open the control properties sheet.
In the Appearance section, set the Set Table Color property to by Table. You
will see that the Color property above it is now accessible.
8. Zoom from the Color property and select the Text color.
9. Zoom from the Row Highlight Color and select the color you definedpreviously, Row Highlight.
10. Click on the Placement property and then click the Zoom button.
11. Set the value of 100 in the Height property. Click OK.
The Placement property will show: 0, 0,0,100.

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Defining the column header:
12. Create a line.
13. In the Name column, type: Column Heading.
14. From the Class column, select Rich Client Display.
15. From the Attribute column, select Column.
16. Set the Color property to Text Caption.
17. Set the Font property to Text Caption.
Now you need to set the name and code models so that when they are placed in a
Rich Client table, they have specific properties:
18. In the Model repository, park on the Codemodel.
19. Zoom into the properties.
20. In the Style section, park on the Rich Client
table property and click the Zoom
button. This opens a property sheet for an
Edit control.
21. Set the Border property to No.
22. Set the Color property to Edit Control.
23. Repeat steps 18 to 22 for the Name model.

Now you need to apply the models:
1.
2.
3.
4.
5.

Zoom into the Program repository.
Zoom into the Customers - Line Mode and zoom into the Form Designer.
Park on the table and zoom into the control properties.
In the Model property, zoom into the models and select Table.
Inherit the properties for Set Table Color, Color, Row Highlight Color andPlacement.
6. Open the Customer Code column properties.
7. In the Model property, zoom into the models and select Column.
8. Inherit the properties for Color and Font.
9. Repeat steps 6 to 8 for the Customer_Name and the Gold_Membershipcolumns.
10. Park on the Customer_Code Edit control and inherit the property for Border andColor.
11. Park on the Customer_Name Edit control and inherit the property for Borderand Color.

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Lesson 10 – Events and Handlers
During the lesson you raised the Set Gold Membership event but there was no handler
for it:
1.
2.
3.
4.

Zoom into the Customers - Screen Mode program.
Zoom into the Logic Editor.
Create a header line (Ctrl+H) and select Event.
In the Event dialog box, select User and then select Set Gold Membership fromthe list of User events.
5. Add a detail line and Update the Gold_Membership variable with True.
6. Add a detail line and Update the Credit_Amount variable with the value
Credit_Amount*1.2.
You were asked to enable the end user to delete a customer.
1.
2.
3.
4.

Zoom into the Customers - Line Mode program.
Zoom into the Form Designer.
Place a Button control at the top of the form.
Zoom into the control properties.

5. Park on the Format property and remove the text which is initially Button.
6. Park on the Button style property and select Image Button from the combo box.
7. Park on the Image List file name property and type
%WorkingDir%\images\Delete.png.
8. From the Event Type property, select Internal.
9. From the Event property, select Delete Line.
10. Set the Color to Text Caption. This will make the button transparent for images
that have a transparent color.
11. From the toolbar, click the Fit Control Size
icon.

Now you will create the handler for this:
1.
2.
3.
4.
5.
6.

Zoom into the Logic Editor.
Create a header line (Ctrl+H) and select Event.
In the Event dialog box, select Internal and then select Delete Line.
Set the Propagate property to Yes.
Add a detail line and select Raise Event.
In the Event dialog box, select Internal and then select Close from the list.

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This means that the program will close when you delete a line. However, you were
only asked to do this if the program was called from the Customers - Line Mode
program. In this case you know that the P.Customer Code parameter has a value:
7. Zoom from the Cnd property and enter the following expression:
P.Customer Code > 0
You were asked to add a button to allow the user to add a customer. As with themodify record situation, this involves both the calling program and the called program.
1. Zoom into the Customers - Line Mode program.
2. Zoom into the User Events repository by pressing CTRL+U.
3. Add a line and set the name to Add Customer.
4. Set the Trigger type to None.
5. Zoom into the Form Designer.
6. Place a Button control at the top of the form.
7. Zoom into the control properties.
8. Park on the Format property and remove the text, which is initially Button.
9. Park on the Button style property and select Image Button from the combo box.
10. Park on the Image List file name property and type
%WorkingDir%\images\Add.png.
11. From the Event Type property, select User.
12. From the Event property, select Add Customer.
13. Set the Color to Text Caption.
14. Click the Fit Control Size icon.
Your form will look similar to the following image.

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15. Zoom into the Logic Editor.
16. Create a header line (Ctrl+H) and select Event.
17. In the Event dialog box, select User and then select Add Customer.
18. Create a detail line for the Call Program operation.
19. Select the Customers - Screen Mode program from the list.
Since you are adding a new customer, you do not need to send the customer code asa parameter to the Customers - Screen Mode program. However, that program expects
parameters and if you use syntax checking, F8, on the Customers - Line Mode
program, you will get an error.
20. From the Arguments field, zoom to the Arguments repository.
21. Create a line and check the Skip box. In this case, when the customer code ispassed to the called program, it will be passed as zero.
Now you need to handle the "create" situation in the Customers - Screen Mode
program. Remember that the program is opened in Modify mode and in the current
scenario, the P.Customer Code value is zero. You need to open the task in Create
mode. How do you open the same task in Modify mode in one scenario and in Createmode in another scenario? By using a parameter, of course.
22. Zoom into the Customers - Screen Mode program.
23. Park on the first line, the Main Source definition, and create a line.
24. From the drop-drown list, select Parameter.
25. You are now parked in a field displaying ??. Type in P.Create Mode?.
26. Set the Picture to Logical.
27. Open the Task Properties dialog box by pressing CTRL+P.
28. In the Initial mode property, select By Exp.
29. Zoom from the Exp: box to the right of the Initial Mode.
30. In the Expression Editor, add an expression: IF (P.Create Mode?, 'C', 'M')
This means that if True is passed in the P.Create Mode parameter, the task will
be in Create mode and if not it will be in Modify mode.
A better method of doing this would be to use the MODE literal. Your expression willthen be: IF (P.Create Mode?, 'C'MODE, 'M'MODE).
Now you need to call the program with the new parameter:
1. Zoom into the Customers - Line Mode program.
2. Zoom into the Add Customer logic unit.
3. Zoom into the Call Program detail line.
4. From the Arguments field, zoom to the Arguments repository.
5. Create a line as the first line, meaning before the line where you checked theSkip box.

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6. Zoom from the Exp column and add the following expression: 'TRUE'LOG.

7. Add a detail line after the Call Program operation.
8. Select the Raise Event operation from the drop-down list.
9. In the Event dialog box, from the Event Type drop-down list, select Internal.
10. From the Event field, select the View Refresh event and click OK.
You added a parameter as the first parameter in the Customers - Screen Mode
program. However, you called this same program from another handler, the Modify
Records handler. You need to make a change there.
11. Zoom into the Modify Records handler.
12. Zoom into the Call Program detail line.
13. From the Arguments field, zoom to the Arguments repository.
14. Create a line as the first line, meaning before the line where you passed theCustomer Code to the called program.
In this case, you can either zoom from the Exp column and add an expression,'FALSE'LOG, or you can check the Skip box.
15. Check the Skip box.
You can now execute the application.

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Lesson 11 – Conditioning a Block of Operations
You were asked to update the Credit_Amount value according to the following logic
when adding a new customer:
For all customers whose Salary_Amount is more than 8000:
For customers who do not have Gold Membership, the Credit_Amountvalue will be updated with the Salary_Amount*2.
For customers who have Gold Membership, the Credit_Amount value will
be updated with the Salary_Amount*3.
If the Salary_Amount is more than 1000, but less than 8000, update theCredit_Amount with the Salary_Amount.
If the Salary_Amount is less than 1000, update the Credit_Amount with 50% of the
Salary_Amount.
In this solution, you will do this in a Variable Change logic unit for the Salary_Amount.
You can do this in a Record Suffix logical unit with no changes to the actual code. The
advantage to the user for doing this in the Variable Change logic unit is that the user
can see the change to the Credit_Amount and make manual changes as well.
1. Zoom into the Customers - Screen Mode program and zoom into the Logic
Editor.
2. Zoom into the Variable Change logic unit for the Salary_Amount.
3. Add a detail line after the Raise Event for Set Gold Membership.
4. Add a Block If operation and set the condition to: Stat (0,'C'MODE).
This will return True if the program is in Create mode.
5. Add a nested Block If operation and set the condition to: Salary_Amount >8000.
6. Add a detail line and set an Update operation for the Credit_Amount variable.
7. Zoom from the With property and add an expression:
IF (Gold_Membership, Salary_Amount *3, Salary_Amount *2)
Remember that when dealing with a logical data type, you only need to use thename of the variable; you do not need to add Gold_Membership = 'True'LOG.
8. Add a Block Else operation and set the condition to:
Salary_Amount > 1000 AND Salary_Amount <= 8000

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9. Add a detail line and set an Update operation for the Credit_Amount variable.
10. Zoom from the With property and add an expression for Salary_Amount.
11. Add another Block Else operation and set the condition to:
Salary_Amount <= 1000
12. Add a detail line and set an Update operation for the Credit_Amount variable.
13. Zoom from the With property and add the following expression:
Salary_Amount * 0.5.

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Lesson 12 – One-to-One Data Relationships
Orders ScenarioFirst you will make the changes to the Orders scenario.
1. Zoom into the Orders program.
2. Add two parameters:a. P.Task Mode, which will be an Alpha parameter, one character in length. Thiscan hold Q for Query, C for Create or M for Modify.
b. P.Order Number, a numeric parameter of size 6.
3. Park on the Order Number column of the Orders data source and zoom into
the Range From property.
4. Set the following expression:
CndRange (P.Order Number > 0, P.Order Number)If you execute the Orders program directly, the first order will always be
displayed.
5. Enter the same expression for the Range To property.

6. Open the Task Properties dialog box and from the Initial mode property, selectBy Exp.
7. Zoom into the Exp field and define an expression.

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There are a few ways to define the expression for the Initial mode.
Simply use the parameter. Since P.Task Mode will contain C, for example, you cansimply use that. This is problematic when using a multilingual system because Q is
Query in English but in German it may be A for Abfrage.
Use the IF function. You can do this as follows:
IF (P.Task Mode = 'C','C'MODE, IF (P.Task Mode = 'M','M'MODE, 'Q'MODE))
Use the CASE function. You have not learned this function in this course. You canread about it in the Magic xpa Help. When using the CASE function, the function
will be:CASE (A,'C','C'MODE,'M','M'MODE, 'Q'MODE)
You were also asked to set the current date as the initial date when you are creating a
new order. This is a simple request. You use the Init property. For a Column variable,
the Init property is evaluated only when the program is in Create mode:
8. Park on the Order_Date variable. Zoom into the Init property and set thefollowing expression: Date ().
You were asked to add a button so that the user could delete the order if the programis in Modify mode.
9. Zoom into the Form Designer.
10. Place a Button control at the top of the form.
11. Zoom into the control properties.
12. Park on the Format property and remove the text, which is initially Button.
13. Park on the Button style property and select Image Button from the combo box.
14. Park on the Image List file name property and type:%WorkingDir%\images\Delete.png
15. From the Event Type property, select Internal.
16. From the Event property, select Delete Line.
17. Set the Color to Text Caption. This will make the button transparent for images
that have a transparent color.
18. Park on the Visible property and set the following condition: Stat (0,'M'MODE).
19. From the toolbar, click the Fit Conrol Size
icon.

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Now you will create the handler for this:
1.
2.
3.
4.
5.
6.

Zoom into the Logic Editor.
Create a header line (Ctrl+H) and select Event.
From the Event dialog box, select Internal and then select Delete Line.
Set the Propagate property to Yes.
Add a detail line and select Raise Event.
From the Event dialog box, select Internal and then select Close from the list.

This means that the program will close when you delete a line.

Now you need to create the List of Orders program that displays the list of orders:
1. Create a program and name it List of Orders. Remember to set the Public name
2.
3.
4.
5.
6.
7.

to RunMe and to check the External box.
Zoom to the List of Orders program.
From the Task Properties dialog box, set the Task type to Rich Client.
Set the Initial Mode to Query.
Open the Data View Editor of the Orders program.
Create a Main Source definition for the Orders data source and use theOrder_Number index.
Add the following columns from the Orders data source:
Order_Number
Order_Date
Customer_Code

8. Create a header line and from the comb box, select Link Query.
9. Select the Customers data source.
10. Zoom from the Index property and select the first index. The Customer_Code isadded automatically.
11. In the column’s Locate from and Locate to properties, zoom and select theCustomer_Code field from the Orders data source.
12. Add a line and select the Customer_Name column.
Since the List of Orders program is a display only program, there is no need to add alink success indication.

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Define the Suppliers - Line Mode form as follows:
1. Zoom into the form properties and select the Table Display Form model.
2. Zoom into the Form Designer.
3. Drop a Table control onto the form. Zoom into the control properties and selectthe Table mode.
4. Attach the Order Number to the Table control. Zoom into the control properties
and select the Edit Control model.
5. Open the Order_Number column properties.
6. Select the Column Header model.
7. Set the Column title property to Number.
8. Attach the Order Date to the Table control. Zoom into the control properties
and select the Edit Control model.
9. Open the Order_Date column properties.
10. Select the Column Header model.
11. Attach the Customer Name to the Table control. This is already connected to
the Edit Control property.
12. Open the Customer Name column properties.
13. Select the Column Header model.
14. Increase the width of the table so that all three columns are visible.
15. Increase the height of the table.
You now need to add the buttons for Add and Modify. To do this you need to add
User events:
1.
2.
3.
4.
5.
6.
7.
8.

Zoom into the User Events repository by pressing CTRL+U.
Add a line and set the name to New Order.
Set the Trigger type to None.
Add a line and set the name to Change Order.
Set the Trigger type to None.
Zoom into the Form Designer.
Place a Button control at the top of the form.
Zoom into the control properties.

9. Park on the Format property and remove the text, which is initially Button.
10. Park on the Button style property and select Image Button from the combo box.
11. Park on the Image List file name property and type
%WorkingDir%\images\Add.png.
12. From the Event Type property, select User.
13. From the Event property,select New Order.
14. Set the Color to Text Caption.
15. Click the Fit to Size icon.

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16. Place a Button control at the top of the form, to the right of the Add button.
17. Zoom into the control properties.
18. Park on the Format property andremove the text, which is initially
Button.
19. Park on the Button style property andselect Image Button from the combobox.
20. Park on the Image List file nameproperty and type
%WorkingDir%\images\Edit.png.
21. From the Event Type property, selectUser.
22. From the Eventproperty, select Change Order.
23. Set the Color to Text Caption.
24. Click the Fit Control Size icon.
Now you need to handle the events:
1.
2.
3.
4.
5.
6.

Zoom into the Logic Editor.
Add a header line and select the New Order User event.
Create a detail line for the Call Program operation.
Select the Orders program from the list.
Zoom from the Arguments property.
In the Arguments dialog box:

a. Add a line with the expression: 'C'. You are entering in Create mode.
b. Add another line and check the Skip box. Since this is Create mode,
there is no need to pass an order.
7. Add a detail line and raise the View Refresh internal event.
8. Add a header line and select the Change Order User event.
9. Create a detail line for the Call Program operation.
10. Select the Orders program from the list.
11. Zoom from the Arguments property.
12. In the Arguments dialog box:
a. Add a line with the expression: 'M'. You are entering in Modify mode.
b. Add another line, zoom from the Variable list and select the Order Number.
13. Add a detail line and raise the View Refresh internal event.

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Now you will handle the case where the user taps an order in the list. This raises theinternal event Click.
14. Add a header line and select the Click internal event.
15. Create a detail line for the Call Program operation.
16. Select the Orders program from the list.
17. Zoom from the Arguments property.
18. In the Arguments dialog box:
c. Add a line with the expression: 'Q'. You are entering in Query mode.
d. Add another line, zoom from the Variable list and select the Order
Number.
19. Add a detail line and raise the View Refresh internal event.
If you execute the application and then tap the Add push button, Magic xpa will raise
the New Order event and will display the Orders program in Create mode, but it will
also raise the Click event. This is because tapping raises the Click event. You need tohandle this event only when the tap is made on a control on the table.
20. Park on the header line for the Click internal event.
21. Zoom from the on: property and select the Order Number control.
22. Repeat steps 14 to 21 for the Order Date control.
23. Repeat steps 14 to 21 for the Customer Name control.

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Products Scenario
In the following exercise you will define the Products data source. Then, you will create
the Products program to display the products. You will use the Link operation to extend
the data view and display the supplier details. Finally, you will use the Link Successindication property to check the validity of the Supplier_Code value.

Defining the Products Data Source
1.
2.
3.
4.
5.

In the Data repository, create a line.
In both the Name and Data source name column, type: Products.
From the Database column, zoom and select Getting Started.
Click on the Columns tab.
Press F4 for each of the columns and define the following columns:

Name

Model

AttributePictureProduct_Code

Code

Numeric

5

Product_Name

0

Alpha

60

Description

0

Alpha

100

Supplier_Code

Code

Numeric

9

Product_Price0

Numeric

6.2

Stock_Quantity

0

Numeric

6

6. Click the Indexes tab.
7. Create a line (press F4).
8. In the Name column, type ProductCode. Check that the Type is set to Unique.
9. In the Name column, type SupplierCode. Check that the Type is set to Unique.
10. From the ProductCode index, zoom (F5) to the Segment repository.
11. Create a line and press F5.
12. Select the ProductCode. Check that the number 1 now appears in the Column
column.
13. Define two index segments for the SupplierCode index.
a. Press F4, and then press F5 to select the Supplier_Code.
b. Press F4, and then press F5 to select the Product_Code.

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Before continuing, you need to add data to the Products data source. The explanation
for this is in the Exercise section of the lesson.

Creating the Products Program
Create the Products program according to the following steps:
1.
2.
3.
4.
5.

Set the Task type to Rich Client.
Set the Initial Mode to Query.
Define the Products data source as the program’s Main Source.
Select all of the Products data source columns.
Add a Link Query operation to the Suppliers data source using the
Supplier_Code index.
6. Select the following additional columns: Supplier_Name and Phone_Number.
7. From the Supplier_Code column, set the Supplier_Code (from the Products data
source) as the Locate From and Locate To expressions.

Defining the Products Form
1. Set the form’s model to Table Display Form.
2. Place all of the Products data source columns on the form, as well as the
Supplier_Name (to the right of the Supplier Code) and the Phone_Number fromthe Suppliers data source.
3. Attach all Label controls to the Text Caption model.
You can mark all of them by continuously pressing the Ctrl button and clicking
on each Label control. Then, go to the Model property and select the Text
Caption model.
4. Right-click on the Font property for each of the Label controls and select Inherit.
5. Fit the size of the Label controls to the displayed text.
6. Move the Edit controls to a position in which the Label controls are fully
displayed.
7. Attach all Edit controls from the Products data source to the Edit Control model.

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8. Attach all Edit controls from the Suppliers data source to the Display only
model.

Now you need to define placement for the variables.
9. Select the following controls, both Label and Edit: Product Price, Stock
Quantity, and Supplier Code. Select also the Supplier Name and the Supplier
Number.
10. Zoom into the control properties. Zoom into the Placement property and enter
100 in the Y property.

The Placement value will be: 0,0,100,0.
The controls’ Product Name and Description both need to increase in height andwidth. Because the controls are displayed one underneath the other, they both have toshare the increase in height. They both will then increase only 50%.
11. Select the Product_Name Edit control and zoom into the control properties.

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12. Zoom into the Placement property and enter 100 in the Width property andenter 50 in the Height property. The Placement value will be: 0,100,0,50.
13. Select the Description Label control and zoom into the control properties.
14. Zoom into the Placement property. As the Product_Name increases in height by
50%, the Description must move downwards by 50%. Enter 50 in the Y
property. The Placement value will be: 0,0,50, 0.
15. Select the Description Edit control and zoom into the control properties.
This must move downwards in the same way as its Label control moved. It also
increases in height by 50%.
16. Zoom into the Placement property and enter 100 in the Width property andenter 50 in the Height property.
17. Enter 50 in the Y property. The Placement value will be: 0,100,50,50.
This program will be called from a program that you will create soon; therefore youneed to create a parameter.
18. Zoom into the Data View Editor.
19. Add a parameter named P.Product Code, which will be based on the model
for Code.
20. Park on the Product code column of the Products data source and zoom into theRange From property. Set the following expression:
CndRange (P.Product code > 0, P.Product Code).
21. Enter the same expression for the Range To property.
You will now add the button enabling you to edit the product:
1. Place a Button control at the top of the form.
2. Zoom into the control properties.
3. Park on the Format property and remove the text, which is initially Button.
4. Park on the Button style property and select Image Button from the combo box.
5. Park on the Image List file name property and type
%WorkingDir%\images\Edit.png.
6. From the Event Type property, select Internal.
7. From the Event property, select Modify Records.
8. Set the Color to Text Caption. This will make the button transparent for images
that have a transparent color.
9. Click the Fit Conrol Size

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icon.

382

Now you need to create the All Products program. This is a simple program and you
have created many similar programs.
1. Create the All Products program.
2. Zoom into the All Products program and in the Task Properties dialog box, set
the Task type to Rich Client.
3. Set the Initial Mode to Query.
4. Define the Products data source as the program’s Main Source.
5. Select the Product_Code and the Product_Name columns.
Now you will define the form:
1. Zoom into the Form Designer.
2. Set the form’s model to Table Display Form.
3. Drop a Table control onto the form and set the model to Table.
4. Increase the size of the table so that it fills the default form:

5. Drop the Product_Name variable onto the table. The variable is too big to fit on
the table:

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6. Decrease the width of the Edit control so that it fits in the table. There will still
be a horizontal scrollbar.
7. Set the Model to Edit control.
8. Open the Column properties.
9. Set the Model to Column Header.
10. You need to manually decrease the Width property of the column so that it fits
in the table. Enter the same width as the Edit control, approximately 68 units.
The Table control is defined so that it increases only in height. You need to increase it
horizontally as well:
11. Park on the Table control and zoom into the control properties.
12. Zoom into the Placement property and enter 100 in the Width property.

Now, when the user taps a row in the table, you need to call the Products program.
Remember that a tap raises the Click internal event.
1.
2.
3.
4.
5.
6.
7.

Zoom into the Logic Editor.
Add a header line and select the Click internal event.
Zoom from the on: property and select the Product Name control.
Create a Details line for the Call Program operation.
Select the Products program from the list.
Zoom from the Arguments property.
In the Arguments dialog box add a line, zoom from the Variable List and selectthe Product Code variable.

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Lesson 13 – Selecting Data from a List
The following exercise summarizes what you learned in this lesson.
First you will create the two models:
1. Zoom into the Model repository.
2. Create a line and in the Name column, type: Browse button.
3. From the Class column, select Rich Client Display.
4. From the Attribute column, select Push button.
5. Zoom into the Model properties.
6. Park on the Format style and type … (three dots).
7. Zoom into the Raise Event property and the Event dialog box opens.
8. In the Event type combo box, select Internal
9. Zoom into the Event List and select the Zoom event.
10. Create a line and in the Name column, type: Image button.
11. From the Class column, select Rich Client Display.
12. From the Attribute column, select Push button.
13. Park on the Format property and remove the text, which is initially Button.
14. Park on the Button style property and select Image Button from the combo box.
15. Park on the Image List file name property and type
%WorkingDir%\images\Edit.png.
16. Zoom into the Raise Event property and the Event dialog box opens.
17. In the Event type combo box, select Internal.
18. Zoom into the Event list and select Zoom.
19. Set the Color to Text Caption.
This will make the button transparent for images that have a transparent color.

Add an Image to the Products Program
You will now add an image to the Products program:
1. Zoom into the Products program.
2. Zoom into the Form Designer.
3. Move the Supplier details downwards and move
the Stock Quantity below the Product Price tomake way for the Image control as shown in theimage on the right.

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4. From the Toolbox, select the Image control.
5. Place the Image control on the form next to the Product_Price.
6. Open the Image Properties.
7. Expand the Data property, zoom
from the Expression line and create
an expression:'%WorkingDir%'&'products\'&Trim(Product_Name)&'.jpg'
8. From the Style property, select No
Border.
9. From the Color property, select Text
Caption. This is to ensure that theimage is transparent on the
background.
10. From the Image style property, select Scaled to Fit.

Take into account that you previously defined placement for the other controls. In thiscase you would want the image to move together with the product price.
11. Zoom into the Placement property and set 100 in the Y property.
What changes would you make if you wanted the width and height of the image toincrease along with the form? Hint: You will also need to make changes to othercontrols as well.

Creating the Products Selection List
This selection list will be similar to the other selection list but you will also display theimage in the table.
1. In the Program repository, create a program named Select Products.
2. From the Task type property, select Rich Client.
3. From the Initial mode property, select Query.
4. From the Selection table property, select Yes.
5. In the Data View Editor, set the Main Source to Products. Use the Product_Codeindex.
6. Add a parameter, P.Product Code, and attach it to the Code model.
7. Add the Product_Code and the Product_Name columns from the Products data
source.
8. Set the P.Product Code parameter as the Locate from property expression for
the Product_Code.

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9. In the Logic Editor, create a header line and set the logic unit type to Record.
Set the Level to Suffix.
10. Add an Update operation in which you update the P.Product Code parameterwith the Product_Code.
Now you will define the Products selection list’s form.
1.
2.
3.
4.

Open the Form Editor.
Attach the form to the Table Display Form model.
Zoom to the form.
Drop the Table control on the form. Set the Model property to Table.

5. Increase the width of the table so that it fills the form width as shown in theimage below:

6. Select the Customer_Name variable and place it on the table. Select the Edit
control model.
7. Since the width of the control is too wide for the table, you need to decrease it.
Set the Width property to 62.
8. Press Alt+Click on the Customer_Name column and select the Column Heading
model. Set the Width property to 62.
Now you are going to add the image to the table:
9. From the Toolobx, drop the Image control on the table.
10. Open the Image Properties.
11. Expand the Data property, zoom from the Expression line and create an
expression: '%WorkingDir%'&'products\'&Trim(Product_Name)&'.jpg'
Magic xpa searches for images relative to the working directory. Therefore you canalso define the expression as: '\products\'&Trim(Product_Name)&'.jpg'. Duringruntime, Magic xpa copies the images to the cache of the device.
12. From the Style property, select No Border.
13. From the Color property, select Text Caption.
14. From the Image style property, select Scaled to Fit.

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The image needs to be a thumbnail, so you can decrease the width and height:
15. Set the Width property to 5.
16. Set the Height property to 1.5.
17. Press Alt+Click on the Image column and select the Column Heading model.
Set the Width property to 5.
18. Increase the height of the table to the end of the form.
You may find that after adding the image to the form, the form property’s row heightwas changed. If that happens, zoom into the Table properties and set the Row Heightproperty to 1.875.

Adding a Select Button
As was mentioned before, the unique behavior of a Selection List program is achieved
when the internal Select event is raised.
1. Place a Button control at the top of the form.
2. Zoom into the control properties. Set the Model to the new Image button modelthat you defined.
3.
4.
5.
6.

Park on the Image List file name property and change the image to OK.png.
From the Event Type property, select Internal.
From the Event property, select Select.
Click the Fit Command Size
icon.

Adding the Exit Button
Add the exit button.
1. Place a Button control at the top of the form.
2. Zoom into the control properties. Set the Model to the new Image button modelthat you defined.
3.
4.
5.
6.

Park on the Image List file name property and change the image to Exit.png.
From the Event Type property, select Internal.
From the Event property, select Exit.
Click the Fit Control Size
icon.

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The form will look similar to the image below.

Since the image is small, you can decide whether to add functionality so that when theuser taps a row, the Products program is called.

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Lesson 14 – One-to-Many Data Relationships
Countries and cities have a one-to-many data relationship. Each country can have
many cities.
Now you will practice what you learned so far, by creating a program that displays alist of countries and their related cities.

Defining the Country&City Code Model
1.
2.
3.
4.
5.
6.

Open the Model repository.
Create a line.
In the Name column, type: Country&City CodeIn the Attribute column, select Numeric.
In the property sheet, set the Picture to 6.
In the Style node, park on the Rich Client table property. This is the property
that governs the look and feel of this variable when it is dropped on a table.

7. Click the Zoom
button. This opens a control property sheet.
8. Set the Model to Edit Control.

Defining the Countries Data Source
1.
2.
3.
4.

In the Data repository, create a line.
In the Name and Data source name columns, type: Countries.
In the Database column, zoom to select Getting Started.
From the Options menu, select Get Definition.

The definition of the Countries data source has now been successfully imported.
5. In the Column repository, park on the Country_Code.
6. Zoom from the Model column and select the Country&City Code model.
7. Re-inherit the Picture property.

Defining the Cities Data Source
1. In the Data repository, create a line.
2. In the Name and Data source name columns, type: Cities.
3. In the Database column, zoom to select Getting Started.
4. Use the Get Definition utility to import the definition of the Cities data source.
5. Set the Country_Code’s model property to the Country&City Code model andre-inherit the Picture property.
6. Set the City_Code’s model property to the Country&City Code model and reinherit the Picture property.

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Creating the Countries Program
1. Open the Program repository.
2. Create a line and name the program: Countries.
3. Zoom into the program.
4. Define the Task type as Rich Client.
5. Set the Initial mode to Query.
6. Set the Main Source to Countries.
7. Set the Main Source index to Country_Code.
8. Create a line and select all of the Countries columns (2 columns).

Designing the Countries Form
1. Open the Form Editor. Set the Model to Table Display Form.
2. Zoom to the Countries form.
3. Add a Table control. Set the Model to Table.
4. Add the Country_Code variable to the table.
5. Click on the column and open the control properties.
6. Set the Model to Column Header.
7. Set the Column Title property to Code.
8. Set the Width to 9.5.
9. Drop the Country_Name variable on to the table.
10. Set the Model to Edit control.
11. Set the Width to 40.
12. Click on the column and open the control properties.
13. Set the Model to Column Header.
14. Set the Column Title property to Country.
15. Set the Width to 41.
16. Increase the width of the table so that there is no horizontal scrollbar.
17. Increase the height of the table to fill the form.

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391

Creating the Cities Subtask:
1.
2.
3.
4.

From the Navigator pane, park on the Countries task and create a subtask.
In the Task name property, type: Cities.
Define the Task type as Rich Client.
Set the Initial Mode to Query.

In the Data View Editor:
1. Create a line.
2. Create a P.Country_Code parameter with the Country&City Code model.
3. Set the Main Source to Cities.
4. Set the Main Source index to Country_and_City.
5. Create a line and select all of the Cities columns.
6. Park on the Country_Code column (of the Cities data source) definition line.
7. In the Range from and To properties, set the Country_Code parameter.
8. Open the Form Editor.
9. Park on the Cities form.
10. Open the Form Properties and set the Model to Table Display Form.
11. Remove the expression in the Wallpaper property.
12. Set the Color property to Text caption.
13. Zoom to the Cities form.
14. Add a Table control. Set the Model to Table.
15. Add the City_Code variable to the table.
16. Click on the column and open the control properties.
17. Set the Model to Column Header.
18. Set the Column Title property to Code.
19. Set the Width to 9.5.
20. Drop the City_Name variable on to the table.
21. Set the Model to Edit control.
22. Set the Width to 33.
23. Click on the column and open the control properties.
24. Set the Model to Column Header.
25. Set the Column Title property to City.
26. Set the Width to 34.
27. Increase the width of the table so that there is no horizontal scrollbar.
28. Increase the height of the table to fill the form.
Designing the Countries Form
1. Using the Navigation pane, navigate to the Countries task.
2. Open the Form Designer.
3. Add a Subform control to the form.

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4.
5.
6.
7.
8.
9.

Open the Subform Control Properties.
From the Connect to property, select SubTask.
From the PRG/TSK num property, select the Cities subtask.
Zoom from the Arguments property and select the Country_Code column.
Increase the Subform control so that it fits the form.
Close the program and save the changes.

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Lesson 16 – Reports
You were asked to print a single invoice from the List of Orders program.
To print a specific invoice, you need to pass the order number as an argument.
1. Zoom to the Invoice program.
2. In the Data View Editor, park on the first line and create a Parameter line.
3. Type in the name P.Order_Number and set the parameter type to Numeric andset the Picture to 6.
4. Park on the Order_Number column in the Orders data source.
5. From the Range entry, zoom to the Expression Editor and create an expression
for the P.Order_Number parameter.
6. Type the same expression for the To entry.
7. Close the program and save the changes.

Creating the Print Event
In the List of Orders program, you will add the Print handler. The Print event handler
will call the Invoice program and pass the Order_Number as a parameter.
1. Zoom to the List of Orders program.
2. Add a Virtual variable named PDF Name with an attribute of Alpha and alength of 255.
3. Open the Logic Editor.
4. Park on the last line in the editor.
5.
6.
7.
8.

Create an Event logic unit for the Print event.
Zoom to the Event dialog box.
From the Event type property, select User.
From the Event property, zoom and select the Print event.

9. Park on the Event line and create a line.
10. Set the Call Program operation to call the Invoice program.
11. From the Arguments entry, zoom to the Argument repository and create a line.
12. Zoom from the Var column and pass the Order_Number column from the
Variable list.
13. Add a detail line and update the PDF Name variable with the expression:ServerFileToClient('%TempDir%Invoice.pdf')
14. Add a detail line and call the Display PDF program.
15. Zoom into the Argument repository and add a line.
16. Zoom into the Var column and select the PDF Name variable.

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17. Open the Form Editor and zoom to the form.
18. From the Models pane, drag the Image button model and drop it on thetable.
19. Open the control property sheet and change the image file name to Print.png.
20. From the Raise Event property, select User from the Event type field and selectthe Print user event that you defined in the Main Program.
21. Click the Fit Control Size icon.
You can now run the application and view the results. Remember that this is valid for
iOS and Desktop.
You were asked to create a Suppliers List report in the same way that you created theCustomers List report.
1. In the Program repository, create a program: Print Suppliers.
2.
3.
4.
5.
6.

Zoom (F5) to the program. The Task Properties dialog box will open.
In the Task type property, select Batch.
Set the Initial mode to Query.
Click OK.
In the Data View Editor, set the Suppliers data source as the task’s Main
Source.
7. Select the Suppliers data source’s columns: Supplier_code, Supplier_Name,
Address, Phone_Number, in that order.
8. From the Task menu, select I/O Devices (Ctrl+I).
9. Add a line and define a printer named Print Suppliers.
10. In the Exp/Var column, zoom and set the following expression:'%TempDir%SupplierList.pdf'
11. Open the Form Editor.
12. Define the forms 3-7 as shown in the image below:

13. For each form use the GUI Print Form model.

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Page Header Form
1. Drop an image on the form and set the name to%WorkingDir%images\Print_Logo.jpg.
2. Set the Image style to Scaled to Fit.
3. Set the Width of the image to 17.4.
4. Set the Height to 3.
5. Remember to use Center Horizontally and Center Vertically.

Header Form
1. Drop a Text control on the form and set the text to Suppliers List.
2. Set the Font to Report Header.
3. Set the Color to Report Header.

Print Suppliers Form
1.
2.
3.
4.

Zoom to the Print - Supplier form.
From the Control palette, select a Table control and place it on the form.
Change the Height property to 1.
Select the following variables, one by one, from the Variable palette and placethem on the Table control: Supplier_Code, Supplier_Name, Address andPhone_Number.
5. For each column:
a. Press Alt+Click on the column field.
b. In the Column properties (Alt+Enter), from the Font property, zoom and selectthe Text Caption font.
c. For the Supplier_Code column, change the title to Code.
d. For the Phone_Number column, change the title to Phone.

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e. In the Color property, zoom and select the Text Caption color.

Footer Form
1. From the Control palette, select an Edit control and place it on the form.
2. Open the Edit control properties and from the Data property, enter a new
expression: 'Total Number of Suppliers: '&Trim(Str(Counter(0),'6'))
3. In the Format property, type: 40.
4. In the Font and Color properties, select Text Caption.
5. Park on the Edit control and move the control to the left.
6. In the Command palette, click the Fit Size ( ) command icon.
7. Click the Vertical center of form ( ) command icon. This will center the Edit
control on the form

The Page Footer Form
1. Drop an image on the form and set the name to%WorkingDir%images\Print_Footer.jpg.
2. Set the Image style to Scaled to Fit.
3. Set the Width of the image to 18.76.
4. Set the Height to 1.67.
Remember to use Center Horizontally and Vertically.

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Printing the Forms
1. In the Logic Editor, from the Task Prefix logic unit, print the Header form.
2. From the Record Suffix logic unit, print the Print Suppliers form.
3. From the Task Suffix logic unit, print the Footer form.
4. From the Task menu, select I/O Devices (Ctrl+I).
5. Open the Print Suppliers I/O properties (Alt+Enter).
6. In the Page Header form property, set the Page Header form (#3).
7. In the Page Footer form property, set the Page Footer form (#7).
8. In the PDF property, select Yes.
9. Click OK.
10. Close the program and save the changes.
You need to call the Print Suppliers program from the Suppliers - Line Mode program
as you did during the lesson.
In this course you are defining reports for a few programs each with its own Print
handler. Instead of defining the handler in each program, you can define it in theMain Program. The definition will then be available for all the programs.
1. Zoom to the Suppliers - Line Mode program.
2. Add a Virtual variable named PDF Name with an attribute of Alpha and alength of 255.
3. Open the Form Editor and zoom to the form.
4. From the Control palette, select the Push Button control and drop it on the form.
Select the Image button model.
5. Open the control property sheet and change the image file name to Print.png.
6. From the Raise Event property, select User from the Event type field and selectthe Print user event that you defined in the Main Program.
7. Use the Fit to Size icon on the palette.
8. Zoom into the Logic Editor.
9. Add a header line for the Print User event.
10. Add a detail line and call the Print - Suppliers program.
11. Add a detail line and update the PDF Name variable with the expression:ServerFileToClient('%TempDir%SupplierList.pdf')
12. Add a detail line and call the Display PDF program.
13. Zoom into the Argument repository and add a line. Zoom into the Var column
and select the PDF Name variable.

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You can now run the application and view the results. Remember that this is valid for
iOS and Desktop.

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Lesson 17 – Processing Data by Groups
You were asked to create a report that displayed each supplier and a list of its
products. You will use the Group logic unit.
1. Create a program: Print Products by Supplier.
2. In the Task Properties dialog box, from the Task type property, select Batch.
3. In the Initial mode property, select Query.
4. Define the data view in the same way as the image below:

Solutions400Creating the Task Forms
Use the image below as a guideline for setting the task forms. You have created similar
forms in the last two lessons:

1. The Page Header form and the Page Footer forms are the same as previous
reports.
2. Set the Supplier Header form to a height of 1cm.
3. In the Supplier Header form, place an Edit control with the expression:'Product list for: '&Trim(Supplier_Name)
4. Set the Format property to 44.
5. Set the Font property to Report Header.
6. Set the Color property to Report Header.
7. Set the Product List form to a height of 2.2cm.
8. Zoom to the Product List form.
9. From the Control palette, select a Table control and place it on the form
10. Select the Product_Code, Product_Name, Product_Price and Stock_Quantity
variables and place them on the Table control.
11. Mark the Product_Code column and set the Color to Text Caption and the Font
to Text Caption.
12. Set the Column Title property to Code.
13. Mark all of the other columns and set the Color to Text Caption and the Font to
Text Caption.
14. Mark the Product_Price column and set the Column Title property to Price.
15. Mark the Stock_Quantity column and set the Column Title property to Stock.

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16. Set the Supplier Footer form to a height of 2cm.
17. Zoom into the Supplier Footer form and place an Edit control with theexpression:'Total number of products for '&Trim (Supplier Name)&': '&Trim(Str(J,' Total
num_Products'))
18. Set the Format to 60.
19. Set the Font property to Text Caption.
20. Set the Color property to Text Caption.

Defining the I/O Device
1. From the Task menu, select I/O Devices (Ctrl+I).
2. Add a line and set the Name to Products by Supplier.
3. From the Exp/Var column, zoom and set the following expression:'%TempDir%SupplierProductList.pdf'
4. Open the I/O Properties dialog box.
5. From the Page header form property, zoom to the Form list and select the Page
Header form.
6. From the Page footer form property, zoom to the Form list and select the Page
Footer form.
7. Set the PDF property to Yes.

Defining the Task Logic
1. Open the Logic Editor and create a header line.
2. Set a Group Prefix logic unit for the Supplier_Code variable (from the Products
data source).
3. Add a Form Output detail operation and print the Supplier Header form.
You were asked to print each new supplier on a new page:
4. Zoom into the properties of the Form operationand select Top from the Page property. This will
print this form at the top of each page.
5. Add an Update Variable detail operation andupdate the Total Number of Products variablewith zero.
Now you will print out the detail form for each product in the group. In addition, youneed to increase the counter variable value by one, for each city in the group.
6. Create a Record Suffix logic unit.
7. Add a Form Output detail operation and print the Product List form.

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8. Add an Update Variable detail operation and update the Total Number of
Products variable with Total Number of Products +1. This increases the counterof the number of products.
Now you need to print the footer showing how many products there are for that
supplier. This is performed in the Group Suffix logic unit.
9. Create a Group Suffix logic unit for the Supplier_Code variable.
10. Add a Form Output detail operation and print the Supplier Footer form
You can now run the program.

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Lesson 20 – Offline Implementation
You are asked to implement the situation where the client updates the server.
1. Zoom into the Offline Countries program that you created in this lesson.
2. Add a Rich Client subtask and name it Add Country. Uncheck the Offline box.
3. Set the Initial mode to Create.
4. Select Local Countries as the Main source and select all three records.
5. Add a Virtual variable named Last synchronization timestamp and link it to theTimestamp model. You will use this for the synchronization.
6. Zoom into the Logic Editor and add a Record Suffix logic unit.
7. Add an Update Variable operation and update the Last Modified variable withthe following expression: DStr (Date (),'YYYYMMDD')&TStr (Time(),'HHMMSS')This will create a string concatenating the date and time.
8. Add a User event named Submit Country to Server. Set the Force Exit property
to Post record update.
By using Post Record Update, the engine first writes the modified record to the
database and then executes the logic units of the triggered event.
9. Zoom into the form and display only the Country_Code and the Country_Namevariables. You can use the Pop Up form property to True.
10. Add a Button control to the form named Submit to Server, which raises the User
event named Submit Country to Server.
Now you will update the calling program, the Offline Countries, so that it will call the
Add Country subtask.
1. Return to the Offline Countries program and add a User event named Add
Country.
2. Zoom into the Logic Editor and add an Event logic unit for the Add Country
User event.
3. In the Add Country logic unit, call the Add Country subtask.
4. Raise the View Refresh internal event.
5. Zoom into the Form Designer and place a Button control at the top of the form.
6. Zoom into the control properties. Set the Model to the Image button model.
7. Park on the Image List file name property and change the image to Add.png.
8. From the Event Type property, select User.
9. From the Event property, select Add Customer.
10. Click the Fit Control Size
icon.

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The Offline Countries program is an Offline program and needs the program images
so that they can be displayed. As you learned in the lesson, these need to be copied tothe client:
1. Zoom into the Start program.
2. Park on the Block If line and add a line after it. Within the block, it does notmatter where you add the line.
3. Add an Evaluate Expression operation and use the expression:ServerFileToClient('%WorkingDir%images')

Synchronization logic
You now need to recreate the logic that you used in the Start program. You learned
that synchronizing data from the server to the client involved the following steps:
Fetch the last timestamp that a successful synchronization was performed.
Use the DataViewToDataSource function to synchronize the data according to thetimestamp.
Update the timestamp with the current date and time.
You will now create the program that performs the synchronization:
1. Zoom into the Program repository and create a program named Sync Countries
from client.
2. Set the Task type to Rich Client.
3. Uncheck the Interactive box to make this a non-interactive task.
4. Set the End task condition to Yes.
5. Set the Evaluate condition to Before entering record.
6. Zoom into the task and select Local Countries as the Main source.
7. Select all of the fields from the Local Countries data source.
8. Add a Parameter named P.Last Sync with a model of Timestamp.
9. Park on the Last modified column, zoom into the Range from property, and set
the expression: P.Last Sync. This ranges all of the entries since the lastsynchronization.
10. Zoom into the Logic Editor and add a Task Suffix logic unit.
11. Add an Evaluate Expression operation:
DataViewToDataSource (0, 'Country_Code,Country_Name,Last
Modified','6'DSOURCE, '','')'6'DSOURCE is the Countries data source

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Now you need to call this program from the Main Program because Offline programs
cannot call server programs.
1. Zoom into the Main Program.
2. Zoom into the Logic Editor and then zoom into the Sync countries logic unit.
3. Add a line and use a Call operation to call the Sync countries from client
program.
4. Zoom into the Arguments property, add a line and select the P.Current
Timestamp parameter.
5. Set the condition on the line to Not (P.Sync from Server?).
Now you need to retrieve the last timestamp and call the synchronization program:
1. Zoom into the Offline Countries program and zoom into the Add Country
subtask.
2. Add a subtask named Fetch last sync data and uncheck the Interactive box.
3. Set the End task condition to Yes and the Evaluate condition to After updatingrecord.
4. Zoom into the Data View Editor and set the Main source to the Local synctable.
5. Select all of the columns from this table.
6. Add a Record Suffix logic unit, add an Update operation and update the Last
synchronization timestamp variable from the parent task with the Last Modified
Country column from this subtask.
You will now add the update subtask of the last successful timestamp.
1. Return to the Add Country subtask.
2. Add a subtask named Update last sync data and uncheck the Interactive box.
3. Set the End task condition to Yes and the Evaluate condition to After updatingrecord.
4. Zoom into the Data View Editor and add a Link Write operation to the Local
sync table. Remember that with a Link Write operation, if no record exists, onewill be added. In the course example, there is already a record in the table.
5. Select the Idx column and set an expression with the value 1 for the Locatefrom and Locate to columns. Use the same expression for the Init expression.
6. Add the Last Modified Country column as well.
7. Add a Record Suffix logic unit, add an Update operation and update the Last
Modified Country column with the Last synchronization timestamp variable fromthe parent task.

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You are now ready to use the methodology.
1. Return to the Add Country subtask.
2. Zoom into the Logic Editor and add an event logic unit for the Submit Country
to Server event.
3. Add a Block If operation and set the expression to ServerLastAccessStatus()=0.
This means that if there is a problem with the server, the Block operation will beignored.
4. Add a line and define a Call operation that calls the Fetch last sync datasubtask.
5. Add a Raise Event operation and select the Sync countries User event.
6. Zoom into the Arguments property, add a line and select the Last
synchronization timestamp variable to match the P.Current Timestamp
parameter.
7. Add a second line, zoom into the Exp column and create an expression ofFalse to match the P.Sync from Server parameter. This means that the logic unit
in the Main Program will handle the event and call the Sync Data from Client
program.
If you have a situation in which you have multiple client devices, then the server table
may also have been updated. You can also add a call to sync the client data from theserver:8. Add a Raise Event operation and select the Sync countries User event.
9. Zoom into the Arguments property, add a line and select the Last
synchronization timestamp variable to match the P.Current Timestamp
parameter.
10. Add a second line, zoom into the Exp column and create an expression of
TRUE to match the P.Sync from Server parameter.
11. Add an Update Variable operation and update the Last synchronization
timestamp variable with the following expression: DStr (Date(),'YYYYMMDD')&TStr (Time(),'HHMMSS')This will create a string concatenating the date and time.
12. Add a Call operation after the Update operation that updates the Last
synchronization timestamp variable and call the Update last sync data subtask.
13. After the Block End operation, add a line and raise the Exit internal event.

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Remember that when you clicked the Submit to Server button, there may not have been
server access and as a result, the server was not updated with the client data. As aresult, you could also perform a client to server synchronization in the Start program
process.
1. Zoom into the Start program.
2. Park on the line with the Raise Event operation for the Sync countries and add
a line after it.
3. Add a Raise Event operation and select the Sync countries User event.
4. Zoom into the Arguments property, add a line and select the Last Country
timestamp variable to match the P.Current Timestamp parameter.
5. Add a second line, zoom into the Exp column and create an expression for
FALSE to match the P.Sync from Server parameter.
You can now execute the Start program and from the Offline Countries program, add
Mexico as country number 25.

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