Patent Publication Number: US-7908562-B2

Title: System and a method for presenting items to a user with a contextual presentation

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related by subject matter to the inventions disclosed in the following commonly assigned applications: U.S. patent application Ser. No. 10/646,941, filed on Aug. 21, 2003, entitled “SYSTEMS AND METHODS FOR SEPARATING UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM FROM THEIR PHYSICAL ORGANIZATION”; U.S. patent application Ser. No. 10/646,940, filed on Aug. 21, 2003, entitled “SYSTEMS AND METHODS FOR THE IMPLEMENTATION OF A BASE SCHEMA FOR ORGANIZING UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM”; U.S. patent application Ser. No. 10/646,632, filed on Aug. 21, 2003, entitled “SYSTEMS AND METHODS FOR THE IMPLEMENTATION OF A CORE SCHEMA FOR PROVIDING A TOP-LEVEL STRUCTURE FOR ORGANIZING UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM”; U.S. patent application Ser. No. 10/647,058, filed on Aug. 21, 2003, entitled “SYSTEMS AND METHOD FOR REPRESENTING RELATIONSHIPS BETWEEN UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM”; U.S. patent application Ser. No. 10/646,575, filed on Aug. 21, 2003, entitled “SYSTEMS AND METHODS FOR INTERFACING APPLICATION PROGRAMS WITH AN ITEM-BASED STORAGE PLATFORM”; U.S. patent application Ser. No. 10/646,646, filed on Aug. 21, 2003, entitled “STORAGE PLATFORM FOR ORGANIZING, SEARCHING, AND SHARING DATA”; U.S. patent application Ser. No. 10/646,580, filed on Aug. 21, 2003, entitled “SYSTEMS AND METHODS FOR DATA MODELING IN AN ITEM-BASED STORAGE PLATFORM”; U.S. patent application Ser. No. 10/691,886, filed on even date herewith, entitled “SYSTEM AND METHOD FOR THE PRESENTATION OF ITEMS STORED ON A COMPUTER”; U.S. patent application Ser. No. 10/691,888, filed on even date herewith, entitled “SYSTEM AND A METHOD FOR PRESENTING RELATED ITEMS TO A USER.” 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     TECHNICAL FIELD 
     The present invention relates generally to the field of computer software. More particularly, the present invention relates to a system and method for displaying items stored on a computer to a user. 
     BACKGROUND OF THE INVENTION 
     Providing users of computers with the ability to quickly find and display a piece of information, no matter what the information&#39;s format or location, is a challenge that the computer industry has struggled with for many years. Today this problem is more salient then ever as increasing numbers of individuals utilize computers in their daily routines and as the types of information stored on a computer continues to diversify. 
     Traditionally, as in Microsoft Corporation&#39;s WINDOWS® 98™, this stored information is kept within a data store on the computer in a hierarchical fashion organized with files of information or media stored within folders. While this method of data storage has been widely used for many years, it is limited in that some data resides outside of the file hierarchy and users are constrained to format and locational limitations when searching for desired pieces of information. Accordingly, providers of computer software are currently working on data storage alternatives to the traditional file hierarchy. 
     An example of such a data storage alternative is disclosed in the commonly owned, co-pending application “SYSTEM AND METHODS FOR REPRESENTING UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM BUT INDEPENDENT OF PHYSICAL REPRESENTATION”, U.S. patent application Ser. No. 10/647,058. This co-pending application was filed on Aug. 21, 2003 and discloses a data store that unifies storage into a single database. This database is the one place where all the data is stored; there is only one way to represent data to the database and only one way to query for data. By replacing antiquated file systems with this modern database technology, the data store will be easily searchable, more reliable, more accessible, and more resilient. 
     Once this unified data store is in place, there becomes a need to provide users with the appropriate tools and capabilities to interact with the stored data. Conventional operating systems, such as Microsoft Corporation&#39;s WINDOWS® 2000™, include a shell utility that provides a user interface for viewing various information about the computer. The shell typically includes a file system browser which enables users to navigate through the file system and locate and open files and folders. For example, Microsoft Corporation&#39;s WINDOWS® EXPLORER™ is a file system browser utility included with WINDOWS® 2000™. 
     The shell also enables users to view non-file items such as printers or fonts. This navigation is possible because a typical shell is programmed with the specific functionality to display these special items as if they were located in the file system. For example, in WINDOWS® 2000™, a user may open a “Printers” folder located within the Settings option on the Start Menu. Because printers are pieces of hardware and not files, this graphical representation of the printers is accomplished through utilization of custom code directed at displaying the printers as if they were files residing in the “Printers” folder. However, the use of custom code and custom drawing exceptions is complex for developers to implement, can be unreliable, and reduces the resiliency of the shell browser. Furthermore, if no custom code or custom drawing exceptions are in place for a type of data, the shell will be unable to display items of that type. Accordingly, conventional shells are limited in capabilities and in flexibility when displaying certain items to a user. 
     Another limitation of conventional shell browsers is a restricted ability to display items in a relational manner. Typically a shell browser is operable to display items only in the hierarchical fashion in which they are stored—organized within files stored within folders. For example, if a user desires to view all the picture files stored on a computer, that user must first place all such picture files in the same folder. Because the shell has limited capacity to determine relationships between items, it is difficult for a user to view files in a relationship driven context. 
     Furthermore, conventional shell browsers are limited in their ability to display sets of items within a contextually tailored environment that pairs pertinent information and tasks with the set of displayed items. Developers, by providing such pairings, can provide users with the appropriate information and tools needed to navigate among the items while facilitating the performance of commons tasks associated with the items. The prior art, however, does not allow developers to provide such experiences without the use of custom code. 
     An example of files presented in an enhanced environment through the utilization of custom code is the My Pictures folder which is included in Microsoft Corporation&#39;s WINDOWS® XP™ operating system. When image files are stored in the My Pictures folder, a user can view images at different sizes, rotate them, view a slide show, print images, or copy images to a CD. The shell in WINDOWS®XP™ has utilized custom code to incorporate these image-related tasks into this folder&#39;s display so that a user, when choosing to store pictures in this particular folder, will easily be able to navigate among the pictures and to perform common tasks with respect to the files. However, only files stored in the My Pictures folder are displayed in this environment, and custom code is utilized to create this functionality. While the My Pictures folder is an improvement over traditional presentation of items, developers still have limited ability to define such content-rich environments without utilizing custom code. 
     Accordingly, there is a need for an improved shell that is capable of displaying each item within a universal data store, and further, there is a need for an improved shell that is configured to present items within a universal data store in a relationship driven context. There is also a need for improved capabilities within the shell for developers to create custom environments that display items with appropriate contextual information and related tasks without needing custom code. 
     SUMMARY OF THE INVENTION 
     The present invention meets the above needs and overcomes one or more deficiencies in the prior art by providing a system to present items stored in a data store to a user with a contextual presentation. In one aspect of the present invention, a computer system is provided which includes a data store. At least a portion of the items in the data store include one or more field entries. An explorer is included which interacts with the data store, selects items having one or more desired field entries, and displays the selected items according to an explorer display schema. 
     Another aspect of the present invention includes a computer-implemented method for presenting items to a user with a contextual presentation. A desired field entry corresponding to a field entry associated with at least one item in the data store is selected. An explorer display schema is defined. The method accesses the data store to select one or more items including the desired field entry and displays the one or more selected items according to the explorer display schema. 
     A further aspect of the present invention includes an explorer for presenting a plurality of items. The explorer includes a field entry selection component which selects a desired field entry. An item selection component accesses the data store to select one or more items having the desired field entry, and a display presentation component presents the selected items to the user. 
     A still further aspect of the present invention provides an application program for presenting items to a user. The program includes an item selection module configured to access a data store and select items having a desired field entry. The program also includes a shell interaction component configured to interact with a shell browser to present selected items according to an explorer display schema. 
     Another aspect of the present invention is a computer-implemented method for establishing an explorer for presenting items with a contextual presentation. The method includes selecting a desired field entry corresponding to a field entry associated with at least one item in the data store. Explorer attributes are defined, and one or more items associated with the desired field entry are presented to the user with a display schema including the explorer attributes. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The present invention is described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is a block diagram of a computing system environment suitable for use in implementing the present invention; 
         FIG. 2A  is a block diagram illustrating a computer system divided into three component groups: the hardware component, the hardware/software interface system component, and the application programs component; 
         FIG. 2B  illustrates the traditional tree-based hierarchical structure for files grouped in folders in a directory in a file-based operating system; 
         FIG. 3  is a block diagram illustrating a storage platform in accordance with the present invention; 
         FIG. 4  illustrates the structural relationship between Items, Item Folders, and Categories in various embodiments of the present invention; 
         FIG. 5  is a diagram of the data contained within an item according to one embodiment of the present invention; 
         FIG. 6  is a flow diagram showing a method for presenting one or more items to a user in accordance with one embodiment of the present invention; 
         FIG. 7  is a flow diagram showing a method for presenting one or more items to a user in accordance with one embodiment of the present invention; 
         FIG. 8  is a diagram showing a view schema hierarchy in accordance with one embodiment of the present invention; 
         FIG. 9  is a diagram showing a view schema hierarchy including an explorer view schema in accordance with one embodiment of the present invention; 
         FIG. 10  is a flow diagram showing a method for presenting items to a user in accordance with one embodiment of the present invention; and 
         FIG. 11  and  FIG. 12  are flow diagrams showing methods for presenting related items to a user in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     I. Introduction 
     The subject matter of the present invention is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. Moreover, although the term “step” may be used herein to connote different elements of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. 
     The present invention provides an improved system and method for displaying items stored on a computer to a user. An exemplary operating environment for the present invention is described below. 
     A. Exemplary Operating Environment 
     Numerous embodiments of the present invention may execute on a computer.  FIG. 1  and the following discussion is intended to provide a brief general description of a suitable computing environment in which the invention may be implemented. Although not required, various aspects of the invention may be described in the general context of computer executable instructions, such as program modules, being executed by a computer, such as a client workstation or a server. Generally, program modules include routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types. Moreover, the invention may be practiced with other computer system configurations, including hand held devices, multi processor systems, microprocessor based or programmable consumer electronics, network PCs, minicomputers, mainframe computers and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. 
     As shown in  FIG. 1 , an exemplary general purpose computing system includes a conventional personal computer  20  or the like, including a processing unit  21 , a system memory  22 , and a system bus  23  that couples various system components including the system memory to the processing unit  21 . The system bus  23  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM)  24  and random access memory (RAM)  25 . A basic input/output system  26  (BIOS), containing the basic routines that help to transfer information between elements within the personal computer  20 , such as during start up, is stored in ROM  24 . The personal computer  20  may further include a hard disk drive  27  for reading from and writing to a hard disk, not shown, a magnetic disk drive  28  for reading from or writing to a removable magnetic disk  29 , and an optical disk drive  30  for reading from or writing to a removable optical disk  31  such as a CD ROM or other optical media. The hard disk drive  27 , magnetic disk drive  28 , and optical disk drive  30  are connected to the system bus  23  by a hard disk drive interface  32 , a magnetic disk drive interface  33 , and an optical drive interface  34 , respectively. The drives and their associated computer readable media provide non volatile storage of computer readable instructions, data structures, program modules and other data for the personal computer  20 . Although the exemplary environment described herein employs a hard disk, a removable magnetic disk  29  and a removable optical disk  31 , it should be appreciated by those skilled in the art that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs) and the like may also be used in the exemplary operating environment. Likewise, the exemplary environment may also include many types of monitoring devices such as heat sensors and security or fire alarm systems, and other sources of information. 
     A number of program modules may be stored on the hard disk, magnetic disk  29 , optical disk  31 , ROM  24  or RAM  25 , including an operating system  35 , one or more application programs  36 , other program modules  37  and program data  38 . A user may enter commands and information into the personal computer  20  through input devices such as a keyboard  40  and pointing device  42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite disk, scanner or the like. These and other input devices are often connected to the processing unit  21  through a serial port interface  46  that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port or universal serial bus (USB). A monitor  47  or other type of display device is also connected to the system bus  23  via an interface, such as a video adapter  48 . In addition to the monitor  47 , personal computers typically include other peripheral output devices (not shown), such as speakers and printers. The exemplary system of  FIG. 1  also includes a host adapter  55 , Small Computer System Interface (SCSI) bus  56 , and an external storage device  62  connected to the SCSI bus  56 . 
     The personal computer  20  may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer  49 . The remote computer  49  may be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the personal computer  20 , although only a memory storage device  50  has been illustrated in  FIG. 1 . The logical connections depicted in  FIG. 1  include a local area network (LAN)  51  and a wide area network (WAN)  52 . Such networking environments are commonplace in offices, enterprise wide computer networks, intranets and the Internet. 
     When used in a LAN networking environment, the personal computer  20  is connected to the LAN  51  through a network interface or adapter  53 . When used in a WAN networking environment, the personal computer  20  typically includes a modem  54  or other means for establishing communications over the wide area network  52 , such as the Internet. The modem  54 , which may be internal or external, is connected to the system bus  23  via the serial port interface  46 . In a networked environment, program modules depicted relative to the personal computer  20 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. 
     As illustrated in the block diagram of  FIG. 2A , a computer system  200  can be roughly divided into three component groups: the hardware component  202 , the hardware/software interface system component  204 , and the applications programs component  206  (also referred to as the “user component” or “software component” in certain contexts herein). 
     In various embodiments of a computer system  200 , and referring back to  FIG. 1 , the hardware component  202  may comprise the central processing unit (CPU)  21 , the memory (both ROM  24  and RAM  25 ), the basic input/output system (BIOS)  26 , and various input/output (I/O) devices such as a keyboard  40 , a mouse  42 , a monitor  47 , and/or a printer (not shown), among other things. The hardware component  202  comprises the basic physical infrastructure for the computer system  200 . 
     The applications programs component  206  comprises various software programs including but not limited to compilers, database systems, word processors, business programs, videogames, and so forth. Application programs provide the means by which computer resources are utilized to solve problems, provide solutions, and process data for various users (machines, other computer systems, and/or end-users). 
     The hardware/software interface system component  204  comprises (and, in some embodiments, may solely consist of) an operating system that itself comprises, in most cases, a shell and a kernel. An “operating system” (OS) is a special program that acts as an intermediary between application programs and computer hardware. The hardware/software interface system component  204  may also comprise a virtual machine manager (VMM), a Common Language Runtime (CLR) or its functional equivalent, a Java Virtual Machine (JVM) or its functional equivalent, or other such software components in the place of or in addition to the operating system in a computer system. The purpose of a hardware/software interface system is to provide an environment in which a user can execute application programs. The goal of any hardware/software interface system is to make the computer system convenient to use, as well as utilize the computer hardware in an efficient manner. 
     The hardware/software interface system is generally loaded into a computer system at startup and thereafter manages all of the application programs in the computer system. The application programs interact with the hardware/software interface system by requesting services via an application program interface (API). Some application programs enable end-users to interact with the hardware/software interface system via a user interface such as a command language or a graphical user interface (GUI). 
     A hardware/software interface system traditionally performs a variety of services for applications. In a multitasking hardware/software interface system where multiple programs may be running at the same time, the hardware/software interface system determines which applications should run in what order and how much time should be allowed for each application before switching to another application for a turn. The hardware/software interface system also manages the sharing of internal memory among multiple applications, and handles input and output to and from attached hardware devices such as hard disks, printers, and dial-up ports. The hardware/software interface system also sends messages to each application (and, in certain case, to the end-user) regarding the status of operations and any errors that may have occurred. The hardware/software interface system can also offload the management of batch jobs (e.g., printing) so that the initiating application is freed from this work and can resume other processing and/or operations. On computers that can provide parallel processing, a hardware/software interface system also manages dividing a program so that it runs on more than one processor at a time. 
     A hardware/software interface system shell (simply referred to herein as a “shell”) is an interactive end-user interface to a hardware/software interface system. (A shell may also be referred to as a “command interpreter” or, in an operating system, as an “operating system shell”). A shell is the outer layer of a hardware/software interface system that is directly accessible by application programs and/or end-users. A “shell browser” provides a user interface allowing a user to view and to interact with the hardware/software interface. In contrast to a shell, a kernel is a hardware/software interface system&#39;s innermost layer that interacts directly with the hardware components. 
     While it is envisioned that numerous embodiments of the present invention are particularly well-suited for computerized systems, nothing in this document is intended to limit the invention to such embodiments. On the contrary, as used herein the term “computer system” is intended to encompass any and all devices capable of storing and processing information and/or capable of using the stored information to control the behavior or execution of the device itself, regardless of whether such devices are electronic, mechanical, logical, or virtual in nature. 
     B. Traditional File Based Storage 
     In most computer systems today, “files” are units of storable information that may include the hardware/software interface system as well as application programs, data sets, and so forth. In all modern hardware/software interface systems (Windows, Unix, Linux, Mac OS, virtual machine systems, and so forth), files are the basic discrete (storable and retrievable) units of information (e.g., data, programs, and so forth) that can be manipulated by the hardware/software interface system. Groups of files are generally organized in “folders.” In Microsoft Windows, the Macintosh OS, and other hardware/software interface systems, a folder is a collection of files that can be retrieved, moved, and otherwise manipulated as single units of information. These folders, in turn, are organized in a tree-based hierarchical arrangement called a “directory” (discussed in more detail herein below). In certain other hardware/software interface systems, such as DOS, z/OS and most Unix-based operating systems, the terms “directory” and/or “folder” are interchangeable, and early Apple computer systems (e.g., the Apple IIe) used the term “catalog” instead of directory; however, as used herein, all of these terms are deemed to be synonymous and interchangeable and are intended to further include all other equivalent terms for and references to hierarchical information storage structures and their folder and file components. 
     Traditionally, a directory (a.k.a. a directory of folders) is a tree-based hierarchical structure wherein files are grouped into folders and folder, in turn, are arranged according to relative nodal locations that comprise the directory tree. For example, as illustrated in  FIG. 2B , a DOS-based file system base folder (or “root directory”)  212  may comprise a plurality of folders  214 , each of which may further comprise additional folders (as “subfolders” of that particular folder)  216 , and each of these may also comprise additional folders  218  ad infinitum. Each of these folders may have one or more files  220  although, at the hardware/software interface system level, the individual files in a folder have nothing in common other than their location in the tree hierarchy. Not surprisingly, this approach of organizing files into folder hierarchies indirectly reflects the physical organization of typical storage media used to store these files (e.g., hard disks, floppy disks, CD-ROMs, etc.). 
     In addition to the foregoing, each folder is a container for its subfolders and its files—that is, each folder owns its subfolders and files. For example, when a folder is deleted by the hardware/software interface system, that folder&#39;s subfolders and files are also deleted (which, in the case of each subfolder, further includes its own subfolders and files recursively). Likewise, each file is generally owned by only one folder and, although a file can be copied and the copy located in a different folder, a copy of a file is itself a distinct and separate unit that has no direct connection to the original (e.g., changes to the original file are not mirrored in the copy file at the hardware/software interface system level). In this regard, files and folders are therefore characteristically “physical” in nature because folders are the treated like physical containers, and files are treated as discrete and separate physical elements inside these containers. 
     II. A Universal Data Store 
     The storage platform utilized by the present invention extends and broadens the data platform beyond the kinds of existing file systems discussed above, and is designed to be a store for all types of data. A data store designed to store all types of data may be referred to as a universal data store. An example of a universal data store suitable for use with the present invention is described in the commonly owned, co-pending application “SYSTEM AND METHODS FOR REPRESENTING UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM BUT INDEPENDENT OF PHYSICAL REPRESENTATION”, U.S. patent application Ser. No. 10/647,058 filed on Aug. 21, 2003, which is hereby incorporated by reference. 
     A. Storage Platform Overview 
     Referring to  FIG. 3 , a storage platform  300  in accordance with the present invention comprises a universal data store  302  implemented on a database engine  314 . In one embodiment, the database engine  314  comprises a relational database engine with object relational extensions. In one embodiment, the relational database engine  314  comprises the Microsoft SQL Server relational database engine. 
     The universal data store  302  implements a data model  304  that supports the organization, searching, sharing, synchronization, and security of data. Specific types of data are described in schemas, such as schemas  340 , and the storage platform  300  provides tools  346  for deploying those schemas as well as for extending those schemas, as described more fully below. 
     A change tracking mechanism  306  implemented within the universal data store  302  provides the ability track changes to the data store. The universal data store  302  also provides security capabilities  308  and a promotion/demotion capability  310 . The universal data store  302  also provides a set of application programming interfaces  312  to expose the capabilities of the universal data store  302  to other storage platform components and application programs (e.g., application programs  350 A,  350 B, and  350 C) that utilize the storage platform. 
     The storage platform of the present invention still further comprises an application programming interfaces (API)  322 , which enables application programs, such as application programs  350 A,  350 B, and  350 C, to access all of the foregoing capabilities of the storage platform and to access the data described in the schemas. The storage platform API  322  may be used by application programs in combination with other APIs, such as the OLE DB API  324  and the Microsoft Windows Win32 API  326 . 
     The storage platform  300  of the present invention may provide a variety of services  328  to application programs, including a synchronization service  330  that facilitates the sharing of data among users or systems. For example, the synchronization service  330  may enable interoperability with other data stores  340  having the same format as data store  302 , as well as access to data stores  342  having other formats. The storage platform  300  also provides file system capabilities that allow interoperability of the universal data store  302  with existing file systems, such as the Windows NTFS files system  318 . 
     In at least some embodiments, the storage platform  320  may also provide application programs with additional capabilities for enabling data to be acted upon and for enabling interaction with other systems. These capabilities may be embodied in the form of additional services  328 , such as an Info Agent service  334  and a notification service  332 , as well as in the form of other utilities  336 . 
     In at least some embodiments, the storage platform is embodied in, or forms an integral part of, the hardware/software interface system of a computer system. For example, and without limitation, the storage platform of the present invention may be embodied in, or form an integral part of, an operating system, a virtual machine manager (VMM), a Common Language Runtime (CLR) or its functional equivalent, or a Java Virtual Machine (JVM) or its functional equivalent. 
     Through its common storage foundation, and schematized data, the storage platform of the present invention enables more efficient application development for consumers, knowledge workers and enterprises. It offers a rich and extensible programming surface area that not only makes available the capabilities inherent in its data model, but also embraces and extends existing file system and database access methods. 
     B. The Data Model 
     The universal data store  302  of the storage platform  300  of the present invention implements a data model that supports the organization, searching, sharing, synchronization, and security of data that resides in the store. In the data model of the present invention, the fundamental unit of storage information may be referred to as an item. The data model provides a mechanism for declaring items and item extensions and for establishing relationships between items and for organizing items in folders and in categories. 
     In one embodiment of the present invention, the data model relies on two primitive mechanisms, Types and Relationships. Types are structures that provide a format which governs the form of an instance of the Type. The format is expressed as an ordered set of Properties. A Property is a name for a value or set of values of a given Type. For example, a U.S. Postal Address type might have the properties Street, City, Zip, State. Properties may be required or optional. 
     Relationships can be declared and represent a mapping between the sets of instances of two types. For example, there may be a Relationship declared between the Person Type and the Location Type called LivesAt which defines which people live at which locations. The Relationship has a name, two endpoints, namely a source endpoint and a target endpoint. Relationships may also have an ordered set of properties. Both the Source and Target endpoints have a Name and a Type. For example the LivesAt Relationship has a Source called Occupant of Type Person and a Target called Dwelling of Type Location and in addition has properties StartDate and EndDate indicating the period of time for which the occupant lived at the dwelling. Note that a Person may live at multiple dwellings over time and a dwelling may have multiple occupants so the most likely place to put the StartDate and EndDate information is on the relationship itself. 
     Relationships define a mapping between instances that is constrained by the types given as the endpoint types. For example the LivesAt relationship cannot be a relationship in which an Automobile is the Occupant because an Automobile is not a Person. 
     1. Items 
     As mentioned above, the fundamental unit of storage information in a universal data store according to the present invention may be referred to as an item. An item is a unit of storable information that, unlike a simple file, is an object having a basic set of properties that are commonly supported across all objects exposed to an end-user or application program by the storage platform. Those skilled in the art will recognize that the universality of the universal data store is made possible, in part, because each item in the data store includes data indicating these basic properties stored in accordance a data schema that is constant for each item. 
     The universal data schema provides a universal foundation that establishes a conceptual framework for creating and organizing items and properties. The universal data schema defines certain special types of items and properties, and the features of these special foundational types from which subtypes can be further derived. The use of this universal data schema allows a programmer to conceptually distinguish items (and their respective types) from properties (and their respective types). Moreover, the universal data schema sets forth the foundational set of properties that all items may possess as all items (and their corresponding item Types) are derived from this foundational item in the universal data schema (and its corresponding item Type). By storing each item according to this universal data schema, a shell browser is able to interpret and present each item in the data store along with its basic properties to the user. An example of a universal data schema suitable for use with the present invention is described in the commonly owned, co-pending application “SYSTEM AND METHODS FOR REPRESENTING UNITS OF INFORMATION MANAGEABLE BY A HARDWARE/SOFTWARE INTERFACE SYSTEM BUT INDEPENDENT OF PHYSICAL REPRESENTATION”, U.S. patent application Ser. No. 10/647,058 filed on Aug. 21, 2003, which is hereby incorporated by reference. 
     Items also have properties and relationships that are commonly supported across all item types including features that allow new properties and relationships to be introduced. Those skilled in the art will recognize that this property and relationship data may be referred to as metadata associated with an item. As described below, the metadata may be stored in accordance with an item decoration schema. This item decoration schema may indicate an appropriate manner which to present the item to a user. 
     Items are the objects for common operations such as copy, delete, move, open, print, backup, restore, replicate, and so forth. Items are the units that can be stored and retrieved, and all forms of storable information manipulated by the storage platform exist as items, properties of items, or relationships between items, each of which is discussed in greater detail herein below. 
     Items are intended to represent real-world and readily-understandable units of data like Contacts, People, Services, Locations, Documents (of all various sorts), and so on. 
     Items are stand-alone objects; thus, if you delete an item, all of the item&#39;s properties are also deleted. Similarly, when retrieving an item, what is received is the item and all of its properties contained in the item&#39;s metadata. Certain embodiments of the present invention may enable one to request a subset of properties when retrieving a specific item; however, the default for many such embodiments is to provide the item with all of its immediate and inherited properties when retrieved. Moreover, the properties of items can also be extended by adding new properties to the existing properties of that item&#39;s type. These “extensions” are thereafter bona fide properties of the item and subtypes of that item type may automatically include the extension properties. The extensions may also be referred to as metadata associated with a file. 
     2. Item Folders And Categories 
     Groups of items can are organized into special items called item Folders (which are not to be confused with file folders). Unlike in most file systems, however, an item can belong to more than one item Folder, such that when an item is accessed in one item Folder and revised, this revised item can then be accessed directly from another item folder. In essence, although access to an item may occur from different item Folders, what is actually being accessed is in fact the very same item. However, an item Folder does not necessarily own all of its member items, or may simply co-own items in conjunction with other folders, such that the deletion of an item Folder does not necessarily result in the deletion of the item. 
     Items may also belong to Categories based on common described characteristic such as (a) an item Type (or Types), (b) a specific immediate or inherited property (or properties), or (c) a specific value (or values) corresponding to an item property. For example, an item comprising specific properties for personal contact information might automatically belong to a Contact Category, and any item having contact information properties would likewise automatically belong to this Category. Likewise, any item having a location property with a value of “New York City” might automatically belong to a NewYorkCity Category. 
     Categories are conceptually different form item Folders in that, whereas item Folders may comprise items that are not interrelated (i.e., without a common described characteristic), each item in a Category has a common type, property, or value (a “commonality”) that is described for that Category, and it is this commonality that forms the basis for its relationship to and among the other items in the Category. Moreover, whereas an item&#39;s membership in a particular Folder is not compulsory based on any particular aspect of that item, for certain embodiments all items having a commonality categorically related to a Category might automatically become a member of the Category at the hardware/software interface system level. Conceptually, Categories can also be thought of as virtual item Folders whose membership is based on the results of a specific query (such as in the context of a database), and items that meet the conditions of this query (defined by the commonalities of the Category) would thus comprise the Category&#39;s membership. 
       FIG. 4  illustrates the structural relationship between items, item Folders, and Categories in various embodiments of the present invention. A plurality of items  402 ,  404 ,  406 ,  408 ,  410 ,  412 ,  414 ,  416 ,  418 , and  420  are members of various item Folders  422 ,  424 ,  426 ,  428 , and  430 . Some items may belong to more than one item Folder, e.g., item  402  belong to item Folders  422  and  424 . Some items, e.g., item  402 ,  404 ,  406 ,  408 ,  410 , and  412  are also members of one or more Categories  432 ,  434 , and  436 , while other times, e.g., items  414 ,  416 ,  418 , and  420 , may belong to no Categories (although this is largely unlikely in certain embodiments where the possession of any property automatically implies membership in a Category, and thus an item would have to be completely featureless in order not to be a member of any category in such an embodiment). In contrast to the hierarchical structure of folders, both Categories and item Folders have structures more akin to directed graphs as shown. In any event, the items, item Folders, and Categories are all items (albeit of different item Types). 
     In contrast to files, folders, and directories, the items, item Folders, and Categories of the present invention are not characteristically “physical” in nature because they do not have conceptual equivalents of physical containers, and therefore items may exist in more than one such location. The ability for items to exist in more than one item Folder location as well as being organized into Categories provides an enhanced and enriched degree of data manipulation and storage structure capabilities at the hardware/software interface level, beyond that currently available in the art. 
     3. Relationships 
     Items may also contain relational information which allows relationships between two or more items to be determined. Relationships are binary relationships where one item is designated as source and the other item as target. The source item and the target item are related by the relationship. Relationships may be classified into: Containment and Reference relationships. The containment relationships control the life-time of the target items, while the reference relationships do not provide any life-time management semantics. 
     The Containment relationship types are further classified into Holding and Embedding relationships. A holding relationship controls the life-time of the target through a reference counting mechanism. Holding relationships do not contain their targets but control the life-time of the targets. When all holding relationships to an item are removed, the item is deleted. The embedding relationships enable modeling of compound items and can be thought of as exclusive holding relationships. An item can be a target of one or more holding relationships, but an item can be target of exactly one embedding relationship. An item that is a target of an embedding relationship cannot be a target of any other holding or embedding relationships. Embedded relationships contain their targets and control life-time of the targets. Those skilled in the art will recognize that a single target can be in at most one embedded relationship, while a single target can be in multiple holding relationships. 
     Reference relationships do not control the lifetime of the target item. They may be dangling—the target item may not exist. Reference relationships can be used to model references to items anywhere in the global item name space (i.e. including remote data stores). 
     Fetching an item does not automatically fetch its relationships. Applications or the shell must explicitly request the relationships of an item. In addition, modifying a relationship does not modify the source or the target item; similarly, adding a relationship does not affect the source/target item. Relationships between two items may be declared and stored with an item or the shell or an application, through utilization of the relational information, may determine the two items are related. 
     The Reference relationship does not control life time of the item it references. Even more, the reference relationships do not guarantee the existence of the target, nor do they guarantee the type of the target as specified in the relationship declaration. This means that the Reference relationships can be dangling. Also, the reference relationship can reference items in other data stores. Reference relationships can be thought of as a concept similar to links in web pages. 
     In at least one embodiment, the storage platform of the present invention supports ordering of relationships. The ordering is achieved through a property named “Order.” There is no uniqueness constraint on the Order field. The order of the relationships with the same “order” property value is not guaranteed, however it is guaranteed that they may be ordered after relationships with lower “order” value and before relationships with higher “order” field value. It should be noted that property “Order” is not in the base relationship definition. Rather, this is an extrinsic property which is stored as part of the relationship between source and target. 
     As previously mentioned, an item may be a member of an item Folder. In terms of Relationships, an item may have a relationship with an item Folder. In several embodiments of the present invention, certain relationships are represented by Relationships existing between the items. 
     4. Extensibility 
     Referring to  FIG. 3 , the storage platform is provided with an initial set of schemas  340 , as described above. In addition, however, in at least some embodiments, the storage platform allows customers, including independent software vendor (ISVs), to create new schemas  344 . 
     C. Database Engine 
     As mentioned above, the data store is implemented on a database engine. In one embodiment, the database engine comprises a relational database engine that implements the SQL query language, such as the Microsoft SQL Server engine, with object relational extensions. It is understood, however, that different database engines may be employed. Indeed, in addition to implementing the storage platform conceptual data model on a relational database engine, it can also be implemented on other types of databases, e.g. object-oriented and XML databases. 
     III. Presentment of Items to a Viewer 
     Items in the universal data store are presented to a user by a shell browser. Such browsers are well-known in the art and, as explained above, a shell browser provides a user interface allowing a user to view and to interact with the hardware/software interface. 
     A. Default Display View 
     As noted above, each item in the universal data store is stored in accordance with a universal data schema. This schema includes a mechanism for describing items called type associations. Each type association has a basic representation in the shell; by storing an item in accordance with a type association, the shell is able to display an item according to at least a basic or default display view. 
     A type association is a property associated with an item; when placing data into the universal data store one or more properties associated with the data must be declared so as to determine what type of item it is. These properties may be included as metadata associated with the data. The shell has a set of default type associations which represent the most basic and minimal properties which must be declared for an item. 
       FIG. 5  displays an item  500 . The item  500  is stored in accordance with the universal data schema and includes a set of item data  502  and a set of metadata  504  including property declarations. The item data  502  may be any set of data appropriate for inclusion within the data store. For example the item data  502  may be associated with a word processing document. The property declarations metadata  504  includes at least a basic type declaration for the item  500 . For example, a default type association may be a Document type and the metadata  504  may set forth that the item  500  is a Document type item. Because the shell includes a default display view for each default type association, the shell may display the item  500  according the default display view for the Document type. The default display view for Documents types may, for example, include an icon used only with Document type items. By presenting the word processing item with this icon, a user can quickly recognize that the item  500  is a document. Those skilled in the art will recognize that any variety of default type associations and default display attributes are acceptable for the present invention. 
     B. Item Decoration View 
     Beyond property declarations, metadata associated with an item may include data indicating how the shell should decorate an item&#39;s presentation. Decorations, in this case can be though of as “hints” as to how to represent the item to a user. This metadata may be stored in accordance with an item decoration schema. The item decoration schema defines the item decoration view that the shell may utilize to present the item. For example, the item decoration data may describe the most important declared properties for an item. These “high value” properties may be the most desirable for presentation in the shell. 
     Item  500  may optionally include item decoration data  506  stored in accordance with an item decoration schema. To present the item  500 , the item decoration data  506  may indicate a set of view fields appropriate for the presentation of the item  500 . View fields are projections of declared properties, and common view fields may include “title,” “author,” “date of creation” or “last edited.” The shell includes a set of standard view fields and independent software venders (ISVs) may define view fields which are appropriate for presentation of their data. When developing new item types, ISVs can either map item properties they define to the shell&#39;s view fields or they can provide their own view fields. 
     For example, the item data  502  may contain song data. The set of declared properties  506  may include properties such as song title, artist, date recorded, album, song length, and other declarations appropriate for such a song item. The item decoration data  506  may indicate that view fields “Title,” “Artist” and “Album” should be displayed to the user when presenting the item  500  in the shell. 
     The item decoration data  506  may describe more truly decorative items regarding the item data  502  such as text presented with a declared property. For instance, one of the property declarations  504  may indicate a bitrate value to describe the quality of the recording. This property may be stored an integer BITRATE. The item decoration data  506  may request that the bitrate be displayed and also may decorate this field as “[BITRATE] kilobytes per second.” In this method the bitrate field is appropriately decorated so that a user can easily understand the meaning of the bitrate value in a view field. 
     Those skilled in the art will recognize that the item decoration data  506  and its corresponding item decoration view may dictate a wide variety of presentation attributes. Item decorations can be any aspect of the display supported by the shell. Some common other item decorations are, for example, data formatting, default sort order, and default icon size. Additionally, the item decoration data  506  may describe common controls to use in displaying a given item. For example, a Ratings field might use a ratings control that represent the rating as a series of stars. The item decoration data  506  may describe tasks or verbs appropriate for use with an item. Those skilled in the art will recognize that the terms “task” and “verb” describe some action to be undertaken with regard to an item and such terms may be used interchangeable. For example, “Edit” or “Preview” may be appropriate tasks/verbs associated with an item. The shell may be furthered configured to launch applications in support of these tasks upon a user selection to perform the action with respect to the item. 
     Those skilled in the art will recognize that item decorations will change and grow over time. The invention contemplates that, when the new item decorations are implemented, new items can utilized these decorations, while older items will continue to display properly by utilizing the older display attributes provided by the shell. 
       FIG. 6  displays a flow diagram illustrating a method  600  for presenting items to the user according to the present invention. At  602 , the method  600  accesses a universal data store in response to a request to present one or more items to the user. At  604 , the method considers one or more items selected for presentation. Items containing metadata stored in accordance with an item decoration schema are presented to the user according to an item decoration view as indicated at  606 . Items which do not contain such metadata are presented according to a default display view as indicated at  608 . Those skilled in the art will recognize that, as discussed above, these schemas and presentation views may include various display attributes which may be used in the presentation of each item in the data store. 
     C. Shell View 
     As described above, an item decoration view is sufficient to fully present a given item or a homogeneous set of items, comprised of items having like item decoration views. To display items with different item decoration schemas, the shell provides shell view schemas that present items according to shell decoration views. A shell view schema allows the shell or ISVs to declare appropriate views for given sets of heterogeneous data. 
     Items chosen for representation within a shell decoration view may include a common characteristic. Those skilled in the art will recognize that a wide variety of common characteristics may be acceptable for a shell decoration view. For example, a shell view schema could define a “Picture” view used to display common and appropriate fields and metadata for all known picture types (e.g., .GIF, .JPEG, .BMP, .TIFF, etc). The shell view schema overrides conflicting display attributes for a given item decoration view and presents each picture item according the shell view schema. As another example, the shell could provide a “Document” shell view that is optimized around appropriate columns and metadata for the items produced by typical productivity applications, such a word processing documents, spreadsheets, or databases, even though the item decorations for each of these items may vary greatly from each other. Such a view has value by providing common properties among each of these documents. Those skilled in the art will recognize that, when later document types are installed, the shell view will be able to present these new items according to the consistent shell view even though the new type may not have been considered when the view was first created. 
     In addition to shaping the view fields appropriate for a given set of heterogeneous items, shell view schema may define further display attributes. For example, the view state, including icons properties, the size of the preview pane, and default sort order may be defined by the shell view schema. The view schema also contains property decorations, such as data formatting, to apply to various columns. 
     In cases where the shell view schema and the item decoration schema conflict, the shell view schema acts as an override. In cases where a display element is missing from a shell view schema, the shell view will fall back to the item decoration view for an appropriate display. In this way, the shell view can craft an appropriate view when displaying data not originally anticipated. Additionally, in one embodiment of the present invention, the shell view can defer to the item decoration view to provide a non-conflicting decorative element. For example, the shell view may make use of the “high value” metadata from the set of items it contains to construct an appropriate set of columns and metadata to display the items. 
     Those skilled in the art will recognize that the shell view schemas may provide a wide variety of display attributes and that ISVs may want to provide such shell views. The display attributes may include, without limitation: the size of the preview pane, metadata to display within the preview pane, custom controls to be used, and tasks and verbs appropriate for the presented items. 
       FIG. 7  displays a flow diagram illustrating a method  700  for presenting items to the user according to the present invention. At  702 , the method  700  accesses the data store in response to a request to present one or more items to a user. At  704 , a determination is made whether each item selected for presentation includes the same item decoration schema. If all items have such a common schema, the items are presented according to that schema as indicated at  706 . If the presented items include items having different or no item display schemas, at  708  the set of items is presented according to a shell decoration view. As discussed above, such a shell view may be appropriate for presentation of a heterogeneous set of items. An optional step of presenting one or more of the selected items with display elements from an item decoration view is included at  710 . While these display elements may not conflict with the shell decoration view, the elements may enhance the presentation of items by the shell. 
     Turning to  FIG. 8 , a diagram of an exemplary view schema hierarchy  800  is presented. The bottom layer of the hierarchy is the item view schema  802 . The item view schema  802  provides the basic display needed to represent an item or, if no view schema is supplied, provides a default display. Schemas that are above the item view schema  802  can defer or fall back upon its display elements when required. 
     Shell view schema  804  resides above the item view schema  802 . As discussed above, a shell view schema may be utilized to display a set of items with diverse item views. The shell view schema defines tasks  806 , preview pane characteristics  808 , columns  810  and decorations  812  which are used to display items according to the shell view  804 . The shell view may fall back upon the item view schema  802  to provide non-conflicting item decorations for use with the shell view  804 . Additionally, user view settings  814  may reside within the shell view. These setting represent a user&#39;s desired presentation format for the shell items. Those skilled in the art will recognize that any number is display attributes may be defined within a display schema and that a user may be presented with numerous options and controls in relation to display settings. 
     D. Explorer Display View 
     The shell may also be configured to present items according to an explorer display view. An “explorer” may be referred to as a storage application and may be provide by the shell or by an ISVs. In one embodiment of the current invention, an explorer may be created to provide a holistic experience that aids users managing a large set of items. For example, the explorer may enable a user to view, query, navigate, launch into tasks, or organize selected items in a data store. The term “explorer” should not imply a location where the displayed items reside, and terms such as “activity center,” “viewer” and “library” may be used interchangeably with “explorer” to describe a storage application according to the present invention. 
       FIG. 9  shows an exemplary explorer schema hierarchy  900 . The bottom layer of the hierarchy is the item view schema  902 . The item view schema  902  provides the basic display needed to represent an item, and the explorer view schema  904  can defer or fall back upon its display elements when required. 
     The explorer view schema includes a shell view schema  906  and explorer decorations  908 . The explorer decorations  908  decorate the explorer as a whole and provide display elements such as distinctive colors and branding elements. These explorer decorations  908  persist among the various views the explorer provides. Those skilled in the art will recognize that a wide variety of display attributes may be appropriate for the explorer decorations  908 . For example, data queries or tasks/verbs associated with the explorer items may be appropriate for display with an explorer. Displayed tasks will preferably be coupled with an application capable of performing the task. 
     The explorer view schema may optionally include a shell view schema  906  or multiple shell view schemas. The shell view schema  906  may be configured to provide a shell view for a subset of explorer items. For example, an explorer may be configured to display song items to a user. A first shell view schema may be included to provide a display of albums and a second shell view schema may be included to provide a display of song tracks. In this manner, both types of items will have appropriate views within the explorer. As discussed above, the utilization of shell view relates to the presentation of a set of items which, optionally, may share a common characteristic. 
     The explorer may also rely on shell views included within the shell. If items selected for presentation within an explorer are not supported by any of the shell views included by the explorer, the shell may provide an appropriate shell view for use within the explorer. Similarly and as discussed above, the explorer may also fall back to an item display view or a default display view provided by the shell. This functionality insures that any item which can be displayed by the shell is also capable of display within the explorer. The explorer can be configured to defer to these shell provided display schemas or may rely upon them to, for example, provide a display for unanticipated data. 
       FIG. 10  presents a method  1000  for presenting items in an explorer display according to the present invention. At  1002 , the method  1000  accesses the data store and, at  1004 , selects items to be displayed in the explorer. The selection of explorer items may rely on consideration of item declarations also referred to as field entries. As discussed above, items in a data store may contain property information. This information is declared when an item is placed in the data store and may be updated throughout the life of the item. Such declarations may be considered field entries corresponding to a set of property fields. For example entries in a property field “author” may contain the authorship information for a given item. 
     It may be desirable to present items sharing one or more field entries. For example, an explorer including each item authored by a particular person may be desired. By considering the field entries of the author field, the explorer is able select such explorer items authored by that particular person from the data store. Those skilled in the art will recognize that the mechanics of such a database query are well known. 
     At  1006 , a determination is made whether the explorer includes a shell view which is appropriate for the presentation of an explorer item. If no such appropriate shell view is found in the explorer, the method  1008  utilizes a view contained in the shell as indicated at  1008 . If a proper shell view is included in the explorer, the method  1000 , at  1010 , utilizes that shell view to present the item. At  1012 , an optional step of utilizing decorative elements from an item display schema is performed. As described above, the explorer may use non-conflicting decorations from an item view schema to enhance the presentation of an item. At  1014 , the explorer item is presented to the user according to the shell and items views. The explorer decorative properties are presented at  1016 . These properties may be a wide variety of display attributes and may include data queries or task associated with the explorer items. 
     E. Explorer Development 
     Explorers may be created for a wide variety of item types. In one embodiment of the present invention, explorers can be defined with little or no programming. By allowing explorers to be created in a data-driven way, ease of development is enhanced while providing a consistent look and feel across explorers. 
     In certain embodiments, explorers may allow restrictions on what types (including item extensions and file extensions) of items they can present or explorers can choose to allow items of all types. Also explorers can choose to allow items types with a specific set of item extensions. For example, a Legal Item Explorer may display all items with a “LegalItemExtension” attached. Explorers can choose to allow items of a certain type and any file extension that maps to that type. For example, a Music Item Explorer can show all music file extensions such as mp3 or wma. Furthermore, explorers can choose to allow items of a certain set of file extensions only. If an explorer is restricted to a certain set of types, then items of other types cannot be saved or dropped into this explorer. Explorers can redefine type associations for the types that they allow, and explorers may choose to selectively disallow overrides or may choose to disallow addition of new commands. Furthermore explorers can decide whether they will let end-users override type associations within the explorer. 
     Considering the foregoing, those skilled in the art will recognize that by providing data-driven development techniques for creating an explorer for use within an item-type environment, explorers may be defined a declarative manner and without the use of custom code. 
       FIG. 11  displays a method  100  for presenting items according to an explorer display schema. At  1102 , the method  1100  selects a desired field entry. As discussed above, this desired field entry may correspond to a declared property associated with an item. For example, a “photo album” explorer may have a desired field entry requiring inclusion of items containing picture data. 
     At  1104 , an explorer display schema is defined. This display schema may include a shell view schema and explorer decorations. The explorer decorations decorate the explorer as a whole and provide display elements such as distinctive colors and branding elements. These explorer decorations persist among the various views the explorer provides. A wide variety of display attributes may be appropriate for the explorer decorations. For example, data queries or tasks/verbs associated with the explorer items may be appropriate for display with an explorer. Displayed tasks will preferably be coupled with an application capable of performing the task. The explorer view schema may include a shell view schema or multiple shell view schemas. The shell view schema may be configured to provide a shell view for a subset of explorer items. 
     At  1106 , the method  1100  accesses the data store to select the explorer items. The explorer items are associated with the desired field entry. Those skilled in the art will recognize that the selection of such items in a database are well known in the art. Those skilled in the art will further recognize that developers may create explorers configured for such interaction. Development of explorers capable of accessing a data store is contemplated by the instant invention. 
     At  1108 , the explorer items are displayed according to an explorer display schema. The explorer display schema is described above, and this display may also include interaction with a shell browser. For example the shell may provide one or more shell views. In addition, item decoration elements from an item decoration schema may be utilized to enhance the presentation of the explorer items. 
     As those skilled in the art will recognize, the explorer storage application may be considered an application and/or an extension of the shell browser. Consequently, the foregoing description is appropriate for both depictions of the present invention. As an application, the explorer program may include a shell interaction module that is configured to interact with the shell browser. Such interaction allows the program to communicate information with the shell and allows the software to work together to present items. The shell interaction module may facilitate the accessing of the data store and may provide display attributes. Such interaction between an application and the shell is well known in the art. 
     E. Presentation of Related Items 
     The present invention may also display related items in the data store to the user. As described above, the items in a data store may include items having one or more declared properties. An item may have declared relationships which elucidate the other items in the data store which share a relationship. For instance, an item containing an email address may declare a relationship to an item containing other contact information for the owner of the email address. The shell may utilize this declared relationship to present the other contact information upon a user request. The shell may also determine relationships by considering an item&#39;s declared properties. For example, a set of documents may be related if they share a common property; items with an extension “LegalItemExtension” may be related if a common value is stored as part of the extension. Such a relationship may be determined by a data query well known in the art. 
       FIG. 12  displays a method  1200  for presenting related items according to the present invention. At  1202 , the method  1200  accesses the data store and, at  1204 , relationships between items in the data store are determined. As described above, such a determination utilizes the declared properties included with an item. This determination may be in response to a user input. For example, an item having a set of declared item characteristics may be displayed to a user. The item characteristic and relational information may be displayed with the item. The user may select one of the characteristics and input a request to see other items sharing the item characteristic. At  1206 , the method  1200  presents related items to the user. Such presentation may include any display schema known in the art. 
     Alternative embodiments and implementations of the present invention will become apparent to those skilled in the art to which it pertains upon review of the specification, including the drawing figures. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description.