Abstract:
An architecture for a computing environment wherein transactions preferably model the enterprise and its business processes directly, allowing third-party systems, like ERP, supply chain and Web portals, to be more loosely coupled. Because the system will often be distributed throughout the enterprise, reliance on central critical servers is reduced. The system of the present invention can also fill-in gaps in the functionality of legacy systems, as well as invoke complex applications and direct automated systems. The system offers an architecture where users can model their particular enterprises in business terms so that disparate applications can be linked without custom programming.

Description:
[0001]    This application claims the benefit of copending provisional application serial No. 60/228,219, filed Aug. 25, 2000, which is relied on herein and incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to message processing in a network of interconnected computers and other electronic devices. More particularly, the present invention relates to a system for moving messages among the interconnected computers based on the transactions to be performed.  
           [0003]    It is often necessary in various commercial enterprises to route messages among interconnected computers. For example, an enterprise resources planning (ERP) system installed in a production facility may need to communicate with computers used to control production equipment on the plant floor. Frequently, however, these various computers will have disparate operating systems and communication protocols.  
           [0004]    One common approach to allow communication between disparate computers in a common enterprise utilizes a centralized, content-based routing software engine. Content-based routing uses the content of a particular piece of information to determine where it needs to be sent. A series of pre-programmed adapters may be provided by the software vendor to help integrate the routing engine to various environments.  
           [0005]    It is not unusual for a content-based routing engine to require a large amount of custom programming in order to operate in a particular situation. For example, significant custom programming will be required if the individual implementations of the environment have been significantly customized beyond that which the adapters are programmed to expect. Moreover, an extensive amount of programming may be required for implementation and maintenance in an environment of constantly changing interfaces and application logic found in the world of manufacturing plant automation and B2B trading partners.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention recognizes and addresses the foregoing disadvantages, and others, of prior art constructions and methods. Accordingly, it is an object of the present invention to provide an improved system for moving messages among interconnected computers.  
           [0007]    It is a further object of the present invention to provide an improved system for moving messages among interconnected computers that substantially reduces or eliminates the need for custom programming.  
           [0008]    It is a further object of the present invention to provide a system for moving messages among interconnected computers in a network based on the transactions to be performed.  
           [0009]    Unlike the prior art, the architecture of the present invention is not based upon a central server that simply maps data and routes messages between existing applications. Instead, transactions of the present invention model the enterprise and its business processes directly, allowing third-party systems, like ERP, supply chain and Web portals, to be more loosely coupled. Because the system will often be distributed throughout the enterprise, reliance on central critical servers is reduced.  
           [0010]    In addition, the system of the present invention can fill-in gaps in the functionality of legacy systems, as well as invoke complex applications and direct automated systems. The system offers an environment where users can model their particular enterprises in business terms (the often complex and usually incomplete mix of real systems in which businesses are run), not computer languages. Thus, disparate applications can be linked without custom programming.  
           [0011]    Other objects, features and aspects of the present invention are provided by various combinations and subcombinations of the disclosed elements, which are discussed in greater detail below. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which:  
         [0013]    [0013]FIG. 1 is a block diagram of a plurality of disparate computers interconnected according to the present invention;  
         [0014]    [0014]FIG. 2 is a block diagram showing more detail regarding one of the computers of FIG. 1;  
         [0015]    [0015]FIG. 3 is a diagrammatic representation of a “context” which may be generated during use of the system shown in FIG. 1;  
         [0016]    [0016]FIG. 4 is a diagram showing various agents that may be used in a system of the present invention;  
         [0017]    [0017]FIG. 5 is a flow chart showing operation of a server agent;  
         [0018]    [0018]FIG. 6 is a flow chart showing operation of an interface agent;  
         [0019]    [0019]FIG. 7 is a flow chart showing operation of a user login agent;  
         [0020]    [0020]FIG. 8 is an exemplary configuration set up screen display;  
         [0021]    [0021]FIG. 9 is a diagram showing an exemplary referential relationship among preferred configuration objects; and  
         [0022]    [0022]FIG. 10 is a further diagram of a system in accordance with the present invention by which a simplified example may be described. 
     
    
       [0023]    Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.  
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0024]    It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the invention, which broader aspects are embodied in the exemplary constructions.  
         [0025]    [0025]FIG. 1 is a diagrammatic representation illustrating the manner in which various “trading partners” may be interconnected in accordance with the present invention. Specifically, a total of four trading partners  10   a - d  (also referred to as TP 1 -TP 4 ) communicate with one another via a “transaction-based environment”  11  by which messages are directed according to the transaction to be performed. This is in contrast to many systems of the prior art which have relied on specific message routing from one computer to another.  
         [0026]    Further details of the transaction partners can be discerned from FIG. 2, which illustrates transaction partner TP 1  for purposes of illustration. In this case, a computer running an application  12  has also been loaded with “agents” and “configuration objects” to be explained more fully below. As a result, an interface  14  exists on the computer for the purposes of communicating with other trading partners. Messages (including events) sent by application  12  are converted by interface  14  into a “context” which dictates the action to be taken.  
         [0027]    It is useful at this point to described in detail the agents that may be utilized in a system of the present invention, as well as the objects which model the topography of an enterprise in which the system is employed.  
         [0028]    I. Agents  
         [0029]    Any number of “agents” may be running on any number of computers supporting a distributed application according to the present invention. Agents may be implemented as “processes” or “tasks,” depending on the operating system of the individual computer.  
         [0030]    Agents running on a given computer communicate with each other using message queues, implemented according to the facilities provided by the operating system. By default, message queues are implemented in memory. The queues to certain types of agents can be configured to be disk queues, freeing the application from limitations on the number of outstanding messages and their retention across computer restarts.  
         [0031]    Each computer which supports these agents normally has a local copy of the configuration (i.e., the collection of “configuration objects”). Agents typically  10   ad  configuration records into shared memory regions as they are referenced, so that subsequent references to those records are efficient.  
         [0032]    Each agent, as it handles transactions and applications, holds current Element values in a data structure referred to as “context.” As shown in FIG. 3, context  16  may be configured having a header  18 , followed by a sequence of element value nodes  20 , each of which identify the Element whose value is stored using its object identifier, the size of the value stored, and the value itself.  
         [0033]    Additionally, message nodes and address nodes (e.g., message nodes  22 ) may appear among the element value nodes. These are similar to the element value nodes, except that they contain the text of messages or address info added and/or used by network agents and related verbs.  
         [0034]    To facilitate efficient lookup, header  18  contains a hash-table of pointers to element value nodes. So that more than one Element can be added to context  16  with the same hash-value, element value nodes  20  may contain a pointer to the next node with the same hash value.  
         [0035]    Additional header fields include the object identifier of the current Transaction (if one has been selected), a unique transaction identifier, sending and destination agent object identifiers, and sending and destination system object identifiers.  
         [0036]    As shown in FIG. 4, the agents in a particular application may include server agents  24 , interface agents  26 , network agents  28  and user login agents  30 .  
         [0037]    Referring now to FIG. 5, a server agent processes requests for transaction services. When a server agent is started on a particular computer (as indicated at  32 ), it reads its configuration object (as indicated at  34 ) to determine whether it should read requests from a memory-resident message queue or a disk queue. It then waits (as indicated at  36 ) to receive request messages from the queue.  
         [0038]    A transaction service request is identified as a transaction request or a transaction advice. The agent sending a transaction request expects a response. The agent sending a transaction advice does not expect a response. Other possible request message types include administrative requests, such as shut-down (as indicated at  38 ).  
         [0039]    Multiple server agents may be started for a particular server configuration object. In this case, all agents wait for requests on a common queue. This allows multiple requests to he handled simultaneously. During the course of processing a request, a server agent may need to make a request of some other agent. In this case, the server agent waits for the response to its request on an agent-specific (i.e. process- or task-specific) message queue.  
         [0040]    Upon receipt of a transaction request or advice, the server agent makes the transaction context contained in the message the current transaction context. It then looks up the configuration object associated with the transaction object identifier contained in the message (as indicated at  40 ), and invokes the associated ruleset (as indicated at  42 ). In addition to other actions, such as data table access/modifications and requests of other agents, the ruleset typically makes changes to the transaction context. It is the resulting context that is returned to the requesting agent. Once the ruleset is complete, the agent&#39;s local copy of the context is discarded, and the agent returns to its request queue for the next request message (as indicated at  44 ).  
         [0041]    Referring now to FIG. 6, an interface agent translates between a stream of messages to and from some external entity into a set of transaction requests and responses. When an interface agent is started on a particular computer (as indicated at  46 ), it reads its configuration object to determine whether it should read requests from a memory-resident message queue or a disk queue (as indicated at  48 ). It then waits to receive request messages from the queue (as indicated at  50 ).  
         [0042]    A request message sent to an interface agent may be an incoming message from an associated network agent, or a transaction request/advice or response from some other agent (e.g., Server, User Login, or other Interface).  
         [0043]    An incoming message from a network agent comprises a context containing message and possibly address nodes. In place of a transaction object identifier, the context contains a reserved token identifying it as an incoming message (identification indicated at  52 ).  
         [0044]    Upon receipt of an outgoing transaction request/advice or response context, the interface agent makes the received context the current context. It then invokes its out ruleset (as indicated at  54 ), which may compose and send outgoing message requests to a network agent, invoke additional transactions, or initiate a transaction response. Once the ruleset is complete, the agent returns to waiting for messages from its queue (as indicated at  56 ).  
         [0045]    Upon receipt of an incoming message context from a network agent, the interface agent invokes its in ruleset (as indicated at 58). The in ruleset may examine the text of the message received, invoke transactions, or restore a previously pended transaction context and initiate a response. Once the ruleset is complete, the agent returns to waiting for messages from its queue (as indicated at  56 ).  
         [0046]    A network agent handles the protocol by which communications with an external entity are implemented, converting a sequence of events and associated timings into a stream of incoming and outgoing messages. When a network agent is started on a particular computer, it reads its configuration object to determine whether it should read requests from a memory-resident message queue or a disk queue, and to discover the details of its particular communications protocol (it also reads its associated protocol configuration object). It then waits to receive request messages from the queue, while it handles communications with the external entity.  
         [0047]    Upon receipt of an outgoing message request from its associated interface agent, the network agent sends, or queues to send as soon as possible, the associated message to the external entity. Upon receipt of an incoming message from an external entity, the network agent composes a context containing the text of the received message and sends the context to its associated interface agent.  
         [0048]    Referring now to FIG. 7, a user login (aka screen) agent handles application presentation services, including full-screen presentation and capture of data, and full-screen user access to application functionality. Upon invocation (as indicated at  60 ), a user login agent prompts the user for username and password (as indicated at  62 ). The user login agent then reads its configuration object (as indicated at  64 ). If a user configuration object corresponding to the entered username is found (as indicated at  66 ), and the entered password matches the associated password information, the associated ruleset is invoked (as indicated at  68 ). The Ruleset may use a variety of verbs to invoke menus, listings and data-entry screens identified by Screen configuration objects. If a user is not found, the agent exits (as indicated at  70 ).  
         [0049]    II. Configuration  
         [0050]    Users configuring an application according to the present invention will be presented a series of screens, such as that shown in FIG. 8, that describe different and independent aspects of the particular computing environment. The resulting “configuration objects” are stored on disk as a set of records of varying length in a file with associated indexes. At run-time, configuration objects are read as they are referenced into memory regions which are shared among executing agent processes, including server agents (transaction service agents), interface agents, network agents and user login agents (i.e., screen agents).  
         [0051]    Each configuration object has an object type, an object id, an object name, and an object version. Users configuring an application may generally refer to objects by their object type and object name, which uniquely identify them. Object type and object id also uniquely identify a configuration object. The object id may be arbitrarily assigned when a configuration object is created. Object type and object id are generally used internally by the system to store relationships among configuration objects and values of objects at run-time. The combination of object type and id is often referred to here as an object identifier.  
         [0052]    The referential relationships among configuration objects is shown in FIG. 9. With this as a backdrop, various configuration objects will now be described.  
         [0053]    (1) Class (Data Dictionary Object)  
         [0054]    Class configuration objects identify data types and associated default values. Classes are generally used as attributes of other objects, such as Data Elements.  
                                                   Attribute   Description                           Data Type   Identifies the structure of data.               Possible values may include binary               integer (1, 2, 4, or 8 bytes), binary               floating point (4 or 8 bytes)               character (fixed-length, null-               terminated, or leading length               byte/word; character set ASCII or               EBCDIC), bit string (fixed-length or               leading length byte/word), packed               decimal (signed or unsigned; fixed               length or leading length byte), or               object identifier.           Extent1   Specifies the length of data. For               variable-length Data Types, specifies               the maximum number of characters,               digits or hits. For binary Data               Types, specifies the number of               significant digits (precision).           Extent2   For floating point Data Types,               specifies the number of decimal places               to display.           Default Label   The label to use when displaying or               prompting for data.           Default   (2) The headers to use when displaying           Headers   columns of data.           Default   A description to use when displaying           Description   or prompting for data (the default               help text).           Default Value   The object identifier of a Function               which determines a default value for               the data when no explicit value has               been set.           Default   The object identifier of a Function               which determines whether or not the               value set for the data is valid (as               defined by the application).           Class   The object identifier of a Class which               describes the format of the data.           Label   The label to use when displaying or               prompting for data; if not specified,               inherited from the Class.           Headers   (2) The headers to use when displaying               columns of data; if not specified,               inherited from the Data Class.           Description   A description to use when displaying               or prompting for data (the default               help text); if not specified,               inherited from the Class.           Default Value   The object identifier of a Function               which determines a default value for               the element when no explicit value has               been set; if not specified, inherited               from the Class.                                              
 
         [0055]    Item configuration objects identify atomic units of data which may have a system-wide value on the current System. Because the value of an Item is held in configuration, all agents active on a given system see the value assigned to the Item most recently by any agent.  
                                                   Attribute   Description                           Data Type   Identifies the structure of data.               Possible values may include binary               integer (1, 2, 4, or 8 bytes), binary               floating point (4 or 8 bytes),               character (fixed-length, null-               terminated, or leading length               byte/word; character set ASCII or               EBCDIC), bit string (fixed-length or               leading length byte/word), packed               decimal (signed or unsigned; fixed               length or leading length byte), or               object identifier.           Extent1   Specifies the length of data. For               variable-length Data Types, specifies               the maximum number of characters,               digits or bits. For binary Data Types,               specifics the number of significant               digits (precision).           Extent2   For floating point Data Types,               specifies the number of decimal places               to display.           Dimension   Identifies the number values which may               be set. If greater than one, the Item               may be thought of as an array.           Value   The value returned when this Item is               referenced.                      
 
         [0056]    (4) Record (Data Dictionary Object)  
         [0057]    Record configuration objects identify arrangements of fields, which may be Elements or sub-Records. These arrangements may be positional, in which the fields and the order in which they appear is pre-determined; bit-mapped, in which case certain fields appear in the record only if an associated controlling bit is set; or tagged, in which case fields may appear in any order, and are identified by a preceding unique tag (possibly with an associated field length indicator).  
                                                   Attribute   Description                           Type   Identifies the type of field               arrangement. Possible values include               positional, bit-mapped, and tagged               (tag before length, length before tag,               or tag only).           Tag Class   The object identifier of a Class which               specifies the structure of field tags               (if Type is tagged). The object               identifier of a Class which specifies               the structure of field length               indicators (if Type is tagged).           Fields   Identifies the fields which may appear               in the record. Each entry in Fields               has the following attributes:            Object    The object identifier of an            Identifier    Element or Record which describes                this field.            Dimension    Identifies the number times this                field is repeated at this                position (i.e., the field is an                array of values). The array                dimension may depend on the value                of another field in the record,                in which ease Dimension is                negative and its absolute value                represents which entry in Fields                specifies the array dimension.            Optional    (flag) If set, indicates that the                field need not appear in every                instance of the Record.           Bit-Mapped   (flag) If set, indicates that the               field&#39;s existence in any instance               of the record depends on the               value of a bit in a bit-map.           Existence   (flag) If set, indicates that the           Depends   field&#39;s existence in any instance               of the record depends on the               value returned by the Function               identified by the Exists               attribute.           Length Depends   (flag) If set, indicates that the               field&#39;s length in any instance of               the record depends on the value               returned by the Function               identified by the Length               attribute.           Terminated   (flag) If set, indicates that the               field&#39;s length varies (up to its               maximum length), in that the end               of the field is marked by one of               a set of Terminators.           Escaped   (flag) If set, and Terminated is               set, indicates that Terminators               may be included the field data if               preceded by an Escape character.           Parent Bit-map   The Object Identifier of the               field which acts as the bit map               containing the bit which controls               the existence of this field (if               Bit-Mapped is set).           Parent   More than one field may have the           Occurrence   Parent Bitmap&#39;s Object               Identifier. If the intended               Parent Bit-map is not the first               of these, this indicates which               one it is (if Bit-Mapped is set).           Bit-map Format   Identifies how the Parent Bit-map               is to be interpreted. Possible               values include binary encoded,               character encoded (a string of               “0” and “1” characters), and               hexadecimal encoded.           Bit-map   Identifies which bit in the           Position   Parent Bit-map controls the               existence of this field (if Bit-               Mapped is set).           Tag Value   The particular tag value that               identifies this field (if Type is               tagged). When this value is               encountered in the record, the               field is assumed to follow               (possibly following with an               associated length indication).           Terminators   A set of characters, any of which               indicate the end of this field               when they appear (if Terminated               is set).           Escape   A character which, when it               appears in the field data,               indicates that the character               which follows it is to be treated               as field data (if Terminated and               Escaped are set).           Exists   The object identifier of a               Function which when evaluated (as               a particular instance of a Record               is being analyzed) determines               whether or not this field appears               in the record (if Existence               Depends is set).           Length   The object identifier of a               Function which when evaluated (as               a particular instance of a Record               is being analyzed) determines the               length of this field as it               appears in the record (if Length               Depends is set).                      
 
         [0058]    (5) File (Data Dictionary Object)  
         [0059]    File (or Table) configuration objects identify long term storage (typically on disk) for data records.  
                                                   Attribute   Description                           Organization   Specifies how the data is stored.               Possible values include (but are not               limited to) Fixed (records are of a               specified length in a operating-system               native flat file), Varying (vfile               format, in which all records have a               leading and trailing length word, the               trailing length word falling on the               nearest even byte boundary; deleted               records are identified by a negative               record length), or Queue (internal               format for holding messages destined               for a particular agent).           Record   The object identifier of a           Definition   Record which describes the format of               records in the File.           System   The object identifier of a System               which identifies the location of the               file in a distributed system. If not               set, an instance of the File can exist               on each System.           Data Path   The operating-system and Organization               dependent path which locates the data.               This may specify, for example, a               directory and file name, and may be               relative.           Open Mode   The way in which multiple agent               processes coordinate access to the               data in the File. Possible values may               include record locking, and exclusive.           Deleted   The object identifier of an Index by           Record   which areas of the data from which           Index   records have been deleted may be               located.           Indexes   A list of object identifiers, each               identifying an Index by which records               may be located and sorted.                      
 
         [0060]    (6) Index (Data Dictionary Object)  
         [0061]    Key configuration objects are used to sort records in Files (Tables).  
                                                   Attribute   Description                           File   The object identifier of the               associated File (Table).           Data Path   The operating-system and File               Organization dependent path which               locates the indexing data. This may               specify, for example, a directory and               file name, and may be relative.           Collation   Determines sort order. Possible values               include ascending or descending ASCII,               Alphabetic or numeric.           Key   A list of object identifiers, each           Definitions   identifying a Key that specifies what               record-associated data is assembled to               create entries in the index. Since               more than one Key may be specified,               records may have multiple index               entries.                      
 
         [0062]    (7) Key (Data Dictionary Object)  
         [0063]    Index configuration objects specify what record-associated data is assembled to create entries in an associated Index.  
                                                   Attribute   Description                           File (Table)   The object identifier of the               associated File (Table).           Mode   Indicates whether entries in the Index               are created for records which are               missing some or all of the values from               which Components are resolved.           Index   The object identifier of the               associated Index.           Components   Each component entry identifies               Elements in the Record from which data               is to be taken to form an entry in the               Index. These data are concatenated to               form the entry.           Element   The object identifier of the element               from which the component is taken.               This is fully qualified, as necessary,               with the object identifiers of any               sub-Records in which the Element               appears, and, in the case of arrays               (of the Element and/or any sub-Record)               the desired array instance(s).           Offset   If set, identifies the first byte of               the Element value to be used.           Length   If set, identifies the number of bytes               of the Element value to be used. Note               that Offset and Length might be               thought of as a sub-string of the               value.                      
 
         [0064]    (8) System (System Topology Object)  
         [0065]    System configuration objects identify the locations where transaction handling agents or resources reside. A “system” may represent a particular software application, a computer, a group of computers, a communications network, or other equipment with which a distributed implementation of the present architecture may communicate and which offers transaction services. Systems on which the present architecture is installed and which support one or more transaction-handling agents which share the current configuration are referred to as “internal” to the distributed implementation. Others may be referred to as “external.” It is possible for a single computer to house multiple Systems (both internal and external) simultaneously. Note that it is not necessary to identify as Systems those applications, computers, networks or equipment which only originate Transactions (i.e., which offer no transaction services).  
                                                   Attribute   Description                           Interface ID   The object identifier of an Interface               through which to communicate with the               System. Does not need to be specified               for “internal” systems.                      
 
         [0066]    (9) Server (System Topology Object)  
         [0067]    Server (transaction service) configuration objects identify entities which process transactions. Servers are “internal” if their associated System is “internal,” and “external” otherwise.  
                                                   Attribute   Description                           System   The object identifier of the System on               which the Server agent executes.           Queue   The object identifier of a File that               holds requests destined for the Server               agent. If not set, requests are held               in memory. Does not need to be               specified if the System attribute               specified is “external”.                      
 
         [0068]    (10) Transaction (System Topology Object)  
         [0069]    Transaction configuration objects identify atomic units of work in an application implemented according to the invention.  
                                                   Attribute   Description                           Ruleset   The object identifier of a Ruleset               that specifies how the Transaction is               to be processed. Does not need to be               specified if all of the Servers               specified are “external”.           Servers   A list of object identifiers               identifying the Servers which are               capable of processing the Transaction.                      
 
         [0070]    (11) Interface (System Topology Object)  
         [0071]    Interface configuration objects identify agents which handle the flow of transactions to and from external applications, computers, communications networks or other equipment.  
                                                   Attribute   Description                           System   The object identifier of the System on               which the interface agent executes.           Queue   The object identifier of a Pile that               holds requests destined for the               interface agent. If not set, requests               are held in memory.           In Ruleset   The object identifier of a Ruleset               which specifies how to interpret               incoming messages or events. This               ruleset may specify the interpretation               rules completely, or may select an In               Message which specifies additional               interpretation rules.           Out Ruleset   The object identifier of a Ruleset               which specifies how to construct               outgoing messages or events. This               ruleset may specify the construction               rules completely, or may select an Out               Message which specifies additional               construction rules.           Networks   A list of object identifiers               identifying the Networks which handle               messages passing to and from the               external applications, computers,               communications networks or other               equipment.                      
 
         [0072]    (12) In Message, Out Message (System Topology Object)  
         [0073]    In Message and Out Message configuration objects identify additional message processing rules to be invoked by interfaces. For example, the In Ruleset for a given Interface may have rules which identify categories of messages, and select appropriate In Message types for detailed analysis depending on the category. Note that this is most useful for interfaces that must handle complex sets of messages.  
                                                             Attribute   Description                           Ruleset   The object identifier of a Ruleset                that specifies how the message is to           be processed (analyzed or           constructed).                      
 
         [0074]    (13) Network (System Topology Object)  
         [0075]    Network configuration objects identify agents which handle messages and/or event notifications to and from external applications, computers, communications networks or other equipment.  
                                                                                                                                                                                                                                                   Attribute   Description                       System   The object identifier of the System on                which the Network agent executes.                Queue   The object identifier of a File that                holds requests destined for the           Network agent. If not set, requests           are held in memory.                Interface   The object identifier of the Interface                to which the Network agent sends           incoming messages, and from which it           receives outgoing messages.                Type   Identifies the type of external                application, computer, communications           network or other equipment with which           to communicate (e.g. generic,           Intermec)                Protocol   The object identifier of a Protocol                object which specifies protocol type           and parameters necessary for           communication with the external           application, computer, communications           network or other equipment.                Type   Identifies the type of external                application, computer, communications           network or other equipment with which           to communicate (e.g. generic,           Intermec)                Network Info   Identifies any additional, Network                Type-specific communications           parameters.                (14)   Protocol (System Topology Object)              Protocol configuration objects identify           communications protocol parameters necessary for           communications with external applications, computers,           communications networks or other equipment.                Attribute   Description                       Type   The type of communications protocol to                use. Possible values include (but are           not limited to) async, bisync, TCP/IP           (client or server), UDP, X25 (PVC or           SVC), LU2, LU6.2, etc.                      
 
         [0076]    Additional attributes vary depending on the Type selected. For example, async attributes include Baud Rate, Character Size, Stop Bits, Parity, Flow Control, and Record Demarcation (which includes record length if records are of a fixed length, or the end-of-record character otherwise). Similarly, TCP/IP Client attributes include Destination Host Name, Service Name, and Record Demarcation.  
         [0077]    (15) Device (System Topology Object)  
         [0078]    Device configuration objects identify external devices that the application would like to manage. The application can send explicit messages to Devices (e.g. “print” commands to a label printer). Additionally, the system can manage the download of configuration data (e.g. form definitions, programs, etc.) to Devices.  
                                                                                                                                     Attribute   Description                           Type   The type of Device (e.g. Intermec                label printer).                Address   Device address information by which                messages to/from the Device are           routed/identified.                Network   The object identifier of the Network                which handles communications with the           Device.                Control   Names which identify configuration           Entries   data (formats, programs, etc.)                currently downloaded to the Device.           The names are Type specific, but           normally those of Control objects           which further specify what           configuration data is downloaded.                      
 
         [0079]    (16) Control (System Topology Object)  
         [0080]    Control configuration objects identify configuration data that may be downloaded to Devices (e.g. form definitions, programs, etc.), or additional Network-specific configuration (e.g. data-point definitions).  
                                                                                                             Attribute   Description                           Type   The type of Device (e.g. Intermec                label printer).                Buffer Type   Specifies bow Buffer is to be                interpreted. Possible values include           (but are not limited to) Direct           (Buffer contains literal download           data), Indirect (Buffer contains the           pathname of a file which contains the           download data), or Data Point (Buffer           contains a list of data point           definitions).                Buffer   Contains control information (as                specified by Buffer Type).                      
 
         [0081]    (17) Screen (Application Presentation Object)  
         [0082]    Screen configuration objects identify application presentation screens, used for user input and/or display of data.  
                                                                                                                                                                                                   Attribute   Description                           Detail Object   The object identifier of a Menu,                Listing, or Data Entry that specifies           the details of the data presentation.                Title   Text which may appear as a screen                title.                Actions   A list of object identifiers of                Rulesets which can be invoked at the           request of the user when the Screen is           active, via associated function key or           button. Each Action has an associated           label that should describe the           function implemented by the Ruleset.                Access Control   A list of entries controlling who may                use this Screen, and which of the           Actions they are allowed. Each entry           has the following attributes:                User or   The object identifier of a User or           Group   Group for which access is being                specified. The system first checks           for an entry for the current user; if           none exists, the system checks for an           entry for the current user&#39;s group.                Access   Allowed or disallowed. The disallowed           Type   value is useful for excluding a                particular member of a group while           still allowing access for the group.                Allowed   Indicates which of the Actions may be           Actions   invoked by the user or group.                      
 
         [0083]    (18) Menu (Application Presentation Object)  
         [0084]    Menu configuration objects identify application presentation menus. When a Screen which refers to a Menu is invoked, a list of selections from which the user may select is displayed.  
                                                                                                             Attribute   Description                           Selections   A list of entries that determines what                actions are available from the Menu.           Each entry has the following           attributes:                Action   The object identifier of a Ruleset                which can be invoked at the request of           the user when the Menu is active, via           associated key-press or button.                Label   Text which should describe the                function implemented by the Ruleset.           One of the letters of the Label may be           identified as a “hot key,” in which           case it will appear underlined (or           otherwise highlighted) to indicate           that this selection may be made by           pressing the associated letter key.                      
 
         [0085]    (19) Listing (Application Presentation Object)  
         [0086]    Listing configuration objects identify application presentation listings. When a Screen which refers to a Listing is invoked, a list is displayed which is constructed from a specified set of records in a table.  
                                                                                                                                                                                     Attribute   Description                           Index   The object identifier of an Index                which determines the File from which           records are selected, and the order in           which they appear.                Record   The object identifier of a Record           Determination   which determines how the records are                to be interpreted. By default, the           Record Definition attribute of the           associated File is used.                First Key   The object identifier of a Function                which, when evaluated, determines the           value of key of the first record to be           displayed in the list.                Last Key   The object identifier of a Function                which, when evaluated, determines the           value of key of the last record to he           displayed in the list.                Filter   The object identifier of a Function                which, when evaluated for each record,           determines whether or not the record           is to be included in the list.                Display   The object identifier of a Function                which, when evaluated for each record,           determines the text to be displayed           list.                      
 
         [0087]    (20) Data Entry (Application Presentation Object)  
         [0088]    Data Entry configuration objects identify data entry screens. When a Screen which refers to a Data Entry is invoked, a specified arrangement of fields is displayed. Some or all of the fields may be edited by the user, as allowed by the configuration.  
                                                                                                             Attribute   Description                           Record   The object identifier of a Record                which determines the set of fields           which are to appear on the screen.                Fields   A set of entries which determines how                each of the Elements in the Record are           to be displayed. Each entry has the           following attributes:                Label   The column and row at which the field           Location   label is to be displayed.           Label   The number of characters of field           Length   label to display.           Label   Display attributes of the label (e.g.           Display   underlined, hold, dim, etc.)           Modes           Field   The column and row at which the field           Locations   is to be displayed.           Field   The number of characters of field to           Length   display.           Field   Display attributes of the field (e.g.,           Display   underlined bold, dim, etc.)           Modes           Field   Controls how data is entered (e.g.,           Control   normal, output-only, select-only,           Modes   etc).           Detail   The object identifier of a Ruleset           Ruleset   which is invoked when the user                requests details about this field.           This Ruleset can implement any           application functionality, but           typically allows selection of a value           for the field.                      
 
         [0089]    (21) Report (Application Presentation Object)  
         [0090]    Report configuration objects identify reports which may be displayed or printed. A Report consists of optional title and header lines, primary lines composed of a set of columns, and alternate lines of arbitrary text that may be interspersed with the primary lines.  
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             Attribute   Description                           Index   The object identifier of an Index                which determines the File from which           records are selected, and the order in           which they appear.                First Key   The object identifier of a Function                which, when evaluated, determines the           value of key of the first record from           which to generate report lines.                Last Key   The object identifier of a Function                which, when evaluated, determines the           value of key of the last record from           which to generate report lines.                Report Format   Identifies the format of the report                (e.g., standard, free-format, form,           etc.)                Title Lines   The object identifiers of Functions                which, when evaluated, determine the           text to appear in the report titles           (at the top of each page in a standard           format report).                Header Fields   The object identifiers of Functions                which, when evaluated, determine the           text to appear in the report headers           (typically on each page before column           headers, and primary and alternate           report lines, although, in the ease of           form reports, Header Field values may           appear anywhere on the form). Each           Header Field also has associated           formatting information, such as           indent, width and justification.                Page Breaks   The object identifiers of Functions                which, when evaluated after reading a           record, determine whether to insert a           page break before generating any           additional primary or alternate lines.                Pre-Processing   The object identifier of a Ruleset                which is evaluated after reading each           record and before any additional           processing is done.                Post-   The object identifier of a Ruleset           Processing   which is evaluated before reading the                next record, after all processing for           the current record is complete.                Filter   The object identifier of a Function                which is evaluated after reading each           record and performing the Pre-           Processing and which determines           whether primary lines are generated           (or Slave processing occurs) for the           record.                Slave   The object identifier of a Report                controls report formatting. For each           record read as specified in the           current Report, a complete set of           records is processed as defined by the           Slave Report configuration.                Alternate   Entries which control arbitrary text           Lines   lines which may appear on the report.                Each entry has the following           attributes:                Filter   The object identifier of a Function                which is evaluated for each record to           determine whether this Alternate Line           is to be generated.                Contents   The object identifier of a Function                which, when evaluated, determines the           text to appear.                Explode   The object identifier of a Ruleset                which can be invoked when the           Alternate Line text is selected by a           user who is viewing the report online.                Format   Text width, indent and justification.           Location   Whether the Alternate Line is to be                generated before or after the primary           line, and/or at the end of the report.                Primary Line   Includes: number of column headers and           Format   footers; whether to suppress column                headers and footers on pages on which           no primary line appears; whether or           not footers “float” (appear           immediately after the last detail           line) or are fixed at the bottom of           each page.                Primary Line   The object identifier of a Ruleset           Explode   which can be invoked when the primary                line is selected by a user who is           viewing the report on-line.                Primary Line   Entries which control primary text           Columns   lines appearing on the report. Each                entry controls a column of output and           has the following attributes:                Contents   The object identifier of a Function or                Element which, when evaluated,           determines the text to appear in the           column.                Format   Column width, indent and                justification.                Headers   The object identifiers of a Function                which, when evaluated, determine the           text to appear at the top of the           column on each page. Each of the           Headers has associated formatting           information, including justification.                Footers   The object identifiers of a Function                which, when evaluated, determine the           text to appear at the bottom of the           column on each page. Each of the           Footers has associated formatting           information, including justification.                      
 
         [0091]    (22) User (User Access Object)  
         [0092]    User configuration objects identify users who may access applications via application presentation objects.  
                                                                                     Attribute   Description                           Group Name   The Group to which the User belongs.                Password information against which to           verify entered passwords.                Ruleset   The object identifier of a Ruleset                which is invoked when the User logs           in. If not set, the Ruleset for the           Group is invoked.                      
 
         [0093]    (23) Group (User Access Object)  
         [0094]    Group configuration objects identify groups of users who may access applications via application presentation objects.  
                                                   Attribute   Description                           Default   The object identifier of a Ruleset           Ruleset   which may be invoked when a User in               this Group logs in.                      
 
         [0095]    (24) Ruleset (Rule Management Object)  
         [0096]    Ruleset configuration objects encode application-specific functionality. Rulesets are composed using a set of verbs to form rules. A rule is composed of an antecedent and a consequent. An antecedent is a conjunction of conditionals (constructed of verbs), evaluated one at a time. If the conditionals return a non-false value, the rule is said to be fired. A consequent is a list of statements (constructed of verbs) to be evaluated when the rule is fired. The first rule to be fired completes the invocation of the Ruleset, and none of its subsequent rules are evaluated.  
         [0097]    The syntax is as follows:  
                                                   Ruleset: = always: Stmt; [[Stmt;] . . . ]           Ruleset: = Rule [Rule . . . ] [DfltRule ]           Rule: =  if: Cond [[ &amp; Cond] . . . ]                then: Stmt; [[ Stmt; ] . . . ]]           DfltRule: =  otherwise: Stmt; [[ Stmt;] . . . ]           Cond: =  verb ([arg . . . ] )           Stmt: =  verb ([arg . . . ] )           Arg: =  verb ([arg . . . ] )           Arg: =  literal (test string, name or number)                      
 
         [0098]    (25) Function (Rule Management Object)  
         [0099]    Function configuration objects encode application-specific functionality. When invoked, a Function returns a value. Functions are composed by nesting verbs.  
         [0100]    The syntax is as follows:  
                                                   Function: =  verb ([arg . . . ]);           Arg: =  verb ([arg . . . ])           Arg: =  literal (text string, name or number)                      
 
         [0101]    III. Example  
         [0102]    With reference to FIG. 10, a hypothetical transaction can be followed through a system of the present invention. Imagine the transaction is a financial transaction that must check with an external system for verification. The result of the transaction will be sent back to the originating external system as a response.  
         [0103]    STEP I Message Origination  
         [0104]    Network agent NET 1  (indicated at  80 ) using Protocol PROT 1  reads in a message from its external system  82 .  
         [0105]    NET 1  sends this message to its associated Interface agent IFC 1  (indicated at  84 ).  
         [0106]    IFC 1  examines the message to determine what type of message it is. Using the appropriate record structure (REC 1 ) as a map, it then binds the message into an initialized Context. This puts the message data into the various data Elements within Context, making the transaction context independent of the message layout.  
         [0107]    IFC 1  then sends the Context to the appropriate Server agent SVR 1  (indicated at  86 ) for processing. Actually, the routing to the correct server takes place automatically within the system. This allows for busy servers to be alleviated during periods of heavy stress.  
         [0108]    STEP II Initial Processing  
         [0109]    SVR 1  reads the Context and performs the desired Transaction TRN 1 .  
         [0110]    TRN 1  needs to request information from external system  2  (indicated at  88 ) about the information in Context.  
         [0111]    STEP III Information Request  
         [0112]    Context is sent to interface agent IFC 2  (indicated at  90 ).  
         [0113]    IFC 2  builds a message from Context using REC 2 .  
         [0114]    The message is sent to network agent NET 2  (indicated at  92 ).  
         [0115]    NET 2  reads the message and transmits it to external system  2  using PROT 2 .  
         [0116]    STEP IV Information Response  
         [0117]    Some time later, NET 2  reads a message in from external system  88 .  
         [0118]    NET 2  sends the message to IFC 2 .  
         [0119]    IFC 2  identifies the message as the response to TRN 1 . It binds the message into the Context of TRN 1  instead of an initialized Context. Thus, the response from the external system becomes part of our Context.  
         [0120]    IFC 2  sends the Context back to SVR 1 .  
         [0121]    STEP V Secondary Processing  
         [0122]    SVR 1  uses the response information in additional processing.  
         [0123]    TRN 1  updates files with the initial result.  
         [0124]    TRN 1  sends Context to another server agent SVR 2  (indicated at  94 ) for additional processing.  
         [0125]    SVR 2  reads the Context and performs TRN 2 .  
         [0126]    TRN 2  updates files with the results.  
         [0127]    Context is sent back to the originating Interface IFC 1  as a response. Thus, the transaction request has been fulfilled.  
         [0128]    STEP VI Send Result  
         [0129]    IFC 1  builds a message from Context using REC 3 .  
         [0130]    The message is sent to NET 1 .  
         [0131]    NET 1  reads the message and transmits it using PROT 1 .  
         [0132]    While preferred embodiments of the present invention and preferred methods of practicing same have been shown and described, modifications and variations may be made by thereto by those of ordinary skill in the art without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention so further described in such appended claims.