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document resume ed 422 922 ir 057 080 author lorents alden c title gui and object oriented programming in cobol pub date 1997 00 00 note 9p in proceedings of ...

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                                       DOCUMENT RESUME
            ED 422 922                                                    IR 057 080
            AUTHOR            Lorents, Alden C.
            TITLE             GUI and Object Oriented Programming in COBOL.
            PUB DATE          1997-00-00
            NOTE              9p.; In: Proceedings of the International Academy for
                              Information Management Annual Conference (12th, Atlanta, GA,
                              December 12-14, 1997); see IR 057 067.
            PUB TYPE          Reports   Descriptive (141)     Speeches/Meeting Papers (150)
            EDRS PRICE        MF01/PC01 Plus Postage.
            DESCRIPTORS       *Computer Interfaces; *Computer Science Education; Computer
                              Software Development; *Computer System Design; Curriculum
                              Development; Design Preferences; Higher Education;
                              *Programming; *Programming Languages
            IDENTIFIERS       COBOL Programming Language; *Graphical User Interfaces;
                              *Object Oriented Programming
            ABSTRACT
                              Various schools are struggling with the introduction of
            Object Oriented (00) programming concepts and GUI (graphical user interfaces)
            within the traditional COBOL sequence. 00 programming has been introduced in
            some of the curricula with languages such as C++, Smalltalk, and Java.
            Introducing 00 programming into a typical COBOL sequence presents some
            interesting challenges. There are a number of new concepts to introduce along
            with various design issues that are relatively new to 00 program design, such
            as file maintenance and data objects. Most C++ programming courses tend to
            work with objects that are more user interface related, such as traditional
            GUI objects. This paper describes an example of using 00 COBOL and Dialog
            Systems (GUI builder) in an advanced programming applications course.
             (Author/AEF)
            ********************************************************************************
                         Reproductions supplied by EDRS are the best that can be made
                                          from the original document.
            ********************************************************************************
                            GUI AND OBJECT ORIENTED PROGRAMMING IN COBOL
                              U.S. DEPARTMENT OF EDUCATION                                                                                                                         "PERMISSION TO REPRODUCE THIS
                           Office of Educational Research and Improvement                                                                                                         MATERIAL HAS BEEN GRANTED BY
         .C4             EDUCATIONAL RESOURCES INFORMATION
         C1                               CENTER (ERIC)                                                    Alden C. Lorents
         ON             0 This document has been reproduced as                                                                                                                              T. Case
         C 1N               received from the person or organization                         Northern Arizona University
         Tr                 originating it.
                        0 Minor changes have been made to
         0                  improve reproduction quality.
        44                                                                                                                                                                        TO THE EDUCATIONAL RESOURCES
                            Points of view or opinions stated in this
                           document do not necessarily represent                                                                                                                  INFORMATION CENTER (ERIC)."
                           official OERI position or policy.
                        Various schools are struggling with the introduction of Object Oriented (00) programming concepts and
                        GUI within the traditional COBOL sequence. 00 programming has been introduced in some of the
                        curriculums with languages such as C++, Smalltalk, and Java.                                                                          Introducing 00 programming into a
                        typical COBOL sequence presents some interesting challenges. There are a number of new concepts to
                        introduce along with various design issues that are relatively new to 00 program design such as file
                        maintenance and data objects. Most C++ programming courses tend to work with objects that are more
                        user interface related such as traditional GUI objects. This paper describes an example of using 00
                        COBOL and Dialog Systems (GUI builder) in an Advanced Programming Applications course.
                                                      INTRODUCTION                                                                                                  GUI AND COBOL
                                                                                                                                                         USING DIALOG SYSTEMS
                        "COBOL is in a unique position to bridge the past                                                             Adding GUI (windows) to COBOL program
                        with the future. COBOL practitioners bring a                                                                  development is very easy today with the use of
                        wealth of experience spanning all phases of the
                        software life cycle including analysis, design,                                                               either Micro-Focus Dialog Systems or IBM Visual
                        implementation,                        database               integration,                 and                Age for COBOL. The examples shown in this
                        maintenance" [Arranga, 1997]. The inventory of                                                                paper were done using Dialog Systems.                                                      The
                        legacy systems continues to be estimated at                                                                   window shown in figure 1 is a passenger
                        around 180 billion lines of COBOL code. Some                                                                  reservation window that is used to maintain data
                        organizations                      (typically                technology                    and                using a traditional VSAM file structure with a
                        engineering based companies) have migrated                                                                    primary key (itinerary number) and two
                        away from using COBOL. They have done this by                                                                 alternate keys (passenger name and flight
                        going to client-server systems using databases                                                                number).
                        such as Oracle, Sybase and DB2 along with client                                                                                                    FIGURE 1
                        tools such as Visual Basic, Powerbuilder, and
                        Oracle tools.                     Many organizations are still
                        committed to their COBOL based systems                                                                         file
                        because of the high investment in these systems,                                                                   Passenger
                        the high cost to rebuild the systems, and the                                                                           Itinerary No: 1000005                Name: !Anderson Ole
                        inability of the newer client-server technologies to                                                                                                         Phone: 520.526.8396
                        handle the loads in large systems (salability). 00
                        COBOL, GUI builders (such as Micro Focus                                                                                    Date: 01/25/1997                   Flight No:       0099        Fare: 10101.00
                        Dialog Systems and IBM Visual Age for COBOL)
                        and the integration of these products with                                                                        NEXT OUERY COMPLETED
                        common object standards (Common Object
                        Request Broker Architecture                                         CORBA), may
                        provide an alternative for many of these                                                                          OFM1                                                                               I
                        organizations to migrate their legacy systems into                                                                                                                                jaP.               !plant
                        newer systems based on the new technologies.
                        Proceedings of the 12°' Annual Conference of the International Academy for Information Management                                                                                                          107
                                                                                                                                    2
                                                                                                                                                                                                             FIGURE 2
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                                                                                                                                                                                                                                                                                                                                                                                              I
                                            The window is built using the Dialog Systems
                                            object palette or object pull down menu shown in                                                                                                                                                                                                              FIGURE 3
                                            figure 2.                                     Objects available include primary
                                            window,                               secondary                                    window                              (clipped                            and                                 FLD NO                                FIELDNAME                                                          FORMAT LENGTH
                                            unclipped), dialog box, message box, entry field,
                                            multiple line entry field, push button, radio                                                                                                                                                            1                           X300-ITINERARY-NO                                                            9                                 6.00
                                            button, check box, list box, selection box, text box,
                                            group box, bitmap and notebook.                                                                                                                                                                          2                          X300-NAME                                                                     X                             20.00
                                            Normally you start the build process by defining                                                                                                                                                         3                          X300-PHONE                                                                    X                             12.00
                                            a set of data to be used with the window. The data                                                                                                                                                       4                           X300-DATE                                                                    X                              10.00
                                            is referred to as a data block and is defmed                                                                                                                                                             5                          X300-FLIGHT-NO                                                                9                                4.00
                                            similar to COBOL. The data block can be entered                                                                                                                                                          6                          X300-FARE
                                            in Dialog Systems or imported from a COBOL                                                                                                                                                                                                                                                                        9                                4.02
                                            data definition.                                               The data block used for this                                                                                                                                         X300-ACTION                                                                  X                                  1.00
                                            window is shown in figure 3.
                                                                                                                                                                                                                                                     8                          X300-MESSAGE                                                                 X                              40.00
                                            Normally a data element is defined for each field                                                                                                                                           application program knows which button the user
                                            supported on the window along with any other                                                                                                                                                pushed when control is turned over to the
                                            fields necessary to support communication                                                                                                                                                   application program. Each of the other fields is
                                            between the window and the application                                                                                                                                                      associated with a entry field or display field on
                                            program. X300-Action is used to communicate a                                                                                                                                               the window.                                            A copy block (file) of COBOL
                                            code to the application program, so the
                                            108                                                      Proceedings of the 12 'h Annual Conference of the International Academyfor Information Management
                                                                                    FIGURE 4
            definitions corresponding to each field on the
            window is generated by a command on the file
            menu. This file is called using a copy statement      GLOBAL DIALOG:
            in the Working Storage Section of the COBOL                  ESC
           program. This assures that the data definitions                       MOVE "X" X300-ACTION
            in the application program are exactly the same                      RETC
            as the data definitions on the window.                       CLOSED-WINDOW
                                                                                 MOVE "X" X300-ACTION
           The operation of a window is controlled by events.                    RETC
            Events can be trapped at various levels such
            global (events associated with all windows in the     LOCAL DIALOG:
            set), for each specific window, and for each                 @MNU-EXIT
            specific object on a window. Examples of events                      MOVE "X" X300-ACTION
            include window created, closed window, item                          RETC
            selected, mouse over, button selected, gained
            focus, lost focus and various other events. Each      DIALOG FOR PUSH BUTTON : PB-ADD
            event can be trapped at different levels and                 BUTTON-SELECTED
            programmed to carry out various functions. This                      MOVE "A" X300-ACTION
            programming is called script and is executed as                      RETC
            part of the windows operating system. Figure 4                       REFRESH-OBJECT $WINDOW
            shows some examples of script that are used on
            this window. Escape and Closed-Window have
            been defined in this application to exit the          Two blocks of data (data block and control block)
            application. The application program has been         pass between the application program and the
            programmed to exit when it sees an 'X' in the         Dialog Systems Program (DSRUN) each time
            action code.   The command RETC is a script           control is passed from one to the other. The
            command to leave the window and return to the         application program calls the Dialog Systems
            calling (application) program.  The local dialog      program with a subprogram Call Statement. The
            for the window traps the exit menu selection          code in the application program that is used to
            under File and also closes the application. If the    communicate with Dialog Systems is shown in
            escape and closed-window events under GLOBAL          Figure 5.   The program-initialize routine is
            were moved to LOCAL for the window win-pass,          executed once at the beginning of the application
            then those events would be trapped only when          to set up some of the parameters in the control
            that window is in focus.                              block. The Call-Dialog routine is used each time
                                                                  the application program returns control to the
            Script is written for each button to tell the         window. Note that the Call statement calls
            application program which routine to execute          Dialog-System as a subprogram using the control
            when control is returned to the application           block and the data block.
            program. When the application program returns         Setting up windows like this allows faculty to
            to the window, the window program continues to        illustrate all of the components of client-server
            execute the script that is was on when it turned      programming using COBOL as the application
            control over to the application program.    The                    The client (window program) is
            ADD push button script illustrates this with the      language.
            execution of the REFRESH-OBJECT $WINDOW               running various scripts that control operations at
            command after it returns from the calling             the client.  The application program could be
            program.     The application program sends            running on any platform such as an application
            additional data back to the window, and the           server. If the application program has embedded
            window must be refreshed in order to display that     SQL to an Oracle server, you are able to illustrate
            data. The window is displayed at the end of any       full 3-tier architecture in a COBOL environment.
            script that is executed after control has been        Dialog Systems supports a robust windows
            returned to the window program.                       environment including data validation, list boxes
            Proceedings of the 12th Annual Conference of the International Academy for Information Management  109
                                                                 4
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...Document resume ed ir author lorents alden c title gui and object oriented programming in cobol pub date note p proceedings of the international academy for information management annual conference th atlanta ga december see type reports descriptive speeches meeting papers edrs price mf pc plus postage descriptors computer interfaces science education software development system design curriculum preferences higher languages identifiers language graphical user abstract various schools are struggling with introduction concepts within traditional sequence has been introduced some curricula such as smalltalk java introducing into a typical presents interesting challenges there number new to introduce along issues that relatively program file maintenance data objects most courses tend work more interface related this paper describes an example using dialog systems builder advanced applications course aef reproductions supplied by best can be made from original u s department permission rep...

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