Pageable Maps › Map-Paging Sessions › Sequence of Events in a Map-paging Session

Sequence of Events in a Map-paging Session

1. The map-paging session is initiated according to specifications or commands in the CA ADS dialog or application program that uses the pageable map.

   More information

   • For more information about CA ADS statements for pageable maps, see the CA ADS Reference Guide.
   • For more information about PL/I statements for pageable maps, see Appendix G, “PL/I DML Statements for Pageable Maps”.
   • For more information about Assembler or COBOL statements, see the CA IDMS DML Reference Guide for Assembler or the CA IDMS DML Reference Guide for COBOL.
2. Detail occurrences are created by statements in the dialog or program. Occurrences are stored sequentially in the order that they are created and are divided into pages based on the number of detail occurrences that can fit on the terminal screen at one time. A detail occurrence is displayed on the terminal screen only when the map page to which the occurrence belongs is displayed.
3. A map page is displayed by the CA ADS runtime system or the DC runtime system as a result of one of the following:
   • The first detail occurrence on the second page of occurrences is constructed. The first page of detail occurrences in a map-paging session is automatically displayed. The CA ADS process or program module that creates detail occurrences continues to execute and can create additional detail occurrences.
   • A display command is issued by the dialog (except when the command immediately follows the display of the first page of occurrences, as described previously).
   • A display is done automatically when the dialog has no premap process

   The CA ADS runtime system (which executes CA ADS dialogs) and the DC runtime system (that executes application programs) are both referenced by the term program runtime system in the remainder of this section. The term runtime mapping system refers to a separate part of the runtime system that handles only mapping functions at runtime.

   Note: For more information about display commands for pageable maps, see Building and Displaying Fields.

4. The terminal operator optionally modifies map data fields in the header or footer areas or in any of the detail occurrences of the current map page. Map-field modifications are subject to restrictions specified at map-definition or map runtime:
   • At map-definition time, fields can be protected from operator input.
   • At map runtime, modifications can be restricted by specifications made in the CA ADS dialog or application program:
     • The paging mode option (UPDATE/BROWSE) determines whether modifications can be made to a pageable map.
     • Map modification commands determine whether modifications can be made to individual fields.

   Note:

   • For more information about paging mode options, see "Map-Paging Session Options".
   • For more information about modification commands, see "Map Inquiry and Modification”.
5. The terminal operator optionally makes a paging request to specify the next map page to be displayed in either of the following ways:
   • By pressing a control key associated with paging forward or backward one page:
     • <PF8> pages the detail area forward one page.
     • <PF7> pages the detail area backward one page.

     These control key settings are system generation options.

   • By specifying an integer value in the page field (if any) on the map.
   • By typing first or last over the page field on the map.
     • First brings the operator to the first page of detail occurrences.
     • Last brings the operator to the last page of detail occurrences.
6. The terminal operator presses a control key, initiating the following:
   • The internal representation of data fields is updated to reflect changes made by the terminal operator if the operator pressed any key other than <Clear>, <PA1>, <PA2>, <PA3>.
   • The $PAGE value is updated if a paging request was made in any of the following ways:
     • The operator pressed a key associated with paging forward or backward
     • The operator specified a value in the page field (if any) on the map
     • The dialog or program set the value of the $PAGE field on the previous mapin operation
   • The flow of control is determined by the paging-type option specified for the dialog or program

     Note: For more information about paging-type specifications,see Building and Displaying Fields.

7. Modified detail occurrences are retrieved by commands in the dialog or program. Data is updated to program variable storage according to specifications made for each field.

   Note: For information about retrieval commands for pageable maps, see Retrieving Modified Data.

8. Detail occurrences are modified by either the program runtime system or the mapping runtime system, as specified by the paging-type for the map-paging session.

   Note: For information about paging-type options, see "Building and Displaying Fields".

9. Additional detail occurrences are created at any time by commands in the dialog or program. New detail occurrences are stored at the end of the set of detail occurrences in the session scratch record.

   Note: For information about commands that create new detail occurrences, see Building and Displaying Fields.

10. A page of the map is displayed by either the program runtime system or the mapping runtime system, as specified by the paging-type for the map-paging session.
11. The map-paging session is terminated according to specifications or commands in the CA ADS dialog or application program that uses the pageable map.