Specifying Paging and Update Requests

Pageable Maps › Dialog and Program Operations › Map-Paging Session Options › Specifying Paging and Update Requests

Specifying Paging and Update Requests

Paging-type Specification

The paging-type specification for a dialog or program determines whether the program or the runtime mapping system handles paging and update requests. Paging and update requests are made when the operator presses a control key:

A paging request to display a different page of the map is made if either of the following cases applies when the operator presses a control key:
- The control key is associated with paging forward or backward.
- The value in the $PAGE field has been altered by the operator or the dialog/program that uses the map, and the control key is not <Clear>, <PA1>, <PA2>, or <PA3> (which do not transmit data).
An update request (to update operator modifications to the scratch record for the paging session) is made when the MDT is set on for fields and the operator presses a control key other than <Clear>, <PA1>, <PA2>, or <PA3>.

Three Types of Paging

One paging-type option must be specified for a dialog or program that uses a pageable map. The paging options affect the flow of control when an operator presses a control key during a paging session as described in the following table:

Option	Affect on flow of control
NOWAIT	(default) Specifies that the runtime mapping system automatically handles all paging and update transactions. Control is passed to the program runtime system only when neither an update nor a paging request is made when the operator presses a control key.
WAIT	Specifies that runtime mapping automatically handles paging transactions that do not cause data to be updated. Control is passed to the program runtime system when an update or non-paging request is made.
RETURN	Specifies that the mapping runtime system does not handle any terminal transactions in the paging session. Control is passed to the program runtime system whenever the operator presses a control key.

Note: Runtime mapping does not update program variable storage unless a MAP IN command is issued. In cases where the operator can update data, it is recommended that WAIT or RETURN be specified for the map-paging session so that data can be retrieved as it is updated.

CA ADS automatically handles all MAPIN and MAPOUT commands.

Paging Type	Paging request		Non-paging request

Paging Type	No MDT set	Any MDT set **	No MDT set	Any MDT set **
NOWAIT	Runtime mapping displays the requested map page	Runtime mapping displays the requested map page	Control passes to the program runtime system	Runtime mapping redisplays the same map page
WAIT	Runtime mapping displays the requested map page	Control passes to the program runtime system	Control passes to the program runtime system	Control passes to the program runtime system
RETURN	Control passes to the program runtime system	Control passes to the program runtime system	Control passes to the program runtime system	Control passes to the program runtime system

* If <Clear>, <PA1>, <PA2>, or <PA3> is pressed, and that key is not associated with backward or forward paging, refer instead to the Non-paging Request heading.

** If <Clear>, <PA1>, <PA2>, or <PA3> is pressed, refer to the No MDT Set column under the same heading.

How to Specify the Paging-type

The paging-type is specified for a CA ADS dialog or application program as follows:

Language	Option/Clause
CA ADS	NOWAIT/WAIT/RETURN option—Map Specifications screen in ADSC PAGING TYPE clause
COBOL or PL/I	NOWAIT/WAIT/RETURN clause—STARTPAGE statement
Assembler	TYPE=NOWAIT/WAIT/RETURN clause—#STRTPAG macro

Note

For more information on CA ADS specifications 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 COBOL or Assembler pageable map statements, see the CA IDMS DML Reference Guide for Assembler or the CA IDMS DML Reference Guide for COBOL.