topic Re: chain statement in Application Development and Automation Discussions

chain statement

Former Member — Mon, 20 Aug 2007 04:45:54 GMT

what do chain - endchain statement do?

Re: chain statement

Former Member — Mon, 20 Aug 2007 04:50:01 GMT

Hi,

The CHAIN and ENDCHAIN statement controls a set of fields in PAI event of screen.

To ensure that one or more PAI modules are only called when several screen fields meet a particular condition, you must combine the calls in the flow logic to form a processing chain. You define processing chains as follows:

CHAIN.

...

ENDCHAIN.

All flow logic statements between CHAIN and ENDCHAIN belong to a processing chain. The fields in the various FIELD statements are combined, and can be used in shared conditions.

CHAIN.

FIELD: <f1>, <f 2>,...

MODULE <mod1> ON CHAIN-INPUT|CHAIN-REQUEST.

FIELD: <g1>, <g 2>,...

MODULE <mod2> ON CHAIN-INPUT|CHAIN-REQUEST.

...

ENDCHAIN.

All flow logic statements between CHAIN and ENDCHAIN belong to a processing chain. The fields in the various FIELD statements are combined, and can be used in shared conditions.

CHAIN.

FIELD: <f1>, <f 2>,...

MODULE <mod1> ON CHAIN-INPUT|CHAIN-REQUEST.

FIELD: <g1>, <g 2>,...

MODULE <mod2> ON CHAIN-INPUT|CHAIN-REQUEST.

...

ENDCHAIN.

When this command is used, all of the fields on the screen that belong to the processing chain (all of the fields listed in the field statements) are made ready for input again. Other fields are not ready for input. Whenever the MODULE statement appears within a processing chain, even if there is only one FIELD attached to it, all of the fields in the chain (not only the affected field) are made ready for input again, allowing the user to enter new values. If the fields in the processing chain are only checked once, the PAI processing continues directly after the FIELD statement, and the preceding modules are not called again.

CHAIN.

FIELD: <f1>, <f 2>,...

MODULE <mod1> ON CHAIN-INPUT|CHAIN-REQUEST.

FIELD: <g1>, <g 2>,...

MODULE <mod2> ON CHAIN-INPUT|CHAIN-REQUEST.

...

ENDCHAIN.

Check this out

http://help.sap.com/saphelp_nw04/helpdata/en/9f/dbabbd35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_47x200/helpdata/en/d1/801ca2454211d189710000e8322d00/frameset.htm

<b>Sample Code</b>

PROCESS BEFORE OUTPUT.

MODULE INIT_SCREEN_100.

PROCESS AFTER INPUT.

MODULE CANCEL AT EXIT-COMMAND.

CHAIN.

FIELD: INPUT1, INPUT2.

MODULE MODULE_1 ON CHAIN-INPUT.

FIELD INPUT3 MODULE MODULE_* ON *-INPUT.

MODULE MODULE_2 ON CHAIN-REQUEST.

ENDCHAIN.

FIELD INPUT1 MODULE C1 AT CURSOR-SELECTION.

CHAIN.

FIELD: INPUT2, INPUT3.

MODULE C2 AT CURSOR-SELECTION.

ENDCHAIN.

MODULE CURSOR AT CURSOR-SELECTION.

Regards,

Padmam.

Re: chain statement

former_member194669 — Mon, 20 Aug 2007 04:50:28 GMT

Hi,

FIELD and MODULE are used to monitor a field on the screen and then on INPUT or ON REQUEST you would like to execute a module where in you want to validate the value and if there is an error you will raise an error message using MESSAGE statement and mesage type 'E'.

So when you raise an error message from this module only this field will be made editable, I mean open for edit, rest all will be non-editable this is to make sure that you correct yor error for these field before you make entries in other fields.

Similarly if you want to monitor a group of fields on the screen and then on error want only this group of screen fields to be editable so that error is resolved. Then you need to use CHAIN and ENDCHAIN to group these fields.

CHAIN.

FIELD FLD1.

FIELD FLD2.

FIELD FLD3.

MODULE validate_input ON CHAIN-INPUT.

ENDCHAIN.

aRs

Re: chain statement

Former Member — Mon, 20 Aug 2007 04:51:36 GMT

Chain and EndChain blocks group input fields and modules for validation. Different user commands are checked in a case/endcase block of a PAI.

===================

Process after input.

Chain.

Field: planfli-cityfrom, planfli-cityto, actfli-fldate, planfli-carrid.

Module action_request.

EndChain.

Sometimes you want to check several fields as a group. To do this, include the fields in a FIELD statement, and enclose everything in a CHAIN-ENDCHAIN block. Example **** Screen flow logic: **** CHAIN. FIELD: SPFLI-CARRID, SPFLI-CONNID. MODULE CHECK_FLIGHT. ENDCHAIN. When an error is found inside a chain, the screen is re-displayed, and all fields found anywhere in the chain are input-enabled. All non-chain fields remain disabled. How can you test flow logic? Check function checks the syntax,data-consisteny and screen layout of the screen. To test the syntax, from the menu path choose screen--~~>check~~--~~-> syntax. To test the data consistency, from the menu path choose screen>check~~--~~> consistency. To check the layout,from ythe menu path choose screen->check~~--->layout.

reward if useful

Re: chain statement

Former Member — Mon, 20 Aug 2007 05:01:04 GMT

hi,

chain ......... endchain statement provides the user to use a no. of validations. in module pool programming we can have validations at flow logic level using FIELD ST. using field st we can have only one validation to perform at a time.

if there is any requirement for us to do a no.of validation then in such no.of . validations can be given as a group using CHAIN..........ENDCHAIN st.

if helpful reward some points.

with regards,

Suresh Aluri.

Re: chain statement

Former Member — Mon, 20 Aug 2007 05:10:17 GMT

Hi Pradeep.

Chain and End Chain is the set of field of PAI Event in Module pool.

It can be used in Flow Logic in Module pool.

It is used to After Error message came to enable particular fields in screen

Example:

***********

PAI:

*****

CHAIN.

FIELD: ZMARA-MATRN.

ENDCHAIN.

If u use any error message in PAI, these coding will use to you