chain ,endchain

[Former Member]

pls explain in detail CHAIN and ENDCHAIN

[Former Member]

Hi,

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.

The additions ON CHAIN-INPUT and ON CHAIN-REQUEST work like the additions ON INPUT and ON REQUEST that you use for individual fields. The exception is that the module is called whenever at least one of the fields listed in a preceding FIELD statement within the chain meets the condition. So <mod1> is called when one of the fields <fi> meets the condition. <mod2> is called when one of the fields <f i> or <g i> meets the condition.

Within a processing chain, you can combine individual FIELD statements with a MODULE statement to set a condition for a single field within the chain:

CHAIN.

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

FIELD <f> MODULE <mod1> ON INPUT|REQUEST|*-INPUT

|CHAIN-INPUT|CHAIN-REQUEST.

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

ENDCHAIN.

The module <mod1> is called when screen field <f> meets the specified condition for individual fields. <mod2> is called when one of the fields <fi> or <f> meets the condition. If you use the addition ON CHAIN-INPUT or ON CHAIN-REQUEST with FIELD <f>, the condition also applies to the entire chain and module <mod1> and <mod2> are both called.

In cases where you apply conditions to various combinations of screen fields, it is worth setting up a separate processing chain for each combination and calling different modules from within it.

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

check the demo example

DEMO_DYNPRO_FIELD_CHAIN

<b>Reward If Helpful</b>

[Former Member]

Hi,

CHAIN & ENDCHAIN :

The statements CHAIN and ENDCHAIN of the dynpro flow logic define processing chains. Between CHAIN and ENDCHAIN, the statements FIELD and MODULE can be executed. The statements between CHAIN and ENDCHAIN form a processing chain. Processing chains cannot be nested. The CHAIN statement can be specified in the event blocks at PAI and PBO , however, in the event block at PBO it has no effect.

A processing chain allows the joint processing of all the screen fields stated between CHAIN and ENDCHAIN after FIELD statements:

The contents of all screen fields combined to a processing chain by the FIELD statements can be checked in the shared conditions ON CHAIN-INPUT and ON CHAIN-REQUEST of the MODULE statement.

A warning or error message in a module called within a processing chain resets all input fields whose screen fields are combined in this processing chain using FIELD statements to ready-for-input. After a user input, the PAI processing resumes at the CHAIN statement at the latest.

Example

Call dialog modules to check input values. The screen fields input1 and input2 are checked in individual dialog modules check_1 and check_2. The screen fields input3 to input5 are checked in a processing chain in a shared dialog module check_chain. Warning or error messages in the dialog modules either make only one input field input1 or input2 ready for input again or all three input fields input3 to input5.

PROCESS AFTER INPUT.

MODULE leave_dynpro AT EXIT-COMMAND.

FIELD input1 MODULE check_1 ON REQUEST.

FIELD input2 MODULE check_2 ON REQUEST.

CHAIN.

FIELD input3.

FIELD input4.

FIELD input5.

MODULE check_chain ON CHAIN-REQUEST.

ENDCHAIN.

MODULE handle_user_command.

Reward if useful.

[paruchuri_nagesh]

hi

chain, endchain

can be used to procees group of fields together

whenever user enters a invalid value in one field

all the input fields are reenabled for user input

reward if u find useful

regards

Nagesh.Paruchuri

[Former Member]

Hi,

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.

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

check the demo example

DEMO_DYNPRO_FIELD_CHAIN

Thanks,

Reward If Helpful.