transaction

[Former Member]

hi all ,

what is the use of chain and endchain and field ?

thanks & regards

kanny

[Former Member]

Hi,

CHAIN.
  FIELD: <f1>, <f 2>,... 
  MODULE <mod1>. 
  FIELD: <g1>, <g 2>,... 
  MODULE <mod2>. 
...
ENDCHAIN.

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.

Refer the demo program DEMO_DYNPRO_FIELD_CHAIN

Regards

Sudheer

[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.

The functions of the FIELD statement for controlling data transport also apply when you use processing chains. Within a processing chain, screen fields are not transported until the FIELD statement. Processing chains also have another function for the FIELDS statements that they contain. This is described in the section on validity checks.

regards,

sai ramesh

[Former Member]

hi,

For example if there are 10 fields in the screen and for 5 fields whenever the user enters wrong values u like to give some error message. You can declare that fields in the chain enchain so that only those fields will be input enabled and all other fields will disabled.

CHAIN.
FIELD chk_connobj.
FIELD chk_inst.
FIELD chk_devloc.
FIELD ehaud-haus.
FIELD eanl-anlage.
MODULE modify_screenfields.
ENDCHAIN.
 
*&---------------------------------------------------------------------*
*& Module modify_screenfields INPUT
*&---------------------------------------------------------------------*
* text
*----------------------------------------------------------------------*
 
MODULE modify_screenfields INPUT.
CLEAR okcode.
okcode = sy-ucomm.
CASE okcode.
WHEN 'ENTER' OR 'EXECUTE'.
 
IF chk_connobj IS INITIAL AND chk_inst EQ c_x AND
chk_devloc EQ c_x.
IF ehaud-haus IS INITIAL.
SET CURSOR FIELD 'EHAUD-HAUS'.
MESSAGE e000(zo_spa) WITH text-017. " Enter Connection obj
ELSE.
PERFORM conn_obj_check.
ENDIF.
ENDIF.
 
ENDMODULE. " modify_screenfields INPUT

Rgds

Reshma