RE: Subfile Positioning Question -- RPG400-L

Hi Amitava,

There are two fields you need to worry about when maintaining positionwithin a subfile:

1) The field you define as SFLRCDNBR - when you populate this field the OSwill attempt to display the subfile page which contains the row with thisRRN. You would usually set this to 1 when first displaying your subfile.This forces display of the first page. A common error is to use your RRNfield as the SFLRCDNBR field - this usually results in your subfiledisplaying the last page built because SFLRCDNBR contains the RRN of thelast row you wrote. Another common error is to never update this value asyou navigate through the subfile - this results in you always going back tothe first page whenever you press enter (as page 1 contains row 1).

2) Within the file information data structure for your display file is afield which contains the RRN of top row of the currently displayed page.This field is in positions 378-379 and is a binary field.

So, to maintain position - immediately after you display your subfile pagesave the RRN of the top row in your SFLRCDNBR field. This forces the OS tore-display the current page when you press Enter. That's it!

You can take this further - when validating subfile entries you can placethe RRN of the row in error into the SFLRCDNBR field and the OS willautomatically take you to the page containing the row in error next time thesubfile is displayed. This allows the user to enter details on many pages -you will simply take them to the errors as you validate.


For simple position maintenance you need to use the following code:

F-spec:
FYourFile  cf   e             workstn infds(dspinf)


D-Spec:
* INFDS for display file...
Ddspinf           DS
D Sfl_rrn               376    377I 0
D Sfl_top               378    379I 0


C-Spec:
C                   Exfmt     CTL1

* Maintain subfile position...
C                   If        Sfl_top > 0
C                   Eval      F01pos = Sfl_top
C                   Endif

Note: Only populate your SFLRCDNBR field (F01pos above) with a value greaterthan 0 or the display will error next time the subfile is displayed. (I havediscovered that if you use ERRMSGID in the DDS to validate control formatfields the infds is cleared when the error is issued - this results in theinfds sfl_top field being set to zero. As a result the display errors whendisplaying the next time after an error was issued)


HTH

Larry Ducie