Re: Multiple sequentially numbered fields and indicators in /FREE -- RPG400-L

Hi Pete,

In RPG III I would have written something like:

FIELD1    CHAIN   MYFILEFMT       97
*IN99     IFEQ      *ON
SETON 20ENDIF
FIELD2    CHAIN  MYFILEFMT       97
*IN99     IFEQ      *ON
SETON 21ENDIF

The problem with numeric indicators is that it's not possible to give themmeaningful names. That makes your program difficult to read for the nextguy. I think it's a really good idea to replace them with namedindicators, even though it's a bit of a departure from RPG III, its a loteasier to read.

In RPG IV, you can specify the INDDS keyword on your F-spec. It tells thesystem that when reading the display file, you don't want to import theindicators into your prorgram. Instead, you want to map those indicatorsacross a data structure.

To do that, you'll code something like this (to save e-mail space, I'll doonly 5 fields):


     FSCREEN    CF   E             WORKSTN INDDS(ScreenInds)

     D ScreenInds      ds
     D   ExitKey                       N   overlay(ScreenInds:03)
     D   CancelKey                     N   overlay(ScreenInds:12)
     D   RIHI_Field                    N   overlay(ScreenInds:20)
     D                                     dim(5)

NOTE: You must have the INDARA keyword in your display file to use this.

If your display file has CF03(03) (or CA03(03)) so that indicator 03 isset on when F3 is pressed, the above example will call that idnicator"ExitKey" in your RPG program. It simply maps *IN03 of the display fileto "ExitKey" in RPG -- just gives it a new name in the RPG. *IN03 in RPGwill no longer reflect the exit key.

Likewise, you can do that with your reverse image/highlight fields. Inthe example above, I've used an array. Indicator 20 will map toRIHI_Field(1), Indicator 21 to RIHI_Field(2), etc. This is anotherbeautiful thing about this data structure support...

You can map your FIELD1 FIELD2 FIELD3 to an array using a data structureas well:


     D ArrayFields     ds
     D   Field1
     D   Field2
     D   Field3
     D   Field4
     D   Field5
     D   Field                             like(Field1) Dim(5)

This defines an array named "Field" that has the same properties asField1. Now you cna reference Field1 as FIELD(1), and Field2 as FIELD(2),etc.


This makes it easy to use a loop to verify the fields:

     D f               s             10I 0

     /free

          // set all RIHI indicators off.

          RIHI_Field(*) = *OFF;

          // set on the ones that aren't in MYFILEFMT:

          for f = 1 to 5;

             chain Field(f) MYFILEFMT;

             if not %found;
                RIHI_Field(f) = *ON;
             endif;

          endfor;

You can also blank out all of your selection fields by doing:

          FIELD(*) = ' ';

Much more elegant than RPG III, easier to read, easier to maintain thecode because there's only one place where the CHAIN is done instead ofmany.


Just my opinion, of course.