Re: Indicator Redux -- RPG400-L

Hi Dave,

Maybe a little historical perspective would help. RPG has always hadjust 99 indicators. At some point, programmers were allowed to accessthem as if they were in an array (the *IN array). After display fileswere introduced, they started eating up all the available indicators inorder to position cursors, set display attributes and what not. Prettysoon, there weren't enough indicators for both the display file and RPG.

The solution was to allow display files to have their own set of 99indicators. This is done by specifying the INDARA keyword in thedisplay file, and the INDDS keyword on the file spec in the RPGprogram. Once you've done this, RPG has its 99 indicators in the *INarray, and the display file references the 99 indicators in the datastructure specified in the INDDS keyword on the file spec.

Now it is possible to have the display file's indicator data structureoverlay the *IN array, by making the data structure based, and havingits basing pointer point to the beginning of the *IN array. If you dothis, you're back to one set of 99 indicators, which negates theintention of having a separate set of indicators. And it's a waste ofcoding time, since you have the same effect by leaving off the INDARAand INDDS keywords.

The only reason I've ever seen for mapping a data structure to the *INarray is to allow naming the 99 RPG indicators so you don't have to use*IN34 or *IN(27), which are not very meaningful. But you don't need touse INDARA or INDDS to do this. Simply define a based data structurewhose pointer points to the address of *IN01. This data structure doesNOT have to be specified in an INDDS keyword. You don't even need adisplay file. In other words, you could have a program with an INDARAdisplay file where INDDS points to data structure ABC, and a separatebased data structure XYZ that overlays the *IN array. That way you canname the 99 RPG indicators and the 99 display file indicators.


hth,
*Peter Dow* /
Dow Software Services, Inc.
909 793-9050
pdow@xxxxxxxxxxxxxxx <mailto:pdow@xxxxxxxxxxxxxxx> /



Turnidge, Dave wrote:

This "pointer" thing is new for me, as far as USING it is concerned. If
I'm reading your code correctly, you are setting up a data structure
over the *IN array. Yes? Where or how does this get related to the
INDARR and INDDS? Would I use the *IN pointer method INSTEAD of INDARR

and INDDS, or use both?

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Lapeyre, Francis
Sent: Wednesday, December 06, 2006 10:34 AM
To: RPG programming on the AS400 / iSeries
Subject: RE: Indicator Redux

I do it with a pointer, because I often have to condition things on the
output specifications. But it will work on display files, as well.

       // Define indicators

     D P_Indicators    S               *   Inz(%ADDR(*IN))

     D Indicators      DS                  Based(P_Indicators)

     D Update_Mode                         Like(*IN)
Overlay(Indicators:01)

Begsr *INZSR;// List or update mode?Update_Mode = (%PARMS > 0 And P_Update = 'Y');Endsr;

Francis Lapeyre
IS Dept. Programmer/Analyst
Stewart Enterprises, Inc.

E-mail: flapeyre@xxxxxxxx

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Turnidge, Dave
Sent: Wednesday, December 6, 2006 10:12 AM
To: RPG programming on the AS400 / iSeries
Subject: Indicator Redux

I have looked through the archives having to do with Indicator Arrays,
and am confused. It appears that there are two arrays(?): one for
display file indicators, and one for RPG indicators.

When I started on my current project I was told that I didn't need to
use the "pointer method" to define my indicators, but now I am running
into a problem. I have set up variable "ExcludeSys" for position 27 in
my indicator data structure. However, when I turn ExcludeSys *ON, *IN27

is not *ON, and, I WANT it to be on.

Please help me understand the difference (if there is one) and/or how to
be able to use a variable name and have the action continue on to the
indicator. Also, if there is a page in a Redbook (or equivalent) that
explains this from IBM's "easy to understand" viewpoint <G> a link would
be nice...

Thank you,

Dave

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