Re: Internal Display file overlay

Normally, OS/400 waits until you do an input operation from the screen
before it actually displays the screen to the user.  The idea is that
if you're going to output multiple times, it's more efficient to do all
the output into a buffer, and then dump the buffer to the terminal once.

The FRCDTA DDS keyword is used to override this behavior.  When using
FRCDTA, every time you do a write operation to your display file, the
screen will appear for the user.   This is assuming, of course, that
you used DDS to create your screen...  The only other method of making
display files that I can think of is via the Sys/36 environment, and
I'm not entirely sure how you'd do a "FRCDTA" in that situation.

Then, in your RPG program, you need to do an output operation to the
display when you want it to show up.   As you pointed out, you can't
use the WRITE operation unless you also pass a data structure that 
displays the fields to be displayed.   The other alternative, is to
use EXCPT, and create output specs for your display -- that would be
the traditional way of working with a "program described" file.

HTH


On Fri, 15 Jun 2001, Jim Langston wrote:

> Short version:
> How do I display a record format described internal to the program
> to the display without waiting for user input before continuing?
> 
> Long Version:
> I'm modifying an existing program that uses an internally described
> display file processed by the cycle.  What I am doing, or attempting
> to do, is stick a sub file in the middle of this.
> 
> Well, in testing I got this to work fine.  I copied the display file
> record into 2 records, chopped out a portion that I'm going to stuff
> my sub file into.  It works great in my test program, I display the
> subfile (by WRITEing it) which has KEEP specified.  Then I let the 
> cycle take care of the internally described file (which has OVERLAY
> defined) and it's doing what I want.  
> 
> But, running into a snag when I am moving it to development.  If the
> user doesn't want the display file to be shown, I have to show the
> original info there that was copied into another record format.  
> 
> I've tried using WRITE but RPG complains that I need a Data Structure
> to write, which I don't want to do.  So I tried READ which works, after
> a fashion.  It will display the display file record on the screen, but
> then waits for an ENTER before it continues with the cycle, that just
> ain't gonna work.
> 
> Changing the display file to externally described is not an option in 
> this case.
> 
> Regards,
> 
> Jim Langston
> 

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