Larry,
Have a read on this thread topic. I know it has INVITE, which
you say you do not like but not why. It uses the DTAQ parameter of the
display file.
http://archive.midrange.com/rpg400-l/199911/msg00419.html
Thanks, Matt
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[
mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Larry Ducie
Sent: Monday, April 23, 2007 6:04 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: Getting a program to move off an EXFMT (or READ) without using
INVITE
Hi chaps,
Is there a way (API or set of APIs) that allow you to move a program
from an
EXFMT without requiring the device to send data? I am aware of the
INVITE
keyword, but for many reasons I do not want to use it.
Currently, I have written some software that allows me to refresh the
screen
whenever I need to, but I would like a more gracious way to do it..
It works like this (simplified):
------------------------------------------------------------------------
----
----------------------------------------------
init - enable signals, set a handler sub-proc for sigalarm signals.
dou f key pressed or whatever
prepare the screen (load subfile, etc)
call sub-proc to set an alarm in 1 second (send a signal via a call to
alarm() )
exfmt(e) the screen
call sub-proc to disable the alarm (call alarm(0) )
if %error and sds_excpid = MY_ALARM_ERROR
close display file
open display file
endif
process F keys
process entered data
enddo
The handler sub-proc checks some values and if the screen requires
refreshing it sends an *ESCAPE message to the program - this pops the
screen
off the exfmt(e) and resets the screen - nothing pressed/ entered so the
screen loop causes the screen to be rebuilt and redisplayed. If it is
not
necessary to re-display the screen the sub-proc sets the alarm to go in
another second, as so on...
------------------------------------------------------------------------
----
----------------------------------------------
The benefit of this is that I only refresh the screen if something
changes
before the user presses a valid F key or presses Enter. So in most cases
it
is just like any normal screen process. However, I just don't like
having to
use an *ESCAPE message to pop the screen off the EXFMT. The program
still
thinks the device is waiting for input so I can't write to the display
file
without closing and re-opening it - major drawback. Mostly it doesn't
matter
because this technique would only be used on front-end screens anyway.
It
does work like a charm though. The screens refresh really well, but only
when they need to. A guy here has written a cool demo chat application
based
on it - google chat in RPG - who'd have thunk it! :-)
So, any ideas if there is a workstation API that will knock the program
off
the EXFMT without putting the display file or device into an error
state?
Your help would be appreciated.
Cheers
Larry Ducie
midrange.com
