Re: Screen I/O

fzoufaly_at_gaviota.cic.itcr.ac.cr writes:

>I am developing a system using Forms 3.0 and I REALLY need to perform
>some screen Input Output, something like display at 1,10 'Hello' and input varx.
>I cannot perform this operations directly using forms.

You should be able to do this with a combination of pop up pages and moving to a separate block to perform the input.

The ability to write this type of Forms code is pretty much central to getting beyond the most basic uses of Forms, and this tends to suggest that you have not had any formal training in Forms or much practical experience with it yet. (This isn't intended to be criticism, just an observation.)

Pop Up pages are quite powerful, but in my opinion are very badly described in the Oracle manual, and not all that better described in 'The Forms Developer's Companion', which is in general a VERY GOOD book. They really aren't all that complicated, once you figure them out. (I finally tore apart one of the sample Forms from the IOUG utilities disk, studied it for a few minutes, and exclaimed 'EUREKA!' when I figured out how EASY it was.)

To use them correctly you will probably need to give more than passing thought to WHERE blocks are supposed to appear on the page. (My 'standard' page layout has been divided into at least five different regions for various control blocks, status blocks, message areas, etc, and there are also other blocks designed to pop up and replace other areas as need arises.)

You will also have to pay attention to make sure that the operator doesn't inadvertently go to the wrong block, by considering and programming triggers to perform the right actions for such things as 'next block', 'previous block', 'up', 'down', 'exit', 'accept/commit', etc. Often the desired action is either 'go_block' back to the original block, or 'null;'.

>I would like to use C and Forms user_exits to realize this operation.
>Right now I am working with OS/2 but I would like to port my software
>to different platforms. (I know that i would probably need to rewrite
>the C code for each different platform).

I doubt that this is really necessary, and using standard Forms techniques will make the resulting apps a whole lot easier to port.

---
Michael Nolan, Sysop for the DBMS RoundTable on GEnie
nolan_at_notes.tssi.com, dbms_at_genie.geis.com
(posted from nolan_at_helios.unl.edu)