Re: RPG UDDS Generic File Display/Update (Null fields in program described files)

On 2019-01-14 3:05 AM, Frank Kolmann wrote:

After some attempts to cater for NULL values I have figured out that UDDS is fundamentally in conflict with NULL values.
UDDS requires a program described Display file, and ANY program described file makes the RPG compiler create the program with ALWNULL(*NO).
Further, Full Free Form RPG does not allow Program described files so UDDS has effectively gone the way of the Dodo.
...

Possibly separate modules some with ALWNULL(*USRCTL) some with ALWNULL(*NO) but I suspect this will cause the CRTPGM to fail,

I haven't been following this thread in detail since I'm not familiar with UDDS.

So I'm not sure whether what I'm going to say will make any real effect difference here...

But RPG does allow program-described files in full free form. You'd code something like WORKSTN(1000) for the device keyword for a program-described display file.

Also, RPG allows null-value support in general in a module if it has a program-described file. With ALWNULL(*USRCTL), it will handle the null-indicators for any other externally-described files in the module.

You can CRTPGM where RPG modules had different ALWNULL settings The ALWNULL setting is internal to the module, so it isn't something that CRTPGM knows about.