Screen signatures and the concept of a 5250 Screen

Did you notice how you did not have to select screen elements to identify the preceding two screens? Since they were created from DDS they each have a unique "signature". Their unique signatures were enough to identify each screen as being different.

That is an easy rule to remember – a different screen signature means use a different screen name. Unfortunately, it's not quite that simple - sometimes screens with different signatures are given the same screen name.

This is usually done when different screen signatures represent subtle variations of what is considered to be the same 5250 screen. In these cases, the variant name may also be used to identify different variations of the same screen name.

The key question: What is a "5250 screen" exactly?

There is no answer to that question.

Imagine an RPG program, using display file DSP, to display records named HEAD, BODY and FOOT (say) onto a 5250 screen. The visual result of this is said to comprise a 5250 screen named "Screen1" (say).

However, what if under some circumstances, it displays records HEAD, BODY, BODY_EXT and FOOT.

Is the resulting 5250 screen a new screen, or just a variation of "Screen1"?

There is no correct answer to the preceding question, because the thing that is called "Screen1" is really just a concept.

Both possible answers are equally correct - so aXes eXtensions allow you to answer the question either way.

If you decide these are two variations of the same screen you simply say this …

Signature

Name

DSP+HEAD+BODY+FOOT

"Screen1"

DSP+HEAD+BODY+BODY_EXT+FOOT

"Screen1" with variant name "BODY_EXT"

Or, if you decide they are different screens, you say this ...

Signature

Name

DSP+HEAD+BODY+FOOT

"Screen1"

DSP+HEAD+BODY+BODY_EXT+FOOT

"Screen2"

So what exactly is a "5250 screen"?

It's whatever you want it to be.

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