topic Re: Variables from selection screens in Application Development and Automation Discussions

Variables from selection screens

Former Member — Mon, 24 Sep 2012 14:01:59 GMT

Hi,

I have several selection screens building on each other. Every screen is packed in an INCLUDE structure since ABAP is telling me that selection screens are not possible within a FORM routine. That should have the same effect as if I copied the code into my main program, so using variables should not be a problem.

However, I am having sort of a circular problem using some variables I declare in that selection screen using the keyword PARAMETER: When I try to work with those variables - "outside" of the INCLUDE, back in my main program - ABAP is telling me that [variable_name] is not declared by a DATA statement - which, in fact, it isn't... When I try declaring it before the INCLUDE function, ABAP is telling me - pointing to a line in the INCLUDE - that [variable_name] is already declared... A circular problem.

Can anybody help me with that one?

Thanks a lot!

Regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Mon, 24 Sep 2012 14:08:38 GMT

Hello,

I hope you are creating a main program and including all the includes in it. If this is not working I would suggest -

Build a structured dialog program (module pool) with multiple screens.

Best Regard,

swanand

Re: Variables from selection screens

Former Member — Mon, 24 Sep 2012 14:26:29 GMT

Hi,

yes, I have a main program and there are multiple INCLUDE structures (all referenced into the main program), one for each selection-screen, one for all the declarations for an internal table and one for the actual SELECT.

Thanks for helping!

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Mon, 24 Sep 2012 14:41:29 GMT

The parameters of a selection-screen are just a global variable, so the point where you need to use it has to be placed after them.

It's not clear are you managed your main program, I mean where you place the include with declarations.

Max

Re: Variables from selection screens

Jelena_Perfiljeva — Mon, 24 Sep 2012 17:55:47 GMT

I can only guess that you put INCLUDE clause somewhere after a routine (FORM ... ENDFORM). INCLUDE that contains parameters / selection screen needs to be inserted at the very top of the program. Also I think you may need to have START-OF-SELECTION event, but am not 100% sure it's technicaly required. It's better to add it anyway though, makes the code more clear.

When you use INCLUDE it's as if you copy-paste the code into your program. There is a lot of customization we can do just with the selection screen code though. Maybe you don't even need multiple screens/INCLUDEs...

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 11:50:42 GMT

Hi Jelena,

I have only INCLUDEs, no FORM routines. But there are four selection screens right now, one after the other so one can - in theory, doesn't work yet - use the variables from the last. Of course, If I could make my selection screen dynamic (with more elements appearing at the touch of a button) I might be able to assemble all my variables with just one or two.

I know that somehow I can use the AT SELECtION SCREEN event, but that's where my knowledge ends right now.

Can you help me there?

For starters, when the user enters the nr. 4 (meaning he wants to query data from four DB tables), there should be four edit_fields for the table name - depending on the nr. the user enters. Would that be doable in only one screen?

Thanks a lot!

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 12:19:28 GMT

You should past your code, it doesn't matter if you use or don't use the includes, I mean after inserting the include in a main program, they belong to it, so it would be the same thing if you wrote all codes in the main program (so without to use the include).

Max

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 12:24:50 GMT

Hi Max,

yes, I guess that would be best. Just give me a while to put together the code - I have to paste it into an editor and insert the code from the INCLUDEs in the corresponding places.

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 12:29:37 GMT

One simple way of having "dynamic" looking selection screens is to add the NO-DISPLAY option to each parameter. Then in the AT SELECTION-SCREEN OUTPUT event code a loop at screen loop and set the screen-invisible flag off on the ones you want to show. Like this:

AT SELECTION-SCREEN OUTPUT.

LOOP AT SCREEN.

CASE SCREEN-NAME.

WHEN 'P_TBL1' OR '<p_tbl1_lablename>. "You can discover the label name via debug or the screen painter for screen 1000.

if p_nbr > = 1.

screen-invisible = '0'.

modify screen.

endif.

WHEN 'P_TBL2' OR '<p_tbl2_labelname>.

if p_nbr >=2.

screen-invisible = '0'.

modify screen.

endif.

WHEN etc.....

ENDCASE.

ENDLOOP..

If I understand your requirements I believe this will work for you. No need for INCLUDES at all. Just code it in the program.

Re: Variables from selection screens

Jelena_Perfiljeva — Tue, 25 Sep 2012 13:31:15 GMT

Friedrich, please read this blog if you're interested in building a dynamic selection screen. There is also more information available on SCN and other web sites - google it.

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 13:57:39 GMT

Hi Larry,

yes, looks like that would work, but that wouldn't do because it implies I have to code all elements that could possibly be needed - my task is to make it 100% dynamic, so I have no idea e.g. how many tables the user wants, how many fields from those etc. - I cannot prepare everything because the program will face a virtually infinite number of possibilities.

@ Jelena

Thanks. I will read it through and see what I can learn.

@ Max

Give me a while, I need to edit the comments in the code so you will understand what I meant to do - right now, the screens are hard-coded and I had to use some weird labels so ABAP wouldn't complain about my naming the same variable too often etc.

Thanks for all the help!

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 15:10:28 GMT

Hi Jelena,

that blog is nice indeed - I can actually understand how that would work 😉 Unfortunately, what I've answered to Larry's proposal goes for this - it won't help with what I need to do. I need to make it 100% dynamic. I have realized there is lots of stuff around on the net. I will research.

@ Max

Here it is - I have decided to keep the main program and the INCLUDEs separate to give you a more accurate picture of what I've done so far. There are two files, one with the main program and one with my four INCLUDEs. I hope the comments are sufficient to point out how I'm trying to get this to work.

The dialogs are so far only "painted", they have no connection to the report running afterwards. I guess if I knew how to use the variables from one of those screens in the next, I could also use them in the report.

Thanks a lot!

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 17:04:47 GMT

I've loaded your code and there's no sy-ntax errors, the only thing you've placed a call of a selection-screen just after the definition of the previous one, so the effect is all selection-screens will be opened in cascaded.

Max

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 19:13:02 GMT

Sapperdapper,

You did not say it needed to be THAT dynamic!

You might have a look at the way SAP has written the selection screen for SE16. Is that the way you are wanting it to work?

I currently have a request for an application that works in a similar way, but have not found the time to develop it yet. I was going to study SE16 to get some ideas.

However, I am thinking the INCLUDE idea may not work very well. Maybe using field symbols would be better.

Re: Variables from selection screens

Jelena_Perfiljeva — Tue, 25 Sep 2012 20:08:04 GMT

There is a code sample already available on SCN for a dynamic selection screen. I have not tested it myself (never had such need), but if you Google 'dynamic selection screen' or even 'dynamic ABAP', you'll find many existing posts on the subject.

There was a great eLearning video on the old SDN on dynamic programming (ASSIGN, etc.), but I cannot find it on the new web site, unfortunately. As one of the examples it had a completely dynamic program, like SE16.

Re: Variables from selection screens

Former Member — Tue, 25 Sep 2012 22:35:41 GMT

Wow!, that looks awesome. I am going to bookmark that code sample. I have just the application for it.

Thanks Jelena!

Re: Variables from selection screens

Former Member — Wed, 26 Sep 2012 08:19:41 GMT

Hi Larry,

yes, I need to make my program that dynamic - not right away, I can take it step-wise, so maybe I can use your sample code to begin with and just allow for up to four or five tables.

I will also have a look at the way SE16 works.

Do you mean field symbols as an alternative to INCLUDEs? I am using the INCLUDEs as a means to keep my code in several bits so it can be maintained and edited, I understand field_symbols have a different purpose - though admittedly I haven't yet understood what to use them for and how exactly. That was proposed to me elsewhere, though, I believe that I have to work on understanding just how field_symbols work.

@ Jelena

That code sample does look awesome - I will try reading and understanding what it does. My primary concern is not filtering, but selecting fields to export, but I could well use a part of that logic - to enter a table name and get a clickable list of all the fields in the table. That is one part of what the user will enter in the dialog(s): The tables the user wants to export from (which then have to be joined) and the fields from them.

@ Max

Yes, the code such as it is is working - that is my "demonstration report" which I am indending to use to show what things will look like, what I intend to do. The thing is, those selection screens are static, designed so to speak "backwards" - I had the SELECT statement first, all hard-coded with four tables and filling the data into an internal table - the main part actually - and based on that (nr. of tables and fields), I designed the selection screens with fields for all the info needed.

Okay, thanks for all your help so far! I will work on understanding more of all this and working through some tutorials seems a good idea. I'll be back 😉

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Wed, 26 Sep 2012 08:28:32 GMT

Just a consideration

some sample code of dynamic selection screen (just like SE16) need to regenerate the program, so in this case you need to prevent a dump, if several users run the program at the same time.

Max

Re: Variables from selection screens

Former Member — Wed, 26 Sep 2012 08:46:17 GMT

Hi Max,

that's not a problem - or rather, it won't be my concern until far in the future when I have the program up and running. In all probability, there will be only a handful of users authorized to use this - the current scenario I'm building this for is HR tables - and only one user at a time.

Thanks anyway for mentioning!

Best regards,

Sapperdapper

Re: Variables from selection screens

Former Member — Wed, 26 Sep 2012 09:07:52 GMT

Hi Larry,

I'm again reading about field_symbols and it seems they are just what I need: If I understand correctly, I can write ABAP statements using field_symbols and at runtime, those will be "filled with" some value, no?

So, I could e.g. write a SELECT <fs1> FROM <fs2> statement and assign to that <fs> the value from some dialog_field - so that, given the user enters the table name 'KNA1' and the field name 'KUNNR' in the dialog, that will execute as
>SELECT KUNNR FROM KNA1<

Is that right? In my large "ABAP reference" book, there's just two pages on them, so it must be real simple. That's what I want to do actually - the user will enter a lot of table and field names in the dialog(s) and I want to use those (as pointers to existing DB objects) in the actual report program.

Thanks a lot!

Best regards,

Sapperdapper