topic Re: Syntax Error after creating enhancements for subroutine in Application Development and Automation Discussions

Syntax Error after creating enhancements for subroutine

Former Member — Mon, 08 Mar 2010 18:56:00 GMT

Problem:

Creating enhancement sections gives a syntax error when creating enhancement options and implementations for a subroutine and then ceating enhancement options and implementations for the call to that same subroutine.

Syntax Error:

"Different number of parameters in FORM and PERFORM (routine: SET_LAYOUT, number of formal parameters: 2, number of actual parameters: 1)

Here's the following scenario:

A subroutine is defined in a program.

The subroutine is called within the same program.

I then executed these steps:

1. Defined an enhancement section around the subroutine definition

2. Defined an enhancement section around the subroutine call.

3. Implemented the enhancement section around the subroutine definition and add an additional parameter.

Currently, this gives a syntax error as expected, since the call to the subroutine needs 1 more parameter.

4. Implemented the enhancement section for the subroutine call. I change the call in the implementation so it passes the new parameter.

A syntax check to this gives an error. The syntax checker is not only checking the new implementation, but also the original subroutine that should have been overwritten.

The enhancement sections use the same enhancement spot, and the enhancement implementations use the same implementation.

I tried various combinations of using different enhancement spots and/or implementations, but all give the same syntax error. I tried separating the subroutine in a different include and retried my testing, but it still gave the same syntax error.

Here's the sample code I first created to try troubleshooting the problem:

<pre>

ENHANCEMENT-SECTION ZEP_Z_MICHAEL_02 SPOTS ZES_Z_MICHAEL .

PERFORM set_layout

CHANGING

wa_layout.

END-ENHANCEMENT-SECTION.

$$-Start: ZEP_Z_MICHAEL_02----

ENHANCEMENT 2 ZEI_TEST_SECTIONS.

"inactive version

PERFORM set_layout

using 'X'

CHANGING

wa_layout.

ENDENHANCEMENT.

$$-End: ZEP_Z_MICHAEL_02----

ENHANCEMENT-SECTION ZEP_Z_MICHAEL_01 SPOTS ZES_Z_MICHAEL STATIC .

FORM set_layout

CHANGING p_wa_layout TYPE slis_layout_alv.

p_wa_layout-zebra = 'X'.

wa_layout-no_colhead = 'X'..

p_wa_layout-colwidth_optimize ='X'.

wa_layout-window_titlebar = 'Woot'.

ENDFORM. "set_layout

END-ENHANCEMENT-SECTION.

$$-Start: ZEP_Z_MICHAEL_01----

ENHANCEMENT 1 ZEI_TEST_SECTIONS.

"inactive version

FORM set_layout

using p_test type boolean

CHANGING p_wa_layout TYPE slis_layout_alv.

p_wa_layout-zebra = 'X'.

wa_layout-no_colhead = 'X'..

p_wa_layout-colwidth_optimize ='X'.

wa_layout-window_titlebar = 'Woot'.

ENDFORM. "set_layout

ENDENHANCEMENT.

$$-End: ZEP_Z_MICHAEL_01----

</pre>

Please let me know if you think I am doing something wrong.

Thanks,

Mike

Edited by: Michael Herman on Mar 8, 2010 8:11 PM

Re: Syntax Error after creating enhancements for subroutine

alex_cook — Mon, 08 Mar 2010 23:14:29 GMT

Howdy,

As you've found, when you create an enhancement, both enhancements get compiled/executed. In effect you've overloaded the subroutine (as opposed to overriding it), which is not supported in ABAP, hence the compiler just uses the first subroutine with that name.

Personally I like Sandra's option of passing via ABAP memory.

Cheers

Alex

Re: Syntax Error after creating enhancements for subroutine

Sandra_Rossi — Tue, 09 Mar 2010 08:58:03 GMT

By the way, using a static attribute of a custom class will do the trick too. With that, it's easier to determine where "this memory" is used via the where-used list, though consumes more memory.

Re: Syntax Error after creating enhancements for subroutine

Former Member — Tue, 09 Mar 2010 15:15:33 GMT

I don't think that's the issue. If 2 forms contain the same name, the syntax error would be: A FORM already exists with the name "SET_LAYOUT". Besides, the syntax checker doesn't give an error after enhancing the defintion of the subroutine. It gives an error for the call to the subroutine.

Regards,

Mike

Re: Syntax Error after creating enhancements for subroutine

Former Member — Tue, 09 Mar 2010 15:18:07 GMT

Last solution, and maybe the best one, pass parameter via ABAP memory: you'll avoid duplicate code or the custom static class.

These are definitely a good solutions, especially since the parameter itself is optional(in my situation). (The actual standard code contains 2 subroutines and both are called by about 14 standard and nonstandard programs, but only a few need to pass a variable with a value). I would only have to mod the standard code that needs to pass the variable to the subroutine instead of all the code that calls the subroutine. Thanks Sandra!

I would still like to know why enhancing a subroutine interface and calling it gives a syntax error, or if it's simply not supported. If anyone can answer that question, that would be great. The tutorials, blogs, forums, and other information on the web doesn't seem to address this issue.

Regards,

Mike

Re: Syntax Error after creating enhancements for subroutine

thomas_decker — Wed, 31 Mar 2010 08:26:48 GMT

The solution in this case is to use static enhancement options in both cases. Dynamic options are resolved in IF-clauses that contain also the original source. Hence we get a syntax error.

Regards,

Thomas.

Re: Syntax Error after creating enhancements for subroutine

Former Member — Wed, 31 Mar 2010 13:53:26 GMT

That's it! I was pretty sure I had tried this, but apparently I hadn't. Thanks Thomas!

Re: Syntax Error after creating enhancements for subroutine

Sandra_Rossi — Wed, 31 Mar 2010 14:32:02 GMT

Thx Thomas too!

To be sure to understand, does that mean this line:

> ENHANCEMENT-SECTION ZEP_Z_MICHAEL_02 SPOTS ZES_Z_MICHAEL .

has to be replaced with this one:

> ENHANCEMENT-SECTION ZEP_Z_MICHAEL_02 SPOTS ZES_Z_MICHAEL STATIC.

Thx

Re: Syntax Error after creating enhancements for subroutine

Former Member — Wed, 31 Mar 2010 15:14:31 GMT

Yes, Sandra. That is what did and it worked with no syntax errors!

I'm not sure if this is getting off topic or not, but the SAP documentation(taken from the SAP help after pressing F1 on the keyword static in ERP6) seems misleading:

"The STATIC addition is intended for the enhancement of data declarations, while the statement ENHANCEMENT-POINT without the STATIC addition is designed for the enhancement of executable coding."

I would think the enhancement section ZEP_Z_MICHAEL_02 would fall under the category of executable code, while the enhancement section ZEP_Z_MICHAEL_01 would fall under the category of declarative code.

Unfortunately, all the SAP enhancement sections I come accross are dynamic. The SAP help explains the reasoning for this:

"In contrast to the statement ENHANCEMENT-POINT, the addition STATIC of the statement ENHANCEMENT-SECTION can only be used with maximum caution for changes of data declarations, because a replacement and no completion is carried out. Especially application development within SAP should not use the addition STATIC at all with ENHANCEMENT-SECTION as the change will be active in the entire customer system. "

I do not know what the word "completion" means in the previous quote, so I can't determine why it would matter. Regardless, if a developer wanted to change a standard subroutine declaration, they would also have to mod an enhancement section to change it to static. This seems to defeat the purpose of using enhancements, but maybe this scenario is not what enhancements were intended for.

Re: Syntax Error after creating enhancements for subroutine

Sandra_Rossi — Wed, 31 Mar 2010 16:21:23 GMT

Thx for the references. I prefer Thomas explanation, it's really much more short and simple to understand!