Comments on: ABAP Freak Show – July 1st – ABAP OO Tutorial Part 1

By: Thomas Jung

Thomas Jung — Mon, 06 Jul 2009 12:26:23 +0000

>always thought that ABAP was originally procedural due to the fact that it was somehow compiled down to C (I’m not sure why I assumed this)

ABAP doesn’t really compile down to C code. The confusion is maybe the fact that the ABAP Compiler and the ABAP virtual machine are both implemented in C/C++. However ABAP creates a byte code that is interpreted by the ABAP virtual machine – actually a lot like the way Java works. But this doesn’t really effect OO/Procedural.

ABAP was procedural simply because that was the way most programming languages were designed when ABAP first came about. Procedural ABAP design is largely a mixture of concepts from COBOL and C.

By: Simon

Simon — Mon, 06 Jul 2009 07:05:49 +0000

Hi Thomas,

Thanks for doing these – they are really useful. I am not sure if this question even makes sense, but I will ask it anyway … I always thought that ABAP was originally procedural due to the fact that it was somehow compiled down to C (I’m not sure why I assumed this) – did something change in the underlying implementation of ABAP to allow for ABAP OO?

Keep up the great work. Really enjoy listening and learning about this stuff.

Simon

By: Thomas Jung

Thomas Jung — Thu, 02 Jul 2009 12:23:40 +0000

Thanks for the questions. These aspects of integration into the UI for Classic Dynpro constructs are all things I will cover in Part 4 of the tutorial.

For any screen related elements (Selection Screens or Full Dynpro screens), you still need a program. Yes it is old style, but by the time OO was coming along in ABAP we were already beginning the transition to new UI technologies and I suppose the investment in a full OO version of classic dynpro just wasn’t worth it.

However in part 4 I will talk about how to keep this program as mostly an empty shell and divert most of your processing into a class.

Finally, yes the range table is the only way of declaring a parameter or variable to access a select-option. You can at least create range tables as data dictionary table types. I will show that in part 4 as well.

By: Steffen Froehlich

Steffen Froehlich — Thu, 02 Jul 2009 08:20:14 +0000

Thanks Thomas for the beginners oo-tutorials. I’ve got two questions about OO and selection screens.

The way people start programs in ERP are done by transactions. So Tcodes can link directly to OO-Classes. Is there a way to use theses powerful selection-screens in OO methods, because for an selection screen you ever need to create a program (which seems a little bit old style ).

When using a selection options with ranges for an data-element like:

SELECT-OPTIONS: so_matnr FOR mara-matnr.

and you want using it in OO-context you’ve declare a separate range-table like this:

DATA: ltr_matnr TYPE RANGE OF mara-matnr.
ltr_matnr[] = so_matnr[].
CALL METHOD zcl_class=>init_attr
CHANGING matnr = ltr_matnr.

Are there other / smarter ways, today?