cl_abap_structdescr finding data element descriptions of program defined structure

[Former Member]

I have an program built structure (not ddic). with several fields, all defined with ddic data elements.

TYPES:
    BEGIN OF ty_selected,
      material       TYPE matnr,
      matl_type      TYPE mtart,
      lab_office     TYPE labor,
      plant          TYPE werks_d,
      status         TYPE mmsta,
    END   OF ty_selected.
DATA: gs_selected type ty_selected.

I want to retrieve the description text of the data elements that are in this structure. I just can't seen to get it.  I figured it out for ddic structures but not program defined ones.

For ddic structures I am using class cl_abap_structdescr like this:

DATA: ref_struct        TYPE REF TO cl_abap_structdescr,
      ls_struct         TYPE zmatl, " ddic type
      lt_ddic_info      TYPE ddfields,
      w_head            TYPE ty_return.
   FIELD-SYMBOLS:
     <ddic_info> TYPE LINE OF ddfields.

   ref_struct ?= cl_abap_typedescr=>describe_by_data( ls_struct ).
   lt_ddic_info = ref_struct->get_ddic_field_list( ).

   LOOP AT lt_ddic_info ASSIGNING <ddic_info>.
     MOVE <ddic_info>-fieldname TO w_head-fieldname.
     MOVE <ddic_info>-fieldtext TO w_head-fieldtext.
     APPEND w_head TO f_return.
   ENDLOOP.

I figure there should be something similar I can do for program defined structures, but no joy.

Can anyone help me please?

Thanks

[custodio_deoliveira]

Hi Larry,

Yes, there is a way. You need to read each component individually (class cl_abap_elemdescr ). See code below:

TYPES:
     BEGIN OF ty_selected,
       material       TYPE matnr,
       matl_type      TYPE mtart,
       lab_office     TYPE labor,
       plant          TYPE werks_d,
       status         TYPE mmsta,
     END   OF ty_selected.

DATA: ref_struct        TYPE REF TO cl_abap_structdescr,
       ref_element       TYPE REF TO cl_abap_elemdescr,
       ddic              TYPE dfies,
       component         TYPE    abap_compdescr.

ref_struct ?= cl_abap_typedescr=>describe_by_name( 'TY_SELECTED' ).

LOOP AT ref_struct->components INTO component..

   ref_element ?= cl_abap_typedescr=>describe_by_name( 'TY_SELECTED-' && component-name  ).
   ddic = ref_element->get_ddic_field( ).

   WRITE: / ddic-scrtext_m.

   IF sy-subrc <> 0.
*handle exception
   ENDIF.

ENDLOOP.

Regards,

Custodio

[rosenberg_eitan]

Hi,

Very similar to  version but using by describe_by_data all the way .

*----------------------------------------------------------------------*
TYPES: BEGIN OF tp_level_1 .
        INCLUDE TYPE scarr AS scarr RENAMING WITH SUFFIX _scarr .
        INCLUDE TYPE spfli AS spfli RENAMING WITH SUFFIX _spfli .
TYPES: END OF tp_level_1 .
*----------------------------------------------------------------------*
START-OF-SELECTION .
  PERFORM test_01 .
*----------------------------------------------------------------------*
FORM test_01 .

  DATA: st_level_1 TYPE tp_level_1 .
  DATA: ob_abap_structdescr TYPE REF TO cl_abap_structdescr .

  ob_abap_structdescr ?= cl_abap_typedescr=>describe_by_data( st_level_1 ) .

  DATA: st_components LIKE LINE OF ob_abap_structdescr->components .
  FIELD-SYMBOLS: <component> TYPE ANY .

  DATA: ob_abap_elemdescr TYPE REF TO cl_abap_elemdescr .
  DATA: st_dfies TYPE dfies .

  LOOP AT ob_abap_structdescr->components INTO st_components .

    ASSIGN COMPONENT st_components-name OF STRUCTURE st_level_1 TO <component> .

    ob_abap_elemdescr ?= cl_abap_typedescr=>describe_by_data( <component> ) .
    st_dfies = ob_abap_elemdescr->get_ddic_field( ) .

    WRITE: / st_components-name , st_dfies-fieldtext .

  ENDLOOP .

ENDFORM .                                                   "test_01
*----------------------------------------------------------------------*

Regards.

[SuhaSaha]

My 2 cents...

If we use the attribute CL_ABAP_STRUCTDESCR->COMPONENTS, then we'll have to code explicitly to get the RTTI for the individual components. On the other hand, if we use the method CL_ABAP_STRUCTDESCR->GET_COMPONENTS( ) then the framework does that implicitly.

DATA: lo_struct_descr   TYPE REF TO cl_abap_structdescr,



      lt_struct_fields  TYPE cl_abap_structdescr=>component_table,

      lwa_struct_field  TYPE cl_abap_structdescr=>component,



      lo_elem_descr     TYPE REF TO cl_abap_elemdescr.



* Get RTTI object for the local structure

lo_struct_descr ?= cl_abap_typedescr=>describe_by_data( gs_selected ).



* Get the components of the structure

lt_struct_fields = lo_struct_descr->get_components( ).



LOOP AT lt_struct_fields INTO lwa_struct_field.



* Get the RTTI for the component

  lo_elem_descr ?= lwa_struct_field-type.



  cl_demo_output=>write_text(

    |{ lwa_struct_field-name },| &&

    |Text: { lo_elem_descr->get_ddic_field( )-scrtext_l } \n|

                            ).

ENDLOOP.



cl_demo_output=>display( ).

For ABAP 740 lovers, here's the shorter version

LOOP AT CAST cl_abap_structdescr( cl_abap_typedescr=>describe_by_data( gs_selected ) )->get_components( )
        INTO DATA(wa_structure_field).

  cl_demo_output=>write_text( |{ to_mixed( wa_structure_field-name ) } \t|  &&
                              |{ CAST cl_abap_elemdescr( wa_structure_field-type )->get_ddic_field( )-scrtext_l } \n|
                            ).

ENDLOOP.

cl_demo_output=>display( ).

BR,

Suhas

Message was edited by: Suhas Saha

[custodio_deoliveira]

I'm loving Eitan's and Suhas' answers (both better than mine). I reckon this is what happens when the question is good.

To be honest I thought about doing both, but implemented mine first and got lazy

From now on I'll follow Suha's example and will always post ABAP 740 replies as well.

Cheers,

Custodio

[SuhaSaha]

Hello Custodio,

Our development system is still on ABAP 731, so i don't get to use the new version of ABAP regularly

The sandbox had been upgraded to 740 last December & i write all the demo programs there in 740 using AiE

BR,

Suhas

[custodio_deoliveira]

^same scenario here

[rosenberg_eitan]

Hi

It seems that you get two different answers if you have a type like this:

cl_abap_structdescr->components :

ob_abap_structdescr->get_components :

Regards.

[custodio_deoliveira]

Yep, would need to work with get_components( ) and apply some fancy recursive logic here I reckon.

[rosenberg_eitan]

Hi,

You are right.

Actually I did a test (with recursion) but I do not like it since you have to manage the "RENAMING WITH SUFFIX" manually .

And what can I say I am lazy and I love kiss(http://en.wikipedia.org/wiki/KISS_principle) .

Code:

*----------------------------------------------------------------------*
CLASS cl_components DEFINITION .
  PUBLIC SECTION.
    METHODS get_components
            IMPORTING st_abap_componentdescr TYPE abap_componentdescr
            CHANGING  it_ddfields TYPE ddfields .
ENDCLASS .                    "cl_event_receiver DEFINITION
*----------------------------------------------------------------------*
CLASS cl_components IMPLEMENTATION.
*----------------------------------------------------------------------*
  METHOD get_components .
    DATA: it_component_table TYPE cl_abap_structdescr=>component_table .
    FIELD-SYMBOLS: <st_component_table> LIKE LINE OF it_component_table .
    DATA: ob_abap_structdescr TYPE REF TO cl_abap_structdescr .
    ob_abap_structdescr ?= st_abap_componentdescr-type .
    it_component_table = ob_abap_structdescr->get_components( ) .
    DATA: st_ddfields LIKE LINE OF it_ddfields .
    DATA: ob_abap_elemdescr TYPE REF TO cl_abap_elemdescr .
    DATA: is_ddic TYPE abap_bool .
    LOOP AT it_component_table ASSIGNING <st_component_table> .
      CASE <st_component_table>-type->kind .
        WHEN cl_abap_typedescr=>kind_struct .
          me->get_components(
            EXPORTING
              st_abap_componentdescr = <st_component_table>
            CHANGING
              it_ddfields = it_ddfields ) .
        WHEN cl_abap_typedescr=>kind_elem .
          CLEAR st_ddfields .
          ob_abap_elemdescr ?= <st_component_table>-type .
          is_ddic = ob_abap_elemdescr->is_ddic_type( ) .
          IF is_ddic EQ abap_true .
            st_ddfields = ob_abap_elemdescr->get_ddic_field( ) .
          ELSE .
            st_ddfields-intlen = <st_component_table>-type->length .
            st_ddfields-decimals = <st_component_table>-type->decimals .
            st_ddfields-inttype = <st_component_table>-type->type_kind .
          ENDIF .
          CONCATENATE <st_component_table>-name st_abap_componentdescr-suffix
            INTO st_ddfields-fieldname .
          APPEND st_ddfields TO it_ddfields .
        WHEN OTHERS.
          CONTINUE .
      ENDCASE.
    ENDLOOP .
  ENDMETHOD .                    "get_components
ENDCLASS .                    "cl_components IMPLEMENTATION
*----------------------------------------------------------------------*
*----------------------------------------------------------------------*
TYPES: BEGIN OF tp_level_1 .
        INCLUDE TYPE scarr AS scarr RENAMING WITH SUFFIX _scarr .
TYPES:  flag TYPE boolean .
TYPES:  c_field TYPE c LENGTH 1 .
TYPES:  n_field TYPE n LENGTH 1 .
TYPES:  s_strng TYPE string .
TYPES:  it_return TYPE bapirettab .
TYPES:  ob_gui_alv_grid TYPE REF TO cl_gui_alv_grid .
TYPES: END OF tp_level_1 .
*----------------------------------------------------------------------*
*----------------------------------------------------------------------*
FORM test_06 .
  DATA: st_level_1 TYPE tp_level_1 .
  DATA: st_abap_componentdescr TYPE abap_componentdescr .
  st_abap_componentdescr-type ?= cl_abap_typedescr=>describe_by_data( st_level_1 ) .
  DATA: ob_components TYPE REF TO cl_components .
  DATA: it_ddfields TYPE ddfields .
  CREATE OBJECT ob_components .
  ob_components->get_components(
    EXPORTING st_abap_componentdescr = st_abap_componentdescr
    CHANGING  it_ddfields = it_ddfields ) .
  BREAK-POINT .
ENDFORM .                                                   "test_06
*----------------------------------------------------------------------*

Regards.

Eitan.

[SuhaSaha]

I would say horses-for-courses, use the method that suits your requirement.

[former_member214137]

Hi Suhas,

Thanks for posting your solution. I used your solution to help check that the data uploaded via file was of the correct field length.

DATA: ls_message       TYPE ty_messages,

          lx_exception     TYPE REF TO cx_root,

          lt_struct_fields TYPE cl_abap_structdescr=>component_table,

          ls_struct_comps  TYPE cl_abap_structdescr=>component,

          lo_strucdescr    TYPE REF TO cl_abap_structdescr,

          lo_elemdescr     TYPE REF TO cl_abap_elemdescr,

          lv_length        TYPE string,

          lv_index         TYPE i,

          ls_data          LIKE LINE OF data.

    TRY.

*      "dynamically check data is not longer than allowed field length

        lo_strucdescr ?= cl_abap_typedescr=>describe_by_data( ls_data ).

        lt_struct_fields = lo_strucdescr->get_components( ).

        DO lines( lo_strucdescr->components ) TIMES.

          lv_index = sy-index.

          ASSIGN COMPONENT lv_index OF STRUCTURE is_raw_data TO FIELD-SYMBOL(<fs>).

          READ TABLE lt_struct_fields INDEX lv_index INTO ls_struct_comps.

          lo_elemdescr ?= ls_struct_comps-type.

          CHECK lo_elemdescr IS BOUND.

          IF strlen( <fs> ) > lo_elemdescr->output_length.

            rv_error = 'X'.

            lv_length = lo_elemdescr->output_length.

            ls_message-type = 'E'.

            CONCATENATE 'Row' iv_row ls_struct_comps-name 'is longer than allowed length of'                lv_length INTO ls_message-message SEPARATED BY space.

            APPEND ls_message TO messages.

            CLEAR: lv_length.

          ENDIF.

        ENDDO.

    ENDTRY.

cheers

Julian

[Former Member]

Thanks everyone!  This is exactly what I was looking for.  I wish I could have given everyone the correct answer points, but it only allows for one.  I have already implemented Syhas' code and it is working great!  Thanks again.

I never can remember how to add a code block to my posts.  Tell me again how that is done.

[custodio_deoliveira]

Hi Larry,

Use the "Advanced editor" then follow this:

Cheers,

Custodio

[Former Member]

Thanks!
But I probably will forget by the next time
I post a question!
Maybe I should spend a little more time on here and try to answer a few questions myself.
And I won't forget how to do it!

[rosenberg_eitan]

Hi,

This is a very good idea .

SCN is a great place to remember stuff .

You might search for something and than you find your OWN answers....

Regards .

[Former Member]

I always search for the answer first.  That is why I don't post a question very often.  I find the answer most of the time without posting.