How do I read and print a generic internal table?

Question

I'm pretty new to this. I'm currently studying abap for my job and I have a problem that I can't seem to work out. How would I go about creating a Function Module that takes any kind of internal table and write it to the screen? I'm looking for a very generic solution that can work with any kind of internal table as input.

Answer 1

This is the exact reason SAP has developed ALV (ABAP List Viewer). One of the shortest way to display any (non-nested) table is the following.

  DATA: go_alv  TYPE REF TO cl_salv_table.

  CALL METHOD cl_salv_table=>factory
    IMPORTING
      r_salv_table = go_alv
    CHANGING
      t_table      = itab.

  go_alv->display( ).

Answer 2

This would be the simplest way for a table whose line type is only flat data objects, taken from page 33 of This SAP Development Guide.

FIELD-SYMBOLS: <row> TYPE ANY,
               <comp> TYPE ANY.

LOOP AT itab INTO <row>.
  DO.
    ASSIGN COMPONENT sy-index OF STRUCTURE <row> TO <wa_comp>.
    IF sy-subrc <> 0.
      SKIP.
      EXIT.
    ENDIF.
    WRITE <wa_comp>.
  ENDDO.
ENDLOOP.

A more robust way would be to use introspection containing Run-Time Type Services, a set of classes that let you introspect the details of a data object. This would give you the details mentioned by vwegert. An even better option would be to put it in an ALV grid.

Answer 3

It is possible, but you have to think about a lot of stuff:

• column widths, dynamically sizing columns
• currency fields / fields with units
• date formatting in a multi-lingual environment
• tables may contain arbitrary data, including nested tables

All things considered, this is not a trivial task. This is best left to the existing components.