An ALV in ten lines with CL_SALV_TABLE

There is a test that separates well-designed APIs from the rest: how much code you need for the simplest case. With CL_SALV_TABLE, showing an internal table on screen is literally two calls. No field catalog, no callbacks, no endless parameters.

The absolute minimum

You have your data in an internal table. You want to see it. This is all:

FORM instance_salv.
  DATA lx_salv_msg TYPE REF TO cx_salv_msg.
  TRY.
      cl_salv_table=>factory(
        IMPORTING
          r_salv_table = go_salv_table
        CHANGING
          t_table      = gt_vehiculos ).
    CATCH cx_salv_msg INTO lx_salv_msg.
      WRITE lx_salv_msg->get_text( ).
  ENDTRY.
ENDFORM.

FORM display_salv.
  go_salv_table->display( ).
ENDFORM.

With one reference declared in the TOP, DATA go_salv_table TYPE REF TO cl_salv_table, you already have a complete ALV: columns derived from the dictionary, sorting, filtering, spreadsheet export and the full standard toolbar, without writing a single line of configuration.

What factory does for you

The static method factory is the heart of it. It takes the table in CHANGING (by reference, not a copy) and returns the ALV object in r_salv_table. From there, everything is asked of the object.

flowchart TB
  A["gt_vehiculos - internal table"] --> B["cl_salv_table=>factory( )"]
  B --> C["go_salv_table - ALV object"]
  C --> D["display( )"]
  D --> E["Full-screen list"]
  B -.->|"if something fails"| X["CATCH cx_salv_msg"]

Notice the TRY ... CATCH cx_salv_msg: it is not decoration. factory can fail (for example, if the table is not suitable) and it reports that with a class exception, not with a sy-subrc you forget to check. That alone is a robustness improvement over the REUSE_ALV family.

From full screen to container

The same factory serves to embed the ALV in a screen control. Only one parameter changes: you pass it the container.

cl_salv_table=>factory(
  EXPORTING
    r_container  = go_custom_container
  IMPORTING
    r_salv_table = go_salv_table
  CHANGING
    t_table      = gt_vehiculos ).

Without r_container you get full screen; with it, the list lives inside your CL_GUI_CUSTOM_CONTAINER (for example, in the bottom half of a splitter). The API is the same; you only decide where it is painted.

Why this matters

• Less error surface: there is no manual catalog to drift out of sync with the structure.
• Cheap change: adding a column to the table adds it to the ALV, for free.
• Readable: whoever reads the code in two years understands factory and display without a manual.

If your read-only list needs more than fifteen lines of plumbing, you are probably using the wrong API.

Next post we jump to interaction: events and hotspots, when the user stops looking and starts clicking.