In today’s article I will show you (and explain!) how you can make a selection screen refresh itself on a regular basis without user intervention.

Are you ready?

Our example shows a parameter that refreshes itself each second.

Because the code is simple I’ll show it all at once and only then will explain it:

PARAMETERS : p_conta TYPE t DEFAULT 300.

CLASS lcl_handler DEFINITION.
  PUBLIC SECTION.
    METHODS: corre_handler FOR EVENT finished OF cl_gui_timer.
ENDCLASS.

DATA o_temporizador TYPE REF TO cl_gui_timer .
DATA o_handler TYPE REF TO lcl_handler .

CLASS lcl_handler IMPLEMENTATION.
  METHOD corre_handler.
    CALL METHOD o_temporizador ->run.
    CALL METHOD cl_gui_cfw =>set_new_ok_code
      EXPORTING
        new_code = 'REFR'.
  ENDMETHOD.
ENDCLASS.

INITIALIZATION.
  CREATE OBJECT o_temporizador.
  CREATE OBJECT o_handler.
  o_temporizador-> interval = '1' .
  CALL METHOD o_temporizador-> run .
  SET HANDLER o_handler-> corre_handler FOR ALL INSTANCES.

AT SELECTION-SCREEN OUTPUT .
  p_conta = p_conta - 1 .

The trick is in using CL_GUI_TIMER class in interaction with the event AT SELECTION-SCREEN OUTPUT.

1. First we declare the parameter that should be automatically updated

2. Then we declare a small class to implement the handler of the event triggered by the end of the timer of CL_GUI_TIMER.

3. Next we declare two instances, one from the timer (CL_GUI_TIMER) and another from our handler LCL_HANDLER.

4. INITIALIZATION event creates the timer and handler objects, sets the timer and links your event to our handler.

5. The implementation method handler restarts the timer and launches an OK code that refreshes the screen, running the event AT SELECTION-SCREEN OUPUT.

6. Finally the event AT SELECTION-SCREEN OUTPUT only decreases our timer.

Quite simple, right? Any doubts?

Thank you Evil Saltine for the photo.

Greetings from Abapinho.