Issue with AT SELECTION-SCREEN ON event

Question

Hi Experts!!
In the below code, p_jan, p_feb are showing as blank though they are filled in. Is this how this event works?
PARAMETERS: p_categ TYPE zpycateg,
                         p_jan TYPE sy-datum,
                         p_feb TYPE sy-datum.
AT SELECTION-SCREEN ON p_categ.
IF NOT p_jan IS INITIAL.
ENDIF.
Please help me out.

Answer 1

Hi
That event works for P_CATEG, here other parameters of the screen can't been seen.
If you want to do a validation has to check several parameters of a selection-screen you should use the event AT SELECTION-SCREEN.
Anyway if you think it's better the event AT SELECTION-SCREEN ON <screen field>, the values of other fields can be picked up bu fm DYNP_VALUES_READ
AT SELECTION-SCREEN ON P_CATEG.
  DATA: T_FIELDS TYPE STANDARD TABLE OF DYNPREAD WITH HEADER LINE.
  T_FIELDS-FIELDNAME = 'P_JAN'. APPEND T_FIELDS.
  T_FIELDS-FIELDNAME = 'P_FEB'. APPEND T_FIELDS.
  CALL FUNCTION 'DYNP_VALUES_READ'
    EXPORTING
      DYNAME     = SY-REPID
      DYNUMB     = SY-DYNNR
    TABLES
      DYNPFIELDS = T_FIELDS.
  READ TABLE T_FIELDS WITH KEY FIELDNAME = 'P_JAN'.
  IF NOT T_FIELDS-FIELDVALUE IS INITIAL.
  ENDIF.
Max