F4 help based on the Value in other field

Question

Hello
I have a requirement in which there are two fields say field1 and field 2 in an ALV grid (in which  new data can be entered). The F4 help of field 2 should be based on the value  the user enters on field1.I have checked out the BC_ALV* programs but there are no clear help .
I have tried setting the parameter id of the first field value and then get that parameter id on_f4 event of the second field.But where can i set the parameter id of the first field . on_f4 of first field does not have its value and there is no event after_f4 . There is a parameter e_afterf4 in data change event but to tirgger that there shud be some event right.
Moreover If at all i get the first field value , i can use FM F4_int_table_value_request to show the refined f4 in field 2 . But I am passing the a field symbol table in my grids set table for first display . what can i pass as parameters here to the FM  F4_int_table_value_request?

Answer 1

hello Kallu ,
  gt_f4_wa-getbefore  = 'X'. --->refreshing layout before F4
  gt_f4_wa-chngeafter = 'X'--> refreshing layout after f4.
see the sample code of F4...no need to pass dynpro details.....
*---locals.
  data:  lt_return type table of ddshretval,
         ls_return type ddshretval,
         begin of lt_kostl occurs 0,
          kokrs type kokrs,
          datbi type datbi,
          bukrs type bukrs,
          prctr type prctr,
         end of lt_kostl,
         ls_f4           type  lvc_s_modi.
  field-symbols: <ls_wa>         type any,
                <t_f4> type lvc_t_modi.
*---get defalut values.
  refresh lt_kostl.
  select kokrs
         kostl as prctr
         datbi
         bukrs
    from csks
    into  corresponding fields of table lt_kostl
           where kokrs eq g_kokrs
             and datbi ge sy-datum
             and bukrs eq yfit_00049-bukrs.
*---call fm to display int values.
  call function 'F4IF_INT_TABLE_VALUE_REQUEST'
    exporting
      retfield        = 'YFIT_00050-PRCTR'
      window_title    = 'Profit Center list'
      value_org       = 'S'
      display         = space
    tables
      value_tab       = lt_kostl
      return_tab      = lt_return
    exceptions
      parameter_error = 1
      no_values_found = 2
      others          = 3.
  if sy-subrc <> 0.
    message id sy-msgid type sy-msgty number sy-msgno
            with sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
  else.
    read table lt_return into ls_return
               with key fieldname = 'F0004'.
    if sy-subrc eq 0.
      assign er_event_data->m_data->* to <t_f4>.
      ls_f4-fieldname = e_fieldname.
      ls_f4-row_id    = es_row_no-row_id.
      ls_f4-value     = ls_return-fieldval.
      ls_f4-error     = space.
      ls_f4-tabix     = space.
      ls_f4-style     = space.
      ls_f4-style2    = space.
      ls_f4-style3    = space.
      ls_f4-style4    = space.
      append ls_f4 to <t_f4>.
    endif.
  endif.
  er_event_data->m_event_handled = 'X'.
regards
Prabhu