Allow to erase values under the input-check of the ALV Grid Control

Question

Hi,<br />
in my ALV Grid I do have a cell which automatically checks the values entered by the user. When the user does not enter the values belonging to the DDIC Domain Value Range of the data element, the cell is rendered with a red border and an ALV error message comes up telling the user to enter the correct values from the F4 help.
In general, this is really great, but in case the user needs to erase the value, this automatical ALV Grid error message keeps popping up asking him to enter at least one value from the value range.
(I assume this is due to the fact that the Domain value range does not contain the value 'empty'.)
<br />
I would like to keep the functionality of checking the entered value but want to switch off the error message in case nothing was entered. How can I achive this?
<br /> <br />
This is what I did so far: <br />
1. Upon initializing ALV Grid, I define the field catalog like this: <br />
ls_fieldcat-fieldname = 'REACTION'.                       "#EC NOTEXT <br />
  ls_fieldcat-edit       = abap_true. <br />
  ls_fieldcat-coltext   = 'Reaction'.                       "#EC NOTEXT <br />
  ls_fieldcat-outputlen = '8'.                              "#EC NOTEXT  <br />
<br />
* This forces the user to set at least one value; not allowing him to delete it!! <br />
  ls_fieldcat-ref_table = 'CRMS_ES_FOREIGN_ATTRIBUTE'.      "#EC NOTEXT <br />
  ls_fieldcat-ref_field =  'REACTION'. <br />
  ls_fieldcat-key = abap_true. <br />
<br />
  ls_fieldcat-checktable = '!'. <br />
  ls_fieldcat-f4availabl  = 'X'. "shows the handle for F4 help <br />
  ls_fieldcat-col_id = 7.
<br />
(I would assume here that the ls_fieldcat - structure would allow an additional field which allows empty values, but I could not find one!) <br />
<br />
2. For my ALV Grid instance, I am registering the F4 during initialization:<br />
call method gr_fkt_grid->register_f4_for_fields <br />
        exporting <br />
          it_f4 = lt_f4. <br />
<br />
      ls_f4-fieldname  = 'REACTION'.   "EC SYNTCHAR <br />
      ls_f4-register   = abap_true. <br />
      insert ls_f4 into table lt_f4. <br />
      call method gr_fkt_grid->register_f4_for_fields <br />
        exporting <br />
          it_f4 = lt_f4. <br />
<br /> <br />
3. Then I am setting the handler while initializing: <br />
      set handler lr_grid_event_receiver->handle_f4 <br />
      for all instances. <br />
<br /> <br />
4. I also have checking methods in PAI for the ALV cells, but they do not apply in this case, <br />
    since ALV itself performs this check described above. I cannot see a chance for <br />
    interfering myself in PAI. <br />
<br />
Does anyone have an idea how I could prevent the ALV Grid of bringing up the message "Enter a valid value" and <br />
allowing to delete the cell content while keeping its checks in case the user enters a wrong value? <br />
<br />
Thank you very much,<br />
regards,<br />
Konrad<br />

Answer 1

Hi Konrad,
Inside the handler method for event DATA_CHANGED,  always suppress the error log by calling method activate_display_protocol with dialog = ''.
Whenever u need error log call  method display_protocol based on ok_code(sy-ucomm).
Ex:
method data_changed.  " Handler method for event 'DATA_CHANGED'
*Suppressing error log
    call method g_o_grid->activate_display_protocol        "  Always suppress error log when grid is changed
      exporting
        i_dialog = ''.
    if er_data_changed->mt_protocol[] is not initial.
      if ok_code = 'BACK' or ok_code = 'SAVE'.      "  Based  on  ok_code display error log
*Display error log
        call method er_data_changed->display_protocol.
      endif.
    endif.
  endmethod.                    "data_changed
Might solve ur problem
Thanks,
Edited by: Sap Fan on Oct 14, 2009 5:35 AM