Updating database table using ALV Grid class CL_ALV_CHANGED_DATA_PROTOCOL

Question

Hi,
I am trying to use class CL_ALV_CHANGED_DATA_PROTOCOL to update a database table from an ALV grid.
I have used program BCALV_EDIT_04 as an example.
I am able to successfully processed inserted or deleted lines using the attributes
MT_DELETED_ROWS
MT_INSERTED_ROWS
but I also want to process modified lines.
I was just wondering whether anyone out there has some example code for this.
I can see that there are the following attributes available
MT_MOD_CELLS
MP_MOD_ROWS.
I would ideally like to use MP_MOD_ROWS rather than  MT_MOD_CELLS but it is not clear to me what type MP_MOD_ROWS is.
If anyone has any example code for this sort of thing, please let me know.
Thanks,
Ruby

Answer 1

hi Ruby,
Yes we can use that *data reference variable *.
It is a variable( something comparable to a pointer ) that points to a int table( table with changed contents )
which ll be created at run-time based on the data type ot the internal table that we pass to the parameter it_outtab of method set_table_for_first_display ...
assign er_data_changed->mp_mod_rows->* to a field-symbol and use it...
Check the below code for example -> method refresh_changed_data
screen flow logic.
PROCESS BEFORE OUTPUT.
  MODULE pbo.
PROCESS AFTER INPUT.
  MODULE pai.
main program.
*       CLASS lcl_event_responder DEFINITION                           *
CLASS lcl_event_responder DEFINITION.
  PUBLIC SECTION.
    DATA  : ls_changed_cell TYPE  lvc_s_modi,
            lv_language     TYPE  spras..
    METHODS refresh_changed_data  FOR EVENT data_changed
                                  OF cl_gui_alv_grid
                                  IMPORTING er_data_changed
                                            e_ucomm.
ENDCLASS.                    "event_responder DEFINITION
TYPES tt_makt TYPE STANDARD TABLE OF makt.
DATA: go_handler         TYPE REF TO lcl_event_responder,
      go_grid            TYPE REF TO cl_gui_alv_grid,
      gt_fieldcat        TYPE lvc_t_fcat,
      gv_language        TYPE spras VALUE 'E',
      gt_outtab          TYPE tt_makt,
      gs_tableline       TYPE LINE OF tt_makt.
FIELD-SYMBOLS : <changed_rows> TYPE tt_makt.
CALL SCREEN 100.
*       MODULE PBO OUTPUT                                             *
MODULE pbo OUTPUT.
  SET PF-STATUS 'BASIC'.
  PERFORM create_and_init_alv CHANGING gt_outtab[]
                                       gt_fieldcat.
ENDMODULE.                    "pbo OUTPUT
*       MODULE PAI INPUT                                              *
MODULE pai INPUT.
  LEAVE PROGRAM.
ENDMODULE.                    "pai INPUT
FORM create_and_init_alv CHANGING pt_outtab LIKE gt_outtab[]
                                  pt_fieldcat TYPE lvc_t_fcat.
  CHECK go_grid IS NOT BOUND.
  CREATE OBJECT go_grid
    EXPORTING
      i_parent = cl_gui_container=>default_screen.
  PERFORM build_display_table.
  PERFORM build_fieldcat CHANGING pt_fieldcat.
  go_grid->set_table_for_first_display( CHANGING  it_fieldcatalog      = pt_fieldcat
                                                  it_outtab            = pt_outtab ).
  go_grid->set_ready_for_input( 1 ).
* raises the 'data_changed' event when we select another cell/any action after changing the data
  go_grid->register_edit_event( EXPORTING i_event_id = cl_gui_alv_grid=>mc_evt_enter ).
  CREATE OBJECT go_handler.
  SET HANDLER go_handler->refresh_changed_data FOR go_grid.
ENDFORM.                               "CREATE_AND_INIT_ALV
FORM build_display_table.
  FREE gt_outtab.
  SELECT * FROM makt UP TO 20 ROWS INTO TABLE gt_outtab WHERE spras EQ gv_language.
ENDFORM.                               "build_display_table
FORM build_fieldcat CHANGING pt_fieldcat TYPE lvc_t_fcat.
  DATA ls_fcat TYPE lvc_s_fcat.
  CALL FUNCTION 'LVC_FIELDCATALOG_MERGE'
    EXPORTING
      i_structure_name = 'MAKT'
    CHANGING
      ct_fieldcat      = pt_fieldcat.
  LOOP AT pt_fieldcat INTO ls_fcat.
    ls_fcat-edit       = abap_true.
    MODIFY pt_fieldcat FROM ls_fcat.
  ENDLOOP.
ENDFORM.                               "build_fieldcat
*       CLASS event_responder IMPLEMENTATION                          *
CLASS lcl_event_responder IMPLEMENTATION.
  METHOD refresh_changed_data.
    ASSIGN er_data_changed->mp_mod_rows->* TO <changed_rows>.
    LOOP AT <changed_rows> INTO gs_tableline.
      BREAK-POINT.
    ENDLOOP.
  ENDMETHOD.                    "click
ENDCLASS.                    "event_responder IMPLEMENTATION
Cheers,
Jose.