Using an extra protocol outside of ALV-Grid data handling

[EnnoWulff]

When editing an ALV-Grid you can send some messages to the user saying that he entered wrong data. Normally and mostly you will get a popup that displays the errors or warnings.



This looks quite ugly.

Therefore I like to use the possibility to define an extra message container for the grids messages. You can do this by passing a container reference with parameter I_APPLOGPARENT when creating the ALV grid.

    CREATE OBJECT mo_alv

      EXPORTING

        i_parent       = io_container_grid

        i_applogparent = io_container_prot

        i_appl_events  = 'X'

      EXCEPTIONS

        OTHERS         = 5.

That looks much nicer:



But then I also wanted to display other messages in this message box that come from other functions but they are important for that grid.

Like: "Please mark a row for executing this function"

First I was struggling because the protocol object used within the ALV grid is PRIVATE *sigh*. So you cannot inherit the CL_GUI_ALV_GRID-class and write a method to access the protcol object MR_DATA_CHANGED.

Then I found two solutions. Both are not perfect but they work:

1. Use the friends concept for accessing protected and private methods (IF_ALV_RM_GRID_FRIEND) see ABAPblog or Tricktresor (example Autosum)


2. Create and destroy a separate instance of class CL_ALV_CHANGED_DATA_PROTOCOL

I will show you the second variation which works pretty well.

Before passing a message you will have to create an instance of CL_ALV_CHANGED_DATA_PROTOCOL and passing the container where the protocol should be shown to the object:

mo_prot = NEW #( i_calling_alv = mo_alv i_container = mo_message_container ).

The ALV-grid protocol container and the extra container cannot be shown simultanously. Before using one you will have to destroy the other.

Demo report

The report shows a selection screen and two docking container.

You can enter data in both. But when entering data in the parameter P_TEST you will get an error message in the alv-grid message container.

If you enter values in the KEY field that do not contain A, B or C, you will get an error message created the normal way in grid event DATA_CHANGED:



The disadvantage is that you cannot use both message senders at once. If there are any errors in the grid then the extra messages will not be shown. If you put the checks in a separate method where to pass the protocol object then you could call this method and add your extra messages to the standard alv grid.

The Code

Here is the complete coding (also at github😞

REPORT ztrcktrsr_alv_edit_protocol.







CLASS lcl_demo DEFINITION.



  PUBLIC SECTION.

    CLASS-METHODS go

      IMPORTING io_container_grid TYPE REF TO cl_gui_container

                io_container_prot TYPE REF TO cl_gui_container.

    CLASS-METHODS set_message

      IMPORTING i_message TYPE clike.



    TYPES: BEGIN OF ts_data,

             key   TYPE char10,

             value TYPE text40,

           END OF ts_data,

           tt_data TYPE STANDARD TABLE OF ts_data WITH DEFAULT KEY.

  PROTECTED SECTION.

    CLASS-DATA mo_alv  TYPE REF TO cl_gui_alv_grid.

    CLASS-DATA mo_message_container TYPE REF TO cl_gui_container.

    CLASS-DATA mo_prot TYPE REF TO cl_alv_changed_data_protocol.

    CLASS-DATA mt_data TYPE tt_data.

    CLASS-METHODS handle_data_changed

                  FOR EVENT data_changed  OF  cl_gui_alv_grid

      IMPORTING er_data_changed sender.



ENDCLASS.                    "lcl_events DEFINITION



CLASS lcl_demo IMPLEMENTATION.



  METHOD go.



    DATA lt_fcat  TYPE lvc_t_fcat.



    "Make sure alv will be started only once

    CHECK mo_alv IS INITIAL.



    "Remember given container for protocol

    mo_message_container = io_container_prot.





    "create alv-grid

    CREATE OBJECT mo_alv

      EXPORTING

        i_parent       = io_container_grid

        i_applogparent = io_container_prot

        i_appl_events  = 'X'

      EXCEPTIONS

        OTHERS         = 5.



    "Register edit event

    mo_alv->register_edit_event( cl_gui_alv_grid=>mc_evt_enter ).



    "enable edit mode

    mo_alv->set_ready_for_input( 1 ).



    "set handler for changing data

    SET HANDLER handle_data_changed FOR mo_alv.



    "Build simple field catalog

    APPEND LINES OF VALUE lvc_t_fcat(

                  ( fieldname = 'KEY'

                    tabname   = 'XX'

                    reptext   = 'Key'

                    datatype  = 'CHAR'

                    inttype   = 'C'

                    outputlen = 10

                    edit      = abap_true )

                  ( fieldname = 'VALUE'

                    tabname   = 'XX'

                    reptext   = 'Value'

                    datatype  = 'CHAR'

                    inttype   = 'C'

                    outputlen = 40

                    lowercase = abap_true

                    edit      = abap_true )

                            ) TO lt_fcat.



    "Make sure user can enter data

    DO 5 TIMES.

      APPEND INITIAL LINE TO mt_data.

    ENDDO.



    " First Display

    mo_alv->set_table_for_first_display(

      CHANGING

        it_fieldcatalog = lt_fcat

        it_outtab       = mt_data

      EXCEPTIONS

        OTHERS          = 4 ).



    "Set focus on grid so user can immediately enter data in grid

    cl_gui_alv_grid=>set_focus( mo_alv ).





  ENDMETHOD.



  METHOD set_message.



    IF mo_prot IS INITIAL.

      "create extra protocol

      mo_prot = NEW #( i_calling_alv = mo_alv i_container = mo_message_container ).

    ELSE.

      "clear older protocol entries

      mo_prot->refresh_protocol( ).

    ENDIF.

    "add user message

    mo_prot->add_protocol_entry( i_msgty = 'E'

                                 i_msgno = '000'

                                 i_msgid = 'OO'

                                 i_msgv1 = i_message

                                 i_fieldname = space ).

    "and display

    mo_prot->display_protocol( ).



  ENDMETHOD.



  METHOD handle_data_changed.



    DATA: ls_good                TYPE lvc_s_modi.



    IF mo_prot IS BOUND.

      "clear extra protocol

      mo_prot->refresh_protocol( ).

      mo_prot->free( ).

      CLEAR mo_prot.

    ENDIF.



    "Loop at all changed fields

    LOOP AT er_data_changed->mt_good_cells INTO ls_good.

      "Read data table

      READ TABLE mt_data ASSIGNING FIELD-SYMBOL(<data>) INDEX ls_good-row_id.

      IF sy-subrc = 0.

        IF ls_good-fieldname = 'KEY' AND ls_good-value CN 'ABC '.

          "Field does not contain A, B or C - That's bad!

          er_data_changed->add_protocol_entry( i_msgty     = 'E'

                                               i_msgno     = '000'

                                               i_msgid     = 'OO'

                                               i_msgv1     = 'Must be ABC!'

                                               i_fieldname = 'KEY'

                                               i_row_id    = ls_good-row_id ).

        ENDIF.



        "Change field

        ASSIGN COMPONENT ls_good-fieldname OF STRUCTURE <data> TO FIELD-SYMBOL(<field>).

        IF sy-subrc = 0.

          <field> = ls_good-value.

        ENDIF.

      ENDIF.

    ENDLOOP.



    "Set focus

    cl_gui_control=>set_focus( mo_alv ).



  ENDMETHOD.                    "handle_data_changed



ENDCLASS.                    "lcl_events IMPLEMENTATION



PARAMETERS p_test TYPE c LENGTH 10.



INITIALIZATION.

  DATA(docker_prot) = NEW cl_gui_docking_container( ratio = 20 side = cl_gui_docking_container=>dock_at_bottom ).

  DATA(docker_grid) = NEW cl_gui_docking_container( ratio = 60 side = cl_gui_docking_container=>dock_at_bottom ).

  lcl_demo=>go( io_container_grid = docker_grid

                io_container_prot = docker_prot ).





AT SELECTION-SCREEN.



  IF p_test IS NOT INITIAL.

    "Demo for showing how to use the extra protocol outside alv data handling

    lcl_demo=>set_message( 'Not allowed to enter something in parameter!!' ).

  ENDIF.