Drop Down in ALV ABAP and NOT in OO - ABAP

Question

Hello Everyone....
I m workin on an ALV which is in simple ABAP and not in OO-ABAP. There is some selection criteria on the first screen , as soon as the user fulfills the requirement an ALV GRID is displayed in which the last column is editable.
  But the Problem is that i wanna make that editable field in ALV as drop down which would contain values from the database table.
  Suggest me some method , so that i dont have to do much changes in my code .
  A Sample code will be very benificial .
Thanx n Regards,
Harpreet.

Answer 1

Hi Harpreet,
[compiled from sap online help - always a good chice]
To make an input/output field into a list box, you must set the value L or LISTBOX in the Dropdown attribute in the Screen Painter. The visLg attribute determines the output width of the list box and the field. You can assign a function code to a list box field. In this case, the PAI event is triggered as soon as the user chooses a value from the list, and the function code is placed in the SY-UCOMM and OK_CODE fields. If you do not assign a function code, the PAI event must be triggered in the usual way – that is, when the user chooses a pushbutton or an element from the GUI status.
If you have assigned a list box to an input/output field, you can use the Value list attribute of the screen element to determine how the value list should be compiled. There are two options:
Value list from input help (recommended)
If you do not enter anything in the value list attribute, the text field uses the first column displayed in the input help assigned to the screen field. The input help can be defined in the ABAP Dictionary, the screen, or a POV dialog module. It should be laid out in two columns. The key is automatically filled.
Value list from PBO modules (not recommended).
If you enter A in the value list attribute, you must fill the value list yourself before the screen is sent (for example, in the PBO event) using the function module VRM_SET_VALUES. When you do this, you must pass an internal table with the type VRM_VALUES to the import parameter VALUES of the function module. VRM_VALUES belongs to the type group VRM. The line type is a structure consisting of the two text fields KEY (length 40) and TEXT (length 80). In the table, you can combine possible user entries from the KEY field with any texts from the TEXT component. You specify the corresponding input/output field in the import parameter ID.
Examples
Example
Dropdown box with a value list from input help (recommended)
*& Report DEMO_DROPDOWN_LIST_BOX                                 *
REPORT demo_dropdown_list_box.
*& Global Declarations                                           *
* Screen Interfaces
TABLES sdyn_conn.
DATA   ok_code TYPE sy-ucomm.
* Global data
TYPES: BEGIN OF type_carrid,
         carrid type spfli-carrid,
         carrname type scarr-carrname,
       END OF type_carrid.
DATA itab_carrid TYPE STANDARD TABLE
     OF type_carrid WITH HEADER LINE.
*& Processing Blocks called by the Runtime Environment           *
* Event Block START-OF-SELECTION
START-OF-SELECTION.
CALL SCREEN 100.
* Dialog Module PBO
MODULE status_0100 OUTPUT.
  SET PF-STATUS 'SCREEN_100'.
ENDMODULE.
* Dialog Modules PAI
MODULE cancel INPUT.
  LEAVE PROGRAM.
ENDMODULE.
MODULE user_command_0100 INPUT.
  CASE ok_code.
    WHEN 'SELECTED'.
      MESSAGE i888(sabapdocu) WITH sdyn_conn-carrid.
ENDCASE.
ENDMODULE.
* Dialog Module POV
MODULE create_dropdown_box INPUT.
  SELECT carrid carrname
                FROM scarr
                INTO CORRESPONDING FIELDS OF TABLE itab_carrid.
  CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
       EXPORTING
            retfield        = 'CARRID'
            value_org       = 'S'
       TABLES
            value_tab       = itab_carrid
       EXCEPTIONS
            parameter_error = 1
            no_values_found = 2
            OTHERS          = 3.
  IF sy-subrc <> 0.
ENDIF.
ENDMODULE.
The next screen (statically defined) for screen 100 is 100. The only input field on the screen is the component SDYN_CONN-CARRID. Its Dropdown attribute is set to L, and it has the output length 20. The Value list attribute is empty, and it has the function code SELECTED. The function codes of the buttons EXECUTE and CANCEL. CANCEL are defined in the GUI status as having the function type E.
The screen flow logic is as follows:
PROCESS BEFORE OUTPUT.
  MODULE status_0100.
PROCESS AFTER INPUT.
  MODULE cancel AT EXIT-COMMAND.
  MODULE user_command_0100.
PROCESS ON VALUE-REQUEST.
  FIELD sdyn_conn-carrid MODULE create_dropdown_box.
Users cannot enter any values into the screen fields. When they choose the input field on screen 100, the system displays a list box. The Value list attribute is empty, so the system launches the input mechanism. In this case, the event block PROCESS ON VALUE-REQUEST is created in the screen flow logic. This event block controls all other mechanisms. A two-column internal table is filled in the appropriate dialog module and passed to the input help using the F4IF_INT_TABLE_VALUE_REQUEST function module. The system inserts the two columns of the table into the list box.
When the user chooses a line in the list box, the PAI event is triggered using the function code SELECTED and the value in the first column of the internal table is copied to the input field.
Regards,
Clemens