Regarding making hyperlink in OOPs ALV

Question

Please see the following ALV Code. Its based on OOPs. There is no fieldcatalog defined in the program. In the output I want to make a hotspot on the filed VBELN & want to call T.code VA03 using SET PARAMETER ID. Please help. If I would have made it through Function Modules, It could have been easier as I can modify the fieldcatalog. Please help me urgently. Points will be rewarded.
*& Report  ZTEST_OOPS_REPT1                                            *
REPORT  ztest_oops_rept1                        .
Type pool for icons - used in the toolbar
TYPE-POOLS: icon.
TYPE-POOLS: slis.
TABLES: vbak.
To allow the declaration of o_event_receiver before the
lcl_event_receiver class is defined, decale it as deferred in the
start of the program
CLASS lcl_event_receiver DEFINITION DEFERRED.
G L O B A L   I N T E R N  A L   T A B L E S
*DATA: gi_sflight TYPE STANDARD TABLE OF sflight.
To include a traffic light and/or color a line the structure of the
table must include fields for the traffic light and/or the color
TYPES: BEGIN OF st_vbak.
        INCLUDE STRUCTURE vbak.
TYPES: END OF st_vbak.
TYPES: tt_vbak TYPE STANDARD TABLE OF st_vbak.
DATA: gi_vbak TYPE tt_vbak.
*declaration for fieldcatalog
DATA: lit_fieldcat TYPE slis_t_fieldcat_alv,
    ls_fieldcat  TYPE slis_fieldcat_alv.
G L O B A L   D A T A
DATA: ok_code         LIKE sy-ucomm,
    Work area for internal table
      g_wa_vbak    TYPE st_vbak,
    ALV control: Layout structure
      gs_layout       TYPE lvc_s_layo.
Declare reference variables to the ALV grid and the container
DATA:
  go_grid             TYPE REF TO cl_gui_alv_grid,
  go_custom_container TYPE REF TO cl_gui_custom_container,
  o_event_receiver    TYPE REF TO lcl_event_receiver.
DATA:
Work area for screen 200
  g_screen200 LIKE vbak.
Data for storing information about selected rows in the grid
DATA:
Internal table
  gi_index_rows TYPE lvc_t_row,
Information about 1 row
  g_selected_row LIKE lvc_s_row.
                        SELECTION-SCREEN                             *
SELECTION-SCREEN BEGIN OF BLOCK ch1 WITH FRAME.
SELECT-OPTIONS:  s_vbeln FOR vbak-vbeln OBLIGATORY.
SELECTION-SCREEN END OF BLOCK ch1.
C L A S S E S
CLASS lcl_event_receiver DEFINITION.
  PUBLIC SECTION.
    METHODS:
     handle_toolbar FOR EVENT toolbar OF cl_gui_alv_grid
       IMPORTING
         e_object e_interactive,
     handle_user_command FOR EVENT user_command OF cl_gui_alv_grid
       IMPORTING e_ucomm.
ENDCLASS.                    "lcl_event_receiver DEFINITION
      CLASS lcl_event_receiver IMPLEMENTATION
CLASS lcl_event_receiver IMPLEMENTATION.
  METHOD handle_toolbar.
Event handler method for event toolbar.
    CONSTANTS:
Constants for button type
      c_button_normal           TYPE i VALUE 0,
      c_menu_and_default_button TYPE i VALUE 1,
      c_menu                    TYPE i VALUE 2,
      c_separator               TYPE i VALUE 3,
      c_radio_button            TYPE i VALUE 4,
      c_checkbox                TYPE i VALUE 5,
      c_menu_entry              TYPE i VALUE 6.
    DATA:
        ls_toolbar  TYPE stb_button.
  Append seperator to the normal toolbar
    CLEAR ls_toolbar.
    MOVE c_separator TO ls_toolbar-butn_type..
    APPEND ls_toolbar TO e_object->mt_toolbar.
  Append a new button that to the toolbar. Use E_OBJECT of
  event toolbar. E_OBJECT is of type CL_ALV_EVENT_TOOLBAR_SET.
  This class has one attribute MT_TOOLBAR which is of table type
  TTB_BUTTON. The structure is STB_BUTTON
    CLEAR ls_toolbar.
    MOVE 'CHANGE'        TO ls_toolbar-function.
    MOVE  icon_change    TO ls_toolbar-icon.
    MOVE 'Change flight' TO ls_toolbar-quickinfo.
    MOVE 'Change'        TO ls_toolbar-text.
    MOVE ' '             TO ls_toolbar-disabled.
    APPEND ls_toolbar    TO e_object->mt_toolbar.
  ENDMETHOD.                    "handle_toolbar
  METHOD handle_user_command.
  Handle own functions defined in the toolbar
    CASE e_ucomm.
      WHEN 'CHANGE'.
        PERFORM change_flight.
       LEAVE TO SCREEN 0.
    ENDCASE.
  ENDMETHOD.                    "handle_user_command
ENDCLASS.                    "lcl_event_receiver IMPLEMENTATION
S T A R T - O F - S E L E C T I O N.
START-OF-SELECTION.
  SET SCREEN '100'.
*&      Module  USER_COMMAND_0100  INPUT
MODULE user_command_0100 INPUT.
  CASE ok_code.
    WHEN 'BACK'.
      LEAVE TO SCREEN 0.
  ENDCASE.
ENDMODULE.                 " USER_COMMAND_0100  INPUT
*&      Module  STATUS_0100  OUTPUT
MODULE status_0100 OUTPUT.
  SET PF-STATUS 'ZTEST_ALV'.
  SET TITLEBAR 'ZTEST_ALV'.
  DATA:
  For parameter IS_VARIANT that is sued to set up options for storing
  the grid layout as a variant in method set_table_for_first_display
    l_layout TYPE disvariant,
  Utillity field
    l_lines TYPE i.
After returning from screen 200 the line that was selected before
going to screen 200, should be selected again. The table gi_index_rows
was the output table from the GET_SELECTED_ROWS method in form
CHANGE_FLIGHT
  DESCRIBE TABLE gi_index_rows LINES l_lines.
  IF l_lines > 0.
    CALL METHOD go_grid->set_selected_rows
      EXPORTING
        it_index_rows = gi_index_rows.
    CALL METHOD cl_gui_cfw=>flush.
    REFRESH gi_index_rows.
  ENDIF.
Read data and create objects
  IF go_custom_container IS INITIAL.
  Read data from datbase table
    PERFORM get_data.
  Create objects for container and ALV grid
    CREATE OBJECT go_custom_container
      EXPORTING container_name = 'ALV_CONTAINER'.
    CREATE OBJECT go_grid
      EXPORTING
        i_parent = go_custom_container.
  Create object for event_receiver class
  and set handlers
    CREATE OBJECT o_event_receiver.
    SET HANDLER o_event_receiver->handle_user_command FOR go_grid.
    SET HANDLER o_event_receiver->handle_toolbar FOR go_grid.
  Layout (Variant) for ALV grid
    l_layout-report = sy-repid. "Layout fo report
Setup the grid layout using a variable of structure lvc_s_layo
  Set grid title
    gs_layout-grid_title = 'SALES ORDER'.
  Selection mode - Single row without buttons
  (This is the default  mode
    gs_layout-sel_mode = 'B'.  "B for single selection.
  Grid setup for first display
    CALL METHOD go_grid->set_table_for_first_display
      EXPORTING
        i_structure_name = 'VBAK'
        is_variant       = l_layout
        i_save           = 'A'
        is_layout        = gs_layout
      CHANGING
        it_outtab        = gi_vbak.
*-- End of grid setup -
  Raise event toolbar to show the modified toolbar
    CALL METHOD go_grid->set_toolbar_interactive.
  Set focus to the grid. This is not necessary in this
  example as there is only one control on the screen
    CALL METHOD cl_gui_control=>set_focus
      EXPORTING
        control = go_grid.
  ENDIF.
ENDMODULE.                 " STATUS_0100  OUTPUT
*&      Module  USER_COMMAND_0200  INPUT
      text
MODULE user_command_0200 INPUT.
  CASE ok_code.
    WHEN 'BACK'.
      LEAVE TO SCREEN 100.
      WHEN'SAVE'.
      PERFORM save_changes.
  ENDCASE.
ENDMODULE.                 " USER_COMMAND_0200  INPUT
*&      Form  get_data
      text
FORM get_data.
Read data from table VBAK
  SELECT *
    FROM vbak
    INTO TABLE gi_vbak
    WHERE vbeln IN s_vbeln.
ENDFORM.                    " load_data_into_grid
*&      Form  change_flight
Reads the contents of the selected row in the grid, ans transfers
the data to screen 200, where it can be changed and saved.
FORM change_flight.
  DATA:l_lines TYPE i.
  REFRESH gi_index_rows.
  CLEAR   g_selected_row.
Read index of selected rows
  CALL METHOD go_grid->get_selected_rows
    IMPORTING
      et_index_rows = gi_index_rows.
Check if any row are selected at all. If not
table  gi_index_rows will be empty
  DESCRIBE TABLE gi_index_rows LINES l_lines.
  IF l_lines = 0.
    CALL FUNCTION 'POPUP_TO_DISPLAY_TEXT'
      EXPORTING
        textline1 = 'You must choose a line'.
    EXIT.
  ENDIF.
Read indexes of selected rows. In this example only one
row can be selected as we are using gs_layout-sel_mode = 'B',
so it is only ncessary to read the first entry in
table gi_index_rows
  LOOP AT gi_index_rows INTO g_selected_row.
    IF sy-tabix = 1.
      READ TABLE gi_vbak INDEX g_selected_row-index
       INTO g_wa_vbak.
    ENDIF.
  ENDLOOP.
Transfer data from the selected row to screenm 200 and show
screen 200
  CLEAR g_screen200.
  MOVE-CORRESPONDING g_wa_vbak TO g_screen200.
  LEAVE TO SCREEN '200'.
ENDFORM.                    " change_flight
*&      Form  save_changes
Changes made in screen 200 are written to the datbase table
zsflight, and to the grid table gi_sflight, and the grid is
updated with method refresh_table_display to display the changes
FORM save_changes.
Update traffic light field
Update database table
  MODIFY vbak FROM g_screen200.
Refresh grid
  CALL METHOD go_grid->refresh_table_display.
  CALL METHOD cl_gui_cfw=>flush.
  LEAVE TO SCREEN '100'.
ENDFORM.                    " save_changes
*&      Module  STATUS_0200  OUTPUT
      text
MODULE status_0200 OUTPUT.
  SET PF-STATUS 'ZTEST_ALV'.
  SET TITLEBAR 'ZTEST_ALV'.
ENDMODULE.                 " STATUS_0200  OUTPUT
                 " lit_fieldcat_init

Answer 1

Use FM -LVC_FIELDCATALOG_MERGE to derive the field catalog for table VBAK. It will give you the field catalog. You can modify the column VBELN  by changing HOTSPOT = 'X".
and in your code - at the method SET_TABLE_FOR....DISPLAY , you comment out the structure name and pass the modified field catalog.
Hope it helps.