ALV with EDIT and SAVE functionality

Code:

REPORT z_demo_alv_jg.

*******************************************************************
* TYPE-POOLS                                                      *
*******************************************************************
TYPE-POOLS: slis. 

*******************************************************************
* INTERNAL TABLES/WORK AREAS/VARIABLES     *
*******************************************************************
DATA: i_fieldcat TYPE slis_t_fieldcat_alv,
     i_index TYPE STANDARD TABLE OF i WITH HEADER LINE,
     w_field TYPE slis_fieldcat_alv,
     p_table LIKE dd02l-tabname,
     dy_table TYPE REF TO data,
     dy_tab TYPE REF TO data,
     dy_line TYPE REF TO data.

*******************************************************************
* FIELD-SYMBOLS                                                   *
*******************************************************************
FIELD-SYMBOLS:  TYPE STANDARD TABLE,
               TYPE ANY,
               TYPE ANY,
               TYPE STANDARD TABLE.

*******************************************************************
* SELECTION SCREEN                                                *
*******************************************************************
PARAMETERS: tabname(30) TYPE c,
           lines(5)  TYPE n.

*******************************************************************
* START-OF-SELECTION                                              *
*******************************************************************
START-OF-SELECTION.

* Storing table name
 p_table = tabname.

* Create internal table dynamically with the stucture of table name
* entered in the selection screen
 CREATE DATA dy_table TYPE STANDARD TABLE OF (p_table).
 ASSIGN dy_table->* TO .
 IF sy-subrc <> 0.
   MESSAGE i000(z_zzz_ca_messages) WITH ' No table found'.

    LEAVE TO LIST-PROCESSING.
 ENDIF.
* Create workarea for the table
 CREATE DATA dy_line LIKE LINE OF .
 ASSIGN dy_line->* TO .

* Create another temp. table
 CREATE DATA dy_tab TYPE STANDARD TABLE OF (p_table).
 ASSIGN dy_tab->* TO .

  SORT i_fieldcat BY col_pos.

* Select data from table
 SELECT * FROM (p_table)
 INTO TABLE 
 UP TO lines ROWS.

  REFRESH .

* Display report
 CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
   EXPORTING
     i_callback_program       = sy-repid
     i_structure_name         = p_table
     i_callback_user_command  = 'USER_COMMAND'
     i_callback_pf_status_set = 'SET_PF_STATUS'
   TABLES
     t_outtab                 = 
   EXCEPTIONS
     program_error            = 1
     OTHERS                   = 2.

  IF sy-subrc <> 0.

  ENDIF.

*&-----------------------------------------------------------------*
*&      Form  SET_PF_STATUS
*&-----------------------------------------------------------------*
*       Setting custom PF-Status
*------------------------------------------------------------------*
*      -->RT_EXTAB   Excluding table
*------------------------------------------------------------------*
FORM set_pf_status USING rt_extab TYPE slis_t_extab.

  SET PF-STATUS 'Z_STANDARD'.

ENDFORM.                    "SET_PF_STATUS

*&----------------------------------------------------------------*
*&      Form  user_command
*&-----------------------------------------------------------------*
*       Handling custom function codes
*------------------------------------------------------------------*
*      -->R_UCOMM      Function code value
*      -->RS_SELFIELD  Info. of cursor position in ALV
*------------------------------------------------------------------*
FORM user_command  USING    r_ucomm LIKE sy-ucomm
              rs_selfield TYPE slis_selfield.

* Local data declaration
 DATA: li_tab TYPE REF TO data,
       l_line TYPE REF TO data.

* Local field-symbols
 FIELD-SYMBOLS: TYPE table,
                 TYPE ANY.

* Create table
 CREATE DATA li_tab TYPE STANDARD TABLE OF (p_table).
 ASSIGN li_tab->* TO .

* Create workarea
 CREATE DATA l_line LIKE LINE OF .
 ASSIGN l_line->* TO .

  CASE r_ucomm.

*   When a record is selected
   WHEN '&IC1'.

*     Read the selected record
     READ TABLE  ASSIGNING  INDEX
     rs_selfield-tabindex.

      IF sy-subrc = 0.

*       Store the record in an internal table
       APPEND  TO .

*       Fetch the field catalog info
       CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'
         EXPORTING
           i_program_name         = 'Z_DEMO_PDF_JG'
           i_structure_name       = p_table
         CHANGING
           ct_fieldcat            = i_fieldcat
         EXCEPTIONS
           inconsistent_interface = 1
           program_error          = 2
           OTHERS                 = 3.
       IF sy-subrc = 0.

*         Make all the fields input enabled except key fields
         w_field-input = 'X'.

          MODIFY i_fieldcat FROM w_field TRANSPORTING input
         WHERE key IS INITIAL.

        ENDIF.

*       Display the record for editing purpose
       CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
         EXPORTING
           i_callback_program    = sy-repid
           i_structure_name      = p_table
           it_fieldcat           = i_fieldcat
           i_screen_start_column = 10
           i_screen_start_line   = 15
           i_screen_end_column   = 200
           i_screen_end_line     = 20
         TABLES
           t_outtab              = 
         EXCEPTIONS
           program_error         = 1
           OTHERS                = 2.

        IF sy-subrc = 0.

*         Read the modified data
         READ TABLE  INDEX 1 INTO .

*         If the record is changed then track its index no.
*         and populate it in an internal table for future
*         action
         IF sy-subrc = 0 AND  <> .
            = .
           i_index = rs_selfield-tabindex.
           APPEND i_index.
         ENDIF.
       ENDIF.

      ENDIF.

*   When save button is pressed
   WHEN 'SAVE'.

*     Sort the index table
     SORT i_index.

*     Delete all duplicate records
     DELETE ADJACENT DUPLICATES FROM i_index.

      LOOP AT i_index.

*       Find out the changes in the internal table
*       and populate these changes in another internal table
       READ TABLE  ASSIGNING  INDEX i_index.
       IF sy-subrc = 0.
         APPEND  TO .
       ENDIF.

      ENDLOOP.

*     Lock the table
     CALL FUNCTION 'ENQUEUE_E_TABLE'
       EXPORTING
         mode_rstable   = 'E'
         tabname        = p_table
       EXCEPTIONS
         foreign_lock   = 1
         system_failure = 2
         OTHERS         = 3.

      IF sy-subrc = 0.

*       Modify the database table with these changes
       MODIFY (p_table) FROM TABLE .

        REFRESH .

*       Unlock the table
       CALL FUNCTION 'DEQUEUE_E_TABLE'
         EXPORTING
           mode_rstable = 'E'
           tabname      = p_table.

      ENDIF.
 ENDCASE.

  rs_selfield-refresh = 'X'.

ENDFORM.                    "user_command

Selection screen:

Output: