FM GUI_UPLOAD and GUI_DOWNLOAD.

Question

Hi,
    I am new to ABAP world.I hve been given a task to use FM GUI_UPLOAD and GUI_DOWNLOAD.Plz tell me what these functions do , i mean what's there purpose and how to use them in abap code.Plz provide some easy code so that i can understand them properly.
Points will be rewarded for useful answeres.
Thanks.

Answer 1

Hi Amardeep,
FM GUI_UPLOAD is used for uploading the file and GUI_DOWNLOAD is used fot downloading the file. For using these FM you need to first create internal table of all fields with character type. While downloading the file, file will be created in exact format of that of internal table and while uploading the file, you need to created the internal table with same structure as that of the original file.
eg:
DATA: BEGIN OF T_DATA OCCURS 0,
        SERIAL_NO(18)     TYPE C,
        COMP1(18)         TYPE C,
        COMP2(18)         TYPE C,
        MOTOR1(18)        TYPE C,
        MOTOR2(18)        TYPE C,
        CONTROLLER_NO(18) TYPE C,
        REF_NO(18)        TYPE C,
        BODY_NO(18)       TYPE C,
        PLANT(4)          TYPE C,
        PROD_VERSION(4)   TYPE C,
        PROD_DATE(8)      TYPE C,
      END   OF T_DATA.
DATA: BEGIN OF T_ERR_DOWNLOAD OCCURS 0.
        INCLUDE STRUCTURE T_DATA.
DATA:   MSG(60) TYPE C.
DATA: END   OF T_ERR_DOWNLOAD.
SELECTION-SCREEN BEGIN OF BLOCK BK1 WITH FRAME TITLE TEXT-001.
PARAMETERS: P_FLNM   LIKE RLGRAP-FILENAME OBLIGATORY MEMORY ID M1.
SELECTION-SCREEN END   OF BLOCK BK1.
AT SELECTION-SCREEN ON VALUE-REQUEST FOR P_FLNM.
  CALL FUNCTION 'F4_FILENAME'
    EXPORTING
      PROGRAM_NAME  = SYST-CPROG
      DYNPRO_NUMBER = SYST-DYNNR
    IMPORTING
      FILE_NAME     = P_FLNM.
START-OF-SELECTION.
  PERFORM UPLOAD_FILE.
PERFORM PREPARE_ITAB.
  PERFORM DISP_ERROR.
*&      Form  UPLOAD_FILE
      text
-->  p1        text
<--  p2        text
FORM UPLOAD_FILE .
  L_FLNM = P_FLNM.
  CALL FUNCTION 'GUI_UPLOAD'
    EXPORTING
      FILENAME                = L_FLNM
      FILETYPE                = 'ASC'
      HAS_FIELD_SEPARATOR     = 'X'
      HEADER_LENGTH           = 0
      READ_BY_LINE            = 'X'
    TABLES
      DATA_TAB                = T_DATA
    EXCEPTIONS
      FILE_OPEN_ERROR         = 1
      FILE_READ_ERROR         = 2
      NO_BATCH                = 3
      GUI_REFUSE_FILETRANSFER = 4
      INVALID_TYPE            = 5
      NO_AUTHORITY            = 6
      UNKNOWN_ERROR           = 7
      BAD_DATA_FORMAT         = 8
      HEADER_NOT_ALLOWED      = 9
      SEPARATOR_NOT_ALLOWED   = 10
      HEADER_TOO_LONG         = 11
      UNKNOWN_DP_ERROR        = 12
      ACCESS_DENIED           = 13
      DP_OUT_OF_MEMORY        = 14
      DISK_FULL               = 15
      DP_TIMEOUT              = 16
      OTHERS                  = 17.
  IF SY-SUBRC <> 0.
    MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
            WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
  ENDIF.
ENDFORM.                    " UPLOAD_FILE
*&      Form  DISP_ERROR
      text
-->  p1        text
<--  p2        text
FORM DISP_ERROR .
  DATA: L_CNT     TYPE N.
  CLEAR: L_FLNM, L_CNT.
  IF NOT T_ERROR[] IS INITIAL.
    CONCATENATE 'C:\Barcode\' SY-DATUM '_' SY-UZEIT '.xls' INTO L_FLNM.
    DESCRIBE TABLE T_ERROR LINES L_CNT.
    CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
      EXPORTING
        INPUT         = L_CNT
      IMPORTING
        OUTPUT        = L_CNT.
    WRITE:/ 'Error occured in ', L_CNT, ' Records'.
    SKIP.
    WRITE:/ 'Error file:', L_FLNM.
    CALL FUNCTION 'GUI_DOWNLOAD'
      EXPORTING
      BIN_FILESIZE                    =
        FILENAME                        = L_FLNM
       FILETYPE                        = 'ASC'
      APPEND                          = ' '
       WRITE_FIELD_SEPARATOR           = 'X'
      HEADER                          = '00'
      TRUNC_TRAILING_BLANKS           = ' '
      WRITE_LF                        = 'X'
      COL_SELECT                      = ' '
      COL_SELECT_MASK                 = ' '
      DAT_MODE                        = ' '
      CONFIRM_OVERWRITE               = ' '
      NO_AUTH_CHECK                   = ' '
      CODEPAGE                        = ' '
      IGNORE_CERR                     = ABAP_TRUE
      REPLACEMENT                     = '#'
      WRITE_BOM                       = ' '
      TRUNC_TRAILING_BLANKS_EOL       = 'X'
      WK1_N_FORMAT                    = ' '
      WK1_N_SIZE                      = ' '
      WK1_T_FORMAT                    = ' '
      WK1_T_SIZE                      = ' '
    IMPORTING
      FILELENGTH                      =
      TABLES
        DATA_TAB                        = T_ERR_DOWNLOAD
      FIELDNAMES                      =
    EXCEPTIONS
      FILE_WRITE_ERROR                = 1
      NO_BATCH                        = 2
      GUI_REFUSE_FILETRANSFER         = 3
      INVALID_TYPE                    = 4
      NO_AUTHORITY                    = 5
      UNKNOWN_ERROR                   = 6
      HEADER_NOT_ALLOWED              = 7
      SEPARATOR_NOT_ALLOWED           = 8
      FILESIZE_NOT_ALLOWED            = 9
      HEADER_TOO_LONG                 = 10
      DP_ERROR_CREATE                 = 11
      DP_ERROR_SEND                   = 12
      DP_ERROR_WRITE                  = 13
      UNKNOWN_DP_ERROR                = 14
      ACCESS_DENIED                   = 15
      DP_OUT_OF_MEMORY                = 16
      DISK_FULL                       = 17
      DP_TIMEOUT                      = 18
      FILE_NOT_FOUND                  = 19
      DATAPROVIDER_EXCEPTION          = 20
      CONTROL_FLUSH_ERROR             = 21
      OTHERS                          = 22
    IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
    ENDIF.
  ELSE.
    MESSAGE S000 WITH TEXT-008.
  ENDIF.
ENDFORM.                    " DISP_ERROR
**Reward points if useful
Regards,
Archana