How to call a smartform from a driver program

Below Code Snippet shows how to call a smartform from a driver program. 

DATA:   f_name        TYPE rs38l_fnam,
        gwa_ssfcompop TYPE ssfcompop,
        gwa_control   TYPE ssfctrlop,
        gv_job_output TYPE ssfcrescl,
        gv_devtype    TYPE rspoptype,
        i_otf         TYPE  tsfotf.

* Every Smartform is a function module, generated by SAP. Each time the form is modified a new FM is created. Therefore to get the name of the FM of Smartform we have to use the below FM - SSF_FUNCTION_MODULE_NAME. 

CALL FUNCTION 'SSF_FUNCTION_MODULE_NAME'
      EXPORTING
        formname = 'SMARTFORM_NAME'
      IMPORTING
        fm_name  = f_name.

* Get Device Type 

CALL FUNCTION 'SSF_GET_DEVICE_TYPE'
      EXPORTING
        i_language             = sy-langu
*       I_APPLICATION          = 'SAPDEFAULT'
      IMPORTING
        e_devtype              = gv_devtype
      EXCEPTIONS
        no_language            = 1
        language_not_installed = 2
        no_devtype_found       = 3
        system_error           = 4
        OTHERS                 = 5.
    IF sy-subrc <> 0.
* Implement suitable error handling here
    ENDIF.

* Control parameters for print window
    gwa_control-preview = 'X'.
    gwa_control-no_dialog = 'X'.
    gwa_ssfcompop-tdprinter = gv_devtype.
    gwa_ssfcompop-tdcopies = 1.
    gwa_control-getotf = 'X'.

* Smartform Call 

    CALL FUNCTION f_name
      EXPORTING
*       ARCHIVE_INDEX      =
*       ARCHIVE_INDEX_TAB  =
*       ARCHIVE_PARAMETERS =
        control_parameters = gwa_control
*       MAIL_APPL_OBJ      =
*       MAIL_RECIPIENT     =
*       MAIL_SENDER        =
        output_options     = gwa_ssfcompop
*       USER_SETTINGS      = 'X'
        itab               = tab_name
      IMPORTING
*       DOCUMENT_OUTPUT_INFO       =
        job_output_info    = gv_job_output
*       JOB_OUTPUT_OPTIONS =
      EXCEPTIONS
        formatting_error   = 1
        internal_error     = 2
        send_error         = 3
        user_canceled      = 4
        OTHERS             = 5.
    IF sy-subrc <> 0.
* Implement suitable error handling here
    ENDIF.

    APPEND LINES OF gv_job_output-otfdata TO i_otf.

    CALL FUNCTION 'SSFCOMP_PDF_PREVIEW'
      EXPORTING
        i_otf                    = i_otf
      EXCEPTIONS
        convert_otf_to_pdf_error = 1
        cntl_error               = 2
        OTHERS                   = 3.
    IF sy-subrc <> 0.
* Implement suitable error handling here
    ENDIF.