*---------------------------------------------------------------------*
*       FORM ask_for_filename
*---------------------------------------------------------------------*
* [+] Asks the user to choose the output filename/directory via a
*     file chooser popup
*---------------------------------------------------------------------*
FORM ask_for_filename
  CHANGING
    p_fullpath TYPE string.

  DATA:
    lv_title    TYPE string,
    lv_filter   TYPE string,
    lv_ext      TYPE string,
    lv_file     TYPE string,
    lv_path     TYPE string,
    lv_fullpath TYPE string,
    lv_action   TYPE i.

* popup properties
  lv_title = 'Save File'.
  lv_filter = 'PDF files (*.pdf)|*.pdf|'.
  lv_ext = 'pdf'.

* Ask the user for the filename
  CALL METHOD cl_gui_frontend_services=>file_save_dialog
    EXPORTING
      window_title      = lv_title
      file_filter       = lv_filter
      default_extension = lv_ext
    CHANGING
      filename          = lv_file
      path              = lv_path
      fullpath          = lv_fullpath
      user_action       = lv_action
    EXCEPTIONS
      OTHERS            = 99.

  IF sy-subrc = 0
     AND lv_action = cl_gui_frontend_services=>action_ok.
*   set the value if the user clicked OK and there were no errors
    p_fullpath = lv_fullpath.
  ENDIF.

ENDFORM.