Download File from DMS into WD ABAP gives junk data

Question

Hi Experts ,
I want to achieve following functionality in WD ABAP.
User should be able to upload and download any file ( in any fromat ) , to / form document management server.
Since user can upload / download any file so I am using a file download UI , which would open any file in a new window.
I have searched about this in SDN ([ link |https://wiki.sdn.sap.com/wiki/display/Snippets/WDA%20Retrieve%20Data%20from%20DMS%20server]) and I have created a FM which gives me Xstring corresponding to the file in the DMS system.
then I pass this Xstring data to my context 'DATACONTENT' which is bound to file download UI (data property). But When I execute this application I am getting junk data in the new window. Please correct me where I am making a mistake.
following is the code in FM which in turn passes v_xstring ( of type xstring ) to WD ABAP . Then I bind this value to context
'DATACONTENT'.
wd_context->set_attribute( name = 'DATACONTENT' value = V_XSTRING ).
FUNCTION ZTESTING_EP.
""Local Interface:
*"  IMPORTING
*"     VALUE(DOCUMENTTYPE) LIKE  BAPI_DOC_AUX-DOCTYPE DEFAULT 'IVF'
*"     VALUE(DOCUMENTNUMBER) LIKE  BAPI_DOC_AUX-DOCNUMBER DEFAULT 1
*"     VALUE(DOCUMENTPART) LIKE  BAPI_DOC_AUX-DOCPART DEFAULT 000
*"     VALUE(DOCUMENTVERSION) LIKE  BAPI_DOC_AUX-DOCVERSION DEFAULT 00
*"  EXPORTING
*"     VALUE(C) LIKE  BAPIEMPLB-RETURN
*"     VALUE(V_XSTRING) TYPE  XSTRING
*"     VALUE(RETURN) TYPE  BAPIRET2
data: ls_docfiles type bapi_doc_files2,
       ls_dms type dms_doc_files,
       lt_docfiles type standard table of bapi_doc_files2.
select single * from dms_doc_files
   into ls_dms
   where "Retrieve file
MOVE '0000000000000000000000001' to DOCUMENTNUMBER .
MOVE '000' to DOCUMENTPART .
MOVE '00' to DOCUMENTVERSION .
if sy-subrc = 0.
    ls_docfiles-documenttype = DOCUMENTTYPE.
    ls_docfiles-documentnumber = DOCUMENTNUMBER .
    ls_docfiles-documentpart = DOCUMENTPART .
    ls_docfiles-documentversion = DOCUMENTVERSION.
endif.
  call function 'BAPI_DOCUMENT_CHECKOUTVIEW2'
    exporting
      documenttype              = ls_docfiles-documenttype
      documentnumber            = ls_docfiles-documentnumber
      documentpart              = ls_docfiles-documentpart
      documentversion           = ls_docfiles-documentversion
      documentfile              = ls_docfiles
     getstructure              = '1'
     getcomponents             = 'X'
     getheader                 = 'X'
     pf_ftp_dest               = 'SAPFTPA'
     IMPORTING
     return                    = return
   tables
     documentfiles             = lt_docfiles.
MOVE return to return.
  data: i_bin type standard table of sdokcntbin,
        i_info type standard table of scms_acinf,
        v_info type scms_acinf,
        v_id type sdok_phid,
        v_cat type sdok_stcat.
  if sy-subrc = 0.
    loop at lt_docfiles into ls_docfiles.
      v_id = ls_docfiles-docfile.
      v_cat = ls_docfiles-storagecategory.
      call function 'SCMS_DOC_READ'
        exporting
          stor_cat                = v_cat
          doc_id                  = v_id
          phio_id                      =  ls_docfiles-file_id
       tables
         access_info                 = i_info
         content_bin                 = i_bin
       exceptions
         bad_storage_type            = 1
         bad_request                 = 2
         unauthorized                = 3
         comp_not_found              = 4
         not_found                   = 5
         forbidden                   = 6
         conflict                    = 7
         internal_server_error       = 8
         error_http                  = 9
         error_signature             = 10
         error_config                = 11
         error_format                = 12
         error_parameter             = 13
         error                       = 14
         others                      = 15
    endloop.
    if sy-subrc <> 0.
    else.
     data: v_xstring type xstring.
      read table i_info into v_info index 1.
      call function 'SCMS_BINARY_TO_XSTRING'
        exporting
          input_length       = v_info-comp_size
       importing
         buffer             = v_xstring
        tables
          binary_tab         = i_bin
       exceptions
         failed             = 1
         others             = 2
      if sy-subrc <> 0.
      endif.
    endif.
  endif.
ENDFUNCTION.
Thanks in advance
Abhay

Answer 1

Hi Abhay,
I have used the belwo method to achive the same:
1) Call funtion 'CVAPI_DOC_GETDETAIL' to get the document details.This function module returns PT_FILES tables parameter
2) Loop at PT_FILES and call the 'CV120_GET_MIME_TYPE' funtion by passing DAPPL of PT_FILES to get the mime type.
3)call function 'CVAPI_DOC_CHECKOUTVIEW' by passing PT_FILES values form above retrived to the function module in this step
4)Loop at the content and convert to XSTRING using SCMS_XSTRING_TO_BINARY
After getting the XSTRING,MIMETYPE use ATTACH_FILE_FOR_RESPONSE method of CL_WD_RUNTIME_SERVICES to download the file
Sample Code:
CALL FUNCTION 'CVAPI_DOC_GETDETAIL'
      EXPORTING
        pf_dokar     = ls_draw-dokar
        pf_doknr     = iv_documentnumber
        pf_dokvr     = ls_draw-dokvr
        pf_doktl     = ls_draw-doktl
        pf_read_drat = abap_true
      IMPORTING
        psx_draw     = ls_draw
      TABLES
        pt_drat      = et_drat
        pt_files     = et_files
      EXCEPTIONS
        not_found    = 1
        no_auth      = 2
        error        = 3
        OTHERS       = 4.
  ENDIF.
  IF et_files IS NOT INITIAL.
    LOOP AT et_files INTO ls_files.
      CALL FUNCTION 'CV120_GET_MIME_TYPE'
       EXPORTING
         pf_dappl           = ls_files-dappl
*       PF_FILE            =
       IMPORTING
         pfx_mimetype       = lv_mimetype.
      CLEAR lt_files_checkout.
      CLEAR lt_content.
      ls_files_checkout-description = ls_files-description.
      ls_files_checkout-lo_objid = ls_files-lo_objid.
      ls_files_checkout-ph_objid = ls_files-ph_objid.
      APPEND ls_files_checkout TO lt_files_checkout.
      CALL FUNCTION 'CVAPI_DOC_CHECKOUTVIEW'
        EXPORTING
          pf_dokar                 = ls_draw-dokar
          pf_doknr                 = iv_documentnumber
          pf_dokvr                 = ls_draw-dokvr
          pf_doktl                 = ls_draw-doktl
         pf_content_provide       = gc_content_provide
*         PS_API_CONTROL           =
*         PF_STD_URL               = 'X'
       IMPORTING
         psx_message              = ls_message
         psx_draw                 = ls_draw
       TABLES
         pt_files                 = lt_files_checkout
*         PTX_COMPONENTS           =
         ptx_content              = lt_content.
      IF ls_message CA gc_error_a.
        ev_fail = abap_true.
      ELSE.
        CLEAR lt_xdata.
        CLEAR ls_bindata.
*Data into String
        LOOP AT lt_content INTO ls_content.
          lv_size = ls_content-orln.
          ls_xdata-line = ls_content-orblk.
          APPEND ls_xdata TO lt_xdata.
        ENDLOOP.
* --  Convert XData to Xstring
        CALL FUNCTION 'SCMS_BINARY_TO_XSTRING'
          EXPORTING
            input_length = lv_size
          IMPORTING
            buffer       = ls_bindata
          TABLES
            binary_tab   = lt_xdata
          EXCEPTIONS
            failed       = 1
            OTHERS       = 2.
        IF sy-subrc NE 0.
          ev_fail = abap_true.
        ELSE.
          ls_file_list-filename = ls_files-description.
          ls_file_list-mimetype = lv_mimetype.
          ls_file_list-content = ls_bindata.
          ls_file_list-application_id = ls_files-lo_objid.
          ls_file_list-file_id = ls_files-ph_objid.
          APPEND ls_file_list TO et_file_list.
        ENDIF.
      ENDIF.
    ENDLOOP.
  ENDIF.
Regards,
Madhu