ABAP Data to XML file

Question

Hi,
I have read this weblog
/people/patrick.baer/blog/2005/02/24/abap-serialization--part-i-quick-n-easy and tried to serialize ABAP data into XML format.
In fact, I have copied the exact code from this weblog, but somehow this file is not visible in my pc.
DATA example_data TYPE spfli.
select single * from spfli into example_data.
DATA xml_utils TYPE REF TO if_ixml.
xml_utils = cl_ixml=>create( ).
DATA xml_stream_factory TYPE REF TO if_ixml_stream_factory.
xml_stream_factory = xml_utils->create_stream_factory( ).
DATA xml_output_stream TYPE REF TO if_ixml_ostream.
xml_output_stream = xml_stream_factory->create_ostream_uri( system_id =
'file://c:test.xml' ).
try.
CALL TRANSFORMATION id
SOURCE data_node = example_data
RESULT XML xml_output_stream.
catch cx_sy_conversion_base64 CX_SY_CONV_ILLEGAL_DATE_TIME.
write 'there is an exception'.
endtry.
This part of the code, I have also changed to :
xml_stream_factory->create_ostream_uri( system_id =
'file://test.xml' ).
and still the file is not visible.
I presume three reasons:
a) Looking in the wrong place
b) Some configuration, I am not doing properly
c) Something else has to be done, to write a file to system
Any help on this regard, is highly appreciated.
Next issue being, how robust is the approach of serializing ABAP data into XML format, so that a third party system can pick up this data and do a comparison ?
Some parameters that I am looking for in this regards are:
a) Error Validation (can XML data be incorrectly written into a file/while transmitting this data some errors can creep in. If so, how do I rectify it. As far as I know, this data can only be written to Presentation Server or using FTP ,transported to required destination. Is there any other approach ? )
b) Security
Would be great if you could drop some hints for the above procedure.
Regards,
Subramanian V.

Answer 1

I think you are perhaps overestimating the capabilities of the osteam object.  If you want to write the XML to a file the easiest thing to do is render it an ostream_itable (internal ABAP table).  Then you can download it your PC with the GUI_DOWNLOAD function:
parameter: ifile type file_table-filename obligatory
           default 'c:issue.xml'.
****Temp File name for function module call.
data: ifilename type string.
  move ifile to ifilename.
  create object issue
     exporting
       id     = id
       create_mode = abap_false.
  data: g_ixml type ref to if_ixml,
         g_stream_factory type ref to if_ixml_stream_factory,
         xslt_err type ref to cx_xslt_exception,
         g_encoding type ref to if_ixml_encoding,
         ostream type ref to if_ixml_ostream.
  constants:  line_length type i value 4096.
  types:      line_t(line_length) type x,
              table_t type standard table of line_t.
  data: restab type table_t.
  constants:
* encoding for download of XML files
    encoding     type string value 'utf-8'.
  data: ressize type i.
  try.
      g_ixml = cl_ixml=>create( ).
      g_stream_factory = g_ixml->create_stream_factory( ).
      g_encoding = g_ixml->create_encoding( character_set = encoding
        byte_order = 0 ).
      refresh restab.
      ostream =
        g_stream_factory->create_ostream_itable( table = restab ).
      ostream->set_encoding( encoding = g_encoding ).
      call transformation id_indent
        source     asap_issue = issue
        result xml restab
        options
        data_refs = 'embedded'.
      ressize = ostream->get_num_written_raw( ).
    catch cx_xslt_exception into xslt_err.
      data: s type string.
      s = xslt_err->get_text( ).
  endtry.
  call function 'GUI_DOWNLOAD'
    exporting
      bin_filesize = ressize
      filename     = ifilename
      filetype     = 'BIN'
    tables
      data_tab     = restab
    exceptions
      others       = 1.
  call method cl_gui_frontend_services=>execute
     exporting
       document               = ifilename
*    APPLICATION            =
*    PARAMETER              =
*    DEFAULT_DIRECTORY      =
*    MAXIMIZED              =
*    MINIMIZED              =
*    SYNCHRONOUS            =
    exceptions
      cntl_error             = 1
      error_no_gui           = 2
      bad_parameter          = 3
      file_not_found         = 4
      path_not_found         = 5
      file_extension_unknown = 6
      error_execute_failed   = 7
      others                 = 8.
As far as a different system, once you have the data serialized into a string or internal table you have lots of possibilites.  If the other system is an SAP system you could send the data via RFC.  You could always write the XML string to the server file system (via open dataset, transfer to dataset).  You can then FTP the file (using built in SAP FTP functionality) just about anywhere.
What are you looking for as far as robust and secure.  The XML serializer is built in the ABAP Kernel and quite robust.  As far as secure- the data isn't secure at all.  The data is written into a simple string (if written into the file system or your pc - it is a text or binary file that can easily be read by just about anything).  Serializing to XML in and of itself isn't going to provide any security.