topic Re: Reverse XML Special Character Escaping in Application Development and Automation Discussions

Reverse XML Special Character Escaping

alex_campbell — Fri, 31 Jul 2015 23:54:43 GMT

Hi All,

I'm looking for a way to reverse XML Special Character escaping using ABAP. Essentially what I'm looking for is the reverse of the ESCAPE function. I have strings of data that contain escaped XML snippets, like below. I need to parse out the escaped special characters and write the result out to a file. The trivial way would just be to do a "REPLACE" of the 5 basic escaped characters, but I know that the standards are more complicated than that (for example, you can use " in place of " and characters in CDATA must not be escaped). I'd like my solution to be as completely standards-compliant as possible. Does anyone have any advice?

Thanks,

Alex

Example Escaped Snippet:


&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;

Desired Result:

<?xml version="1.0" encoding="utf-8"?>

Re: Reverse XML Special Character Escaping

VenkatRamesh_V — Sat, 01 Aug 2015 09:38:41 GMT

This message was moderated.

Re: Reverse XML Special Character Escaping

alex_campbell — Wed, 05 Aug 2015 14:06:06 GMT

Hi Venkat,

It looks to me like the code you posted will replace the characters '[!@#$%^&*+-= ]' with a spaces. Is that right? If so, it's definitely not what I'm looking for. In my situation, I'm dealing specifcially with special characters that were escaped for XML (so a different set than the ones you've given). And in my case they've already been escaped, so I don't want to replace the special characters, I want to restore them.

Please take a look at the example I've given and let me know if you can help.

Thanks,

Alex

Re: Reverse XML Special Character Escaping

Juwin — Wed, 05 Aug 2015 14:35:27 GMT

Hi Alex,

If you use standard methods provided by SAP to read & parse the XML file, this will be automatically done by the method. Example program is given below. My example XML string, has a node named body and that has a value with > symbol in it, which in escaped form looks like >. The program correctly gets the value back converting > to > symbol and outputs that after execution.


    1  report xml_parse.
    2  
    3  data:lv_xml    type ref to cl_xml_document,
    4       lv_elemnt type ref to if_ixml_element,
    5       lv_value  type string.
    6  
    7  create object lv_xml.
    8  lv_xml->parse_string( |<?xml version="1.0" encoding="UTF-8"?><note><to>Tove</to><from>Jani</from><heading>Reminder</heading><body>&gt;Don't forget me this weekend!</body></note>| ).
    9  lv_elemnt ?= lv_xml->find_node( 'body' ).
   10  lv_value   = lv_elemnt->get_value( ).
   11  write lv_value.

Output from program:

Thanks,

Juwin

Re: Reverse XML Special Character Escaping

alex_campbell — Mon, 17 Aug 2015 20:23:06 GMT

Thanks Juwin!

This is very helpful, unfortunately I've found my situation is more complicated than I had hoped.

The escaped XML snippets that I need to reverse contain material descriptions, and those material descriptions can also contain some of the special XML characters. By reversing the XML escaping, I'm also reversing the escaping of the contents of the material description, which breaks the resulting XML. Using the iXML classes, I have the following result:

Example Escaped Snipped:


&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;&lt;MATERIAL MAKTX=&quot;Material1&quot;(OneInch)&quot;&gt;&lt;MATERIAL&gt;

Result of iXML GET_VALUE (Note the extra Quote in the MAXTX attribute):


<?xml version="1.0" encoding="utf-8"?><MATERIAL MAKTX="Material1"(OneInch)"><MATERIAL>

Ideal Result (The quote for 1" would still be escaped, but the quotes that wrap the attribute value would be reversed):


<?xml version="1.0" encoding="utf-8"?><MATERIAL MAKTX="Material1&quot;(OneInch)"><MATERIAL>

My intuition is that it's not possible for the system to know which escape characters need to be reversed, and which need to remain escaped in order for the resulting XML to be valid. Does anyone know if it's possible to solve this issue? Or are we out of luck?

Re: Reverse XML Special Character Escaping

Juwin — Mon, 17 Aug 2015 20:32:21 GMT

Your escaped XML seems incorrect.

If you escape

<?xml version="1.0" encoding="utf-8"?><MATERIAL MAKTX="Material1"(OneInch)"><MATERIAL>

the result should be

<?xml version="1.0" encoding="utf-8"?><MATERIAL MAKTX="Material1&quot;(OneInch)"><MATERIAL>

and not

<?xml version="1.0" encoding="utf-8"?><MATERIAL MAKTX="Material1"(OneInch)"><MATERIAL>

Thanks,

Juwin