[xsl] Perl and MSXML3 to transform XML with XSL

[James Garriss <jpgarriss@xxxxxxxx>]

No, using Perl and MSXML3 wasn't my first choice.  Yes, it does work.  For 
background, here is an excellent article from xml.com:

  http://www.perl.com/pub/a/2001/04/17/msxml.html

This article shows enough details to load an XML document (and an XSL 
stylesheet) into a DOMDocument:

 # Load the XML file
 $doc_to_transform->{async} = "False";
 $doc_to_transform->{validateOnParse} = "True";
 $boolean_Load = $doc_to_transform->Load($xml_file);

I have figured out how to get detailed error checking out of the two 
loads.  The $doc_to_transform->{parseError} syntax gets me access to line 
numbers, error reasons and so on.  Very nice.

 if(!$boolean_Load)
 {
   # The error message includes file name, line #, position #, and reason.
   PrintMessage("error at line ".$doc_to_transform->{parseError}->{line}." 
position ".$doc_to_transform->{parseError}->{linePos}." reason 
".$doc_to_transform->{parseError}->{reason});
 }

The article also shows how to transform them and save the result:

 # Perform the transformation and save the resulting DOM object to file
 $doc_to_transform->transformNodeToObject($style_sheet_doc, $transformed_doc);
 $transformed_doc->save("$out_file");

Unfortunately the article gives me no hint on how to error check the 
transformNodeToObject, and I've been unable to figure it out on my own.

The closest example I have found is from MSDN:

  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk30/htm/xmcondetecthandlxslerrors.asp?frame=true

They give some JScript examples along this line for transformNode:

 try
 {
   result = source.transformNode(style.XMLDocument);
 }
 catch (exception)
 {
   result = reportRuntimeError(exception);
 }

Which calls this function:

 function reportRuntimeError(exception)
 {
   return "XSL Runtime Error" + exception.description;
 }

What is the equivalent of this try/catch in Perl?  I assume the syntax is 
something like:

 # Perform the transformation and save the resulting DOM object to file
 $doc_to_transform->transformNodeToObject($style_sheet_doc, $transformed_doc)
   or $transformed_doc->{runtimeError}->{description};

This doesn't work; the "or" is always triggered.  Any help is appreciated.

--James Garriss (MITRE)


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