Harald Schmitt wrote:
> Thanks, but it did not solve my problem!
> I have a file like:
> <?xml version="1.0" encoding="UTF-8"?>
> <!DOCTYPE standard [
> 	<!NOTATION GIF SYSTEM "GIF">
> 	<!NOTATION EPS SYSTEM "EPS">
> 
> 	<!ENTITY SLE47659 SYSTEM "47659.eps" NDATA EPS>
> 	<!ENTITY SLE42925 SYSTEM "42925.gif" NDATA GIF>
> ]>
> <standard>
> 	<graphic ent="SLE47659"/>
> 	<graphic ent="SLE42925"/>
> </standard>
> 
> and I want in the output file the content of the files in base64 encoded. 
> First step is to resolve SLE47659 to 47659.eps. 2. Step read the file and 
> encode it as base64. All within XSLT. Step 2 is covered by you and I found a 
> algorithm from Oleg, too. But that does not help without step 1!
> Do you have a base64 encoding in VBScript? Then I could embed it in MSXSL 
> 4.0. There I can do the 1. step.

In .NET you can use extention function to resolve unparsed entities. 
Something like this:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
version="1.0"
xmlns:user="urn:user" exclude-result-prefixes="user">
   <ms:script implements-prefix="user"
       xmlns:ms="urn:schemas-microsoft-com:xslt" language="C#">
   	public string getEntityURI(XPathNodeIterator node, string entityName) {
           if (node.MoveNext()) {
             XmlDocument document = 
((IHasXmlNode)node.Current).GetNode().OwnerDocument;
             XmlEntity entity = 
(XmlEntity)document.DocumentType.Entities.GetNamedItem(entityName);
             return entity.SystemId;
           }
           return "";
         }
   </ms:script>
   <xsl:template match="graphic">
     <xsl:value-of select="user:getEntityURI(., @ent)"/>
   </xsl:template>
</xsl:stylesheet>

And make sure your source XML is loaded to XmlDocument, because 
XPathDocument doesn't preserve DOCTYPE.

-- 
Oleg Tkachenko [XML MVP, MCAD]
http://www.xmllab.net
http://blog.tkachenko.com