RE: [xsl] accessing (xml) objects from xsl

["Michael Kay" <michael.h.kay@xxxxxxxxxxxx>]

> I was using Saxon 6.5.2 and could not get points 1 nor 2 
> working below.

Point 1: calling Java from Saxon. There is a detailed explanation of how
to do this at http://saxon.sourceforge.net/saxon6.5.2/extensibility.html

Point 2: passing a DOM object to XSLT. Saxon 6.5.2 essentially has two
levels of DOM support. When passing parameters, or returning nodes from
Java extension functions, Saxon only accepts DOM nodes that were
constructed using Saxon itself, not nodes constructed with an arbitrary
third-party DOM implementation. The principal source document can be an
arbitrary DOM - though this isn't really recommended, because in general
it's inefficient. If you want to pass a parameter whose value is a
reference to a set of nodes in the principal source document, then the
closest approximation in Saxon to the way yo are doing it in MSXML3 is
to pass an XPath expression as a string parameter, and evaluate this
using saxon:evaluate().

If you're coming from a Microsoft world you probably think of the DOM
and the XSLT processor as pretty closely coupled. With Saxon, they are
quite strongly separated: you can integrate them if you must, but they
aren't a good fit. It's much better to use Saxon's native tree
structures if possible, as these conform to the XPath data model rather
than the DOM data model.

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx  

 I 
> tried it with Xalan-J 2 and point 2 below now seems to work.
> 
> These questions arised from the process of trying to use xsl 
> templates that 
> were created with the MSXML 3.0 XSLT processors and as such 
> we were using 
> their addObject() functionality and passing a DOM tree to be 
> used in the xsl 
> sheet the following way:
> 
> stylesheet tag:
> ====
> <xsl:stylesheet version="1.0" 
> xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; 
> xmlns:preprocessors="urn:pre-process">
> ====
> 
> a parameter using it:
> ====
> <xsl:param name="someparam" 
> select="preprocessors:get-selectNodes('PREPROCPROCESSORS/SOMEP
> ATH/FILE')" /> ====
> 
> Question is: is it possible to get this working (using custom 
> extensions?) 
> with either Saxon or Xalan-J?
> 
> Thanks!
> Sean.
> 
> 
> >From: "Michael Kay" <michael.h.kay@xxxxxxxxxxxx>
> >Reply-To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> >To: <xsl-list@xxxxxxxxxxxxxxxxxxxxxx>
> >Subject: RE: [xsl] accessing (xml) objects from xsl
> >Date: Fri, 5 Jul 2002 10:38:05 +0100
> >
> >The interface between XSLT and Java depends on which XSLT 
> processor you 
> >are using. So you'll need to identify the processor before 
> anyone can 
> >answer the question.
> >
> >Michael Kay
> >Software AG
> >home: Michael.H.Kay@xxxxxxxxxxxx
> >work: Michael.Kay@xxxxxxxxxxxxxx
> >
> > > -----Original Message-----
> > > From: owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> > > [mailto:owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx] On Behalf Of s s
> > > Sent: 04 July 2002 14:28
> > > To: XSL-List@xxxxxxxxxxxxxxxxxxxxxx
> > > Subject: [xsl] accessing (xml) objects from xsl
> > >
> > >
> > > Hello!
> > >
> > > I have looked up these two questions in the archives but 
> don't seem 
> > > to find a complete answer. If anybody could help I would be 
> > > greatful.
> > >
> > > two questions:
> > >
> > > 1) accessing java objects from xslt:
> > > I have tried using the following code to attach a java 
> object to my 
> > > xsl
> > > transformer:
> > >
> > > transformer.setParameter("blop", someObject);
> > >
> > > now I want to call the method in this function from xsl, 
> how do I do 
> > > this? i.e. I would like to call someObject.doSomething('bla') from
> > > the xsl file.
> > > Could someone help me out with an example! thanks...
> > >
> > >
> > > 2) passing a DOM object to xslt: (similar to above)
> > > I am trying to access a DOM element from xslt, but it seems to be 
> > > passed through as null object when it is not!
> > >
> > > -----java-----
> > >   javax.xml.parsers.DocumentBuilderFactory df =
> > >      javax.xml.parsers.DocumentBuilderFactory.newInstance();
> > >   javax.xml.parsers.DocumentBuilder db = df.newDocumentBuilder();
> > >   org.w3c.dom.Document doceroo = db.newDocument();
> > >   org.w3c.dom.Element nds = doceroo.createElement("nds");
> > >   doceroo.appendChild(nds);
> > >   nds.setAttribute("bla","8.5");
> > >   transformer.setParameter("blop", doceroo);
> > > -----java-----
> > >
> > > ---- xsl -----
> > > 	<?xml version="1.0"?>
> > > 	<xsl:stylesheet version="1.0" 
> > > xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
> > > 	<xsl:param name="blop" />
> > > 	<xsl:output method="html" encoding="UTF-8"/>
> > > 	<xsl:template match="*">
> > > 		<html>
> > > 		<body>
> > >
> > > |<xsl:value-of select="$blop" />|
> > >
> > > 		</body>
> > > 		</html>
> > > 	</xsl:template>
> > > 	</xsl:stylesheet>
> > >
> > > ---- xsl -----
> > >
> > > --- result ---
> > > <?xml version="1.0" encoding="UTF-8"?>
> > >
> > > <html>
> > >
> > >   <body>
> > >
> > >       |[#document: null]|
> > >
> > >   </body>
> > >
> > > </html>
> > >
> > > --- result ---
> > >
> > > Sean.
> > >
> > >
> > > _________________________________________________________________
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> > >
> > >
> > >  XSL-List info and archive:  
> > > http://www.mulberrytech.com/xsl/xsl-list
> > >
> >
> >
> >  XSL-List info and archive:  
> http://www.mulberrytech.com/xsl/xsl-list
> 
> 
> 
> 
> 
> _________________________________________________________________
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