RE: Basic question about Namespace handling in XPath 1

See the method setNamespaceContext() method on the interface
javax.xml.xpath.XPath.

Michael Kay
http://www.saxonica.com/ 

> -----Original Message-----
> From: Prakash [mailto:prakash.subramaniam@xxxxxxxxxx] 
> Sent: 28 September 2005 15:12
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: Re:  Basic question about Namespace handling in 
> XPath 1.0 (not necessarily related to XSLT)
> 
> Thanks Geert.
> 
> My question is not in relation to XSLT. I was talking about the 
> namespace prefix resolution in general for XPath.  For 
> example, in Java, 
> JAXP 1.3 has some APIs to process XPath given a context ( 
> likewise DOM 
> Level 3 has some APIs). These APIs are application 
> independent. I guess, 
> the namespace mappings available in scope to the context node will be 
> the deciding factor, right?. Pls, correct me if I am wrong.
> 
> Thanks,
> Prakash
> 
> Geert Josten wrote:
> 
> > Hi,
> >
> > The answer should be pretty clear, it all depends on how 
> you declare 
> > the namespaces in your XSL stylesheet... :)
> >
> >> 1. If we have a XPath like "//sup:name", how will the 
> XPath processor 
> >> know which "sup:name" will have to be returned? (considering that 
> >> there are two sup:name elements that are in two different 
> namespaces.
> >
> >
> > <xsl:value-of select="//sup:name" 
> xmlns:sup="http://www.suppliers.com" 
> > /> will result in the first one.
> >
> > <xsl:value-of select="//sup:name" 
> > xmlns:sup="http://www.anothersuppliers.com" /> will result in the 
> > second one.
> >
> > You will probably choose to assing prefix sup1 to the first 
> namespace 
> > and sup2 to the second. If you want both, you can then 
> simply specify 
> > //sup1:name|//sup2:name (or //*:name in XSLT 2.0 altogether)
> >
> >> 2.  Similarly, if we have a XPath such as "//order", which "order" 
> >> will be considered considering that there are two order 
> elements both 
> >> in default namespace (first order element is actually in null 
> >> namespace whereas the second one in default namespace 
> declared in the 
> >> root element)
> >
> >
> > Likewise. I expect that //order results in the first when you don't 
> > specify a default namespace, and in the second if you use 
> > xmlns="http://www.customers.com".
> >
> > It is adviced not to use default namespaces in XSL 
> stylesheets, though.
> >
> > Cheers,
> > Geert