Re: cannot find the namespace declarations from an extension function

> > But on this list the view should probably be Xalan, hence XSLT and the
> > XPath Data Model. A namespace declaration attribute isn't an attribute
> > in XDM, because it's not on the attribute axis. The fact that 
namespace
> > declaration serialization happens to take attribute form doesn't 
matter.
> > 
> >>> That's why it doesn't show up among the attributes, neither in DOM
> >>> nor in XDM (XPath Data Model).
> 
> Seems like XDM is related to XPath 2.0.

And XSLT/XQuery, which also use the XPath data model. The XPath 2.0 data 
model is derived from the XPath 1.0 data model, which as you said is 
described at

> http://www.w3.org/TR/xpath#data-model

>      * for an xmlns attribute, if the element or some ancestor has an 
> xmlns attribute, and the value of the xmlns attribute for the nearest 
> such element is non-empty
> 
> They are called "attributes"!

They are attributes in the XML syntax sense. They are not Attribute Nodes 
in the XPath 1.0 data model; they are Namespace Nodes. And actually, one 
of the changes in the 2.0 model is that namespace declarations need not 
appear as nodes at all, but just as values that can be retrieved from a 
node; the 1.0 description of "namespace nodes" has some warts and is being 
phased out.

> Also in DOM2 Core there is nothing that suggests that "namespace 
> attributes" are not just regular attributes.
>
> > So I guess DOM (which level?) requires them to show up.

The DOM data models differs in a number of ways from the XPath data model; 
this is one of those differences. In the DOM, namespace declarations are 
indeed handled as attribute nodes... if they appear at all; the DOM 
considers them optional. (See DOM Level 3's discussion of its namespace 
normalization operation.)

Sorry, but the DOM and XPath were tuned for slightly different 
requirements, and you're going to have to get used to working with these 
differences. 

(Admittedly, this is partly because the XML Infoset, which is the official 
description of what information in an XML document is 
available/meaningful, wasn't defined until well after the first release of 
DOM and XPath, and was deliberately left loose enough to accept both 
approaches. If we had the opportunity to do XML over again from scratch, 
the ideal thing would have been to define the Infoset -- including 
namespaces, schemas, base URIs, and all the other afterthoughts -- then 
define the syntax, then define all the tools and standards built on top of 
these. But that would have meant a much longer delay before XML became 
useful, and would probably have killed any chance for its adoption. Some 
day, a few decades from now, maybe we'll all have sufficient time to 
consider going back and doing a massive clean-up pass -- XML 2.0, akin to 
the ANSI C effort -- but XML's still growing too fast for that to be 
practical at this time.)