[XML-SIG] namespace headache

[Uche Ogbuji]

> reading the XML namespace specification makes my brain
> hurt, so I thought I'd ask here before it explodes...
> 
> given the following XML snippet, what's the correct namespace
> for the "attribute" attribute?
> 
> <ns:body xmlns:ns='namespace:'>
>     <ns:member attribute='value'>
>     </ns:member>
> </ns:body>
> 
> I'm not smart enough to figure that out from the specification,
> my intuition says "no namespace", and so does James Clark's
> namespace note (http://www.jclark.com/xml/xmlns.htm) where

[snip]

> class Parser(xmllib.XMLParser):
>     def unknown_starttag(self, tag, attr):
>         print "S", repr(tag), attr
>     def unknown_endtag(self, tag):
>         print "E", repr(tag)
> 
> p = Parser()
> p.feed("""
> <ns:body xmlns:ns='namespace:'>
>     <ns:member attribute='value'>
>     </ns:member>
> </ns:body>
> """)
> p.close()
> 
> gives the following output:
> 
> S 'namespace: body' {}
> S 'namespace: member' {'namespace: attribute': 'value'}
> E 'namespace: member'
> E 'namespace: body'
> 
> instead of 
> 
> S 'namespace: body' {}
> S 'namespace: member' {'attribute': 'value'}
> E 'namespace: member'
> E 'namespace: body'
> 
> can anyone sort this out for me?


Easy enough.  Your instinct (and Mr. Clark) are right and xmllib is wrong.

> (and no, I really have to be able to use xmllib, to make sure
> soaplib.py works under an off-the-shelf Python distribution...)


So the next part of my comment is of no use to you but I'll make it anyway:  
4DOM does get it right:

[uogbuji@borgia uogbuji]$ python
Python 1.5.2 (#1, Mar 21 2000, 18:17:19)  [GCC 2.95.3 19991030 (prerelease)] 
on linux-i386
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> from Ft.Dom.Ext.Reader import Sax2
>>> source = """<ns:body xmlns:ns='namespace:'>
...     <ns:member attribute='value'>
...     </ns:member>
... </ns:body>"""
>>> doc = Sax2.FromXml(source)
>>> member = doc.documentElement.childNodes[1]
>>> member
<Element Node at 135665768: Name = 'ns:member' with 1 attributes and 1 
children>
>>> attr = member.attributes[0]
>>> attr
<Attribute Node at 134895008: Name = "attribute", Value = "value">
>>> att.namespaceURI
>>> attr.localName
'attribute'
>>> attr.nodeName 
'attribute'
>>> import Ft.Dom.Ext
>>> Ft.Dom.Ext.GetAllNs(attr)
{'ns': 'namespace:', 'xml': 'http://www.w3.org/XML/1998/namespace'}
>>>

Hmm.  I just noticed that "1 attributes and 1 children".  Silliness.  I'll 
sort that out...


-- 
Uche Ogbuji                               Senior Software Engineer
uche.ogbuji@fourthought.com               +01 303 583 9900 x 101
Fourthought, Inc.                         http://Fourthought.com 
4735 East Walnut St, Ste. C, Boulder, CO 80301-9036, USA
Software-engineering, knowledge-management, XML, CORBA, Linux, Python