Re: [xml] Using Xpath with default namespace and null prefix

[Liam R E Quin <liam holoweb net>]

On Mon, 2010-02-08 at 10:25 +0100, Daniel Veillard wrote:
> On Mon, Feb 08, 2010 at 03:08:49AM +0100, Iñaki Baz Castillo wrote:
> > Unfortunatelly in my case I'm implementing a XCAP (RFC 4825) client and 
> > server. XCAP reuses Xpath but allows Xpath nodes without prefix matching an 
> > "application specified namespace". This is, the following "Xpath" should work 
>
>   Sorry, that's not XPath behaviour, and not possible with libxml2 which
> implements XPath. I'm very surprized that such a deviation from a W3C
> standard was allowed in an IETF specification, there used to be liaison
> between W3C and IETF to avoid this kind of problems.

XPath 2 makes clear that an application can provide a default namespace
(not to be confused with a default namespace declaration in the
document), so that //foo can match it.

In retrospect I think we should also have introduced some way to add
bindings in XPath, so you could do,
    /document/item/(with prefix x := "http://www.example.org/"; x:para/x:step)/note[3]

Maybe we could consider something like that for XPath 2.1.

However, libxml2 is still on XPath 1.0...

 I also see it reference XML Fragment Interchange CR
> draft, so I really wonder if the liaison work was properly done on
> that IETF specification >:->

The liaison between W3C and IETF does not involve reviews of individual
specs, and never has, except by explicit request -- we don't have the
resources at W3C, and where it would apply in the other direction
(e.g. HTTP) the work has often been joint.

Liam

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Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
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