Expanded names are not enough

John Cowan cowan at locke.ccil.org
Thu Aug 6 21:28:30 BST 1998


James Clark wrote:

> They work just fine with XSL as far as I can see.
> A namespace processor is going to have functions that it calls to expand
> element type names and qualified attribute names.  All that's needed is
> that the namespace processor, in addition to calling these functions to
> expand strings that it knows to be element type names and attribute
> names, make these functions available to applications so that
> applications can call them to expand strings that the application knows
> to be element type names and attribute names.

Indeed.  But the functions can't just globally map prefixes to URIs
and back, as with the previous draft.  They have to have an indication,
explicit or implicit, of context as well.  In the DOM world, a
DOM Node; in the SAX world, it would be necessary to only call
the functions between the declaring elementStart and the corresponding
elementEnd.  Otherwise, there would be no assurance that the relevant
mapping would still be correct.

> I suspect there will be a similar issue with XPointers. If I say:
> 
>   href="http://...#descendant(17,foo:bar)"
> 
> I would expect that the expanded element type names to be matched, not
> the prefixes.  That would mean that to interpret the XPointer, an
> application would need the namespace prefix to namespace URI mapping in
> effect for the element to which href attribute is attached.

So I believed too, but someone on this list pointed out that
because XPointers aren't queries into unknown documents, but
references into known ones, the "foo:" might be the referent's "foo:"
prefix rather than the referer's.  Nobody knows yet.

-- 
John Cowan	http://www.ccil.org/~cowan		cowan at ccil.org
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)




More information about the Xml-dev mailing list