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Re: Specifying key/keyrefs constraints for Link/XPointer 'bare names'.

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 05 Sep 2000 16:01:32 +0100
To: Eric van der Vlist <vdv@dyomedea.com>
Cc: www-xml-schema-comments@w3.org
Message-ID: <f5bya16lw6r.fsf@cogsci.ed.ac.uk>
Eric van der Vlist <vdv@dyomedea.com> writes:

> I am trying to specify a key/keyref (or id/idref) constraint for a XLink
> which is using the 'bare names' [1] XPointer scheme in the same
> document.
> 
> This means that I'll have a key definition like:
> 
> 	<character id="character_Snoopy">
> 
> and a reference like:
> 
> 	<character xlink:href="#character_Snoopy" xlink:type="simple"/>
> 
> The problem in both cases (key/keyref or id/idref) is that the "#" needs
> to be added in the xlink:href reference.
> 
> Even with key/keyref, more flexible than id/idref, the keyref must be
> constructed as a path to an existing node and cannot be the result of a
> XPath function (string-after(@xlink:href, "#") would have done the trick
> otherwise.
> 
> Is there any other way to solve my specific case or any chance that we
> could change this in the spec ?
> 
> PS: a full XPointer would still be a more interesting case since, it's
> the value of the attribute which should then be interpreted as XPath
> expression...
> 
> [1] http://www.w3.org/TR/xptr#bare-names

This is an interesting case, which makes me wonder if we should
revisit the decision to require the XPath expression specifying key
fields to evaluate to an element or attribute node -- anybody remember 
what the argument was on this point?

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Tuesday, 5 September 2000 11:01:35 UTC

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