New W3C XML Schema facet ? [was: RDDL Schematron Schema]

[Eric van der Vlist <vdv@dyomedea.com>]

Jonathan Borden wrote:
> 
> I've added a Schematron schema to RDDL (i probably should make y'all look at
> http://www.rddl.org/ to find it but its at: http://www.rddl.org/rddl.sch).
> Schematron is interesting in that it allows constraints which are otherwise
> very difficult to express in for example RELAX or TREX. For example, an
> xlink:arcrole and xlink:role must have a value of a URI reference, but not a
> relative URI reference. (This could also be expressed in an XML Schema
> pattern).

This doesn't seem obvious to fully test since it's depending on the URI
scheme.

For instance, shouldn't "file:myrole.xml" be considered as a relative
reference even though it will pass through your schematron rule ?

The nature of the URI (absolute|relative) would make an interesting
facet for the W3C XML Schema uriReference datatype [1]...

This example is also showing how useful it would be to be able to "hook"
Schematron like rules into other schema languages... 

My 0.02 Euros

Eric

[1] http://www.w3.org/TR/xmlschema-2/#uriReference

> On the other hand I'm not at all sure how to express the constraint that a
> rddl:resource have a content model of %Flow.mix; from XHTML. Anyone have a
> good idea about this?
> 
> -Jonathan

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Eric van der Vlist       Dyomedea                    http://dyomedea.com
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