Hi David,

The example looks familiar :-).

There is no special support for substitution groups in identity constraint 
XPaths.  You would need to have a selector that is catalog/Shirt | 
catalog/Shoes, or, if all the children of catalog were part of the 
substitution group, you could use catalog/* as your selector.

As far as processors, XQuery and XSLT 2.0 will have some substitution group 
awareness.  For example, in XSLT 2.0 you can create a template whose pattern 
is "schema-element(Product)" and it would match Shirt and Shoes as well. 
Otherwise, I don't know of any special substitution group support in XML 
processors, other than of course XML Schema validators.

Hope that helps,
Priscilla

------------------------------------------------------------------
Priscilla Walmsley
Author, Definitive XML Schema  /  XML in Office 2003
http://www.datypic.com
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"David Blickstein" <db@h...> wrote in message 
news:q7e3e.2746$K%2.1791@n......
> Suppose I have an XML Schema that contains a keyref that is part of a
> substitution group.
>
> Let's say I have a "Product" element that contains a field ProductID that 
> is
> a key reference.   The xs:key selector might be "catalog/Product".
>
> Now if I add elements (let's say "Shirt" and "Shoes") that have "Product" 
> as
> a substitution group (they are derived from and can be substituted for
> product) would <Shirt ProductID=34> be considered a keyref (and validated
> accordingly), or would I have to provide a selector that specifically
> matches "Shirt" and "Shoes"?
>
> A second question is... in general... are XML processors that read-in 
> Schema
> generally "aware" of substitution groups?  That is, in general, do I have 
> to
> modify XML apps everytime a new element tag is added to the Product
> substitution group?
>
> Thanks
>
>