- From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
- Date: 30 Jan 2001 12:54:28 +0000
- To: afo@zurich.ibm.com
- Cc: www-xml-schema-comments@w3.org
I sympathise with your plight. As soon as XPath supports types, it
will be easy to do what you want -- just used a type-based XPath for
your three selectors.
Until then I recommend the following: Put a fixed attribute
declaration for an attribute called e.g. namespaceName on each of your
three core types, i.e.
<attribute name="namespaceName" type="token" use="fixed" value="Sensor"/>
<attribute name="namespaceName" type="token" use="fixed" value="Location"/>
<attribute name="namespaceName" type="token" use="fixed" value="Component"/>
This will be inherited by all subtypes, and appear in the infoset for
all instances. Then your unique's can be
<xs:unique name="UniqueSensors">
<xs:selector xpath="//*[@namespaceName='Sensor']"
<xs:field xpath="@name"/>
</xs:unique>
etc.
Hope this helps
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, 30 January 2001 07:54:31 UTC