- From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
- Date: 27 Mar 2003 14:11:15 +0000
- To: Wendy Attenberger <Wendy.Attenberger@nreis.com>
- Cc: "'xmlschema-dev@w3.org'" <xmlschema-dev@w3.org>
Wendy Attenberger <Wendy.Attenberger@nreis.com> writes: > <Alphabet> > <A> > <B> > <C> > </Alphabet> > In the schema, how do you indicate that at least one item is required (A,B > or C), but also allow for some ("A and B" OR "B and C", etc.) items or all > items(A,B, & C) to be present in the xml? > We've messed around with the <xs:choice>, <xs:all> ,minOccurs and maxOccurs, > but we can't get the right combination? Any ideas? Thanks. Funny you should ask -- the XML Schema Working Group is looking at possible additions to the language for version 1.1 which would provide for this in a simple way. As it stands the only way is by a massive content model, illustrated here for the 3 element case: ((a , ((b , c?) | (c , b?))) | (b , ((a , c?) | (c , a?))) | (c , ((b , a?) | (a , b?)))) Needless to say, this would be pretty large for the 26 element case. ht -- Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh Half-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/ [mail really from me _always_ has this .sig -- mail without it is forged spam]
Received on Thursday, 27 March 2003 09:11:16 UTC