OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help



   Re: [xml-dev] status of "collections" in XPath / XQuery

[ Lists Home | Date Index | Thread Index ]

 From: "Michael Kay" <michael.h.kay@ntlworld.com>
>   Is there thought going on regarding constraints on collections (when they
> are defined)?  I may want to have all
>   invoice numbers in a collection be unique.
>   I haven't seen any proposals that address that. Certainly, XML Schema
> doesn't provide any cross-document validation.
The XLlinkIt validation language at www.xlinkit.com is aimed squarely at this
kind of problem, I think. (Christian Nentwich who sometimes posts on this list is, 
I believe, one of the programmers involved in it.)  

Schematron can do some kinds of inter-document validation, in particular
when there is a link in one document to another, e.g. to a controlled vocabulary.
But it lacks a for-each operator, and so is weak for collections. Xpath 2
may help in this, I don't know.

I gave up trying to figure out a Schematron expression to do this, but undoubtedly
something inefficient based on counting and the document() function could be

Rick Jelliffe


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS