Re: [xml-dev] Unique values in XML documents

[Rick Jelliffe <ricko@allette.com.au>]

 From: "Christian Nentwich" <c.nentwich@cs.ucl.ac.uk>
 
> 
> > I have a series of XML documents. I want to ensure that when any of these
> > documents
> > contains the following element:
> > <id></id>
> > That the value supplied is unique across all <id> elements contained in all
> > the documents.
> 
> You can do this quite easily in xlinkit (see http://www.xlinkit.com) as
> follows:  ...
 
The only choices are XLinkit and Schematron AFAIK. 

XLinkit is clearly superior for this kind of use. I recommend that anyone
who needs to make assertions about constraints involving sets of
documents should look at XLinkit, especially if you need a server-based
solution.

While Schematron can use document() to go between XML documents
(e.g. to check something in an external locally-held controlled vocabulary) quite
happily, I think document() is not robust (e.g. if the externally held document
is unavailable).

Cheers
Rick Jelliffe