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RE: Conditional Levels of a Schema

From: Michael Kay <mike@saxonica.com>
Date: Tue, 7 Apr 2009 09:25:47 +0100
To: "'Dieter Menne'" <dieter.menne@menne-biomed.de>, <xmlschema-dev@w3.org>
Message-ID: <6F87F2413BFB41CCB4330F3202BF611C@Sealion>
> It is A, and Michael and Steve's as well as some of your 
> ideas are exactly to the point. We would like to keep one 
> master document that is the most liberal and has only the 
> minimal set as required items; and separate derived ones; 
> there are a few more variants than those mentioned here, most 
> of them "nested" to form a stack of requirements (the patient 
> case is the only non-nested).
> The idea is that hospital administrators can put up a filter 
> allowing only anonymized files out. Or that researcher who 
> want calibrations information that is not relevant for others 
> can check with their special version of the schema if all 
> required items are there. 
> While Michael's $param idea looked easiest for me at first, I 
> think Steve has made a good point and that his way is 
> preferred because is ensures that the master document is always valid.

I've actually been experimenting with ideas that take the "conditional type
assignment" facility in XSD 1.1 and extend it by allowing access to "schema
parameters" which must be set when starting a validation episode (the
current facility can only be driven by data that appears in the instance
document, not by external data supplied at validation time). This approach
seems to offer a very good fit to your use case (which I think is not at all
uncommon). Unfortunately the schema specs move slowly.

Michael Kay
Received on Tuesday, 7 April 2009 08:26:26 UTC

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