Re: keyrefs

Jeni Tennison wrote:

> Hi Eric,
> 
> 
>>I does more than agree and I would say that, even if "a validatable
>>structure is a big requirement for the markup language" you may
>>consider defining a flexible vocabulary and a (strict) canonical
>>form which can be validated by any schema language (including W3C
>>XML Schema and even DTDs).
>>
>>You can of course also publish the canonicalization process as a
>>XSLT transformation to be perfomed on instance documents before
>>validation.
>>
> 
> Good idea! :)
> 
> Both XML Schema and XSL-FO kinda do this implicitly - they map from an
> XML representation to an abstract representation (schema
> components/formatting objects) and run a certain amount of
> checking/validation on the abstract representation rather than the XML
> representation.


Yes, this is probably done by most of the object oriented applications 
using XML as a "serialization" format: it's easier (IMO) to enforce 
"business rules" using a programing language than a schema language. 
Especially since some of these rules need to be implemented anyway and 
can be reused.

 
> I wonder how many of the schema component constraints could be
> validated using an XML Schema if the schema components were serialized
> in a suitable canonical form...


That's probably one part of the problem.

I wonder also if, keeping W3C XML Schema as it is now, it wouldn't be 
possible to define a canonical (or simple or minimal) XML Schema form 
(eventually using the work done by  Kohsuke Kawaguchi [1]) .

This format could be used directly to build simple schemas, but new 
building blocks could also be created (using a separate namespace) which 
could be XSLT transformed into the canonical form.

It would be a kind of refactoring of W3C XML Schema to remove the 
minefields while keeping just enough common ground to be used by schema 
processors :) ...

[1] http://www.xml.com/pub/a/2001/06/06/schemasimple.html

Eric (daydreaming)

-- 
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
http://xsltunit.org      http://4xt.org           http://examplotron.org
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Received on Friday, 9 November 2001 13:27:45 UTC