- From: Jeni Tennison <jeni@jenitennison.com>
- Date: Fri, 7 Jun 2002 11:31:27 +0100
- To: xmlschema-dev@w3.org, ht@cogsci.ed.ac.uk (Henry S. Thompson)
- CC: John Verhaeg <jverhaeg@metamatrix.com>
Henry wrote:
> Misunderstanding: In the interesting case, i.e. where there is a local use
> with a ref to a global attr decl:
>
> 1) If the global has a fixed value, the local must have the same fixed
> value, or no fixed or default at all. In either case the fixed
> value will be enforced.
>
> 2) When restrictions are checked, the same fallback is applied to
> ensure that no change of fixed value occurs
Ah, right, thanks. I'd missed the fact that in Validation Rule:
Attribute Locally Valid
(http://www.w3.org/TR/xmlschema-1/#cvc-attribute), the attribute is
being checked against the {value constraint} of the attribute
*declaration*, and that there is a separate check against the {value
constraint} of the attribute *use* in Validation Rule: Attribute
Locally Valid (Use) (http://www.w3.org/TR/xmlschema-1/#cvc-au).
I'd also missed the Schema Component Constraint: Attribute Use Correct
(http://www.w3.org/TR/xmlschema-1/#au-props-correct) which states
that the attribute use must have the same value for its value
constraint it the attribute declaration's value constraint is fixed.
Cheers,
Jeni
---
Jeni Tennison
http://www.jenitennison.com/
Received on Friday, 7 June 2002 06:31:30 UTC