- From: Werner Guttmann <werner.guttmann@gmx.net>
- Date: Fri, 22 Sep 2006 21:19:43 +0200
- To: Michael Kay <mike@saxonica.com>
- CC: xmlschema-dev@w3.org, 'Reinhard Pötz' <reinhard.poetz@gmx.net>
Thanks, Michael, for spelling this out so very 'user friednly' .. ;-).
Werner
Michael Kay wrote:
>> when restricting a complex type, is it actually allowed (at
>> all) to change the type of an attribute defined at the
>> complex type to be restricted ?
>>
>
> Yes, subject to the rules in
> http://www.w3.org/TR/xmlschema-1/#derivation-ok-restriction
>
> To paraphrase the rules:
>
> 2.1.1, 3 if there's an attribute that's required in the base type then it
> must be present (and required) in the derived type
>
> 2.1.2 the type of the attribute in the derived type must be a restriction of
> the type of the corresponding attribute in the base type
>
> 2.1.3 if the base type specifies a fixed value, then the derived type must
> specify the same fixed value.
>
> (Wouldn't it be nice if the spec were written like that, instead of saying
> things like "what would have been the {name} and {target namespace} of the
> {attribute declaration} of an attribute use in the set per clause 1 above
> but for the ·actual value· of the use [attribute] of the relevant
> <attribute> among the [children] of <restriction> being prohibited.")
>
> Remember of course, that unlike child elements, attributes are automatically
> inherited from the base type unless you explicitly exclude them (an
> asymmetry I've always found very ugly).
>
> Michael Kay
> http://www.saxonica.com/
>
>
Received on Friday, 22 September 2006 21:12:56 UTC