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Re: Adding attributes to lists

From: Jane Hunter <jane@dstc.edu.au>
Date: Mon, 23 Oct 2000 19:49:54 +1000
Message-Id: <200010230949.e9N9nhc08838@piglet.dstc.edu.au>
To: ht@cogsci.ed.ac.uk (Henry S. Thompson)
cc: www-xml-schema-comments@w3.org
We're already using appinfo to define the dimensions of fixed-sized arrays. See 
below:

<simpleType name="matrix2x2OfInteger">
     <list itemType="integer">
        <annotation><appinfo>
                <mpeg7:dimension value="2 2"/>
         </appinfo></annotation>
     </list>
</simpleType>

But we also need a mechanism for defining the dimensions of variable-sized 
arrays at run-time. An attribute value is the only way that we can do this.

We don't expect an XML Schema processor to validate the size of the list 
against the mpeg7:dim value - this will only be performed by MPEG-7 processors. 
But we would like XML Schema processors not to generate an error when an 
attribute is associated with a list.

jane

> Henry Thompson <ht@cogsci.ed.ac.uk> writes:
> 
> This would amount to run-time type creation, and is not supported in
> v.1.  This is an area we will definitely look at for the next version.
> 
> In the mean time, you can view this as an application-specific
> constraint, and use the <appinfo> element to record the dependency and 
> provoke application-level checking.
> 
> ht

> > Jane Hunter <jane@dstc.edu.au> writes:
> >
> > For MPEG-7 implementations, we'd like to be able to specify the 
> > dimensions of a variable-sized array through an attribute added to a 
> > list. For example:
> > 
> > <simpleType name="listofInteger">
> >    <list itemType="integer"/>
> > </simpleType>
> > 
> > <complexType name="nDimIntegerArray">
> >   <simpleContent>
> >     <extension base="listOfInteger">
> >         <attribute ref="mpeg7:dim"/>
> >     </extension>
> >   </simpleContent>
> > </complexType>
> > 
> > <element name="integerMatrix" type="nDimIntegerArray"/>
> > 
> > <integerMatrix mpeg7:dim="2 4">1 2 3 4 5 6 7 8</integerMatrix>
> 
> This would amount to run-time type creation, and is not supported in
> v.1.  This is an area we will definitely look at for the next version.
> 
> In the mean time, you can view this as an application-specific
> constraint, and use the <appinfo> element to record the dependency and 
> provoke application-level checking.
> 
> ht
Received on Monday, 23 October 2000 05:50:06 GMT

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