- From: Eric van der Vlist <vdv@dyomedea.com>
- Date: Wed, 28 Nov 2001 18:14:24 +0100
- To: Erik Beijnoff <erik@addsystems.com>
- Cc: "'Lieve Laporte'" <lieve.laporte@uz.kuleuven.ac.be>, xmlschema-dev@w3.org
Hi,
Erik Beijnoff wrote:
> >In this case, wouldn't I have to duplicate everything that is inside
> the "actions" element? 'Cause that's quite a lot...
>
> >Regards, Lieve
>
> Ok, here goes...
>
> <xs:complexType name="outer">
> <xs:choice>
> <xs:element name="action" type="actionsWithAccess"/>
> <xs:element name="action" type="actionsWithSettings"/>
> </xs:choice>
> </xs:complexType>
No, you can't do this (having two elements with the same name under a
choice compositor) with W3C XML Schema since it would be breaking the
famous Unique Particle Attribution rule:
"A content model must be formed such that during ·validation· of an
element information item sequence, the particle contained directly,
indirectly or ·implicitly· therein with which to attempt to ·validate·
each item in the sequence in turn can be uniquely determined without
examining the content or attributes of that item, and without any
information about the items in the remainder of the sequence."
http://www.w3.org/TR/xmlschema-1/#cos-nonambig
You can workaround this using a xsi:type attribute in the instance
document to "help" the schema processor but this has (of course)
an impact of the instance document.
Eric
--
See you in Orlando for XML 2001.
http://www.xmlconference.net/xmlusa/
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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 Wednesday, 28 November 2001 12:14:29 UTC