W3C home > Mailing lists > Public > xmlschema-dev@w3.org > February 2001

Re: Bug in XSV?

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 24 Feb 2001 21:42:17 +0000
To: "Roger L. Costello" <costello@mitre.org>
Cc: xmlschema-dev@w3.org
Message-ID: <f5bofvrsqpy.fsf@cogsci.ed.ac.uk>
"Roger L. Costello" <costello@mitre.org> writes:

> Hi Folks,
> 
> XSV is generating an error when a no-namespace schema (containing
> components that reference one another) is <include>d into a schema with
> a targetNamespace.
> 
> Consider this no-namespace schema:
> 
> <?xml version="1.0"?>
> <xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"
>         elementFormDefault="qualified">
>     <xsd:complexType name="CardCatalogueEntry">
>         <xsd:sequence>
>             <xsd:element name="Title" type="xsd:string"/>
>             <xsd:element name="Author" type="xsd:string"/>
>             <xsd:element name="Date" type="xsd:string"/>
>             <xsd:element name="ISBN" type="xsd:string"/>
>             <xsd:element name="Publisher" type="xsd:string" />
>         </xsd:sequence>
>     </xsd:complexType>
>     <xsd:element name="Book" type="CardCatalogueEntry"/>
> </xsd:schema>
> 
> This schema has two components - a complexType CardCatalogueEntry
> component and an element Book component.  The Book component references
> the CardCatalogueEntry component. 
> 
> Consider what happens when these components are included in a schema
> with a namespace.  
> 
> <?xml version="1.0"?>
> <xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"
>         targetNamespace="http://www.library.org"
>         xmlns="http://www.library.org"
>         elementFormDefault="qualified">
>     <xsd:include schemaLocation="BookCatalogue.xsd"/>
>     <xsd:element name="Library">
>         <xsd:complexType>
>              <xsd:sequence>
>                  <xsd:element name="BookCatalogue">
>                      <xsd:complexType>
>                          <xsd:sequence>
>                              <xsd:element ref="Book"/>
>                          </xsd:sequence>
>                      </xsd:complexType>
>             </xsd:sequence>
>         </xsd:complexType>
>     </xsd:element>
> </xsd:schema>
> 
> Note that the targetNamespace is the default namespace.  When the
> no-namespace components (Book and CardCatalogueEntry) are included in
> this schema they take on the targetNamespace.  Consequently, this
> element declaration in the no-namespace schema:
> 
>     <xsd:element name="Book" type="CardCatalogueEntry"/>
> 
> should be referencing a CardCatalogueEntry component in the
> targetNamespace. [Or, is Book still referencing CardCatalogueEntry in
> no-namespace?  Do only the components take on the namespace of the
> <include>ing schema, or do the references also take on the namespace?  I
> am not clear on this.]  

It should be clarified that the reference is resolved to the chameleon
component.

> When I ran this example in XSV I got this error message:
> 
> Undefined type {None}:CardCatalogueEntry referenced as type definition
> of Book

XSV is in error here.

> There are two possibilities:
> 
> {1} XSV has a bug and type="CardCatalogueEntry" is a reference to the
> CardCatalogueEntry in the default namespace (which in my schema is the
> targetNamespace)

Yes.

> {2} There is no bug in XSV and type="CardCatalogueEntry" is a reference
> to the CardCatalogueEntry in no-namespace, and XSV's error message is
> valid.

No.

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Saturday, 24 February 2001 16:42:21 UTC

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