Hello David,
Aside from the missing import for "xml:lang" I believe this schema is
valid. The effective content of the extension is empty and so inherits the
{content type} of the base which is mixed.
See the definition in this section [1] of the spec:
{content type}
...
3.2 If the <extension> alternative is chosen, then the appropriate case
among the following:
3.2.1 If the ·effective content· is empty, then the {content type} of the
type definition ·resolved· to by the ·actual value· of the base [attribute]
This is a mapping from the XML representation of the complex type to its
schema component properties. The clause [2] you've found later only applies
to the complex type definition *component*. After mapping the XML
representation to schema components the base and extension have a
consistent {content type} (both being mixed) so I see no error here.
Thanks.
[1] http://www.w3.org/TR/xmlschema-1/#declare-type
[2] http://www.w3.org/TR/xmlschema-1/#cos-ct-extends
Michael Glavassevich
XML Parser Development
IBM Toronto Lab
E-mail: [email protected]
E-mail: [email protected]
David North <[email protected]> wrote on 03/10/2010 06:45:41
AM:
> Hi,
>
> We think we have discovered an anomaly in Xerces' interpretation of
> the XML schema structures specification.
>
> Clause 1.4.3.2.2.1 of http://www.w3.org/TR/xmlschema-1/#cos-ct-extends
> specifies that when deriving a new complex type by extension from an
> existing complex type, then: "Both {content type}s must be mixed or
> both must be element-only".
>
> As demonstrated by the following schema, Xerces-J does not raise an
> error despite the extension of a mixed complex type by a non-mixed
> one being illegal. Note that no error is raised regardless of
> whether the extension type explicitly sets mixed=false or relies on
> the default value of the mixed attribute (false).
>
> <?xml version="1.0" encoding="UTF-8"?>
> <schema elementFormDefault='qualified' targetNamespace='http://
> www.example.com/test/' xmlns='http://www.w3.org/2001/XMLSchema'
xmlns:eg='
> http://www.example.com/test/'>
> <complexType name='mixedType' mixed='true'>
> <sequence>
> <any processContents='skip' minOccurs='0'
> maxOccurs='unbounded' namespace='http://www.w3.org/1999/xhtml' />
> </sequence>
> </complexType>
> <!-- This extension violates clause 1.4.3.2.2.1 of http://
> www.w3.org/TR/xmlschema-1/#cos-ct-extends
> Xerces-J does not raise any errors or warnings when processing
> this file with full schema checking
> This is still the case even with mixed=false explicitly set on
> the complexType below and/or the complexContent
> Note that the inverse problem applies: move mixed=true from the
> type above onto this one, and Xerces-J fails to complain
> (this case is also forbidden) -->
> <complexType name='extensionType'>
> <complexContent>
> <extension base='eg:mixedType'>
> <attribute use='required' ref='xml:lang' />
> </extension>
> </complexContent>
> </complexType>
> </schema>
>
> Is this intentional behaviour? Eclipse XSD appears to behave
> identically, but we are led to believe that other tools regard such
> schemas as invalid.
>
> We are using xerces-j version 2.9.1
>
> Thanks,
> --
> David North, Software Developer, CoreFiling Limited
> http://www.corefiling.com
> Phone: +44-1865-203192
