correct use of xsi:schemaLocat ion

[Sarah Tegtmeier]

Hi

I have a question about the correct use of the attribute
xsi:schemaLocat ion. My programm has to process XML files where the value of
this attribute causes some problems. The programm is written in C++
using Xerces C++ version 2.3.0. An older older version of the programm
used Xerces C++ version 1.6.0.

The XML files look like the following example:

example.xml
============
<an:root xmlns:an="nsAnt on"
xmlns:bt="nsBer ta"
xmlns:xsi="http ://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocat ion="nsBerta antonFile.xsd">
<!-- content -->
</an:root>

The schema definitions files used by example.xml are

antonFile.xsd
==============
<schema targetNamespace ="nsAnton">
<include schemaLocation= "nsAnton.xs d"/>
<import namespace="nsBe rta" schemaLocation= "nsBerta.xs d"/>
</schema>

nsAnton.xsd
============
<schema targetNameSpace ="nsAnton">
<element name="root">
<!-- content of root-element -->
</element>
</schema>

nsBerta.xsd
============
<schema targetNamespace ="nsBerta">
<!-- vocabularry of schema nsBerta -->
</schema>

When I validate file example.xml with a SAX parser using Xerces C++
version 1.6.0 the file is recognized as valid. xmlspy (professional
edition version 5, release 4) also tells me that the file is valid.
But when i run a SAX parser using Xerces C++ verion 2.3.0 i got the
message
"Schema in antonFile.xsd has a different target namespace
from the one specified in the instance document nsBerta."
and the file is considered as invalid.

So i have two validation results one from Xerces C++ 1.6.0 and xmlspy
5.4 and one from Xerces C++ 2.3.0. But which one is correct?
When I change the value of the schema location attribute to

xsi:schemaLocat ion="nsAnton antonFile.xsd"

the file is considered as valid by all of the three parsers. Hence the
two different validation results of file example.xml are caused by

xsi:schemaLocat ion="nsBerta antonFile.xsd"

in my opinion the classification of Xerces C++ 2.3.0 is correct
because the target namespace of antonFile.xsd is nsAnton and not
nsBerta. I would expect that the target namepace of the schema
defintion file must match the namespace to which the schema definition
file is connected by the attribute xsi:schemaLocat ion, i.e. in

xsi:schemaLocat ion="namespace namespaceFile.x sd"

the condition

namespace == TARGET-NAMESPACE ( namespaceFile.x sd )

must be satisfied.

Is my interpretation correct?

The W3C recommendation (http://www.w3.org/TR/xmlschema-1/) states that
the value of the attribute xsi:schemaLocat ion gives only a hint where an
application can find the definition of a namespace but an application
must not use this information.

I would appreciate information about the correct use of the attribute
xsi:schemaLocat ion.

yours sincerely

Sarah