I am leveraging an existing XML schema that I cannot modify, however, I want to allow for additional child elements (that belong to a different namespace). For example, the existing schema allows for:

<book>
<author/>
<title/>
</book>

And I want to extend the <book> content model to allow:

<book>
<author/>
<title/>
<my:isbn/>
</book>

Am I able to define a my own schema document with a new <book> element definition that would override the existing definition?

Any help is greatly appreciated.

Provided the complex type of <book> is defined as a named type definition, then you can create a type derived from this by extension, or you can redefine the complex type. But if the type was anonymous, you can't. In XSD 1.1 you will be able to use xs:override for this.

Michael Kay

__________________
Michael Kay
http://www.saxonica.com/
Author, XSLT 2.0 and XPath 2.0 Programmer\'s Reference

To clarify, if the element definition is:

<xs:element name="book">
<xs:complexType>
<xs:sequence>
<xs:element ref="author"/>
...
</xs:sequence>
</xs:complexType>
</xs:element>

then I am unable to extend the schema to allow for other child elements that belong to a different namespace. Is this correct?

Thanks again for your help.

>Is this correct?

Yes.

Except of course by creating a different schema using cut and paste.

__________________
Michael Kay
http://www.saxonica.com/
Author, XSLT 2.0 and XPath 2.0 Programmer\'s Reference