How to reuse elements from another Schema / Namespace (i.e. XHTML) with XML Schema?

Question

I\'m trying to define a Schema which allows the use of specific (X)HTML elements in certain places. The problem that I\'m facing is that the Schema fails compiling.

Here

Answer 1

It seems that the "blockquote" element is not defined as global element, thus you can not refer to it directly. If you have a look in the sub part of the xhtml schema http://www.w3.org/MarkUp/SCHEMA/xhtml11-model-1.xsd, you can notice that its type is xhtml.blockquote.type.

So a workaround would be to declare your blockquote like so :

<xs:schema xmlns:html="http://www.w3.org/1999/xhtml" xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:import namespace="http://www.w3.org/1999/xhtml" schemaLocation="http://www.w3.org/MarkUp/Schema/xhtml11.xsd"/>
        <xs:element name="foo">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="blockquote" type="html:xhtml.blockquote.type" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

along with this valid XML instance:

<?xml version="1.0"?>
<foo xmlns:html="http://www.w3.org/1999/xhtml" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="test.xsd">
    <blockquote><html:p>quick brown fox jumped over the lazy dog.</html:p></blockquote>
</foo>

You will notice that the blockquote element is not bound to the html namespace. Since you import other namespace's elements, I think also it would be a better practice to set a default target namespace to your own elements.