XSLT, 2nd Edition

Using XML Schemas with Namespaces

If we’re using an XML Schema with a namespace, we have to make sure the three files (.xml, .xsd, and .xsl) are in sync. It’s slightly more complicated, as you’d expect. First of all, the XML file needs to have a default namespace:

<?xml version="1.0"?>
<!-- parts-list-schema-ns.xml -->
<parts-list xmlns="http://www.oreilly.com/xslt"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.oreilly.com/xslt 
                      parts-list-schema-ns.xsd">
  <component component-id="C28392-33-TT">
    <name>Turnip Twaddler</name>
    <partref refid="P81952-26-PK"/>
    ...

Notice that we’ve defined the default namespace (xmlns=) as http://www.oreilly.com/xslt. The xsi:schemaLocation attribute has two parts, separated by whitespace: the namespace URI and the URI of the schema itself. The schema file uses the same default namespace:

<?xml version="1.0" encoding="UTF-8"?>
<!-- parts-list-schema-ns.xsd -->
<xs:schema 
  xmlns="http://www.oreilly.com/xslt"
  targetNamespace="http://www.oreilly.com/xslt"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <xs:element name="parts-list">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="component" minOccurs="1" maxOccurs="unbounded"/>
        <xs:element ref="part" minOccurs="1" maxOccurs="unbounded"/>
        ...

We also use the XML Schema attribute targetNamespace; it has the same value as the default namespace. Finally, we need to use the namespace in the XSLT file. We define http://www.oreilly.com/xslt as the default namespace and define ...