An Introduction to XML Schemas

Anyway, as this is all that our extremely simple schema document needs in order to validate our extremely simple XML document, we can end the schema with the closing schema element:

</xsd:schema>

The whole file should now look like this:

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:element name="news">
  <xsd:complexType>
  <xsd:sequence maxOccurs="unbounded">
    <xsd:element ref="article"/>
  </xsd:sequence>
  </xsd:complexType>
</xsd:element>
<xsd:element name="article">
  <xsd:complexType>
  <xsd:sequence maxOccurs="1" minOccurs="1">
    <xsd:element ref="headline" />
    <xsd:element ref="story" />
  </xsd:sequence>
  </xsd:complexType>
</xsd:element>
<xsd:element name="headline" type="xsd:string" />
<xsd:element name="story" type="xsd:string" />
</xsd:schema>

Save the document with an .xsd prefix. As schema documents are just well-formed XML documents, you can also save it with an .xml prefix and load it up in a browser. If there are any typos or syntax errors in the schema, it won’t load. You need to use an XML compliant browser of course; for the purpose of this article, I’ve used MS IE6.