XSD: XML Schema Definition

The last time I was seriously involved with XML, DTD seemed to be the accepted way of definining an XML schema. That seems to have been abandoned in favour of a XML-based schema-definition, er, schema, called XSD.

An example of a very simple XML Schema Definition to describe a UK Address

<?xml version="1.0" encoding="utf-8" ?>
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="Address">
 <xs:complexType>
   <xs:sequence>
     <xs:element name="Recipient" type="xs:string" />
     <xs:element name="House" type="xs:string" />
     <xs:element name="Street" type="xs:string" />
     <xs:element name="Town" type="xs:string" />
     <xs:element minOccurs="0" name="County" type="xs:string" />
     <xs:element name="PostCode" type="xs:string" />
     <xs:element name="Country">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:enumeration value="FR" />
           <xs:enumeration value="DE" />
           <xs:enumeration value="ES" />
           <xs:enumeration value="UK" />
           <xs:enumeration value="US" />
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
   </xs:sequence>
 </xs:complexType>
</xs:element>
</xs:schema>

An example:

<?xml version="1.0" encoding="utf-8"?>
<Address xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="SimpleAddress.xsd">
 <Recipient>Mr. Walter C. Brown</Recipient>
 <House>49</House>
 <Street>Featherstone Street</Street>
 <Town>LONDON</Town>
 <PostCode>EC1Y 8SY</PostCode>
 <Country>UK</Country>
</Address>

 

From: http://en.wikipedia.org/wiki/XML_Schema_(W3C)