Special Edition Using XML, Second Edition

attributeGroup

We discussed earlier how you can make use of the ref attribute to make a reference to an attribute declaration that is declared globally within your schema:

<?xml version="1.0" encoding="utf-8"?> 
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:attribute name="sku" type="xs:string"/>

  <xs:element name="catalog">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="item">
          <xs:complexType>
            <xs:attribute ref="sku"/>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

References are one way to organize your attributes and to reuse attributes—another way is the attribute group.

An <attributeGroup> allows you to declare attributes together within a common structure, and then reference that ...