Real World XML

Creating Simple Types Using Facets

Using facets lets you restrict the data a simple type can hold. For example, say that you want to create a simple type named dayOfMonth that can hold only values between 1 and 31, inclusive. In that case, you can define it this way, using the two facets minInclusive and maxInclusive:

<xsd:simpleType name="dayOfMonth"> 
    <xsd:restriction base="xsd:integer">
        <xsd:minInclusive value="1"/>
        <xsd:maxInclusive value="31"/>
    </xsd:restriction>
 </xsd:simpleType>

Now that you've created this new simple type, you can declare elements and attributes of this type.

In ch05_07.xsd, the catalogID simple type is even more powerful than this dayOfMonth simple type. The catalogID simple type uses the pattern facet to specify a ...