Question

I would like to define the XSD for:

<Group id="someid" parent="someid">some string</Group>

This is what I tried:

<xs:element name="Group" minOccurs="0" maxOccurs="unbounded">
    <xs:complexType>
        <xs:simpleContent>
            <xs:restriction base="xs:string">
                  <xs:attribute name="id" type="xs:ID" use="required"/>
                  <xs:attribute name="parent" type="xs:IDREF" use="optional"/>
            </xs:restriction>
        </xs:simpleContent>
    </xs:complexType>
</xs:element>

I use Visual Studio for the XSD design. The validator tells me (while underlining “<xs:restriction”):
“Undefined complexType ‘http://w3.org/2001/XMLSchema:string&#8217; is used as base for a complex type restriction.”

Answer 1

It’s needed to use <xs:extension> instead of <xs:restriction>:

<xs:element name="Group" minOccurs="0" maxOccurs="unbounded">
    <xs:complexType>
        <xs:simpleContent>
            <xs:extension base="xs:string">
                  <xs:attribute name="id" type="xs:ID" use="required"/>
                  <xs:attribute name="parent" type="xs:IDREF" use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>
</xs:element>