Question

I am searching for the best solution of my XML schema (XSD).

I have a response:

<xs:element name="exampleCatalogResponse">
    <xs:complexType>
        <xs:sequence>
            <xs:element name="meta" type="tns:metaType" />
            <xs:element name="data" type="tns:defaultDataType" />
        </xs:sequence>
    </xs:complexType>
</xs:element>

…the defaultDatatype:

<xs:complexType name="defaultDataType">
    <xs:sequence>
        <xs:element name="catalog">
            <xs:complexType>
                <xs:sequence maxOccurs="unbounded">
                    <xs:element name="catalogItem" type="tns:catalogItem" />
                </xs:sequence>
            </xs:complexType>
            <xs:unique name="itemIdConstraint">
                <xs:selector xpath="tns:catalogItem" />
                <xs:field xpath="tns:id" />
            </xs:unique>
        </xs:element>
    </xs:sequence>
</xs:complexType>

…and the catalogItem:

<xs:complexType name="catalogItem">
    <xs:sequence>
        <xs:element name="id" type="xs:nonNegativeInteger" />
    </xs:sequence>
</xs:complexType>

…but now there is a special item which specialize catalogItem:

<xs:complexType name="specialItem">
    <xs:complexContent>
        <xs:extension base="tns:catalogItem">
            <xs:sequence>
                <xs:element name="code" type="xs:string" />
            </xs:sequence>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>

Now I need an specialized Response for my specialItem for answering the request which expects this specialItem.

How can I realise this, without writing another defaultDataType where only the type of catalogItem changes to tns:specialItem?

Answer 1

Thank you for your tipps 13ren,

I used the Subsumption Feature. So the default catalogItem is used everywhere also for the unique expression. And now if i use this in xml i can specify this via type.

  <tns:catalogItem xsi:type="tns:specialItem">
    <tns:id>0</tns:id>
    <tns:code>tns:code</tns:code>
  </tns:catalogItem>
  <tns:catalogItem xsi:type="tns:specialItem">
    <tns:id>1</tns:id>
    <tns:code>tns:code</tns:code>
  </tns:catalogItem>
  <tns:catalogItem>
    <tns:id>2</tns:id>
    <tns:code>tns:code</tns:code>
  </tns:catalogItem>

So the last item is the default, and the two above are specialized items. this works very well for me.