barnum@b... wrote:

> if I have defined a type in a schema, can I subclass it (refine it)
> without rewriting all of the type?
> E.g. I have:
> 	<xs:element name="Apple" type="xs:string"/>
> 	<xs:element name="Banana" type="xs:string"/>
> 	<xs:element name="Citrus" type="xs:string"/>
> 	<xs:complexType name="MyType">
> 		<xs:sequence>
> 			<xs:element ref="Apple"/>
> 			<xs:element ref="Banana" minOccurs="0" maxOccurs="unbounded"/>
> 			<xs:element ref="Citrus"/>
> 		</xs:sequence>
> 	</xs:complexType>
> And I want a derived type (where the new thing is that there must be
> one or more Banana):
> 	<xs:complexType name="MyDerivedType">
> 		<xs:sequence>
> 			<xs:element ref="Apple"/>
> 			<xs:element ref="Banana" maxOccurs="unbounded"/>
> 			<xs:element ref="Citrus"/>
> 		</xs:sequence>
> 	</xs:complexType>
> Can I do this without having to write Apple and Citrus in
> MyDerivedType?

You have not used any type derivation at all as with the above 
definition for MyDerivedType you have defined a new type, there is no 
relation to MyType.
A derivation by restriction looks as follows:

   <xs:complexType name="MyDerivedType">
     <xs:complexContent>
       <xs:restriction base="MyType">
         <xs:sequence>
           <xs:element ref="Apple"/>
           <xs:element ref="Banana" maxOccurs="unbounded"/>
           <xs:element ref="Citrus"/>
         </xs:sequence>
       </xs:restriction>
     </xs:complexContent>
   </xs:complexType>

So you need to list the same elements, you can then restrict the occurance.


-- 

	Martin Honnen --- MVP XML
	http://JavaScript.FAQTs.com/