- From: Anton Mellit <anton_mellit@unitedthinkers.com>
- Date: Sat, 18 May 2002 22:50:13 +0300
- To: "Jeni Tennison" <jeni@jenitennison.com>
- Cc: <xmlschema-dev@w3.org>
> Thus, deriving by restriction is helpful because it enables you to
> express the commonality between a set of elements, and process them in
> the same kind of way.
As I understand the idea of derivation is the following:
If type B is derived from type A then every element of type B can be
considered as an element of type A.
However, type definitions can be as follows:
<xs:complexType name="A">
<xs:sequence>
<xs:element name="child" type="xs:string" minOccurs="1"
maxOccurs="1"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="B">
<xs:complexContent>
<xs:restriction base="A">
<xs:sequence>
<xs:element name="child" type="xs:string" minOccurs="0"
maxOccurs="0"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
If I have element of actual type B, but think of it as of element of type A
then I will fail trying to get value of its element <child>. Please, correct
me if I am wrong.
Regards, Anton
Received on Saturday, 18 May 2002 15:51:16 UTC