Bert,
  I think the file at
https://svn.apache.org/repos/asf/incubator/tuscany/java/sdo/tools/src/test/resources/subgroup.xsddemonstrates
what you want.
Regards, Kelvin.

On 15/05/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:

Hi all,

I've a general question concerning polymorphism and SDO.

Suppose I have a type A that contains a link "b" of type B. There also
exists a subtype "SpecialB" which extends B.

I interpret this link to be a polymorphic link, i.e. instances of this
link should be of type B or of a subtype of B.
This works fine when using the DataObject API (e.g. using the method
DataObject.createDataObject(Property property, Type type)).

However I don't understand how this is mapped into XML/XSD.

If I generate an XSD for type A, how do I express that the link 'b' is
polymorph?

A straigtforward approach like

        <xsd:complexType name="A">
                <xsd:sequence>
                        <xsd:element name="b" type="B" maxOccurs="1"
minOccurs="0"></xsd:element>
                ...
        ...

states that the type of B should be exactly 'B' (at least according to my
incomplete XML knowledge :-).

On the instance level,

        <a><b>...</b></a>

is an xml piece for an object of type A with a link to some b. How would
this look like in case the link is to a SpecialB instance?


So, my question is, how do polymorphic links work in an xml context?

I hope this is clear.


Bert

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