UBL Schema Customization

[Juha Ikävalko <juha.ikavalko@tieke.fi>]

Hi UBL developers,

I have a question related to a following paragraph (Guidelines For The Customization of UBL v1.0 Schemas):

"The derived type MyPartyType can be used anywhere the original PartyType is allowed. The instance document should use the xsi:type attribute to indicate that a derived type is being used. This does not enforce the use of the new type inside a given element, however, so an Order instance could still be created using the standard UBL PartyType. If the user wishes to require the use of the derived type, blocking the possibility of using the original type in an instance, a new derived type must be created from the Order type using refinement and specifying that the MyPartyType must be used."

I use the following (UBL Order-1.0) structure as an example:
|Order
|----|cac:Party
|----|----|cac:Address

If we need to add new properties to the Address component, we create a new FI-AddressType by extending the existing AddressType. Ok, that's simple. But how should we handle a situation where we require the use of derived type in the Order document? Should we also create a new FI-PartyType first by disallowing the use of original AddressType through XSD restriction and then by allowing the use of FI-AddressType through XSD extension? When it's done, should we also create a new FI-Order by disallowing the use of original PartyType through XSD restriction and then by allowing the use of FI-PartyType through XSD extension?

The final structure would be:
|FI-Order
|----|fi-cac:FI-Party
|----|----|fi-cac:FI-Address

Thus a more general question is: 
Is this kind of recursive process always a necessity when the use of derived type is required or is there an easier way to reach the same end result?


With best regards,

Juha Ikävalko
TIEKE Tietoyhteiskunnan kehittämiskeskus ry 
TIEKE Finnish Information Society Development Centre 
Salomonkatu 17 A, 10th floor
FI-00100 Helsinki 
Tel +358 9 4763 0410, Fax +358 9 4763 0399
juha.ikavalko@tieke.fi  http://www.tieke.fi