AW: Delegation & Inheritance

[Dr. Ulrich Mende]

Hi, Jeffrey + Alon -
I fully agree with Alon. I even think, that you  m u s t  use always the
supertype when using delegation.
In normal OO-programming you can put a subtype or subsubtype when a
supertype is needed. This works because of the "Is a" - relationship between
subtype and supertype. If you do so in SAP Business Workflow (transfer a
Z-subtype to a SAP supertype object in a SAP delivered workflow) you will
get a type mismatch.
It is just the delegation - a thing, I have not seen yet in normal
OO-programming - that allowes you to use the old supertype name with your
new events, methods, attributes. For me a supertype name after delegation is
just an ALIAS for the subtype name. This on the other hand will allow you
only  o n e   delegation at a time, while you can have more then one
subtypes for one supertype.
 
Best regards Uli Mende