SourcePro : Essential Tools Module User's Guide : Persistence : Polymorphic Persistence : Designing your Class to Use Polymorphic Persistence
Designing your Class to Use Polymorphic Persistence
Note that the ability to restore the pointer relationships of a polymorphic object is a property of the base class, RWCollectable. Polymorphic persistence can be used by any object that inherits from RWCollectable including your own classes. Designing an RWCollectable Class describes how to implement polymorphic persistence in the classes that you create by inheriting from RWCollectable.