With the memento design pattern, is it wrong to have the Caretaker as an aggregate of the Originator?
+1
A:
No, that's fine if it's what works out as appropriate for your situation. It's not a big leap to understand that the Caretaker's state isn't part of what's preserved in the Memento.
chaos
2009-03-25 13:24:34
+3
A:
Not necessarily. The main purpose behind Memento is that it is possible to deal with different Originators in uniform, transparent way (get Memento, pass it back later to restore state).
The aggregate relation doesn't necessarily prevent that. Different instances of Caretaker might be aggregates of different Originators (although one instance of Caretaker deals with only one instance of Originator) and still get the benefits of transparent state restoration.
Rafał Dowgird
2009-03-25 13:34:00