Reputation: 1284
Should value object hold reference to entity in DDD methodology?
EDIT
@Dmitry:
This is probably my case. Here I attach class diagram where the Account
hold references to collection of IInvoiceable
items. I treat with Tenant
as entity, but it owns only 1 account and i dont think that Account
needs identity. its part of Tenant
. Or should I treat it as Entity? To me it doesnt make sense.
Upvotes: 26
Views: 8063
Reputation: 17350
Yes it can. This would be a relatively obscure case but DDD allows for it and it can be useful. From the DDD book by Eric Evans:
VALUE OBJECTS can even reference ENTITIES. For example, if I ask an online map service for a scenic driving route from San Francisco to Los Angeles, it might derive a Route object linking L.A. and San Francisco via the Pacific Coast Highway. That Route object would be a VALUE, even though the three objects it references (two cities and a highway) are all ENTITIES.
Upvotes: 45
Reputation: 1504
Take a look at this links, hope it will be helpful
http://lostechies.com/jimmybogard/2008/05/21/entities-value-objects-aggregates-and-roots/
Upvotes: 0