DALC Architecture

[David Veeneman]

What is the better way to connect a DALC component and a domain model; an
interface, or an event?

I'm creating an application that looks like this:

[UI] --> [App Manager] --> [Domain Model] --> o-[DALC]

Messages drill down (calls) and bubble up (events); each object knows about
the object to its right. The domain model is responsible for loading and
saving itself, which it delegates to a DALC. The domain model's load and
save methods are programmed to an interface (IWhatever) that the DALC
implements.

Would it be a better approach to have the domain model fire an event that
data needs to be saved? That way, the domain model need know nothing about
the DALC. The DALC subscribes to the event and reads what needs to be saved
from the domain model's properties. That way, we can change the DALC all we
want without breaking the domain model.

Does the benefit of uncoupling the domain model from the DALC outweigh the
cost of the event mechanism?

Thanks in advance for your advice.

David Veeneman
Foresight Systems