Question

On the Domain-Driven Design website I see:

Concentrate all the code related to
the domain model in one layer and
isolate it from the user interface,
application, and infrastructure code.
The domain objects, free of the
responsibility of displaying
themselves, storing themselves,
managing application tasks, and so
forth, can be focused on expressing
the domain model. This allows a model
to evolve to be rich enough and clear
enough to capture essential business
knowledge and put it to work.

What “goes in” the infrastructure code? Does this mean supporting frameworks (for logging, for example)?

I presume “application code” means the domain objects (i.e. the domain model)?

Answer 1

Infrastructure code would be implementations of repositories for instance. You might have in-memory or Hibernate repositories that live in the infrastructure layer, while their interfaces live in the domain layer.

Application code controls the domain objects. It defines services that take user commands and invoke business logic on domain objects, but no business logic lives in that layer.