Implementing Domain-Driven Design

State Representations of Aggregate Instances

If your application provides REST-based resources as discussed in REST (4), these will need to produce state representations of domain objects for clients. It is very important to create representations that are based on use case, not on Aggregate instances. This has very similar motivations as DTOs, which also are tuned for use cases. However, it may be more accurate to think of a set of RESTful resources as a separate model in their own right—a View Model or Presentation Model [Fowler, PM]. Resist the temptation to produce representations that are a one-to-one reflection of your domain model Aggregate states, possibly with links to navigate to deeper state. Otherwise your clients will have to understand ...