Domain Modeling Aggregates

Aggregates

Aggregate is a cluster of domain objects that can be treated as a single unit.
-- Martin Fowler

Creating a Value Object is quite easy you only need to use the Trait IsAggregate this will add the HasAttributes, HasInvariants, HasDomainEvents, HasIdentity and HasEquality Traits. In addition, you could use the Aggregate interface to expose the publishDomainEvents method.

The following example illustrates the implementation of these components.