The goal of Aggregate Store is to be a simple yet effective PHP ORM for domain-driven design aggregates.
It has been inspired by my experiences trying to use Doctrine for persisting DDD aggregates, and a recent discussion with Ross Tuck and Jeroen van der Gulik at a DomCode meetup.
This is an experiment. Use this software at your own risk.
- To make it relatively easy to map between aggregates and database records (yes, I know, the Vietnam of Computer Science)
- To offer a simple collection-oriented repository interface (with methods like
add(),get(),remove()), with a unit of work and changeset calculation behind the scenes - To avoid clutter / feature creep by keeping a narrow scope
The intended use case for this library is any PHP project that has to persist aggregates that are designed using the tactical domain-driven design patterns. The use of CQRS (separation between write model and read model) is assumed.
Because of this, the following assumptions are made:
- Repositories are being used to persist and retrieve (by ID) aggregates
- Aggregates are a cluster of domain objects that can be treated as a single unit. They are usually composed of one or more entities, and may also contain value objects
- All aggregates have one root entity (aggregate root) which owns all other elements inside the aggregate, and which will be persisted / retrieved by the repository
- Aggregates only reference other aggregates by identity; not by having an object reference
- Aggregates are designed to be relatively small; the full aggregate will be (eager) loaded into memory, there is no need for lazy loading
- Aggregates form a transactional consistency boundary: all elements within a single aggregate must be persisted in a single (database) transaction