June 2017
Intermediate to advanced
394 pages
8h 52m
English
Content preview from Domain-Driven Design in PHP
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What Martin Fowler Says...
From http://martinfowler.com/bliki/DDD_Aggregate.html:
Aggregate is a pattern in Domain-Driven Design. A DDD aggregate is a cluster of domain objects that can be treated as a single unit. An example may be an order and its line-items, these will be separate objects, but it is useful to treat the order (together with its line items) as a single aggregate.
An aggregate will have one of its component objects be the aggregate root. Any references from outside the aggregate should only go to the aggregate root. The root can thus ensure the integrity of the aggregate as a whole.
Aggregates are the basic element of transfer of data storage you request to load or save whole aggregates. Transactions should not cross aggregate ...