13: Factories

Chapter Roadmap

Learn why the use of Factories can produce expressive models that adhere to Ubiquitous Language
See how factory methods can be used as Aggregate Behaviors
Consider how to use Factory Methods to create Aggregate instances of their types
Learn how Domain Services can be designed as Factories while interacting with other Bounded Contexts and translating foreign objects to local types.

Shift the responsibility of creating instances of complex objects and Aggregates to a separate object.
Even if these objects have no responsibility in the domain model, they are still part of the domain model.
Factories provide an interface that encapsulates complex assembly without requiring the client to reference concrete classes of objects instantiated.
Factories can create an entire Aggregates as a piece while enforcing their invariants.
An aggregate root that provides a Factory for another Aggregate type will have the primary responsibility of providing main aggregate behavior, the Factory being just one of those.
Factory Methods on aggregates allow you to express the Ubiquitous Language in way not possible through constructors.
When the behavioral name is expressive with respect to the Ubiquitous Language, we have a powerful case for using a Factory Method.

Last updated 28 days ago

Learn why the use of Factories can produce expressive models that adhere to Ubiquitous Language
See how factory methods can be used as Aggregate Behaviors
Consider how to use Factory Methods to create Aggregate instances of their types
Learn how Domain Services can be designed as Factories while interacting with other Bounded Contexts and translating foreign objects to local types.

Shift the responsibility of creating instances of complex objects and Aggregates to a separate object.
Even if these objects have no responsibility in the domain model, they are still part of the domain model.
Factories provide an interface that encapsulates complex assembly without requiring the client to reference concrete classes of objects instantiated.
Factories can create an entire Aggregates as a piece while enforcing their invariants.
An aggregate root that provides a Factory for another Aggregate type will have the primary responsibility of providing main aggregate behavior, the Factory being just one of those.
Factory Methods on aggregates allow you to express the Ubiquitous Language in way not possible through constructors.
When the behavioral name is expressive with respect to the Ubiquitous Language, we have a powerful case for using a Factory Method.

Last updated 28 days ago