The Specification pattern applied to a Repository

The Specification pattern consists of reusable business rules which can be composed together and evaluated against one or multiple candidates.

When used with the Repository pattern, the specification is used to query a datasource.

Note	Github don’t supports the AsciiDoc include directive for some obscure reasons, as a result, you won’t be able to see the code blocks below 🤦 An issue is pending on the Github repository to fix that behavior.

Simple use case

Let’s consider a simple User model:

link:src/Domain/Model/User.php[role=include]

Given we want to find all User matching a business Specification, we declare the following interface:

link:src/Domain/Repository/UserRepository.php[role=include]

With the following list of users:

link:tests/UserRepositoryTest.php[role=include]

When combining…​

the IsActive specification

link:src/Domain/Specification/IsActive.php[role=include]

with the WithRole specification

link:src/Domain/Specification/WithRole.php[role=include]

Then should obtains a list of admin User which are active

link:tests/UserRepositoryTest.php[role=include]