Domain-Driven Design in PHP

Domain Services and Infrastructure Services

It's common to encounter infrastructural dependencies when modeling a Domain Service  — for example, in the case where an authentication mechanism that handles password hashing is required. In this instance, you could use a Separated Interface, which allows for multiple hashing mechanisms to be defined. Using this pattern still provides you with a clear Separation of Concerns between the Domain and the Infrastructure:

namespace Ddd\Auth\Domain\Model;interface SignUp{    public function execute($aUsername, $aPassword);}

Using the preceding interface found in the Domain, we could create an implementation in the Infrastructure layer, like the following:

 namespace Ddd\Auth\Infrastructure\Authentication; ...