ddd-service

I've been starting to learn about DDD and I have couple of questions so that I can improve my understanding of it. So a typical DDD architecture looks like this Domain Layer => this layer should be technology agnostic and should contain the following Domain.Entities (different from the persistence layer Entities, should contain only validation rules ? any other domain business should go here?) Domain.ValueObjects (objects that do not require to be unique in the domain, should contain only validation rules) Domain.Services (this layer should contain business logic that although related to an

I am in the process of refactoring an application and am trying to figure out where certain logic should fit. For example, during the registration process I have to check if a user exists based upon their email address. As this requires testing if the user exists in the database it seems as if this logic should not be tied to the model as its existence is dictated by it being in the database. However, I will have a method on the repository responsible for fetching the user by email, etc. This handles the part about retrieval of the user if they exist. From a use case perspective, registration

I have a tree of Zone objects: class Zone { protected $parent; public function __construct(Zone $parent) { $this->parent = $parent; } } There are no children nor descendants property in the Zone, because I want to avoid the pain of managing these relationships in the domain model. Instead, a domain service maintains a closure table in the database, to map a zone to all its descendants, at any level. Now, I have a User which can be assigned one or more Zones: class User { protected $zones; public function assignZone(Zone $zone) { $this->zones[] = $zone; } } My problem is that, prior to