Passing Entity Manager to Service Layer ZF Doctrine2

I'm trying to pass the entity man开发者_运维知识库ager to a service but havent find a correct way yet. I want to complete remove the em from the controller so thats why I'm finding another way.

I was thinking of this options: 1. I could save it in the registry and then try to access it from the service object. can I access the registry from there? 2. Inject the em to a static variable of a base class for the services in the bootstrap.

What is the correct way yo do it?

thanks

I think generally the best way to do it is to pass the entitymanager as an argument to the constructor.

This allows you to easily replace the entitymanager for example when doing unit tests, and unlike your approaches of 1 and 2, it does not depend on behavior in a base class or global data (the registry is a lot like a global variable)

What you could do to avoid touching the EM in your controllers is using a dependency injection container, such as the one in Symfony2 or the one in ZF2 (not sure if that component is very stable yet).

Another perhaps slightly simpler approach would be to have a sort of a "service locator" object, which you would use in the controller to get instances of your services. You could initialize the locator in your bootstrap with the services, or perhaps with a factory class which creates them.

In any case you will probably require at least some kind of an intermediate object in the controller. Personally I don't really see an issue with simply using the EM itself, unless you have some other reasons besides just not wanting to.

There's nothing wrong, IMO, with letting your controllers know about the EM. I typically use a Zend_Application_Resource to bootstrap Doctrine. That resource facilitates a bootstrap resource called "doctrine" which has an EM available. The abstract controller implements and em() method, which returns the EM.

When instantiating service classes, the constructor simply injects the EM via a call to $this->em() at constructor time.

This is nice, as many times, simple controller actions don't need any special service class, but can instead get away with doing $entity = $this->em()->getRepository('Some\Entity')->find(1); In those cases, I don't see any reason for additional redirection via a service class.