Symfony2.3 Better way to get EntityManager inside a Controller

Question

I'm using Symfony2.3 and I currently using EntityManager as shown inside __construct()

Which its a better aproach using EntityManager from __construct() or using inside each method ? as shown in public indexAction()

/**
 * QuazBar controller.
 *
 */
class QuazBarController extends Controller
{

    public function __construct()
    {
        $this->em = $GLOBALS['kernel']->getContainer()->get('doctrine')->getManager();
    }

    /**
     * Lists all QuazBar entities.
     *
     */
    public function indexAction(Request $request)
    {
        $session    = $request->getSession();
        $pagina     = $request->query->get('page', 1);
        $em         = $this->getDoctrine()->getManager();
    }

score 10 · Accepted Answer · edited Dec 12 '15 at 20:17

If you must have the EntityManager available in your constructor, a good way to get it is injecting it to the constructor.

To do this you must define your controller as a service.

# src/Acme/DemoBundle/Resources/config/services.yml
parameters:
    # ...
    acme.controller.quazbar.class: Acme\DemoBundle\Controller\QuazBarController

services:
    acme.quazbar.controller:
        class: "%acme.controller.quazbar.class%"
    # inject doctrine to the constructor as an argument
    arguments: [ @doctrine.orm.entity_manager ]

Now all you have to do is modify your controller:

use Doctrine\ORM\EntityManager;

/**
 * QuazBar controller.
 *
 */
class QuazBarController extends Controller
{

    public function __construct(EntityManager $em)
    {
        $this->em = $em;
    }
    // ...
}

If you do not require the Entity Manager in the constructor, you can simply get it using the Dependency Injection Container from any method in your controller:

$this->getDoctrine()->getManager();

OR

$this->container->get('doctrine')->getManager();

Controller/setter injection is a good choice because you are not coupling your controller implementation to the DI Container.

At the end which one you use is up to your needs.

Thanks, but if I have a many Controllers (50~) is not a good idea make all **Controller as a Service** right? — NBPalomino, Mar 03 '14 at 19:27
Like I said: "which one you use is up to your needs". Without knowing more about your specific project is difficult to advice how or what else you can do. You may need a base class or use a design pattern. I would just be consistent though out the code, so pick one and stick to it :). Please note that to me the way you are getting the EM in the constructor raises some red flags: the use of the `$GLOBALS` variable being one and the method chaining between multiple objects is another. — Onema, Mar 03 '14 at 19:54

score 0 · Answer 2 · answered Mar 03 '14 at 18:50

In symfony 2.3, I believe that a connection to the doctrine entity manager is built into the controller class.

$em = $this->getDoctrine()->getManager();

Best practice is to make this call in the controllers when you need it. If it's simply convenience, you could derive a controller class and add something like getEm() if you find that too odious.

Often, your own controller class is a good idea, for baking in security restrictions and making your code more DRY.

score 0 · Answer 3 · answered Mar 03 '14 at 19:15

Can we define a constructor in the controller class ? The doctrine is a service. Does it make any difference to get doctrine in constructor or to get wherever you want want it from di. Both ways you get the same service. Why do you want to inject the em that is already injected.

Symfony2.3 Better way to get EntityManager inside a Controller

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