Autowired Controllers as Services for Lazy People

2016-03-10

Disclaimer: Why even use controllers as services?

The goal of this article is not to discuss pro and cons of "controller as service" (further CAS) approach. If you haven't decided yet to use CAS, I recommend checking these articles:

• Symfony2: Make my Controllers Services? [released 2013 by KNPUniversity]
• Symfony2: How to create framework independent controllers? [released 2014]
• Symfony2: Controller as Service [released 2011]

But now, back to the topic.

Autowire service? Easy!

With autowire feature, managing dependencies for services is now as simple as:

services:
    post.publisher:
        class: PostPublisher
        autowire: true # all you got to do is add this line

Autowire controller? Hell!

Managing dependencies for controllers in same way is complicated. To apply the same effect, you have to make following 3 steps:

1. Register controller manually as service to the config

   # app/config/services.yml
   services:
       post_controller: # you have to use this name everywhere, so pick it wisely
           class: PostController
           autowire: true

2. Add @Route annotation with service name

   // src/AppBundle/Controller/PostController.php
   namespace AppBundle\Controller\PostController;
   
   use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
   
   /**
    * @Route(service="post_controller") # watch for typo here!
    */
   class PostController
   {
       public function listAction()
       {
       }
   }

   or route using service name:

   # app/config/routing.yml
   post_list:
       path: /post-list
       defaults:
           _controller: post_controller:listAction
           # and not bundle like approach
           # _controller: AppBundle:Post:list

   This difference is so difficult to spot, that it created question on StackOverflow.

3. Finally, you have to use service name and single colon for referring:

   // any controller
   $this->forward('post_controller:listAction'));

There is nice answer on StackOverflow explaining with more details.

This process is exhausting already and difficult to remember.

Did you make it? Here comes much deeper hell

Even if you do manage to finish these steps, these issues will appear:

• drawback of FrameworkBundle, when it tries to autowire controller

  

• it's complicated to apply constructor dependency injection for extended 3rd party controllers (Sonata, FOS...), due to missing step 2 and 3 (that were mentioned above) and the "bundle naming" inside the bundle's code

Is there some way back from hell to heaven?

Author of autowiring feature and Symfony core contributor Kévin Dunglas sees similar problem and proposes solution with ADR pattern. I think it's the right direction, but it bends controllers too much.

But the goal is to keep controllers' code without touching.

Autowiring in Controllers

This is wheremade Symplify\ControllerAutowire bundle helps. It solves problems mentioned above.

How does it work?

• find controllers in /src directory
• register them as services
• autowire its constructors
• handle routing properly for both "service name" and "bundle name" approaches
• and all on compile time

Let's try it together.

1. Install package

composer require symplify/controller-autowire

2. Register bundle

// app/AppKernel.php
class AppKernel extends Kernel
{
    public function registerBundles()
    {
        $bundles = [
            new Symplify\ControllerAutowire\SymplifyControllerAutowireBundle(),
            // ...
        ];
    }
}

3. Add some dependency for your controller via constructor

// src/AppBundle/Controller/DefaultController.php
namespace AppBundle\Controller;

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Symfony\Component\HttpFoundation\Request;

class DefaultController extends Controller
{
    /**
     * @var EventDispatcherInterface
     */
    private $eventDispatcher;

    public function __construct(EventDispatcherInterface $eventDispatcher)
    {
        $this->eventDispatcher = $eventDispatcher;
    }

    /**
     * @Route("/", name="homepage")
     */
    public function indexAction(Request $request)
    {
        $this->eventDispatcher->dispatch('someEvent');

        return $this->render('default/index.html.twig', [
            // ...
        ]);
    }
}

And that's it!

For further use, just check Readme for Symplify/ControllerAutowire.

Happy coding!