Symfony2 - Autowiring Services with the Controller - php

Question

I am able to use the new autowire feature of Symfony2 to inject a service into a service. However, I cannot inject a service into a controller. What am I not doing/doing wrong?
This is my services.yml file:
services:
home_controller:
class: AppBundle\Controller\HomeController
autowire: true
This is my ServiceConsumerDemo:
namespace AppBundle\Services;
class ServiceConsumerDemo {
private $serviceDemo;
public function __construct(ServiceDemo $serviceDemo) {
$this->serviceDemo = $serviceDemo;
}
public function getMessage(){
return $this->serviceDemo->helloWorld();
}
}
This is ServiceDemo:
namespace AppBundle\Services;
class ServiceDemo
{
public function helloWorld(){
return "hello, world!";
}
}
This is HomeController (which works):
namespace AppBundle\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
class HomeController extends Controller
{
/**
* #Route("/")
*
*/
public function indexAction(Request $request)
{
$message[0] = $this->get('service_consumer_demo')->getMessage();
return new \Symfony\Component\HttpFoundation\JsonResponse($message);
}
}
This is HomeController which does not work
namespace AppBundle\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use AppBundle\Services\ServiceConsumerDemo;
class HomeController extends Controller
{
private $serviceConsumerDemo;
public function __construct(ServiceConsumerDemo $serviceConsumerDemo) {
$this->serviceConsumerDemo = $serviceConsumerDemo;
}
/**
* #Route("/", name="homepage")
*
*/
public function indexAction(Request $request)
{
$message[0] = $this->serviceConsumerDemo->getMessage();
return new \Symfony\Component\HttpFoundation\JsonResponse($message);
}
}
This is the error thrown:
Catchable Fatal Error: Argument 1 passed to
AppBundle\Controller\HomeController::__construct() must be an instance
of AppBundle\Services\ServiceConsumerDemo, none given,
How do I access the Services in the Controller? I understand I need to declare the controller as a service. So I'm mentioning the controller in the services.yml file. Is there anything else that I need to do?

Answer 1

By default, controllers are not considered as services, so you can't use autowiring with them.
However, it's a simple enough fix - add a #Route annotation on the class (i.e. not on an action method in the class) with a service definition.
From the documentation:
The #Route annotation on a controller class can also be used to assign
the controller class to a service so that the controller resolver will
instantiate the controller by fetching it from the DI container
instead of calling new PostController() itself.
For example:
/**
* #Route(service="app_controller")
*/
class AppController extends Controller
{
private $service;
public function __construct(SomeService $service)
{
$this->service = $service;
}
/** #Route("/") */
public function someAction()
{
$this->service->doSomething();
}
}
and in your config:
app_controller:
class: AppBundle\Controller\AppController
autowire: true

Answer 2

Symfony 3.3+ May 2017 UPDATE!
Symfony 3.3 allows native way to approach this.
# app/config/services.yml
services:
_defaults:
autowire: true # all services in this config are now autowired
App\: # no more manual registration of similar groups of services
resource: ../{Controller}
This means App\Controller\SomeController is autowired by default and to be found in app/Controller/SomeController.php file.
You can read:
more about _defaults here
and more about PSR-4 service registration
Thanks to autowiring in Symfony 2.8+ I could create bundle, that adds autowiring even for controllers: Symplify/ControllerAutowire
You can read more about this in the article.
Usage is as simple as:
class YourController
{
public function __construct(SomeDependency $someDependency)
{
// ...
}
}
Nothing more is required.

Answer 3

You do not pass service to your controller in services.yml. Change it to:
services:
service_demo:
class: AppBundle\Services\ServiceDemo
service_consumer_demo:
class: AppBundle\Services\ServiceConsumerDemo
autowire: true
home_controller:
class: AppBundle\Controller\HomeController
autowire: true
arguments:
service: "#service_consumer_demo"