Symfony 2 dependency injection - php

Question

I'm learning symfony 2 dependency injection system. I'm trying to inject Response object in a controller.
ServiceController.php
namespace LD\LearnBundle\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
class ServiceController extends Controller
{
public function indexAction(Response $response)
{
}
}
Here is the content of services.yml file (please note that it's included in app/config/config.yml
services:
ld_response:
class: Symfony\Component\HttpFoundation\Response
ld_bla:
class: LD\LearnBundle\ServiceController
arguments: ["#ld_response"]
When I try to access ServiceController I get
Class LD\LearnBundle\Controller\Response does not exist
500 Internal Server Error - ReflectionException
What I'm doing wrong?

Answer 1

There are 2 things wrong here:
1: "Class LD\LearnBundle\Controller\Response does not exist"
The class doesn't exist. You used Response without importing the namespace, so the error message is quite explicit here.
2: You shouldn't inject the response. It doesn't make any sense at all. The response is not a service, it's a value that should be passed down through method parameters.

Answer 2

Here's the fix:
namespace LD\LearnBundle\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Response; // was missing
class ServiceController extends Controller
{
public function indexAction()
{
return new Response(); // The Controller is responsible of creating the Response.
}
}
Generally, Class <current-namespace>\class does not exist errors hint to a missing use statement.
May I add that:
you shouldn't declare your services in the app/config/config.yml file (create a specific services.yml file. Even better: create it in a bundle)
you shouldn't inject the Response object: it is the responsibility of the controller to create it