Unable to access Symfony2 container in controller extending Symfony\Bundle\FrameworkBundle\Controller\Controller

Question

Original Question

I've read every page of the "book" about service containers, and I'm still baffled because things seem to randomly not work nearly every time I try to use $this->container. For example, I'm building a form in my custom bundle controller following the instructions.

My controller extends the base controller as usual:

namespace Gutensite\ArticleBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Gutensite\ArticleBundle\Entity\Article;

class AdminEditController extends Controller
{

    public function indexAction() {


        $content = new Article();
        $form = $this->createFormBuilder($content)
             ->add('content', 'text');

        // same issue with the shortcut to the service which I created according the instructions
        // $form = $this->createForm('myForm', $myEntity)

        //...more code below...
    }
}

This produces an error:

Fatal error: Call to a member function get() on a non-object in /vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/Controller/Controller.php on line 176

If we look at that file at that line number we see Symfony's code:

public function createFormBuilder($data = null, array $options = array())
{
    return $this->container->get('form.factory')->createBuilder('form', $data, $options);
}

So WHY is symfony's own controller NOT able to access the container->get() function?!

What am I doing wrong?

Along these same lines, I can't figure out why sometimes I can't access the container via $this->container in my own controller (if extend the framework controller or if I reference it by passing it in the construct, etc). It seems random...

---

Background of Project and Structure of Code

I am building a CMS that has user's routes (URLs) stored in a database. So I have one route defined which directs all requests to my main CMS Controller:

gutensite_cms_furl:
# Match Multiple Paths (the plain / path appears necessary)
path:     /
path:     /{furl}
defaults: { _controller: GutensiteCmsBundle:Init:index }
# Allow / in friendly urls, through more permissive regex
requirements:
    furl: .*

The InitController looks up the requested URL and gets the correct Route entity which points to a View entity that defines which Bundle and Controller to load for specific page type being requested, e.g. the route for /Admin/Article/Edit points to content type that is associated with the Article bundle and AdminEdit controller, which then creates a new object for this content type (Gutensite\ArticleBundle\Controller\AdminEditController.php) and executes the required functions. This then injects the necessary variables back into the main ViewController which gets passed to the template to be rendered out to the page.

This main controller extends symfony controller and I have confirmed that the container is accessible in this controller, e.g. $this->container->get('doctrine') works.

// Gutensite\CmsBundle\Controller\InitController.php
namespace Gutensite\CmsBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Gutensite\CmsBundle\Entity;

class InitController extends Controller
{
    public function indexAction(Request $request, $furl)
    {
        // Confirm container is accessible (yes it is)
        $test = $this->container->get('doctrine');

        // Look up the View Entity based on the Route Friendly URL: $furl
        $viewController = $this->container->get('gutensite_cms.view');
        $viewController->findView($furl, $siteId);

        // Load the Requested Bundle and Controller for this View
    $path = $viewController->view->namespace_controller."\\".$viewController->view->controller;
    $content = new $path;
        // Execute the main function for this content type controller, which adds variables back into the $viewController to be passed to the template.
    $content->indexAction($viewController);

        return $this->render(
        $viewController->view->bundle_shortcut.'::'.$viewController->view->getTemplatesLayout(),
            array('view' => $viewController)
    );


    }
}

FYI, the ViewController is defined as a global service:

services:
    gutensite_cms.view:
        class: Gutensite\CmsBundle\Controller\ViewController
        arguments: [ "@service_container" ]

And then Below is a simplified version of the Gutensite/CmsBundle/Controller/ViewController.php

namespace Gutensite\CmsBundle\Controller;
use Doctrine\ORM\EntityManager;
use Symfony\Component\DependencyInjection\ContainerInterface as Container;

class ViewController
{

    protected $container;
    public $routing;
    public $view;

    public function __construct(Container $container) {
        $this->container = $container;
    }

    public function findView($furl, $siteId=NULL) {
        $em = $this->container->get('doctrine')->getManager();
        $this->routing = $em->getRepository('GutensiteCmsBundle:Routing\Routing')->findOneBy(
            array('furl'=>$furl, 'siteId'=>$siteId)
        );

        if(empty($this->routing)) return false;

        // If any redirects are set, don't bother getting view
        if(!empty($this->routing->getRedirect())) return FALSE;

        // If there is not view associated with route
        if(empty($this->routing->getView())) return FALSE;

        $this->view = $this->routing->getView();
        $this->setDefaults();
    }
}

Back in the InitController.php we retrieved the view object and loaded the right bundle and controller function. In this case it loaded `Gutensite\ArticleBundle\Controller\AdminEditController.php which is where we lose access to the service container.

namespace Gutensite\ArticleBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Gutensite\ArticleBundle\Entity\Article;

class AdminEditController extends Controller
{

    protected $request;

    public function __contstruct(Request $request) {
        $this->request = $request;
}


public function indexAction($view)
    {
    // TEST: Test if I have access to container (I do not)
    //$doctrine = $this->container->get('doctrine');

        // This loads createForm() function from the Symfony Controller, but that controller then doesn't have access to container either.
        $form = $this->createForm('view', $content);

    }
}

More Specific Question

So I ASSUMED that if you extend the Symfony Controller, which itself extends ContainerAware, that the object would be "aware of the container". But that evidently is not the case. And that is what I need to understand better. I assume somehow the container has to be injected manually, but why? And is that the standard method?

Answer 1

Ok. Your assumption that merely making an object ContainerAware will automatically cause the container to be injected is incorrect. The PHP new operator does not know anything about dependencies. It's the job of the dependency injection container to take care of automatically injecting stuff. And of course your are not using the container to create your controllers.

Easy enough to fix:

$path = $viewController->view->namespace_controller."\\".$viewController->view->controller;
$content = new $path;
$content->setContainer($this->container);
$content->indexAction($request,$viewController);

I don't really follow your flow. The view stuff seems kind of backwards to me but I trust you can see where and how the container is injected into a Symfony controller. Don't do anything in the controller's constructor which relies on the container.

===============================================================

Instead of using the new operator, you could use the service container.

$contentServiceId = $viewController->view->contentServiceId;
$content = $this->container->get($contentServiceId);
$content->indexAction($request,$viewController);

Instead of having you view return a class name, have it return a service id. You then configure your controller in services.yml and off you go. This cookbook entry might help a bit: http://symfony.com/doc/current/cookbook/controller/service.html

=============================================================

All ContainerAware does is to make the Symfony DependencyInjectContainer inject the container. Nothing more. Nothing less. You might conside reading through here: http://symfony.com/doc/current/components/dependency_injection/index.html just to get basic idea of what dependency injection and dependency injector container are all about.