'Call to a member function get() on a non-object'?

Question

Using symfony2. I have a listener class that is attempting to call a method from a different class (a controller) like so:

        $authenticate = new Authe         


        

Answer 1

I'm adding another answer because what @dev-null-dweller suggests is a bad practice: in almost every case you better to inject only the services you need — not the whole container:

use Doctrine\DBAL\Connection;

public function __construct(Connection $connection)
{
    $this->connection = $connection;
}

my_listener:
    arguments: [ @database_connection ]

Answer 2

Symfony2 uses Dependency Injection pattern, you have to inject container that holds all services (like database connection):

$authenticate = new AuthenticationController();
$authenticate->setContainer($this->container);
$authenticate->isTokenValid($token);

Of course I assume here that your listener class is ContainerAware

[+] To make your listener ContainerAware, pass @service_container to it (example form services.yml)

my.listener:
    class: ACME\MyBundle\ListenerController
    arguments: [ @service_container ]
    tags:
        - { name: kernel.event_listener, event: kernel.controller, method: onKernelController }
    kernel.event_listener:
        event: kernel.controller

and then in constructor of you listener class:

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