Monolog in Symfony from non-controller Class - symfony

Question

I have the following class:
namespace AppBundle\EventListener;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use FOS\UserBundle\Event\UserEvent;
use FOS\UserBundle\FOSUserEvents;
use FOS\UserBundle\Event\FormEvent;
class UserRegistrationListener implements EventSubscriberInterface
{
protected $logger;
public function __construct($logger)
{
$this->logger = $logger;
}
public static function getSubscribedEvents()
{
return array(
FOSUserEvents::REGISTRATION_INITIALIZE => 'onRegistrationInit',
);
}
/**
* take action when registration is initialized
* set the username to a unique id
* #param \FOS\UserBundle\Event\FormEvent $event
*/
public function onRegistrationInit(UserEvent $userevent)
{
$this->logger->info("Log Something");
$user = $userevent->getUser();
$user->setUsername(uniqid());
}
}
and I have been trying for hours to log something with monolog from within it but have had no luck.
I have read much of the documentation and I believe I need to somehow 'Inject' monolog as a service. What I have read however does not seem to be clear to me.
Some details:
#config_dev.yml
monolog:
channels: [chris]
handlers:
mylog:
type: stream
path: "%kernel.logs_dir%/%kernel.environment%_chris.log"
channels: chris
formatter: monolog.my_line_formatter
.
#services.yml
services:
monolog.my_line_formatter:
class: Monolog\Formatter\LineFormatter
arguments: [~, ~, true]
app.user_registration:
class: AppBundle\EventListener\UserRegistrationListener
arguments: [#logger] ## changed to [#monolog.logger.chris] to us custom channel
tags:
- { name: kernel.event_subscriber }
What do I have to do to get Monolog working with my formatter inside this class?
UPDATE:
#griotteau I have done what you have posted in your answer but I still get an error:
CRITICAL - Uncaught PHP Exception Symfony\Component\Debug\Exception\ContextErrorException: "Warning: Missing argument 1 for AppBundle\EventListener\UserRegistrationListener::__construct(), called in ...filepath...\app\cache\dev\appDevDebugProjectContainer.php on line 384 and defined" at ...filepath...\src\AppBundle\EventListener\UserRegistrationListener.php line 18
SOLVED ERROR I already had a service with the same class (not shown in ym question). #griotteau 's answer is correct.

Answer 1

You can pass arguments when you declare your service
In services.yml :
app.user_registration:
class: AppBundle\EventListener\UserRegistrationListener
arguments: [#logger]
tags:
- { name: kernel.event_subscriber }
In your class, add a constructor :
protected $logger;
public function __construct($logger)
{
$this->logger = $logger;
}
So when you want to add a log :
$this->logger->info(...);