Symfony Dependency injection with services - symfony-3.2

Question

Trying to create a service that logs information to a database. The service has to call the Doctrine\ORM\EntityManager in the constuctor, but I keep getting this error:
Catchable Fatal Error: Argument 1 passed to AppBundle\Service\EmailLoggerManager::__construct() must be an instance of Doctrine\ORM\EntityManager, none given, called in /Users/augustwhitlock/Desktop/symfony/SymfonyRepositories/forms/src/AppBundle/Controller/DefaultController.php on line 45 and defined
Here is what I have in my service file
namespace AppBundle\Service;
use Doctrine\ORM\EntityManager;
use AppBundle\Entity\Logger;
class EmailLoggerManager
{
private $em;
public function __construct(EntityManager $em)
{
$this->em = $em;
}
public function logMessageToDatabase($type, $message, $date)
{
$logger = new Logger();
$logger->setMessageType = $type;
$logger->setMessageText = $message;
$logger->setMessageDate = $date;
$this->em->persist($logger);
$this->em->flush();
}
This I how I'm handling the injection of the EntityManager.
app.email_logger_manager:
class: AppBundle\Services\EmailLoggerManager
arguments: ['#doctrine.orm.entity_manager']
At this point I'm just learning about service and trying different things out. But this doesn't want to work.
Here is the edit of the DefaultController. I'm adding lines 45 and 46. There is nothing about it except the class definition.
$emailLoggerManager = new EmailLoggerManager();
$emailLoggerManager->logMessageToDatabase('Info', 'Hiya', new \DateTime());
return new Response('Message Logged');
The whole concept behind the class is to just use doctrine in the service to log things to the database, clearing my controllers from having to be clogged of all that code.

Answer 1

You should call the service from the controller as follows:
$this->get('app.email_logger_manager')
->logMessageToDatabase('Info', 'Hiya', new \DateTime());
instead of instantiating the class directly in the controller.
Furthermore it is advisable to pass the "#doctrine" service instead of #doctrine.orm.entity_manager due to the possibility of the EntityManager being closed.
The constructor would than have to receive Doctrine\Bundle\DoctrineBundle\Registry instead of Doctrine\ORM\EntityManager