Add listener config to EventManager

[alanpoulain]

This PR adds the possibility to have configuration when adding a listener to the event manager.

For now, it contains only a method: when a method is defined, it is used instead of the event name to call the listener.

It will allow to define a custom method when adding a listener for instance in Symfony:

    App\EventListener\FooListener:
        tags:
            - { name: 'doctrine.event_listener', event: preSoftDelete, connection: custom_connection, method: onDelete }

[derrabus]

Thank you for your PR. However, I don't really feel we need this change, to be honest. Those listener objects are a piece of glue code solely meant to be consumed by the EventManager. Why would I want to change the method name?

[alanpoulain]

I'm not sure to follow, those listeners can be declared outside. See for instance https://symfony.com/doc/current/doctrine/events.html#doctrine-lifecycle-listeners.

And if you want to see the related code:
https://github.com/symfony/doctrine-bridge/blob/9431a37baaa77a6e232c37c0564e900793f77c25/DependencyInjection/CompilerPass/RegisterEventListenersAndSubscribersPass.php#L102

Changing the method name can be useful to convey what the method does. Also it follows what can be done with the entity listeners.

[derrabus]

Changing the method name can be useful to convey what the method does.

Sure, then have the handling method with the ugly event name call another method with a name that you can pick.

class MyListener
{
    public function someEvent($eventArgs)
    {
        $this->doSomethingVeryUseful($eventArgs);
    }

    public function doSomethingVeryUseful($eventArgs)
    {
        // your handling logic goes here.
    }
}

Also it follows what can be done with the entity listeners.

Okay, but we apparently did not need to change EventManager to implement that feature. Why is it suddenly necessary for the feature that you have in mind?

[alanpoulain]

Sure it can be done like this but I thought it would be better to have the possibility to explicitly configure it than having a dynamic call by convention.

Okay, but we apparently did not need to change EventManager to implement that feature. Why is it suddenly necessary for the feature that you have in mind?

The entity listeners do not use the EventManager, they use this class:
https://github.com/doctrine/orm/blob/3.3.x/src/Tools/AttachEntityListenersListener.php