title: Doctrine Listener versus Subscriber
body: <p>I'm working in the Symfony2 framework and wondering when would one use a Doctrine subscriber versus a listener.  Doctrine's <a href="http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/events.html">documentation</a> for listeners is very clear, however subscribers are rather glossed over.  Symfony's <a href="http://symfony.com/doc/current/cookbook/doctrine/event_listeners_subscribers.html">cookbook entry</a> is similar.</p>