title: Symfony2: How to create event listener thru entity annotations?
body: <p>I would like to have custom annotations on my entity that will do something on <code>persist</code> event, but defined thru annotations. An example:</p>
  
  <pre><code>/**
  * @ORM\Entity
  * @Searchable("column"="title")
  */
  class Product
  {
  
  }
  </code></pre>
  
  <p>That <code>@Searchable</code> annotation should somehow trigger my code that will read column <code>title</code>, separate words and save into its own table (much simplified example of what I really need).</p>
  
  <p>I am aware I can use doctrine listeners and register them in config.yml but I really need this to be done thru entity annotations so that <code>searchable</code> bundle could be easily reused thru different projects. I read tons of docs, even tried to understand Gedmo behaviours bundle code but I failed. Can somehow show me how to do this, in an idiot-proof way?</p>
  
  <p>I even read <a href="http://php-and-symfony.matthiasnoback.nl/2011/12/symfony2-doctrine-common-creating-powerful-annotations/" rel="nofollow">http://php-and-symfony.matthiasnoback.nl/2011/12/symfony2-doctrine-common-creating-powerful-annotations/</a> but that was kinda too complicated.</p>