title: Doctrine2 __constructor not called when using $em->find(); ? How to load entity properly?
body: <p>I'm learning doctrine2, and having a problem how to call constructor automatically.
  For example, in my entity I have</p>
  
  <pre><code>/**
   * @Entity
   */
  class User{
     ....
     public function __construct() {
         exit('in');
     }
  }
  </code></pre>
  
  <p>and when I get the object this way:</p>
  
  <pre><code>$userObj = $em-&gt;find('User', 1);
  </code></pre>
  
  <p>I do get that object from database, but constructor is never called. 
  I want to put some common things in constructor, like validation rules, or even to put sample code from the doctrine documentation like</p>
  
  <pre><code>        $this-&gt;comments = new ArrayCollection();
  </code></pre>
  
  <p>This ofcourse works when I create new object in code for creating a user like</p>
  
  <pre><code>$user = new User(); //now constructor works just fine
  </code></pre>
  
  <p>Now, what is the "proper" way of getting the entity? I doubt I have to call constructor manually each time I user $em->find() with $user0bj->__construct(); ? This would kinda sucks then... Or I should use something other then ->find() to get single entity properly?
  I know I can user @PrePersist, and I am using it to actually do validation checks etc. 
  I guess that I'm probably missing something here, or I'm trying to use constructor in a poor way. Thanks for any explanations and guides!</p>