title: Symfony2 : form : pre_submit orders
body: <p>I have 2 forms. One is the main form with fields and a collection and inside this fields the other form. On each form (the parent and the child) I add a PRE_SUBMIT subscriber. Now, my problem is, I want to load a method specific to the parent form after execution of the PRE_SUBMIT on the child event.
  Actually, following the documentation, in spite I give priority, I have always this order :
  <code>parent::PRE_SUBMIT -&gt; child::PRE_SUBMIT</code>
  and by the way I want :
  <code>parent::PRE_SUBMIT -&gt; child::PRE_SUBMIT -&gt; parent::PRE_SUBMIT(other)</code>
  Do you have an idea if it's possible to do that and in what way ?</p>