title: Set Default value of choice field Symfony FormType
body: <p>I want from the user to select  a type of questionnaire, so I set a select that contains questionnaires types.</p>
  
  <p>Types are loaded from a an entity <code>QuestionType</code> .</p>
  
  <pre><code> $builder
          -&gt;add('questionType', 'entity', array(
                'class'    =&gt; 'QuizmooQuestionnaireBundle:QuestionType',
                'property' =&gt; 'questionTypeName',
                'multiple' =&gt; false,
                'label' =&gt; 'Question Type'))
          -&gt;add('type', 'hidden')
      ;
  </code></pre>
  
  <p>What am not able to achieve is to set a default value to the resulted select. </p>
  
  <p>I have googled a lot but I got only <a href="http://symfony.com/doc/current/reference/forms/types/entity.html#preferred-choices" rel="nofollow">preferred_choice solution</a> which works only with arrays </p>