title: Set default display value for Symfony2 form field
body: <p>I've got a form with some display only fields in it. These fields are usually DateTime values... but when empty/null I would like to display the string "never".</p>
  
  <p>EDIT:<br>
  To be more explicit: The field should show the DateTime value from the database and if null the string 'never' should be displayed.</p>
  
  <p>How should I do that?</p>
  
  <p>Thanks in advance</p>