title: Symfony2 - How to validate autocomplete entity form type?
body: <p>I have a form with following fields:</p>
  
  <pre><code>$builder
      -&gt;add('title', 'text')
      -&gt;add('body', 'textarea')
      -&gt;add('tags', 'entity', [
          'class' =&gt; 'AppBundle\Entity\Tag',
          'choice_label' =&gt; 'name',
          'expanded' =&gt; false,
          'multiple' =&gt; true,
      ]);
  </code></pre>
  
  <p>User can select multiple tags. Everything works perfectly. But now when the numbers of tag become very large (over 20000 tags), page rendering become very slow because entity type loads all tag into selectbox. Therefore I implement a jQuery autocomplete selectbox to prevent loading all entity but when I submit the form, validator still loads all tags to validate! How can I solve this validation issue? Thank you!</p>