title: symfony3 same validation for model and admin form
body: <p>I'm using FOS User Bundle and <a href="http://It&#39;s%20http://symfony.com/doc/current/bundles/SonataAdminBundle/index.html" rel="nofollow noreferrer">Sonata Admin Bundle</a>.
  I have validation in model like:</p>
  
  <pre><code> //src\AppBundle\Entity\User.php
   //class User extends BaseUser
   /**
   * @var string
   * @Assert\NotBlank(
   *     message = "xxx"
   * )
   * @ORM\Column(name="address", type="text")
   */
  private $address;
  </code></pre>
  
  <p>I want to use same validation in my AdminController - is there any option how to inherit model's validation? Now I must do it like:</p>
  
  <pre><code>//src\AppBundle\Admin\UserAdmin.php
  //class UserAdmin extends AbstractAdmin
  public function validate(ErrorElement $errorElement, $object)
  {
      $errorElement
          -&gt;with('address')
          -&gt;assertNotBlank()
          -&gt;end();
  }
  </code></pre>