symfony - Symfony2 My custom form field type isn't populated with data from entity -

i created simple custom field

class inputwithdescriptiontype extends abstracttype { public function configureoptions(optionsresolver $resolver) {     $resolver->setdefaults(array(         'description'         => '',     ));  }  public function buildform(formbuilderinterface $builder, array $options) {    $builder        ->setattribute('description', $options['description'])    ; }  public function buildview(formview $view, forminterface $form, array $options) {     $view->vars['description'] = $options['description']; }  public function getparent() {     return 'text'; }  public function getname() {     return 'input_with_description'; } } 

and added form

$builder         ->add('name')         ->add('about', 'input_with_description', array(             'description' => "description",             'label' => "label",         )) 

when submitting form data saved when try edit entity using form custom fields empty. may problem be?

public function configureoptions(optionsresolver $resolver)     {         $resolver->setdefaults(array(             'data_class' => 'appbundle\entity\product'         ));     } 

replace 'appbundle\entity\product' entity class.