Using Symfony's Form Event to remove some of the data sent to a form -

i have checkboxes , want find out items checked checkboxes , send them database. made this:

class notneededfieldssubscriber implements eventsubscriberinterface {     public static function getsubscribedevents()     {         return array(formevents::pre_bind => 'prebinddata');     }      public function prebinddata(formevent $event)     {             $data = $event->getdata();          $count = count($data['items']);          ($i=0; $i < $count; $i++){              if (!array_key_exists('enabled', $data['items'][$i])){                    unset($data['items'][$i]);                             }          }                 $event->setdata($data);      } } 

when test see $event->getdata has want.

in controller:

 $form = $this->formfactory->create(new itemtype(), $item);          if ($request->ismethod('post')) {             $form->bind($request);                            if ($form->isvalid()) {                        $this->em->persist($item);                     $this->em->flush();                 }         }          return $this->redirect($this->router->generate('home')); 

the problem still checked , unchecked items in database :(

any ideas why , how fix this? in advance! :)

as checkbox in fact collection, maybe should refer part of documentation : http://symfony.com/doc/current/cookbook/form/form_collections.html#allowing-tags-to-be-removed

specially "doctrine: ensuring database persistence" part. have manually remove enities still stored in database not in form anymore

        // filter $originaltags contain tags no longer present     foreach ($task->gettags() $tag) {         foreach ($originaltags $key => $todel) {             if ($todel->getid() === $tag->getid()) {                 unset($originaltags[$key]);             }         }     }      // remove relationship between tag , task     foreach ($originaltags $tag) {         // remove task tag         $tag->gettasks()->removeelement($task);          // if manytoone relationship, remove relationship         // $tag->settask(null);          $em->persist($tag);          // if wanted delete tag entirely, can         // $em->remove($tag);     }