Symfony3 return array from query to json -

i have problem, can't return posts array json becouse symfony returns array entity object?

its code:

public function indexaction() {     $em = $this->getdoctrine()->getmanager();      $posts = $em->getrepository('appbundle:post')->findall();      return $this->json($posts); } 

i use $this->json return json data, feature added on sf3. result:

[     {},     {},     {} ] 

i want load posts.

ps. know, can use query builder, , method toarray or something, method use , dry? thx

a best solution enable serializer component in symfony:

#app/config/config.yml framework:    serializer:      ~ 

note: serializer component disabled default, have uncomment config line in app/config/config.yml file.