php - symfony An exception has been thrown during the rendering of a template -

i new in symfony , trying display form using acme/librarybundle.

but there error

"an exception has been thrown during rendering of template ("unable generate url named route "book_new" such route not exist.") in acmelibrarybundle:book:new.html.twig @ line 3."

my form

<form action="{{ path('book_new') }}" method="post" {{ form_enctype(form) }}>     {{ form_widget(form) }}      <input type="submit" /> </form> 

my controller:

namespace acme\librarybundle\controller;  use symfony\bundle\frameworkbundle\controller\controller;  use acme\demobundle\model\book;  use acme\librarybundle\form\type\booktype;  class bookcontroller extends controller {     public function newaction()     {          $book = new book();         $form = $this->createform(new booktype(), $book);          /*$request = $this->getrequest();          if ('post' === $request->getmethod()) {             $form->handlerequest($request);              if ($form->isvalid()) {                 $book->save();                  return $this->redirect($this->generateurl('book_success'));             }         }*/          return $this->render('acmelibrarybundle:book:new.html.twig', array(                  'form' => $form->createview(),          ));      } } 

since book_new not exist in routing.yml, changed acme_library_homepage.

acme_library_homepage: path:     /test defaults: { _controller: acmelibrarybundle:book:new } 

before:

<form action="{{ path('book_new') }}" method="post" {{ form_enctype(form) }}> {{ form_widget(form) }}  <input type="submit" /> 

after

<form action="{{ path('acme_library_homepage') }}" method="post" {{ form_enctype(form) }}> {{ form_widget(form) }}  <input type="submit" />