When creating a form, I get an error. Expected argument of type "string", "AppBundle \ Form \ BookType" given

500 Internal Server Error - UnexpectedTypeException

public function newAction(Request $request) { $book = new Book(); $form = $this->createForm(new BookType(), $book); $form->handleRequest($request); if ($form->isSubmitted() && $form->isValid()) { $em = $this->getDoctrine()->getManager(); $em->persist($book); $em->flush(); return $this->redirectToRoute('book_show', array('id' => $book->getId())); } return $this->render('book/new.html.twig', array( 'book' => $book, 'form' => $form->createView(), )); } class BookType extends AbstractType { /** * @param FormBuilderInterface $builder * @param array $options */ public function buildForm(FormBuilderInterface $builder, array $options) { $builder ->add('name', 'text') ; } /** * @param OptionsResolver $resolver */ public function configureOptions(OptionsResolver $resolver) { $resolver->setDefaults(array( 'data_class' => Book::class, )); } /** * @return string */ public function getName() { return 'book_form'; }

    1 answer 1

    In Symfony3, you can no FormType pass a FormType as an object; you must always pass the full class name. In your case, you need to pass so

     $form = $this->createForm(BookType::class, $book);