Symfony 3 subform submitted as array instead of entity

Question

I am in the middle of converting a project from Symfony 2 to Symfony 3 and have run into a problem. I have an Event entity that has a TwitterSearch entity which is defined by the following in Event.php:

   /**
    * @ORM\ManyToOne(targetEntity="TwitterSearch", cascade={"persist"})
    * @ORM\JoinColumn(name="twitter_search_id", referencedColumnName="id")
    */
    private $twitterSearch;

This is how I have set up the relationship in the EventType:

    $builder->add('twitterSearch', TwitterSearchType::class, array(
        'required'=>false,
    ));

Here is the code from the controller for when the form is submitted:

    $entity = new Event();
    $form = $this->createCreateForm($entity);
    $form->handleRequest($request);

    if ($form->isValid()) { 
       $entity = $form->getData();
       $em = $this->getDoctrine()->getManager();
       $em->persist($entity);
       $em->flush();
    }

This used to work in Symfony 2 but now when the form is submitted the following error is thrown:

Expected value of type "TwitterSearch" for association field "Event#$twitterSearch"
, got "array" instead.

I debugged the code and the twitterSearch attribute of the Event was and array. Does anyone know why it is no longer converting this to an instance of TwitterSearch?

Answer 1

Use EntityType instead.

Example:

$builder->add('twitterSearch', EntityType::class, array(
    'class' => TwitterSearch::class,
    'choice_label' => 'name',
));