Entity form type in Symfony2 - forms

Question

I'm trying to make a RESTFUL api and when I process PUT, it always responded me as
{
"code": 500,
"message": "The form's view data is expected to be an instance of class My\\Bundle\\Entity\\Post, but is a(n) array. You can avoid this error by setting the \"data_class\" option to null or by adding a view transformer that transforms a(n) array to an instance of My\\Bundle\\Entity\\Post."
}
Here is how I write the PUT action.
public function putPostAction($postKey, Request $request){
$post = $this->getDoctrine()->getManager()->getRepository('MyBundle:Post')
->findPost($postKey);
$form = $form = $this->createFormBuilder($post,
array('data_class' => 'My\Bundle\Entity\Post'))->getForm();
// or use createForm like
// $form = $this->createForm(new PostType(), $post);
$form->submit($request);
if($form->isValid()){
$em = $this->getDoctrine()->getManager();
$em->persist($post);
$em->flush();
return $post;
}
return array(
"form" => $form
);
}
Speaking entity type, it looks like
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('cityKey')
->add('status')
->add('text')
->add('imageKey')
->add('createTime')
->add('updateTime')
;
}
/**
* #param OptionsResolverInterface $resolver
*/
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'My\Bundle\Entity\Post',
'csrf_protection' => false
));
}
/**
* #return string
*/
public function getName()
{
return '';
}
Regarding the error message, I modified the Resolver as
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => null,
'csrf_protection' => false
));
}
This time I got another error,
{
"code": 500,
"message": "EntityManager#persist() expects parameter 1 to be an entity object, array given."
}
Any idea? Thanks in advance.

Answer 1

findPost function is returning an array of objects not an object. You should call instead find($id) which returns only one Post object.
So it should be:
$post = $this->getDoctrine()->getManager()
->getRepository('MyBundle:Post')
->find($postKey);