Symfony 2 | Form exception when modifying an object that has a file(picture) field

Question

I\'m using Symfony2. I have an entity Post that has a title and a picture field.

My problem : Everything is fine when I create a post, I have my picture e

Answer 1

I solved the problem setting data_class to null as follows:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
    ->add('title')
    ->add('picture', 'file', array('data_class' => null)
    );
}