Symfony: cascade_validation option is deprecated

Question

I am trying to upgrade my project from symfony2 to symfony3. I want to get rid of this deprecation warning

The "cascade_validation" option is deprecated since version 2.8 and will be removed in 3.0. Use "constraints" with a Valid constraint instead."

Below is my code

->add('student_name', 'collection', array(
                'entry_type' => TextType::class,
                'allow_add' => true,
                'cascade_validation' => true,
                'options' => array(
                    'required' => false
                )
            ))

Can I just remove this line 'cascade_validation' => true without causing any trouble? Or what would be the equivalent code in symfony3?

Answer 1

Just replace

'cascade_validation' => true, 

with 

'constraints' => new \Symfony\Component\Validator\Constraints\Valid(),

Answer 2

In Symfony3 you have to use @Assert\Valid constraint in your parent entity. You can remove the line 'cascade_validation' => true in your FormType class.

class Author
{
    /**
     * @Assert\Valid
     */
    protected $address;
}

http://symfony.com/doc/current/reference/constraints/Valid.html

This Symfony commit contains the change and full example how to upgrade.