使用实体验证表单内的FormType

I have two entities: Company and Location. One company has one location (while one location may "have" multiple companies). Now when a user creates a company, I want him/her to able able, to create the location in the same form. So I use the following

    $builder
        ->add('name', TextType::class, ['label' => 'company.name'])
        ->add('size', IntegerType::class, ['label' => 'company.size'])
        ->add( $builder->create('location', FormType::class, [
                'label' => 'company.location',
                'by_reference' => true,
                'data_class' => 'AppBundle\Entity\Location',
            ])
            ->add('street', TextType::class, [
                'label' => 'location.street',
            ])
            ->add('number', TextType::class, [
                'label' => 'location.number',
            ])

This works fine in creating the form. Now it comes to validation. I added @Assert annotations for both entities in their respective files. While company validation works, location does not get automatically validated.

I managed to get validation by adding constraint properties to the new $builder->create('location') elements, but this means duplicated code (once in Entity and at least once in every form that needs location).

How can I solve it so the form gets validated by using the entity's annotation?

By default validation won't traverse to properties that are objects or collections. Use the valid constraint:

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

You cans set the traverse option for collections as well.