Symfony Dynamic Form Constraints - symfony

Question

Looking for a straightforward way to add constraints dynamically to all of my form fields. So far I've hit upon the idea of using a form type extension, which kind of works: I can modify the form view and then manually check the view on form submission.
However, is there a smarter way to add real Symfony-based constraints in real-time?
(Note that the constraints need to be added to the form in real-time as the form loads based on user configuration in the database.. Predefined form groups and the like won't work.)

Answer 1

I would suggest to use form events.
Use the PRE_SUBMIT event to edit the form before validation.
Recreate your fields with $event->getForm()->add(...) adding your constraints.
Of course you can automatically add the listener to all form using a FormExtension which adds the listener.
EDIT : Some examples from Alsatian67/FormBundle
Your extension should looks like :
class ExtensibleExtension extends AbstractTypeExtension
{
private $extensibleSubscriber;
public function __construct($extensibleSubscriber) {
$this->extensibleSubscriber = $extensibleSubscriber;
}
public function buildForm(FormBuilderInterface $builder, array $options)
{
// Only apply on base form
if($builder->getForm()->isRoot())
{
$builder->addEventSubscriber($this->extensibleSubscriber);
}
}
public function getExtendedType()
{
return FormType::class;
}
}
And your EventListener / EventSubscriber should iterate on all the children :
foreach($event->getForm()->all() as $child){
$childName = $child->getName();
$type = get_class($child->getConfig()->getType()->getInnerType());
$options = $child->getConfig()->getOptions();
$options['constraints'] = array(/* ... */);
$form->add($childName,$type,$options);
}