Using Form Events.
For those who wonder how Form Events are used.
Here is an example where you can modify the form after the user has tapped the submit button.
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\FormEvent;
// ...
/* Listener to order to set a price if it does not exist yet */
$builder->get('price')->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
$data = $event->getData();
// modify it as you wish
$event->setData($data);
});
The FormEvents::PRE_SUBMIT event is dispatched at the beginning of the
Form::submit() method.
If needed, here is an example where you can modify the form price
before you display it.
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\FormEvent;
// ...
/* Listener to order to set a price if it does not exist yet */
$builder->get('price')->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) {
$data = $event->getData();
if (null === $data) { $data = '0.00'; }
$event->setData($data);
});
The FormEvents::PRE_SET_DATA event is dispatched at the beginning of
the Form::setData() method.