Symfony - how to lowercase a form field? - symfony

Question

I'm a beginner to using Symfony 3.4 and I would like to change a form field to lower case but I don't know how or where :(
In my buildForm with maybe a constraint or in my Controller but I can't target the form field ?
I tried in Twig:
<div>{{ form_widget(form.name)|lower }}</div>
I tried in Controller:
$form->get('name')->setData(strtolower($form->get('name')));
I tried in buildForm:
$builder->add('name', TextType::class, ['attr' => array( 'class' => 'text-lowercase' ))
If you need to see my Controller :
public function registerAction(Request $request)
{
/** #var $formFactory FactoryInterface */
$formFactory = $this->get('fos_user.registration.form.factory');
/** #var $userManager UserManagerInterface */
$userManager = $this->get('fos_user.user_manager');
/** #var $dispatcher EventDispatcherInterface */
$dispatcher = $this->get('event_dispatcher');
$user = new User();
$user->setEnabled(true);
$event = new GetResponseUserEvent($user, $request);
$dispatcher->dispatch(FOSUserEvents::REGISTRATION_INITIALIZE, $event);
if (null !== $event->getResponse()) {
return $event->getResponse();
}
$form = $formFactory->createForm();
$user->setUsername("null");
$user->setPassword("null");
$user->setPlainPassword("null");
$form->setData($user);
$form->handleRequest($request);
if ($form->isSubmitted()) {
if ($form->isValid()) {
$user->setPassword(strtolower($form["name"]->getData(). $form["firstname"]->getData()));
$user->setPlainPassword(strtolower($form["name"]->getData(). $form["firstname"]->getData()));
$user->setUsername(strtolower($form["name"]->getData().
$form["firstname"]->getData()));
if($form["roles"]->getData() == 'ROLE_ADMIN')
{
$user->addRole('ROLE_ADMIN');
}
else
{
$user->addRole('ROLE_USER');
}
$event = new FormEvent($form, $request);
$dispatcher->dispatch(FOSUserEvents::REGISTRATION_SUCCESS, $event);
$userManager->updateUser($user);
/*****************************************************
* Add new functionality (e.g. log the registration) *
*****************************************************/
$this->container->get('logger')->info(
sprintf("New user registration: %s", $user)
);
if (null === $response = $event->getResponse()) {
$url = $this->generateUrl('fos_user_registration_register');
$response = new RedirectResponse($url);
}
$dispatcher->dispatch(FOSUserEvents::REGISTRATION_COMPLETED, new FilterUserResponseEvent($user, $request, $response));
return $response;
}
$event = new FormEvent($form, $request);
$dispatcher->dispatch(FOSUserEvents::REGISTRATION_FAILURE, $event);
if (null !== $response = $event->getResponse()) {
return $response;
}
}
return $this->render('#FOSUser/Registration/register.html.twig', array(
'form' => $form->createView(),
));
}
Thank you for any help !

Answer 1

If you are using bootstrap following code should be work:
$builder->add('name', TextType::class, ['attr' => array( 'class' => 'text-lowercase' ))