form_errors does not display anything - symfony

Question

I'm having a hard time displaying errors from forms validation. Nothing is displayed when I fill the form incorrectly.
Here is my controller :
public function Register(Request $request){
$user = new User();
// Accounts must be enabled manually
$authenticator = new GoogleAuthenticator();
$user->setEnabled(false);
$user->setAdmin(false);
$user->setSecret($authenticator->createSecret());
$form = $this->createFormBuilder($user)
->add('email', TextType::class)
->add('email', RepeatedType::class)
->add('password', PasswordType::class)
->add('password', RepeatedType::class)
->add('phone', TelType::class)
->add('secret', HiddenType::class)
->add('save', SubmitType::class, array('label' => 'Register'))
->getForm();
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
// $form->getData() holds the submitted values
// but, the original `$task` variable has also been updated
$user = $form->getData();
// ... perform some action, such as saving the task to the database
// for example, if Task is a Doctrine entity, save it!
// $entityManager = $this->getDoctrine()->getManager();
// $entityManager->persist($task);
// $entityManager->flush();
return $this->redirectToRoute('register_success');
}
return $this->render('register.html.twig', array(
'form' => $form->createView()
));
}
And my template
{{ form_start(form) }}
{{ form_errors(form) }}
<div>
{{ form_errors(form.email) }}
{{ form_label(form.email) }} :
{{ form_widget(form.email.first, { 'attr' : {'placeholder' : 'Email address'}})}}
{{ form_widget(form.email.second, { 'attr' : {'placeholder' : 'Email address (again)'}})}}
</div>
<div>
{{ form_errors(form.password) }}
{{ form_label(form.password) }} :
{{ form_widget(form.password.first, { 'attr' : {'placeholder' : 'Password'}})}}
{{ form_widget(form.password.second, { 'attr' : {'placeholder' : 'Password (again)'}})}}
</div>
<div>
{{ form_errors(form.phone) }}
{{ form_label(form.phone) }} :
{{ form_widget(form.phone, { 'attr' : {'placeholder' : 'International format (+33)'}}) }}
</div>
<div>
{{ form_widget(form.save) }}
</div>
{{ form_end(form) }}
The forms reload with data pre-filled but no errors are displayed (empty line in source code only)
Waiting for your hints
Thanks

Answer 1

One need to setup validators (and therefore error messages) for them to be displayed.
Thanks for your help.

Answer 2

First of all, you do not need to "repeat" your already defined as RepeatedType fields, email and password.
Change to:
$form = $this->createFormBuilder($user)
->add('email', RepeatedType::class, array(
'type' => TextType::class,
'invalid_message' => 'The email fields must match.',
'options' => array('attr' => array('class' => 'email-field')),
'required' => true,
'first_options' => array('label' => 'Email'),
'second_options' => array('label' => 'Repeat Email'),
))
->add('password', RepeatedType::class, array(
'type' => PasswordType::class,
'invalid_message' => 'The password fields must match.',
'options' => array('attr' => array('class' => 'password-field')),
'required' => true,
'first_options' => array('label' => 'Password'),
'second_options' => array('label' => 'Repeat Password'),
));
To display the errors, use:
{{ form_errors(form.email.first)}}
{{ form_errors(form.email.second)}}
{{ form_errors(form.password.first)}}
{{ form_errors(form.password.second)}}
References
Symfony 4 RepeatedType field documentation