I have a field which is non-mapped and required.
$builder->add('termsAndConditions', CheckboxType::class, [
'required' => true,
'mapped' => false,
'attr' => [
'class' => 'c-custom-option',
],
]);
Clientside validation will throw an error when empty, but serverside says it's valid. Currently i do an extra check on form submission $form->isSubmitted() && $form->isValid() && $form->get('termsAndConditions')->getData()==true
but the form->isValid() method shouldn't return true in my opinion