RoleValidator.php

<?php

namespace App\Validator;

use Symfony\Component\Security\Core\Authorization\AuthorizationCheckerInterface;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;

class RoleValidator extends ConstraintValidator
{
    public $security;
    public $checker;

    public function __construct(AuthorizationCheckerInterface $checker)
    {
        // AuthorizationChecker to get the access decision manager
        // https://symfony.com/doc/current/components/security/authorization.html#authorization-checker
        $this->checker = $checker;
    }

    public function validate($value, Constraint $constraint)
    {
        // retrieve the role allowed that are defined in the property Entity
        $roleAllowed = $constraint->role;

        // Does the User have the good Role, if not launch violation
        if(!$this->checker->isGranted($roleAllowed)) {
            $this->context->buildViolation($constraint->message)
                ->setParameter('{{ string }}', $value)
                ->addViolation();
        }
    }
}