RoleExistsConstraintValidator.php

<?php

declare (strict_types=1);
namespace Drupal\user\Plugin\Validation\Constraint;

use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

/**
 * Validates that a role exists.
 */
class RoleExistsConstraintValidator extends ConstraintValidator implements ContainerInjectionInterface {
    
    /**
     * Create a new RoleExistsConstraintValidator instance.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager) {
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) : static {
        return new static($container->get(EntityTypeManagerInterface::class));
    }
    
    /**
     * {@inheritdoc}
     */
    public function validate($value, Constraint $constraint) : void {
        assert($constraint instanceof RoleExistsConstraint);
        if (!is_string($value)) {
            throw new UnexpectedTypeException($value, 'string');
        }
        $roleStorage = $this->entity_type_manager
            ->getStorage('user_role');
        if (!$roleStorage->load($value)) {
            $this->context
                ->addViolation($constraint->message, [
                '@rid' => $value,
            ]);
        }
    }

}