LinkExternalProtocolsConstraint.php

<?php

namespace Drupal\link\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Attribute\HasNamedArguments;
use Symfony\Component\Validator\Constraint as SymfonyConstraint;

/**
 * Defines a protocol validation constraint for links to external URLs.
 */
class LinkExternalProtocolsConstraint extends SymfonyConstraint {
  public function __construct(mixed $options = NULL, public string $message = "The path '@uri' is invalid.", ?array $groups = NULL, mixed $payload = NULL) {
    parent::__construct($options, $groups, $payload);
  }

}