class PathSubscriber

1. 9.x drupal/core/lib/Drupal/Core/EventSubscriber/PathSubscriber.php \Drupal\Core\EventSubscriber\PathSubscriber
2. 9.x drupal/core/modules/system/tests/modules/url_alter_test/lib/Drupal/url_alter_test/PathSubscriber.php \Drupal\url_alter_test\PathSubscriber

class PathSubscriber extends PathListenerBase implements EventSubscriberInterface {

  /**
   * Resolve the system path based on some arbitrary rules.
   *
   * @param Symfony\Component\HttpKernel\Event\GetResponseEvent $event
   *   The Event to process.
   */
  public function onKernelRequestPathResolve(GetResponseEvent $event) {
    $request = $event
      ->getRequest();
    $path = $this
      ->extractPath($request);

    // Rewrite user/username to user/uid.
    if (preg_match('!^user/([^/]+)(/.*)?!', $path, $matches)) {
      if ($account = user_load_by_name($matches[1])) {
        $matches += array(
          2 => '',
        );
        $path = 'user/' . $account->uid . $matches[2];
      }
    }

    // Rewrite community/ to forum/.
    if ($path == 'community' || strpos($path, 'community/') === 0) {
      $path = 'forum' . substr($path, 9);
    }
    if ($path == 'url-alter-test/bar') {
      $path = 'url-alter-test/foo';
    }
    $this
      ->setPath($request, $path);
  }

  /**
   * Registers the methods in this class that should be listeners.
   *
   * @return array
   *   An array of event listener definitions.
   */
  static function getSubscribedEvents() {
    $events[KernelEvents::REQUEST][] = array(
      'onKernelRequestPathResolve',
      100,
    );
    return $events;
  }

}