getRequestContext example

/** * Determines whether a path is local. * * @param string $url * The internal path or external URL being linked to, such as "node/34" or * "http://example.com/foo". * * @return bool * TRUE or FALSE, where TRUE indicates a local path. */
  protected function isLocal($url) {
    return !UrlHelper::isExternal($url) || UrlHelper::externalIsLocal($url, $this->getRequestContext()->getCompleteBaseUrl());
  }

  /** * Returns the request context. * * @return \Drupal\Core\Routing\RequestContext * The request context. */
  protected function getRequestContext() {
    if (!isset($this->requestContext)) {
      $this->requestContext = \Drupal::service('router.request_context');
    }