class MetadataBubblingUrlGenerator

class MetadataBubblingUrlGenerator implements UrlGeneratorInterface {
    
    /**
     * The non-bubbling URL generator.
     *
     * @var \Drupal\Core\Routing\UrlGeneratorInterface
     */
    protected $urlGenerator;
    
    /**
     * The renderer.
     *
     * @var \Drupal\Core\Render\RendererInterface
     */
    protected $renderer;
    
    /**
     * Constructs a new bubbling URL generator service.
     *
     * @param \Drupal\Core\Routing\UrlGeneratorInterface $url_generator
     *   The non-bubbling URL generator.
     * @param \Drupal\Core\Render\RendererInterface $renderer
     *   The renderer.
     */
    public function __construct(UrlGeneratorInterface $url_generator, RendererInterface $renderer) {
        $this->urlGenerator = $url_generator;
        $this->renderer = $renderer;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setContext(SymfonyRequestContext $context) {
        $this->urlGenerator
            ->setContext($context);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getContext() {
        return $this->urlGenerator
            ->getContext();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getPathFromRoute($name, $parameters = []) {
        return $this->urlGenerator
            ->getPathFromRoute($name, $parameters);
    }
    
    /**
     * Bubbles the bubbleable metadata to the current render context.
     *
     * @param \Drupal\Core\GeneratedUrl $generated_url
     *   The generated URL whose bubbleable metadata to bubble.
     * @param array $options
     *   (optional) The URL options. Defaults to none.
     */
    protected function bubble(GeneratedUrl $generated_url, array $options = []) {
        // Bubbling metadata makes sense only if the code is executed inside a
        // render context. All code running outside controllers has no render
        // context by default, so URLs used there are not supposed to affect the
        // response cacheability.
        if ($this->renderer
            ->hasRenderContext()) {
            $build = [];
            $generated_url->applyTo($build);
            $this->renderer
                ->render($build);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function generate($name, $parameters = [], $referenceType = self::ABSOLUTE_PATH) {
        $options['absolute'] = is_bool($referenceType) ? $referenceType : $referenceType === self::ABSOLUTE_URL;
        $generated_url = $this->generateFromRoute($name, $parameters, $options, TRUE);
        $this->bubble($generated_url);
        return $generated_url->getGeneratedUrl();
    }
    
    /**
     * {@inheritdoc}
     */
    public function generateFromRoute($name, $parameters = [], $options = [], $collect_bubbleable_metadata = FALSE) {
        $generated_url = $this->urlGenerator
            ->generateFromRoute($name, $parameters, $options, TRUE);
        if (!$collect_bubbleable_metadata) {
            $this->bubble($generated_url, $options);
        }
        return $collect_bubbleable_metadata ? $generated_url : $generated_url->getGeneratedUrl();
    }
    
    /**
     * {@inheritdoc}
     */
    public function supports($name) {
        return $this->urlGenerator
            ->supports($name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getRouteDebugMessage($name, array $parameters = []) {
        return $this->urlGenerator
            ->getRouteDebugMessage($name, $parameters);
    }

}