Issue #2335661 by Wim Leers, pwolanin, dawehner, Fabianx, larowlan, catch,...

Issue #2335661 by Wim Leers, pwolanin, dawehner, Fabianx, larowlan, catch, Berdir: Outbound path & route processors must specify cacheability metadata

core/core.services.yml

@@ -34,8 +34,8 @@ services:
     arguments: ['@request_stack']
     tags:
       - { name: cache.context }
-  cache_context.url.host:
-    class: Drupal\Core\Cache\HostCacheContext
+  cache_context.url.site:
+    class: Drupal\Core\Cache\SiteCacheContext
     arguments: ['@request_stack']
     tags:
       - { name: cache.context }
@@ -1319,7 +1319,6 @@ services:
       - { name: twig.extension, priority: 100 }
     calls:
       - [setGenerators, ['@url_generator']]
-      - [setLinkGenerator, ['@link_generator']]
   # @todo Figure out what to do about debugging functions.
   # @see http://drupal.org/node/1804998
   twig.extension.debug:

core/lib/Drupal.php

@@ -504,17 +504,22 @@ public static function urlGenerator() {
    *   (optional) An associative array of parameter names and values.
    * @param array $options
    *   (optional) An associative array of additional options.
+   * @param bool $collect_cacheability_metadata
+   *   (optional) Defaults to FALSE. When TRUE, both the generated URL and its
+   *   associated cacheability metadata are returned.
    *
-   * @return string
-   *   The generated URL for the given route.
+   * @return string|\Drupal\Core\GeneratedUrl
+   *   A string containing a URL to the given path.
+   *   When $collect_cacheability_metadata is TRUE, a GeneratedUrl object is
+   *   returned, containing the generated URL plus cacheability metadata.
    *
    * @see \Drupal\Core\Routing\UrlGeneratorInterface::generateFromRoute()
    * @see \Drupal\Core\Url
    * @see \Drupal\Core\Url::fromRoute()
    * @see \Drupal\Core\Url::fromUri()
    */
-  public static function url($route_name, $route_parameters = array(), $options = array()) {
-    return static::getContainer()->get('url_generator')->generateFromRoute($route_name, $route_parameters, $options);
+  public static function url($route_name, $route_parameters = array(), $options = array(), $collect_cacheability_metadata = FALSE) {
+    return static::getContainer()->get('url_generator')->generateFromRoute($route_name, $route_parameters, $options, $collect_cacheability_metadata);
   }
 
   /**
@@ -537,15 +542,20 @@ public static function linkGenerator() {
    *   The link text for the anchor tag.
    * @param \Drupal\Core\Url $url
    *   The URL object used for the link.
+   * @param bool $collect_cacheability_metadata
+   *   (optional) Defaults to FALSE. When TRUE, both the generated URL and its
+   *   associated cacheability metadata are returned.
    *
-   * @return string
+   * @return string|\Drupal\Core\GeneratedLink
    *   An HTML string containing a link to the given route and parameters.
+   *   When $collect_cacheability_metadata is TRUE, a GeneratedLink object is
+   *   returned, containing the generated link plus cacheability metadata.
    *
    * @see \Drupal\Core\Utility\LinkGeneratorInterface::generate()
    * @see \Drupal\Core\Url
    */
-  public static function l($text, Url $url) {
-    return static::getContainer()->get('link_generator')->generate($text, $url);
+  public static function l($text, Url $url, $collect_cacheability_metadata = FALSE) {
+    return static::getContainer()->get('link_generator')->generate($text, $url, $collect_cacheability_metadata);
   }
 
   /**

core/lib/Drupal/Core/Access/RouteProcessorCsrf.php

@@ -7,9 +7,8 @@
 
 namespace Drupal\Core\Access;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\RouteProcessor\OutboundRouteProcessorInterface;
-use Drupal\Core\Access\CsrfTokenGenerator;
-use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Route;
 
 /**
@@ -37,7 +36,7 @@ function __construct(CsrfTokenGenerator $csrf_token) {
   /**
    * {@inheritdoc}
    */
-  public function processOutbound($route_name, Route $route, array &$parameters) {
+  public function processOutbound($route_name, Route $route, array &$parameters, CacheableMetadata $cacheable_metadata = NULL) {
     if ($route->hasRequirement('_csrf_token')) {
       $path = ltrim($route->getPath(), '/');
       // Replace the path parameters with values from the parameters array.
@@ -47,6 +46,11 @@ public function processOutbound($route_name, Route $route, array &$parameters) {
       // Adding this to the parameters means it will get merged into the query
       // string when the route is compiled.
       $parameters['token'] = $this->csrfToken->get($path);
+      if ($cacheable_metadata) {
+        // Tokens are per user and per session, so not cacheable.
+        // @todo Improve in https://www.drupal.org/node/2351015.
+        $cacheable_metadata->setCacheMaxAge(0);
+      }
     }
   }
 

core/lib/Drupal/Core/Cache/HostCacheContext.php

-<?php
-
-/**
- * @file
- * Contains \Drupal\Core\Cache\HostCacheContext.
- */
-
-namespace Drupal\Core\Cache;
-
-/**
- * Defines the HostCacheContext service, for "per host" caching.
- *
- * A "host" is defined as the combination of URI scheme, domain name and port.
- *
- * @see Symfony\Component\HttpFoundation::getSchemeAndHttpHost()
- */
-class HostCacheContext extends RequestStackCacheContextBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function getLabel() {
-    return t('Host');
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getContext() {
-    return $this->requestStack->getCurrentRequest()->getSchemeAndHttpHost();
-  }
-
-}

core/lib/Drupal/Core/Cache/SiteCacheContext.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Cache\SiteCacheContext.
+ */
+
+namespace Drupal\Core\Cache;
+
+/**
+ * Defines the SiteCacheContext service, for "per site" caching.
+ *
+ * A "site" is defined as the combination of URI scheme, domain name, port and
+ * base path. It allows for varying between the *same* site being accessed via
+ * different entry points. (Different sites in a multisite setup have separate
+ * databases.) For example: http://example.com and http://www.example.com.
+ *
+ * @see \Symfony\Component\HttpFoundation\Request::getSchemeAndHttpHost()
+ * @see \Symfony\Component\HttpFoundation\Request::getBaseUrl()
+ */
+class SiteCacheContext extends RequestStackCacheContextBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getLabel() {
+    return t('Site');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getContext() {
+    $request = $this->requestStack->getCurrentRequest();
+    return $request->getSchemeAndHttpHost() . $request->getBaseUrl();
+  }
+
+}

core/lib/Drupal/Core/GeneratedLink.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\GeneratedLink.
+ */
+
+namespace Drupal\Core;
+
+use Drupal\Core\Cache\CacheableMetadata;
+
+/**
+ * Used to return generated links, along with associated cacheability metadata.
+ *
+ * Note: not to be confused with \Drupal\Core\Link, which is for passing around
+ *   ungenerated links (typically link text + route name + route parameters).
+ */
+class GeneratedLink extends CacheableMetadata {
+
+  /**
+   * The HTML string value containing a link.
+   *
+   * @var string
+   */
+  protected $generatedLink = '';
+
+  /**
+   * Gets the generated link.
+   *
+   * @return string
+   */
+  public function getGeneratedLink() {
+    return $this->generatedLink ;
+  }
+
+  /**
+   * Sets the generated link.
+   *
+   * @param string $generated_link
+   *   The generated link.
+   *
+   * @return $this
+   */
+  public function setGeneratedLink($generated_link) {
+    $this->generatedLink = $generated_link;
+    return $this;
+  }
+
+}

core/lib/Drupal/Core/GeneratedUrl.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\GeneratedUrl.
+ */
+
+namespace Drupal\Core;
+
+use Drupal\Core\Cache\CacheableMetadata;
+
+/**
+ * Used to return generated URLs, along with associated cacheability metadata.
+ *
+ * Note: not to be confused with \Drupal\Core\Url, which is for passing around
+ *   ungenerated URLs (typically route name + route parameters).
+ */
+class GeneratedUrl extends CacheableMetadata {
+
+  /**
+   * The string value of the URL.
+   *
+   * @var string
+   */
+  protected $generatedUrl = '';
+
+  /**
+   * Gets the generated URL.
+   *
+   * @return string
+   */
+  public function getGeneratedUrl() {
+    return $this->generatedUrl ;
+  }
+
+  /**
+   * Sets the generated URL.
+   *
+   * @param string $generated_url
+   *   The generated URL.
+   *
+   * @return $this
+   */
+  public function setGeneratedUrl($generated_url) {
+    $this->generatedUrl = $generated_url;
+    return $this;
+  }
+
+}

core/lib/Drupal/Core/Link.php

@@ -121,9 +121,18 @@ public function setUrl(Url $url) {
 
   /**
    * Generates the HTML for this Link object.
+   *
+   * @param bool $collect_cacheability_metadata
+   *   (optional) Defaults to FALSE. When TRUE, both the generated link and its
+   *   associated cacheability metadata are returned.
+   *
+   * @return string|\Drupal\Core\GeneratedLink
+   *   The link HTML markup.
+   *   When $collect_cacheability_metadata is TRUE, a GeneratedLink object is
+   *   returned, containing the generated link plus cacheability metadata.
    */
-  public function toString() {
-    return $this->getLinkGenerator()->generateFromLink($this);
+  public function toString($collect_cacheability_metadata = FALSE) {
+    return $this->getLinkGenerator()->generateFromLink($this, $collect_cacheability_metadata);
   }
 
 }

core/lib/Drupal/Core/PathProcessor/OutboundPathProcessorInterface.php

@@ -7,8 +7,8 @@
 
 namespace Drupal\Core\PathProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\Routing\Route;
 
 /**
  * Defines an interface for classes that process the outbound path.
@@ -20,17 +20,17 @@ interface OutboundPathProcessorInterface {
    *
    * @param string $path
    *   The path to process.
-   *
    * @param array $options
    *   An array of options such as would be passed to the generator's
    *   generateFromPath() method.
-   *
    * @param \Symfony\Component\HttpFoundation\Request $request
    *   The HttpRequest object representing the current request.
+   * @param \Drupal\Core\Cache\CacheableMetadata $cacheable_metadata
+   *   (optional) Object to collect path processors' cacheability.
    *
    * @return
    *   The processed path.
    */
-  public function processOutbound($path, &$options = array(), Request $request = NULL);
+  public function processOutbound($path, &$options = array(), Request $request = NULL, CacheableMetadata $cacheable_metadata = NULL);
 
 }

core/lib/Drupal/Core/PathProcessor/PathProcessorAlias.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\PathProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Path\AliasManagerInterface;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -43,7 +44,7 @@ public function processInbound($path, Request $request) {
   /**
    * Implements Drupal\Core\PathProcessor\OutboundPathProcessorInterface::processOutbound().
    */
-  public function processOutbound($path, &$options = array(), Request $request = NULL) {
+  public function processOutbound($path, &$options = array(), Request $request = NULL, CacheableMetadata $cacheable_metadata = NULL) {
     if (empty($options['alias'])) {
       $langcode = isset($options['language']) ? $options['language']->getId() : NULL;
       $path = $this->aliasManager->getAliasByPath($path, $langcode);

core/lib/Drupal/Core/PathProcessor/PathProcessorFront.php

@@ -7,11 +7,14 @@
 
 namespace Drupal\Core\PathProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
  * Processes the inbound path by resolving it to the front page if empty.
+ *
+ * @todo - remove ::processOutbound() when we remove UrlGenerator::fromPath().
  */
 class PathProcessorFront implements InboundPathProcessorInterface, OutboundPathProcessorInterface {
 
@@ -45,7 +48,7 @@ public function processInbound($path, Request $request) {
   /**
    * Implements Drupal\Core\PathProcessor\OutboundPathProcessorInterface::processOutbound().
    */
-  public function processOutbound($path, &$options = array(), Request $request = NULL) {
+  public function processOutbound($path, &$options = array(), Request $request = NULL, CacheableMetadata $cacheable_metadata = NULL) {
     // The special path '<front>' links to the default front page.
     if ($path == '<front>') {
       $path = '';

core/lib/Drupal/Core/PathProcessor/PathProcessorManager.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\PathProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
@@ -107,10 +108,10 @@ public function addOutbound(OutboundPathProcessorInterface $processor, $priority
   /**
    * Implements Drupal\Core\PathProcessor\OutboundPathProcessorInterface::processOutbound().
    */
-  public function processOutbound($path, &$options = array(), Request $request = NULL) {
+  public function processOutbound($path, &$options = array(), Request $request = NULL, CacheableMetadata $cacheable_metadata = NULL) {
     $processors = $this->getOutbound();
     foreach ($processors as $processor) {
-      $path = $processor->processOutbound($path, $options, $request);
+      $path = $processor->processOutbound($path, $options, $request, $cacheable_metadata);
     }
     return $path;
   }

core/lib/Drupal/Core/Render/Element/Link.php

@@ -9,6 +9,8 @@
 
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Component\Utility\Html as HtmlUtility;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Url as CoreUrl;
 
 /**
  * Provides a link render element.
@@ -75,9 +77,14 @@ public static function preRenderLink($element) {
       $element = static::preRenderAjaxForm($element);
     }
 
-    if (!empty($element['#url'])) {
+    if (!empty($element['#url']) && $element['#url'] instanceof CoreUrl) {
       $options = NestedArray::mergeDeep($element['#url']->getOptions(), $element['#options']);
-      $element['#markup'] = \Drupal::l($element['#title'], $element['#url']->setOptions($options));
+      /** @var \Drupal\Core\Utility\LinkGenerator $link_generator */
+      $link_generator = \Drupal::service('link_generator');
+      $generated_link = $link_generator->generate($element['#title'], $element['#url']->setOptions($options), TRUE);
+      $element['#markup'] = $generated_link->getGeneratedLink();
+      $generated_link->merge(CacheableMetadata::createFromRenderArray($element))
+        ->applyTo($element);
     }
     return $element;
   }

core/lib/Drupal/Core/RouteProcessor/OutboundRouteProcessorInterface.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\RouteProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Symfony\Component\Routing\Route;
 
 /**
@@ -24,10 +25,12 @@ interface OutboundRouteProcessorInterface {
    * @param array $parameters
    *   An array of parameters to be passed to the route compiler. Passed by
    *   reference.
+   * @param \Drupal\Core\Cache\CacheableMetadata $cacheable_metadata
+   *   (optional) Object to collect route processors' cacheability.
    *
    * @return
    *   The processed path.
    */
-  public function processOutbound($route_name, Route $route, array &$parameters);
+  public function processOutbound($route_name, Route $route, array &$parameters, CacheableMetadata $cacheable_metadata = NULL);
 
 }

core/lib/Drupal/Core/RouteProcessor/RouteProcessorCurrent.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\RouteProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Symfony\Component\Routing\Route;
 
@@ -35,7 +36,7 @@ public function __construct(RouteMatchInterface $route_match) {
   /**
    * {@inheritdoc}
    */
-  public function processOutbound($route_name, Route $route, array &$parameters) {
+  public function processOutbound($route_name, Route $route, array &$parameters, CacheableMetadata $cacheable_metadata = NULL) {
     if ($route_name === '<current>') {
       if ($current_route = $this->routeMatch->getRouteObject()) {
         $route->setPath($current_route->getPath());
@@ -43,6 +44,9 @@ public function processOutbound($route_name, Route $route, array &$parameters) {
         $route->setOptions($current_route->getOptions());
         $route->setDefaults($current_route->getDefaults());
         $parameters = array_merge($parameters, $this->routeMatch->getRawParameters()->all());
+        if ($cacheable_metadata) {
+          $cacheable_metadata->addCacheContexts(['route']);
+        }
       }
       else {
         // If we have no current route match available, point to the frontpage.

core/lib/Drupal/Core/RouteProcessor/RouteProcessorManager.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\RouteProcessor;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Symfony\Component\Routing\Route;
 
 /**
@@ -50,10 +51,10 @@ public function addOutbound(OutboundRouteProcessorInterface $processor, $priorit
   /**
    * {@inheritdoc}
    */
-  public function processOutbound($route_name, Route $route, array &$parameters) {
+  public function processOutbound($route_name, Route $route, array &$parameters, CacheableMetadata $cacheable_metadata = NULL) {
     $processors = $this->getOutbound();
     foreach ($processors as $processor) {
-      $processor->processOutbound($route_name, $route, $parameters);
+      $processor->processOutbound($route_name, $route, $parameters, $cacheable_metadata);
     }
   }
 

core/lib/Drupal/Core/Routing/NullGenerator.php

@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Routing;
 
+use Drupal\Core\Cache\CacheableMetadata;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\Routing\RequestContext as SymfonyRequestContext;
 use Symfony\Component\Routing\Exception\RouteNotFoundException;
@@ -50,7 +51,7 @@ protected function getRoute($name) {
   /**
    * {@inheritdoc}
    */
-  protected function processRoute($name, Route $route, array &$parameters) {
+  protected function processRoute($name, Route $route, array &$parameters, CacheableMetadata $cacheable_metadata = NULL) {
   }
 
   /**
@@ -75,7 +76,7 @@ public function getContext() {
   /**
    * Overrides Drupal\Core\Routing\UrlGenerator::processPath().
    */
-  protected function processPath($path, &$options = array()) {
+  protected function processPath($path, &$options = array(), CacheableMetadata $cacheable_metadata = NULL) {
     return $path;
   }
 }

core/lib/Drupal/Core/Routing/UrlGenerator.php

@@ -7,6 +7,8 @@
 
 namespace Drupal\Core\Routing;
 
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\GeneratedUrl;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\Routing\RequestContext as SymfonyRequestContext;
 use Symfony\Component\Routing\Route as SymfonyRoute;
@@ -275,11 +277,13 @@ public function generate($name, $parameters = array(), $absolute = FALSE) {
   /**
    * {@inheritdoc}
    */
-  public function generateFromRoute($name, $parameters = array(), $options = array()) {
+  public function generateFromRoute($name, $parameters = array(), $options = array(), $collect_cacheability_metadata = FALSE) {
+    $generated_url = $collect_cacheability_metadata ? new GeneratedUrl() : NULL;
+
     $options += array('prefix' => '');
     $route = $this->getRoute($name);
     $name = $this->getRouteDebugMessage($name);
-    $this->processRoute($name, $route, $parameters);
+    $this->processRoute($name, $route, $parameters, $generated_url);
 
     $query_params = [];
     // Symfony adds any parameters that are not path slugs as query strings.
@@ -288,7 +292,7 @@ public function generateFromRoute($name, $parameters = array(), $options = array
     }
 
     $path = $this->getInternalPathFromRoute($name, $route, $parameters, $query_params);
-    $path = $this->processPath($path, $options);
+    $path = $this->processPath($path, $options, $generated_url);
 
     if (!empty($options['prefix'])) {
       $path = ltrim($path, '/');
@@ -316,7 +320,8 @@ public function generateFromRoute($name, $parameters = array(), $options = array
         }
       }
 
-      return $base_url . $path . $fragment;
+      $url = $base_url . $path . $fragment;
+      return $collect_cacheability_metadata ? $generated_url->setGeneratedUrl($url) : $url;
     }
 
     $base_url = $this->context->getBaseUrl();
@@ -325,10 +330,11 @@ public function generateFromRoute($name, $parameters = array(), $options = array
     if (!$absolute || !$host = $this->context->getHost()) {
 
       if ($route->getOption('_only_fragment')) {
-        return $fragment;
+        return $collect_cacheability_metadata ? $generated_url->setGeneratedUrl($fragment) : $fragment;
       }
 
-      return $base_url . $path . $fragment;
+      $url = $base_url . $path . $fragment;
+      return $collect_cacheability_metadata ? $generated_url->setGeneratedUrl($url) : $url;
     }
 
     // Prepare an absolute URL by getting the correct scheme, host and port from
@@ -349,13 +355,20 @@ public function generateFromRoute($name, $parameters = array(), $options = array
     } elseif ('https' === $scheme && 443 != $this->context->getHttpsPort()) {
       $port = ':' . $this->context->getHttpsPort();
     }
-    return $scheme . '://' . $host . $port . $base_url . $path . $fragment;
+    if ($collect_cacheability_metadata) {
+      $generated_url->addCacheContexts(['url.site']);
+    }
+    $url = $scheme . '://' . $host . $port . $base_url . $path . $fragment;
+    return $collect_cacheability_metadata ? $generated_url->setGeneratedUrl($url) : $url;
+
   }
 
   /**
    * {@inheritdoc}
    */
-  public function generateFromPath($path = NULL, $options = array()) {
+  public function generateFromPath($path = NULL, $options = array(), $collect_cacheability_metadata = FALSE) {
+    $generated_url = $collect_cacheability_metadata ? new GeneratedUrl() : NULL;
+
     $request = $this->requestStack->getCurrentRequest();
     $current_base_path = $request->getBasePath() . '/';
     $current_base_url = $request->getSchemeAndHttpHost() . $current_base_path;
@@ -418,10 +431,11 @@ public function generateFromPath($path = NULL, $options = array()) {
         }
       }
       // Reassemble.
-      return $path . $options['fragment'];
+      $url = $path . $options['fragment'];
+      return $collect_cacheability_metadata ? $generated_url->setGeneratedUrl($url) : $url;
     }
     else {
-      $path = ltrim($this->processPath($path, $options), '/');
+      $path = ltrim($this->processPath($path, $options, $generated_url), '/');
     }
 
     if (!isset($options['script'])) {
@@ -449,15 +463,20 @@ public function generateFromPath($path = NULL, $options = array()) {
     $base = $options['absolute'] ? $options['base_url'] : $current_base_path;
     $prefix = empty($path) ? rtrim($options['prefix'], '/') : $options['prefix'];
 
+    if ($options['absolute'] && $collect_cacheability_metadata) {
+      $generated_url->addCacheContexts(['url.site']);
+    }
+
     $path = str_replace('%2F', '/', rawurlencode($prefix . $path));
     $query = $options['query'] ? ('?' . UrlHelper::buildQuery($options['query'])) : '';
-    return $base . $options['script'] . $path . $query . $options['fragment'];
+    $url = $base . $options['script'] . $path . $query . $options['fragment'];
+    return $collect_cacheability_metadata ? $generated_url->setGeneratedUrl($url) : $url;
   }
 
   /**
    * Passes the path to a processor manager to allow alterations.
    */
-  protected function processPath($path, &$options = array()) {
+  protected function processPath($path, &$options = array(), CacheableMetadata $cacheable_metadata = NULL) {
     // Router-based paths may have a querystring on them.
     if ($query_pos = strpos($path, '?')) {
       // We don't need to do a strict check here because position 0 would mean we
@@ -469,7 +488,7 @@ protected function processPath($path, &$options = array()) {
       $actual_path = $path;
       $query_string = '';
     }
-    $path = '/' . $this->pathProcessor->processOutbound(trim($actual_path, '/'), $options, $this->requestStack->getCurrentRequest());
+    $path = '/' . $this->pathProcessor->processOutbound(trim($actual_path, '/'), $options, $this->requestStack->getCurrentRequest(), $cacheable_metadata);
     $path .= $query_string;
     return $path;
   }
@@ -483,9 +502,11 @@ protected function processPath($path, &$options = array()) {
    *   The route object to process.
    * @param array $parameters
    *   An array of parameters to be passed to the route compiler.
+   * @param \Drupal\Core\Cache\CacheableMetadata $cacheable_metadata
+   *   (optional) Object to collect route processors' cacheability.
    */
-  protected function processRoute($name, SymfonyRoute $route, array &$parameters) {
-    $this->routeProcessor->processOutbound($name, $route, $parameters);
+  protected function processRoute($name, SymfonyRoute $route, array &$parameters, CacheableMetadata $cacheable_metadata = NULL) {
+    $this->routeProcessor->processOutbound($name, $route, $parameters, $cacheable_metadata);
   }
 
   /**

core/lib/Drupal/Core/Routing/UrlGeneratorInterface.php

@@ -70,9 +70,14 @@ interface UrlGeneratorInterface extends VersatileGeneratorInterface {
    *     set if _url() is invoked by Drupal\Core\Entity\Entity::uri().
    *   - 'entity': The entity object (such as a node) for which the URL is being
    *     generated. Only set if _url() is invoked by Drupal\Core\Entity\Entity::uri().
+   * @param bool $collect_cacheability_metadata
+   *   (optional) Defaults to FALSE. When TRUE, both the generated URL and its
+   *   associated cacheability metadata are returned.
    *
-   * @return
+   * @return string|\Drupal\Core\GeneratedUrl
    *   A string containing a URL to the given path.
+   *   When $collect_cacheability_metadata is TRUE, a GeneratedUrl object is
+   *   returned, containing the generated URL plus cacheability metadata.
    *
    * @throws \Drupal\Core\Routing\GeneratorNotInitializedException.
    *
@@ -85,8 +90,9 @@ interface UrlGeneratorInterface extends VersatileGeneratorInterface {
    * @see static::generateFromRoute()
    * @see \Drupal\Core\Utility\UnroutedUrlAssembler
    * @see \Drupal\Core\Url
+   * @see \Drupal\Core\GeneratedUrl
    */
-  public function generateFromPath($path = NULL, $options = array());
+  public function generateFromPath($path = NULL, $options = array(), $collect_cacheability_metadata = FALSE);
 
   /**
    * Gets the internal path (system path) of a route.
@@ -100,7 +106,7 @@ public function generateFromPath($path = NULL, $options = array());
    * @return string
    *  The internal Drupal path corresponding to the route.
    *
-   * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
+   * @deprecated in Drupal 8.0.x-dev, will be removed before Drupal 8.0.0
    *   System paths should not be used - use route names and parameters.
    */
   public function getPathFromRoute($name, $parameters = array());
@@ -136,9 +142,14 @@ public function getPathFromRoute($name, $parameters = array());
    *     modify the base URL when a language dependent URL requires so.
    *   - 'prefix': Only used internally, to modify the path when a language
    *     dependent URL requires so.
+   * @param bool $collect_cacheability_metadata
+   *   (optional) Defaults to FALSE. When TRUE, both the generated URL and its
+   *   associated cacheability metadata are returned.
    *
-   * @return string
+   * @return string|\Drupal\Core\GeneratedUrl
    *   The generated URL for the given route.
+   *   When $collect_cacheability_metadata is TRUE, a GeneratedUrl object is
+   *   returned, containing the generated URL plus cacheability metadata.
    *
    * @throws \Symfony\Component\Routing\Exception\RouteNotFoundException
    *   Thrown when the named route does not exist.
@@ -148,6 +159,6 @@ public function getPathFromRoute($name, $parameters = array());
    *   Thrown when a parameter value for a placeholder is not correct because it
    *   does not match the requirement.
    */