Issue #2215719 by Wim Leers: Cache tags set by #pre_render callbacks are lost in page cache.

core/includes/common.inc

@@ -3990,6 +3990,12 @@ function drupal_render(&$elements, $is_recursive_call = FALSE) {
   $suffix = isset($elements['#suffix']) ? $elements['#suffix'] : '';
   $elements['#markup'] = $prefix . $elements['#children'] . $suffix;
 
+  // Collect all cache tags. This allows the caller of drupal_render() to also
+  // access the complete list of cache tags.
+  if (!$is_recursive_call || isset($elements['#cache'])) {
+    $elements['#cache']['tags'] = drupal_render_collect_cache_tags($elements);
+  }
+
   // Cache the processed element if #cache is set.
   if (isset($elements['#cache'])) {
     drupal_render_cache_set($elements['#markup'], $elements);
@@ -4196,10 +4202,14 @@ function drupal_render_cache_set(&$markup, array $elements) {
     $data['#post_render_cache'] = $elements['#post_render_cache'];
   }
 
+  // Persist cache tags associated with this element.
+  if (isset($elements['#cache']['tags'])) {
+    $data['#cache']['tags'] = $elements['#cache']['tags'];
+  }
+
   $bin = isset($elements['#cache']['bin']) ? $elements['#cache']['bin'] : 'cache';
   $expire = isset($elements['#cache']['expire']) ? $elements['#cache']['expire'] : Cache::PERMANENT;
-  $tags = drupal_render_collect_cache_tags($elements);
-  \Drupal::cache($bin)->set($cid, $data, $expire, $tags);
+  \Drupal::cache($bin)->set($cid, $data, $expire, $elements['#cache']['tags']);
 }
 
 /**

core/includes/theme.inc

@@ -1967,14 +1967,6 @@ function template_preprocess_html(&$variables) {
     }
   }
 
-  // Initializes attributes which are specific to the html and body elements.
-  $variables['html_attributes'] = new Attribute;
-
-  // HTML element attributes.
-  $language_interface = \Drupal::service('language_manager')->getCurrentLanguage();
-  $variables['html_attributes']['lang'] = $language_interface->id;
-  $variables['html_attributes']['dir'] = $language_interface->direction ? 'rtl' : 'ltr';
-
   $site_config = \Drupal::config('system.site');
   // Construct page title.
   if ($page->hasTitle()) {

core/lib/Drupal/Core/Controller/HtmlControllerBase.php

@@ -71,9 +71,9 @@ protected function createHtmlFragment($page_content, Request $request) {
       );
     }
 
-    $cache_tags = $this->drupalRenderCollectCacheTags($page_content);
-    $cache = !empty($cache_tags) ? array('tags' => $cache_tags) : array();
-    $fragment = new HtmlFragment($this->drupalRender($page_content), $cache);
+    $content = $this->drupalRender($page_content);
+    $cache = !empty($page_content['#cache']['tags']) ? array('tags' => $page_content['#cache']['tags']) : array();
+    $fragment = new HtmlFragment($content, $cache);
 
     // A title defined in the return always wins.
     if (isset($page_content['#title'])) {
@@ -95,13 +95,4 @@ protected function drupalRender(&$elements, $is_recursive_call = FALSE) {
     return drupal_render($elements, $is_recursive_call);
   }
 
-  /**
-   * Wraps drupal_render_collect_cache_tags()
-   *
-   * @todo: Remove as part of https://drupal.org/node/2182149
-   */
-  protected function drupalRenderCollectCacheTags($element, $tags = array()) {
-    return drupal_render_collect_cache_tags($element, $tags);
-  }
-
 }

core/lib/Drupal/Core/Page/DefaultHtmlFragmentRenderer.php

@@ -48,15 +48,14 @@ public function render(HtmlFragment $fragment, $status_code = 200) {
     // hook_page_build(). This adds the other regions to the page.
     $page_array = drupal_prepare_page($page_content);
 
-    // Collect cache tags for all the content in all the regions on the page.
-    $tags = drupal_render_collect_cache_tags($page_array);
-
     // Build the HtmlPage object.
-    $page = new HtmlPage('', array('tags' => $tags), $fragment->getTitle());
+    $page = new HtmlPage('', array(), $fragment->getTitle());
     $page = $this->preparePage($page, $page_array);
     $page->setBodyTop(drupal_render($page_array['page_top']));
     $page->setBodyBottom(drupal_render($page_array['page_bottom']));
     $page->setContent(drupal_render($page_array));
+    // Collect cache tags for all the content in all the regions on the page.
+    $page->setCacheTags($page_array['#cache']['tags']);
     $page->setStatusCode($status_code);
 
     return $page;

core/lib/Drupal/Core/Page/HtmlPage.php

@@ -158,5 +158,15 @@ public function getStatusCode() {
     return $this->statusCode;
   }
 
+  /**
+   * Sets the cache tags associated with this HTML page.
+   *
+   * @param array $cache_tags
+   *   The cache tags associated with this HTML page.
+   */
+  public function setCacheTags(array $cache_tags) {
+    $this->cache['tags'] = $cache_tags;
+  }
+
 }
 

core/modules/system/lib/Drupal/system/Tests/Bootstrap/PageCacheTest.php

@@ -65,7 +65,7 @@ function testPageCacheTags() {
     $cid_parts = array(url($path, array('absolute' => TRUE)), 'html');
     $cid = sha1(implode(':', $cid_parts));
     $cache_entry = \Drupal::cache('page')->get($cid);
-    $this->assertIdentical($cache_entry->tags, array('content:1', 'system_test_cache_tags_page:1'));
+    $this->assertIdentical($cache_entry->tags, array('content:1', 'system_test_cache_tags_page:1', 'pre_render:1'));
 
     Cache::invalidateTags($tags);
     $this->drupalGet($path);

core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php

@@ -500,6 +500,7 @@ function testDrupalRenderPostRenderCache() {
       '#markup' => '<p>#cache enabled, GET</p>',
       '#attached' => $test_element['#attached'],
       '#post_render_cache' => $test_element['#post_render_cache'],
+      '#cache' => array('tags' => array()),
     );
     $this->assertIdentical($cached_element, $expected_element, 'The correct data is cached: the stored #markup and #attached properties are not affected by #post_render_cache callbacks.');
 
@@ -619,6 +620,7 @@ function testDrupalRenderChildrenPostRenderCache() {
           $context_3,
         )
       ),
+      '#cache' => array('tags' => array()),
     );
 
     $dom = Html::load($cached_element['#markup']);
@@ -702,6 +704,7 @@ function testDrupalRenderChildrenPostRenderCache() {
           $context_3,
         )
       ),
+      '#cache' => array('tags' => array()),
     );
 
     $dom = Html::load($cached_parent_element['#markup']);
@@ -727,6 +730,7 @@ function testDrupalRenderChildrenPostRenderCache() {
           $context_3,
         )
       ),
+      '#cache' => array('tags' => array()),
     );
 
     $dom = Html::load($cached_child_element['#markup']);
@@ -830,6 +834,7 @@ function testDrupalRenderRenderCachePlaceholder() {
           $expected_token => $context,
         ),
       ),
+      '#cache' => array('tags' => array()),
     );
     $this->assertIdentical($cached_element, $expected_element, 'The correct data is cached: the stored #markup and #attached properties are not affected by #post_render_cache callbacks.');
 
@@ -920,6 +925,7 @@ function testDrupalRenderChildElementRenderCachePlaceholder() {
           $expected_token => $context,
         ),
       ),
+      '#cache' => array('tags' => array()),
     );
     $this->assertIdentical($cached_element, $expected_element, 'The correct data is cached for the child element: the stored #markup and #attached properties are not affected by #post_render_cache callbacks.');
 
@@ -944,6 +950,7 @@ function testDrupalRenderChildElementRenderCachePlaceholder() {
           $expected_token => $context,
         ),
       ),
+      '#cache' => array('tags' => array()),
     );
     $this->assertIdentical($cached_element, $expected_element, 'The correct data is cached for the parent element: the stored #markup and #attached properties are not affected by #post_render_cache callbacks.');
 
@@ -972,6 +979,7 @@ function testDrupalRenderChildElementRenderCachePlaceholder() {
           $expected_token => $context,
         ),
       ),
+      '#cache' => array('tags' => array()),
     );
     $this->assertIdentical($cached_element, $expected_element, 'The correct data is cached for the child element: the stored #markup and #attached properties are not affected by #post_render_cache callbacks.');
 

core/modules/system/tests/modules/ajax_test/lib/Drupal/ajax_test/Form/AjaxTestForm.php

@@ -27,7 +27,6 @@ public function getFormId() {
   public function buildForm(array $form, array &$form_state) {
 
     $form['#action'] = url('ajax-test/dialog');
-    $form['#cache'] = TRUE;
 
     $form['description'] = array(
       '#markup' => '<p>' . t("Ajax Form contents description.") . '</p>',

core/modules/system/tests/modules/system_test/lib/Drupal/system_test/Controller/SystemTestController.php

@@ -41,14 +41,27 @@ public function lockExit() {
   /**
    * Set cache tag on on the returned render array.
    */
-  function system_test_cache_tags_page() {
+  public function system_test_cache_tags_page() {
     $build['main'] = array(
-      '#markup' => 'Cache tags page example',
       '#cache' => array('tags' => array('system_test_cache_tags_page' => TRUE)),
+      '#pre_render' => array(
+        '\Drupal\system_test\Controller\SystemTestController::preRenderCacheTags',
+      ),
+      'message' => array(
+        '#markup' => 'Cache tags page example',
+      ),
     );
     return $build;
   }
 
+  /**
+   * Sets a cache tag on an element to help test #pre_render and cache tags.
+   */
+  public static function preRenderCacheTags($elements) {
+    $elements['#cache']['tags']['pre_render'] = TRUE;
+    return $elements;
+  }
+
   /**
    * @todo Remove system_test_authorize_init_page().
    */