diff core/lib/Drupal/Core/Asset/CssCollectionRenderer.php @ 5:12f9dff5fda9 tip

Update to Drupal core 8.7.1

--- a/core/lib/Drupal/Core/Asset/CssCollectionRenderer.php	Thu Feb 28 13:11:55 2019 +0000
+++ b/core/lib/Drupal/Core/Asset/CssCollectionRenderer.php	Thu May 09 15:34:47 2019 +0100
@@ -2,54 +2,10 @@
 
 namespace Drupal\Core\Asset;
 
-use Drupal\Component\Utility\Html;
 use Drupal\Core\State\StateInterface;
 
 /**
  * Renders CSS assets.
- *
- * For production websites, LINK tags are preferable to STYLE tags with @import
- * statements, because:
- * - They are the standard tag intended for linking to a resource.
- * - On Firefox 2 and perhaps other browsers, CSS files included with @import
- *   statements don't get saved when saving the complete web page for offline
- *   use: https://www.drupal.org/node/145218.
- * - On IE, if only LINK tags and no @import statements are used, all the CSS
- *   files are downloaded in parallel, resulting in faster page load, but if
- *   @import statements are used and span across multiple STYLE tags, all the
- *   ones from one STYLE tag must be downloaded before downloading begins for
- *   the next STYLE tag. Furthermore, IE7 does not support media declaration on
- *   the @import statement, so multiple STYLE tags must be used when different
- *   files are for different media types. Non-IE browsers always download in
- *   parallel, so this is an IE-specific performance quirk:
- *   http://www.stevesouders.com/blog/2009/04/09/dont-use-import/.
- *
- * However, IE has an annoying limit of 31 total CSS inclusion tags
- * (https://www.drupal.org/node/228818) and LINK tags are limited to one file
- * per tag, whereas STYLE tags can contain multiple @import statements allowing
- * multiple files to be loaded per tag. When CSS aggregation is disabled, a
- * Drupal site can easily have more than 31 CSS files that need to be loaded, so
- * using LINK tags exclusively would result in a site that would display
- * incorrectly in IE. Depending on different needs, different strategies can be
- * employed to decide when to use LINK tags and when to use STYLE tags.
- *
- * The strategy employed by this class is to use LINK tags for all aggregate
- * files and for all files that cannot be aggregated (e.g., if 'preprocess' is
- * set to FALSE or the type is 'external'), and to use STYLE tags for groups
- * of files that could be aggregated together but aren't (e.g., if the site-wide
- * aggregation setting is disabled). This results in all LINK tags when
- * aggregation is enabled, a guarantee that as many or only slightly more tags
- * are used with aggregation disabled than enabled (so that if the limit were to
- * be crossed with aggregation enabled, the site developer would also notice the
- * problem while aggregation is disabled), and an easy way for a developer to
- * view HTML source while aggregation is disabled and know what files will be
- * aggregated together when aggregation becomes enabled.
- *
- * This class evaluates the aggregation enabled/disabled condition on a group
- * by group basis by testing whether an aggregate file has been made for the
- * group rather than by testing the site-wide aggregation setting. This allows
- * this class to work correctly even if modules have implemented custom
- * logic for grouping and aggregating files.
  */
 class CssCollectionRenderer implements AssetCollectionRendererInterface {
 
@@ -90,126 +46,30 @@
         'rel' => 'stylesheet',
       ],
     ];
-    $style_element_defaults = [
-      '#type' => 'html_tag',
-      '#tag' => 'style',
-    ];
 
-    // For filthy IE hack.
-    $current_ie_group_keys = NULL;
-    $get_ie_group_key = function ($css_asset) {
-      return [$css_asset['type'], $css_asset['preprocess'], $css_asset['group'], $css_asset['media'], $css_asset['browsers']];
-    };
+    foreach ($css_assets as $css_asset) {
+      $element = $link_element_defaults;
+      $element['#attributes']['media'] = $css_asset['media'];
+      $element['#browsers'] = $css_asset['browsers'];
 
-    // Loop through all CSS assets, by key, to allow for the special IE
-    // workaround.
-    $css_assets_keys = array_keys($css_assets);
-    for ($i = 0; $i < count($css_assets_keys); $i++) {
-      $css_asset = $css_assets[$css_assets_keys[$i]];
       switch ($css_asset['type']) {
-        // For file items, there are three possibilities.
-        // - There are up to 31 CSS assets on the page (some of which may be
-        //   aggregated). In this case, output a LINK tag for file CSS assets.
-        // - There are more than 31 CSS assets on the page, yet we must stay
-        //   below IE<10's limit of 31 total CSS inclusion tags, we handle this
-        //   in two ways:
-        //    - file CSS assets that are not eligible for aggregation (their
-        //      'preprocess' flag has been set to FALSE): in this case, output a
-        //      LINK tag.
-        //    - file CSS assets that can be aggregated (and possibly have been):
-        //      in this case, figure out which subsequent file CSS assets share
-        //      the same key properties ('group', 'media' and 'browsers') and
-        //      output this group into as few STYLE tags as possible (a STYLE
-        //      tag may contain only 31 @import statements).
+        // For file items, output a LINK tag for file CSS assets.
         case 'file':
           // The dummy query string needs to be added to the URL to control
           // browser-caching.
           $query_string_separator = (strpos($css_asset['data'], '?') !== FALSE) ? '&' : '?';
-
-          // As long as the current page will not run into IE's limit for CSS
-          // assets: output a LINK tag for a file CSS asset.
-          if (count($css_assets) <= 31) {
-            $element = $link_element_defaults;
-            $element['#attributes']['href'] = file_url_transform_relative(file_create_url($css_asset['data'])) . $query_string_separator . $query_string;
-            $element['#attributes']['media'] = $css_asset['media'];
-            $element['#browsers'] = $css_asset['browsers'];
-            $elements[] = $element;
-          }
-          // The current page will run into IE's limits for CSS assets: work
-          // around these limits by performing a light form of grouping.
-          // Once Drupal only needs to support IE10 and later, we can drop this.
-          else {
-            // The file CSS asset is ineligible for aggregation: output it in a
-            // LINK tag.
-            if (!$css_asset['preprocess']) {
-              $element = $link_element_defaults;
-              $element['#attributes']['href'] = file_url_transform_relative(file_create_url($css_asset['data'])) . $query_string_separator . $query_string;
-              $element['#attributes']['media'] = $css_asset['media'];
-              $element['#browsers'] = $css_asset['browsers'];
-              $elements[] = $element;
-            }
-            // The file CSS asset can be aggregated, but hasn't been: combine
-            // multiple items into as few STYLE tags as possible.
-            else {
-              $import = [];
-              // Start with the current CSS asset, iterate over subsequent CSS
-              // assets and find which ones have the same 'type', 'group',
-              // 'preprocess', 'media' and 'browsers' properties.
-              $j = $i;
-              $next_css_asset = $css_asset;
-              $current_ie_group_key = $get_ie_group_key($css_asset);
-              do {
-                // The dummy query string needs to be added to the URL to
-                // control browser-caching. IE7 does not support a media type on
-                // the @import statement, so we instead specify the media for
-                // the group on the STYLE tag.
-                $import[] = '@import url("' . Html::escape(file_url_transform_relative(file_create_url($next_css_asset['data'])) . '?' . $query_string) . '");';
-                // Move the outer for loop skip the next item, since we
-                // processed it here.
-                $i = $j;
-                // Retrieve next CSS asset, unless there is none: then break.
-                if ($j + 1 < count($css_assets_keys)) {
-                  $j++;
-                  $next_css_asset = $css_assets[$css_assets_keys[$j]];
-                }
-                else {
-                  break;
-                }
-              } while ($get_ie_group_key($next_css_asset) == $current_ie_group_key);
-
-              // In addition to IE's limit of 31 total CSS inclusion tags, it
-              // also has a limit of 31 @import statements per STYLE tag.
-              while (!empty($import)) {
-                $import_batch = array_slice($import, 0, 31);
-                $import = array_slice($import, 31);
-                $element = $style_element_defaults;
-                // This simplifies the JavaScript regex, allowing each line
-                // (separated by \n) to be treated as a completely different
-                // string. This means that we can use ^ and $ on one line at a
-                // time, and not worry about style tags since they'll never
-                // match the regex.
-                $element['#value'] = "\n" . implode("\n", $import_batch) . "\n";
-                $element['#attributes']['media'] = $css_asset['media'];
-                $element['#browsers'] = $css_asset['browsers'];
-                $elements[] = $element;
-              }
-            }
-          }
+          $element['#attributes']['href'] = file_url_transform_relative(file_create_url($css_asset['data'])) . $query_string_separator . $query_string;
           break;
 
-        // Output a LINK tag for an external CSS asset. The asset's 'data'
-        // property contains the full URL.
         case 'external':
-          $element = $link_element_defaults;
           $element['#attributes']['href'] = $css_asset['data'];
-          $element['#attributes']['media'] = $css_asset['media'];
-          $element['#browsers'] = $css_asset['browsers'];
-          $elements[] = $element;
           break;
 
         default:
           throw new \Exception('Invalid CSS asset type.');
       }
+
+      $elements[] = $element;
     }
 
     return $elements;