Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Asset;
Chris@0: 
Chris@0: use Drupal\Core\State\StateInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Renders CSS assets.
Chris@0:  */
Chris@0: class CssCollectionRenderer implements AssetCollectionRendererInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The state key/value store.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\State\StateInterface
Chris@0:    */
Chris@0:   protected $state;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a CssCollectionRenderer.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\State\StateInterface $state
Chris@0:    *   The state key/value store.
Chris@0:    */
Chris@0:   public function __construct(StateInterface $state) {
Chris@0:     $this->state = $state;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function render(array $css_assets) {
Chris@0:     $elements = [];
Chris@0: 
Chris@0:     // A dummy query-string is added to filenames, to gain control over
Chris@0:     // browser-caching. The string changes on every update or full cache
Chris@0:     // flush, forcing browsers to load a new copy of the files, as the
Chris@0:     // URL changed.
Chris@0:     $query_string = $this->state->get('system.css_js_query_string') ?: '0';
Chris@0: 
Chris@0:     // Defaults for LINK and STYLE elements.
Chris@0:     $link_element_defaults = [
Chris@0:       '#type' => 'html_tag',
Chris@0:       '#tag' => 'link',
Chris@0:       '#attributes' => [
Chris@0:         'rel' => 'stylesheet',
Chris@0:       ],
Chris@0:     ];
Chris@0: 
Chris@18:     foreach ($css_assets as $css_asset) {
Chris@18:       $element = $link_element_defaults;
Chris@18:       $element['#attributes']['media'] = $css_asset['media'];
Chris@18:       $element['#browsers'] = $css_asset['browsers'];
Chris@0: 
Chris@0:       switch ($css_asset['type']) {
Chris@18:         // For file items, output a LINK tag for file CSS assets.
Chris@0:         case 'file':
Chris@0:           // The dummy query string needs to be added to the URL to control
Chris@0:           // browser-caching.
Chris@0:           $query_string_separator = (strpos($css_asset['data'], '?') !== FALSE) ? '&' : '?';
Chris@18:           $element['#attributes']['href'] = file_url_transform_relative(file_create_url($css_asset['data'])) . $query_string_separator . $query_string;
Chris@0:           break;
Chris@0: 
Chris@0:         case 'external':
Chris@0:           $element['#attributes']['href'] = $css_asset['data'];
Chris@0:           break;
Chris@0: 
Chris@0:         default:
Chris@0:           throw new \Exception('Invalid CSS asset type.');
Chris@0:       }
Chris@18: 
Chris@18:       $elements[] = $element;
Chris@0:     }
Chris@0: 
Chris@0:     return $elements;
Chris@0:   }
Chris@0: 
Chris@0: }