class CssCollectionRenderer in Drupal 8

Renders CSS assets.

Hierarchy

• class \Drupal\Core\Asset\CssCollectionRenderer implements AssetCollectionRendererInterface

1 file declares its use of CssCollectionRenderer

CssCollectionRendererUnitTest.php in core/tests/Drupal/Tests/Core/Asset/CssCollectionRendererUnitTest.php

1 string reference to 'CssCollectionRenderer'

core.services.yml in core/core.services.yml

core/core.services.yml

1 service uses CssCollectionRenderer

asset.css.collection_renderer in core/core.services.yml

Drupal\Core\Asset\CssCollectionRenderer

File

core/lib/Drupal/Core/Asset/CssCollectionRenderer.php, line 10

Namespace

Drupal\Core\Asset

class CssCollectionRenderer implements AssetCollectionRendererInterface {

  /**
   * The state key/value store.
   *
   * @var \Drupal\Core\State\StateInterface
   */
  protected $state;

  /**
   * Constructs a CssCollectionRenderer.
   *
   * @param \Drupal\Core\State\StateInterface $state
   *   The state key/value store.
   */
  public function __construct(StateInterface $state) {
    $this->state = $state;
  }

  /**
   * {@inheritdoc}
   */
  public function render(array $css_assets) {
    $elements = [];

    // A dummy query-string is added to filenames, to gain control over
    // browser-caching. The string changes on every update or full cache
    // flush, forcing browsers to load a new copy of the files, as the
    // URL changed.
    $query_string = $this->state
      ->get('system.css_js_query_string', '0');

    // Defaults for LINK and STYLE elements.
    $link_element_defaults = [
      '#type' => 'html_tag',
      '#tag' => 'link',
      '#attributes' => [
        'rel' => 'stylesheet',
      ],
    ];
    foreach ($css_assets as $css_asset) {
      $element = $link_element_defaults;
      $element['#attributes']['media'] = $css_asset['media'];
      $element['#browsers'] = $css_asset['browsers'];
      switch ($css_asset['type']) {

        // For file items, output a LINK tag for file CSS assets.
        case 'file':
          $element['#attributes']['href'] = file_url_transform_relative(file_create_url($css_asset['data']));

          // Only add the cache-busting query string if this isn't an aggregate
          // file.
          if (!isset($css_asset['preprocessed'])) {
            $query_string_separator = strpos($css_asset['data'], '?') !== FALSE ? '&' : '?';
            $element['#attributes']['href'] .= $query_string_separator . $query_string;
          }
          break;
        case 'external':
          $element['#attributes']['href'] = $css_asset['data'];
          break;
        default:
          throw new \Exception('Invalid CSS asset type.');
      }

      // Merge any additional attributes.
      if (!empty($css_asset['attributes'])) {
        $element['#attributes'] += $css_asset['attributes'];
      }
      $elements[] = $element;
    }
    return $elements;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
CssCollectionRenderer::$state	protected	property	The state key/value store.
CssCollectionRenderer::render	public	function	Renders an asset collection. Overrides AssetCollectionRendererInterface::render
CssCollectionRenderer::__construct	public	function	Constructs a CssCollectionRenderer.