JsCollectionRenderer::render

public JsCollectionRenderer::render(array $js_assets)

public function render(array $js_assets) {
  $elements = array();

  // 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. Files that should not be cached get REQUEST_TIME as
  // query-string instead, to enforce reload on every page request.
  $default_query_string = $this->state->get('system.css_js_query_string') ? : '0';

  // Defaults for each SCRIPT element.
  $element_defaults = array(
    '#type' => 'html_tag',
    '#tag' => 'script',
    '#value' => '',
  );

  // Loop through all JS assets.
  foreach ($js_assets as $js_asset) {
    // Element properties that do not depend on JS asset type.
    $element = $element_defaults;
    $element['#browsers'] = $js_asset['browsers'];

    // Element properties that depend on item type.
    switch ($js_asset['type']) {
      case 'setting':
        $element['#attributes'] = array(
          // This type attribute prevents this from being parsed as an
          // inline script.
          'type' => 'application/json',
          'data-drupal-selector' => 'drupal-settings-json',
        );
        $element['#value'] = Json::encode($js_asset['data']);
        break;

      case 'file':
        $query_string = $js_asset['version'] == -1 ? $default_query_string : 'v=' . $js_asset['version'];
        $query_string_separator = (strpos($js_asset['data'], '?') !== FALSE) ? '&' : '?';
        $element['#attributes']['src'] = file_url_transform_relative(file_create_url($js_asset['data']));
        // Only add the cache-busting query string if this isn't an aggregate
        // file.
        if (!isset($js_asset['preprocessed'])) {
          $element['#attributes']['src'] .= $query_string_separator . ($js_asset['cache'] ? $query_string : REQUEST_TIME);
        }
        break;

      case 'external':
        $element['#attributes']['src'] = $js_asset['data'];
        break;

      default:
        throw new \Exception('Invalid JS asset type.');
    }

    // Attributes may only be set if this script is output independently.
    if (!empty($element['#attributes']['src']) && !empty($js_asset['attributes'])) {
      $element['#attributes'] += $js_asset['attributes'];
    }

    $elements[] = $element;
  }

  return $elements;
}