function JsCollectionRenderer::render

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.

Overrides AssetCollectionRendererInterface::render

File

core/lib/Drupal/Core/Asset/JsCollectionRenderer.php, line 54

Class

JsCollectionRenderer

Renders JavaScript assets.

Namespace

Code

public function render(array $js_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. 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.
    $element_defaults = [
        '#type' => 'html_tag',
        '#tag' => 'script',
        '#value' => '',
    ];
    // Loop through all JS assets.
    foreach ($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'] = [
                    // 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'] = $this->fileUrlGenerator
                    ->generateString($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;
}