function system_js_settings_build

Implements hook_js_settings_build().

Sets values for the core/drupal.ajax library, which just depends on the active theme but no other request-dependent values.

File

core/modules/system/system.module, line 685

Code

function system_js_settings_build(&$settings, AttachedAssetsInterface $assets) {
    // Generate the values for the core/drupal.ajax library.
    // We need to send ajaxPageState settings for core/drupal.ajax if:
    // - ajaxPageState is being loaded in this Response, in which case it will
    //   already exist at $settings['ajaxPageState'] (because the core/drupal.ajax
    //   library definition specifies a placeholder 'ajaxPageState' setting).
    // - core/drupal.ajax already has been loaded and hence this is an AJAX
    //   Response in which we must send the list of extra asset libraries that are
    //   being added in this AJAX Response.
    
    /** @var \Drupal\Core\Asset\LibraryDependencyResolver $library_dependency_resolver */
    $library_dependency_resolver = \Drupal::service('library.dependency_resolver');
    if (isset($settings['ajaxPageState']) || in_array('core/drupal.ajax', $library_dependency_resolver->getLibrariesWithDependencies($assets->getAlreadyLoadedLibraries()))) {
        // Provide the page with information about the theme that's used, so that
        // a later AJAX request can be rendered using the same theme.
        // @see \Drupal\Core\Theme\AjaxBasePageNegotiator
        $theme_key = \Drupal::theme()->getActiveTheme()
            ->getName();
        $settings['ajaxPageState']['theme'] = $theme_key;
    }
}