- * to the current URL, to determine whether the link is "active". If so, an
- * "active" class will be applied to the list item containing the link, as
- * well as the link itself. It is important to use this sparingly since it
- * is usually unnecessary and requires extra processing.
- * For anonymous users, the "active" class will be calculated on the server,
- * because most sites serve each anonymous user the same cached page anyway.
- * For authenticated users, the "active" class will be calculated on the
- * client (through JavaScript), only data- attributes are added to list
- * items and contained links, to prevent breaking the render cache. The
- * JavaScript is added in system_page_attachments().
+ * to the current URL, to determine whether the link is "active". If so,
+ * attributes will be added to the HTML elements for both the link and the
+ * list item that contains it, which will result in an "is-active" class
+ * being added to both. The class is added via JavaScript for authenticated
+ * users (in the active-link library), and via PHP for anonymous users (in
+ * the \Drupal\Core\EventSubscriber\ActiveLinkResponseFilter class).