yii\bootstrap\Nav::isChildActive PHP Метод

    protected function isChildActive($items, &$active)
    {
        foreach ($items as $i => $child) {
            if (ArrayHelper::remove($items[$i], 'active', false) || $this->isItemActive($child)) {
                Html::addCssClass($items[$i]['options'], 'active');
                if ($this->activateParents) {
                    $active = true;
                }
            }
        }
        return $items;
    }