public static function render($pageFile, $parameters = [], $theme = null)
    {
        if (!$theme && (!$theme = Theme::getActiveTheme())) {
            throw new CmsException(Lang::get('cms::lang.theme.active.not_found'));
        }

        $controller = new static($theme);
        $controller->getRouter()->setParameters($parameters);

        if (($page = Page::load($theme, $pageFile)) === null) {
            throw new CmsException(Lang::get('cms::lang.page.not_found_name', ['name'=>$pageFile]));
        }

        return $controller->runPage($page, false);
    }