code: public function getCurrentMenu($menu_flag = null)
      {
          // 当前菜单
          $current_menu = $this->getMenuByFlag($menu_flag);
          if (empty($current_menu)) {
              return null;
          }
          
          // 上级菜单
          $parent_menu = $this->model->get($current_menu['menu_pid']);
          if ($parent_menu['menu_pid'] > 0) {
              return $this->getCurrentMenu($parent_menu['menu_flag']);
          } else {
              return $current_menu;
          }
      }
docs: 当前菜单
  
  @param string $menu_flag
  @return array