code: public function getSiderMenu($user_id)
      {
          // 当前菜单
          $current_menu = $this->getCurrentMenu();
          
          if (empty($current_menu)) {
              return [];
          } else {
              $sider_menu = $this->getMenuByPid($current_menu['menu_pid'], $user_id);
              foreach ($sider_menu as &$menu) {
                  if (isset($menu['sub_menu'])) {
                      $menu['menu_active'] = 0;
                      foreach ($menu['sub_menu'] as &$item) {
                          if ($item['menu_id'] == $current_menu['id']) {
                              $item['menu_active'] = 1;
                              $menu['menu_active'] = 1;
                          } else {
                              $item['menu_active'] = 0;
                          }
                      }
                      unset($item);
                  } else {
                      if ($menu['menu_id'] == $current_menu['id']) {
                          $menu['menu_active'] = 1;
                      } else {
                          $menu['menu_active'] = 0;
                      }
                  }
              }
              unset($menu);
              return $sider_menu;
          }
      }
docs: 侧边菜单
  
  @param number $user_id
  @return array