func (c *PermissionController) Save() {
    flash := beego.NewFlash()
    pid, _ := strconv.Atoi(c.Input().Get("pid"))
    name, url, description := c.Input().Get("name"), c.Input().Get("url"), c.Input().Get("description")
    **if pid == 0{
        flash.Error("请添加父节点")
        flash.Store(&c.Controller)
        c.Redirect("/permission/add?pid=", 302)**
    }else if pid > 0 && len(name) == 0 {...}

func (c *PermissionController) Update() {
    flash := beego.NewFlash()
    id, _ := strconv.Atoi(c.Ctx.Input.Param(":id"))
    pid, _ := strconv.Atoi(c.Input().Get("pid"))
    name, url, description := c.Input().Get("name"), c.Input().Get("url"), c.Input().Get("description")
    **if pid == 0{
        flash.Error("请添加父节点")
        flash.Store(&c.Controller)
        c.Redirect("/permission/edit/" + strconv.Itoa(id), 302)**
    }else if pid > 0 && len(name) == 0 {...}

func (c *UserController) UpdateAvatar() {
	flash := beego.NewFlash()
	f, h, err := c.GetFile("avatar")
	**if err == http.ErrMissingFile {
		flash.Error("请先上传文件")
		flash.Store(&c.Controller)
		c.Redirect("/user/setting", 302)
	}**
	defer f.Close()
	if err != nil {
		flash.Error("上传失败")
		flash.Store(&c.Controller)
		c.Redirect("/user/setting", 302)
		return

<tbody>
         {{range .Permissions}}
         <tr>
           <td>{{.Id}}</td>
           <td>{{.Name}}</td>
           <td>{{.Url}}</td>
           <td>{{.Description}}</td>
           <td>
             **{{if ne .Pid 0}}<a href="/permission/edit/{{.Id}}" class="btn btn-xs btn-warning">编辑</a>{{end}}
             {{if ne .Pid 0}}<a href="javascript:if(confirm('确认删除吗?')) location.href='/permission/delete/{{.Id}}'" class="btn btn-xs btn-danger">删除</a>{{end}}**
           </td>
         </tr>
         {{end}}
</tbody>

func DeleteRolePermissionByPermissionId(permission_id int) { 
    o := orm.NewOrm() 
    permission := Permission{Id:permission_id} 
    o.QueryM2M(&permission,"Roles").Clear() 
} 

func DeleteReplyByTopic(topic *Topic) { 

o := orm.NewOrm() 

replies := Reply{Topic:topic} 

o.Delete(&replies) 
} 

func DeleteReplyByUser(user *User) { 

o := orm.NewOrm() 

reply := Reply{User:user} 

o.Delete(&reply) 
} 

func DeleteRolePermissionByRoleId(role_id int) { 
    o := orm.NewOrm() 
    role := Role{Id:role_id} 
    o.QueryM2M(&role,"Permissions").Clear() 
} 

func SaveRolePermission(role_id int, permission_id int) { 
    o := orm.NewOrm() 
    role := Role{Id:role_id} 
    permission := Permission{Id:permission_id} 
    o.QueryM2M(&role,"Permissions").Add(&permission) 
} 

func FindRolePermissionByRoleId(role_id int) []*Permission { 
    o := orm.NewOrm() 
    role := Role{Id:role_id} 
    o.LoadRelated(&role,"Permissions") 
    return role.Permissions 
} 

func FindPermissionByUser(id int) []*Permission { 

o := orm.NewOrm() 

var permissions []*Permission 

o.QueryTable("permission").Filter("Roles__Role__Users__User__Id",id).All(&permissions) 

return permissions 
} 

func FindPermissionByUserIdAndPermissionName(userId int, name string) bool { 

o := orm.NewOrm() 

var permission Permission 

o.QueryTable("permission").Filter("Roles__Role__Users__User__Id",userId).Filter("Name",name).All(&permission) 

return permission.Id > 0 //如果能查到数据，那么id肯定大于0 
} 
 

func DeleteUserRolesByUserId(user_id int) { 

o := orm.NewOrm() 

user := User{Id:user_id} 

o.QueryM2M(&user,"Roles").Clear() //清除所有原始关系 
} 

func SaveUserRole(user_id int, role_id int) { 

o := orm.NewOrm() 

user := User{Id:user_id} 

role := Role{Id:role_id} 

o.QueryM2M(&user,"Roles").Add(&role) 
} 

func FindUserRolesByUserId(user_id int) []*Role { 

o := orm.NewOrm() 

user := User{Id:user_id} 

o.LoadRelated(&user,"Roles") 

return user.Roles 
}