Hook特性允许我们对特性的Model绑定CURD钩子处理。

相关定义

相关Hook函数：

  1. type (
  2.     HookFuncSelect func(ctx context.Context, in *HookSelectInput) (result Result, err error)
  3.     HookFuncInsert func(ctx context.Context, in *HookInsertInput) (result sql.Result, err error)
  4.     HookFuncUpdate func(ctx context.Context, in *HookUpdateInput) (result sql.Result, err error)
  5.     HookFuncDelete func(ctx context.Context, in *HookDeleteInput) (result sql.Result, err error)
  6. )
  8. // HookHandler manages all supported hook functions for Model.
  9. type HookHandler struct {
  10.     Select HookFuncSelect
  11.     Insert HookFuncInsert
  12.     Update HookFuncUpdate
  13.     Delete HookFuncDelete
  14. }

Hook注册方法：

  1. // Hook sets the hook functions for current model.
  2. func (m *Model) Hook(hook HookHandler) *Model

使用示例

查询birth_day字段时，同时计算出当前用户的年龄：

  1. // Hook function definition.
  2. var hook = gdb.HookHandler{
  3.     Select: func(ctx context.Context, in *gdb.HookSelectInput) (result gdb.Result, err error) {
  4.         result, err = in.Next(ctx)
  5.         if err != nil {
  6.             return
  7.         }
  8.         for i, record := range result {
  9.             if !record["birth_day"].IsEmpty() {
  10.                 age := gtime.Now().Sub(record["birth_day"].GTime()).Hours() / 24 / 365
  11.                 record["age"] = gvar.New(age)
  12.             }
  13.             result[i] = record
  14.         }
  15.         return
  16.     },
  17. }
  18. // It registers hook function, creates and returns a new `model`.
  19. model := g.Model("user").Hook(hook)
  21. // The hook function takes effect on each ORM operation when using the `model`.
  22. all, err := model.Where("status", "online").OrderAsc(`id`).All()