public static void UseLambda(this Cloud cloud)
{
// case 1. use EngineObjectHookContext
cloud.UseHook("Todo", EngineHookType.BeforeSave, (context) =>
{
var todo = context.TheObject;
var by = context.By;
return(Task.FromResult(context.TheObject));
});
cloud.BeforeSave("Todo", (context) =>
{
return(Task.FromResult(context.TheObject));
});
// case 2. use TheObject
cloud.UseHook("Todo", EngineHookType.BeforeSave, (AVObject todoObj) =>
{
return(Task.FromResult(todoObj));
});
cloud.BeforeSave("Todo", (AVObject todoObj) =>
{
return(Task.FromResult(todoObj));
});
// case 3. use TheObject and user
cloud.UseHook("Todo", EngineHookType.BeforeSave, (AVObject todoObj, AVUser by) =>
{
return(Task.FromResult(todoObj));
});
cloud.BeforeSave("Todo", (AVObject todoObj, AVUser by) =>
{
return(Task.FromResult(todoObj));
});
// case 3. use sub-class
AVObject.RegisterSubclass <Todo>();
cloud.UseHook <Todo>(EngineHookType.BeforeSave, (Todo theTodoObj) =>
{
// theTodoObj is an Todo instance.
return(Task.FromResult(theTodoObj));
});
cloud.UseHook <Todo>(EngineHookType.BeforeSave, (Todo theTodoObj, AVUser by) =>
{
return(Task.FromResult(theTodoObj));
});
cloud.BeforeSave <Todo>((todo) =>
{
// todo is an Todo instance.
return(Task.FromResult(todo));
});
cloud.BeforeSave <Todo>((todo, by) =>
{
// todo is an Todo instance.
return(Task.FromResult(todo));
});
cloud.BeforeUpdate("Todo", review =>
{
var updatedKeys = review.GetUpdatedKeys();
if (updatedKeys.Contains("comment"))
{
var comment = review.Get <string>("comment");
if (comment.Length > 140)
{
throw new EngineException(400, "comment 长度不得超过 140 字符");
}
}
return(Task.FromResult(true));
});
EngineHookDelegateSynchronous afterPostHook = (post) =>
{
};
cloud.AfterSave("Post", (EngineObjectHookDeltegateSynchronous)(async post =>
{
// 直接修改并保存对象不会再次触发 after update hook 函数
post["foo"] = "bar";
await post.SaveAsync();
// 如果有 FetchAsync 操作，则需要在新获得的对象上调用相关的 disable 方法
// 来确保不会再次触发 Hook 函数
await post.FetchAsync();
post.DisableAfterHook();
post["foo"] = "bar";
// 如果是其他方式构建对象，则需要在新构建的对象上调用相关的 disable 方法
// 来确保不会再次触发 Hook 函数
post = AVObject.CreateWithoutData <AVObject>(post.ObjectId);
post.DisableAfterHook();
await post.SaveAsync();
}));
}
