Nelson 寫些 iOS 開發的東東

第一版：單純使用 AFNetworking

APIManager

UserViewController

第二版：用 RACSignal 包起來

APIManager

UserViewController

APIManager

第四版：改成 MVVM 模式

UserViewModel

UserViewController

看起來似乎差不多？

Dependencies are most often found in network requests, where a previous request to the server needs to complete before the next one can be constructed, and so on:

ReactiveCocoa makes this pattern particularly easy: