Why

绑定

Observable.combineLatest(firstName.rx_text, lastName.rx_text) { $0 + " " + $1 }
    .map { "Greetings, \($0)" }
    .bindTo(greetingLabel.rx_text) 

也可以适用于UITableView 和 UICollectionView。即使简单的绑定，官方也推荐使用.addDisposableTo(disposeBag)

重试

func doSomethingIncredible(forWho: String) throws -> IncredibleThing

doSomethingIncredible("me")
    .retry(3)

抛出错误时可以重试。

代理

self.resultsTableView
    .rx_contentOffset
    .map { $0.x }
    .bindTo(self.leftPositionConstraint.rx_constant)

KVO

使用rx_observe 和 rx_observeWeakly

view.rx_observe(CGRect.self, "frame")
    .subscribeNext { frame in
        print("Got new frame \(frame)")
    }

或者

someSuspiciousViewController
    .rx_observeWeakly(Bool.self, "behavingOk")
    .subscribeNext { behavingOk in
        print("Cats can purr? \(behavingOk)")
    }

通知

NSNotificationCenter.defaultCenter()
    .rx_notification(UITextViewTextDidBeginEditingNotification, object: myTextView)
    .map { /*do something with data*/ }

瞬时状态

1. 不必要的请求
2. 请求失败
3. 延时请求
4. 执行请求的时候展示什么
5. 重试完也出现错误
   searchTextField.rx_text
   .throttle(0.3, scheduler: MainScheduler.instance)
   .distinctUntilChanged()
   .flatMapLatest { query in
   API.getSearchResults(query)
   .retry(3)
   .startWith([]) // clears results on new search term
   .catchErrorJustReturn([])
   }
   .subscribeNext { results in
   // bind to ui
   }

组合处理

1. 可以灵活取消
2. 不马上开始
3. 限制操作数量
   // this is a conceptual solution
   let imageSubscription = imageURLs
   .throttle(0.2, scheduler: MainScheduler.instance)
   .flatMapLatest { imageURL in
   API.fetchImage(imageURL)
   }
   .observeOn(operationScheduler)
   .map { imageData in
   return decodeAndBlurImage(imageData)
   }
   .observeOn(MainScheduler.instance)
   .subscribeNext { blurredImage in
   imageView.image = blurredImage
   }
   .addDisposableTo(reuseDisposeBag)

合并网络请求

• zip：合并请求
  let userRequest: Observable = API.getUser("me")
  let friendsRequest: Observable = API.getFriends("me")

  Observable.zip(userRequest, friendsRequest) { user, friends in
    return (user, friends)
  }
  .subscribeNext { user, friends in
    // bind them to the user interface
  }
  

• observeOn：切换线程
  let userRequest: Observable = API.getUser("me")
  let friendsRequest: Observable<[Friend]> = API.getFriends("me")

  Observable.zip(userRequest, friendsRequest) { user, friends in
    return (user, friends)
  }
  .observeOn(MainScheduler.instance)
  .subscribeNext { user, friends in
    // bind them to the user interface
  }
  

容易集成

  extension NSURLSession {
    public func rx_response(request: NSURLRequest) -> Observable<(NSData, NSURLResponse)> {
        return Observable.create { observer in
            let task = self.dataTaskWithRequest(request) { (data, response, error) in
                guard let response = response, data = data else {
                    observer.on(.Error(error ?? RxCocoaURLError.Unknown))
                    return
                }

                guard let httpResponse = response as? NSHTTPURLResponse else {
                    observer.on(.Error(RxCocoaURLError.NonHTTPResponse(response: response)))
                    return
                }

                observer.on(.Next(data, httpResponse))
                observer.on(.Completed)
            }

            task.resume()

            return AnonymousDisposable {
                task.cancel()
            }
        }
    }
  }

好处

• 可以组合的 <- 因为 Rx 是组合的昵称
• 可复用的 <- 因为它是可组合的
• 可声明的 <- 因为定义是不可改变的，而只是数据改变
• 可理解的和简洁的 <- 提高抽象水平并且移除过渡状态
• 稳定的 <- 因为 Rx 代码通过了单元测试
• 更少的状态 <- 因为你是单向数据流的建模应用程序
• 没有泄露 <- 因为资源管理是容易的

In short, using Rx will make your code:
Composable <- Because Rx is composition's nickname
Reusable <- Because it's composable
Declarative <- Because definitions are immutable and only data changes
Understandable and concise <- Raising the level of abstraction and removing transient states
Stable <- Because Rx code is thoroughly unit tested
Less stateful <- Because you are modeling applications as unidirectional data flows
Without leaks <- Because resource management is easy