ios - RxSwift : tap a button to do a request with Alamofire, 如何让它工作？

Question

我有一些 UI rx 按钮点击，我想将它连接到网络 rx 部分。

这是 Rx btn tap 部分:

btn.rx.tap.take(1).flatMap {  [unowned self]  () -> Observable<Bool>  in
            // ...
            return NetManager.standard.request()
        }.debug().do(onNext: { _ in
                print("The data flows here")
            }).flatMapLatest { (echo: Bool) -> Observable<Bool> in
            if echo{
                if let app = UIApplication.shared.delegate as? AppDelegate{
                    app.goHome()
                }
                return Observable.of(true)
            }
            else{
                return Observable.of(false)
            }
        }.subscribe(onNext: { (result) in
            // ... , do sth with result
        }).disposed(by: rx.disposeBag)

这是 Alamofire 的网络请求部分:

class NetManager: NSObject {
    
    static let standard = NetManager()
    var dataRequest: DataRequest?
    
    func request() -> Observable<Bool> {
           return Observable<Bool>.create{ (observer) -> Disposable in
                    let data = // ...
                    // ...
                    self.dataRequest = AF.request(aURL, method: HTTPMethod.post, parameters: data, encoder: JSONParameterEncoder.prettyPrinted, headers: aHead).response { (response: DataResponse<Data?>) in
                            self.hud?.hide()
                           if let data = response.data{
                               observer.onNext(true)
                                // ....
                           }
                           else{
                               observer.onNext(false)
                           }
                       }
                    observer.onCompleted()
                    return Disposables.create{}
           }
       }
    
}

这是调试信息:

Controller.swift:141 (viewDidLoad()) -> subscribed

Controller.swift:141 (viewDidLoad()) -> Event completed

Controller.swift:141 (viewDidLoad()) -> isDisposed

结果是，do(next) 部分似乎还没有被调用。因为控制台中没有print。

---

问题是，如何让 rx 逻辑工作？

---

这是我尝试过的:

将btn.rx.tap.flatMap 转为btn.rx.tap.take(1).flatMap

因为来自 this issue

if a flatMap completion would terminate the outer stream, it would mean that no more button taps would be registered in your stream, which don't really make sense.

---

来自this question

  btn.rx.tap.map { () -> Observable<Bool> in

    return NetManager.standard.request()
  }.flatMapLatest { (observer: Observable<Bool>) -> Observable<Bool> in
  
    // of cource, I can subscribe to observer
    /*
     observer.subscribe(onNext: { (echo) in
         
     })
     */
    
    
    // how to get the event element elegantly.
    
    return Observable.of(false)
}.subscribe(onNext: { (_) in
    
}).disposed(by: rx.disposeBag)

如何更优雅地做到这一点。

Answer 1

这里的主要问题是，在执行网络请求时，您没有等待网络调用响应。所以 observer.onComplete() 在 observer.onNext()

之前触发

class NetManager: NSObject {

static let standard = NetManager()
var dataRequest: DataRequest?

func request() -> Observable<Bool> {
       return Observable<Bool>.create { (observer) -> Disposable in
                let data = // ...
                // ...
                self.dataRequest = AF.request(aURL, method: HTTPMethod.post, parameters: data, encoder: JSONParameterEncoder.prettyPrinted, headers: aHead).response { (response: DataResponse<Data?>) in
                        self.hud?.hide()
                       if let data = response.data {
                           observer.onNext(true)
                           // ... 
                       }
                       else {
                           observer.onNext(false)
                       }
                       observer.onComplete() // Moving it here instead will wait for the response
                }
                return Disposables.create { }
       }
   }
}

此时，您的代码应该可以正常工作，但您仍然将一件非常简单的事情复杂化了。

这是要做的事情:

btn.rx.tap
    .flatMap { _ in
        return NetManager.standard.request()
    }
    .subscribe(onNext: { (success) in
        if success {
            if let app = UIApplication.shared.delegate as? AppDelegate {
                app.goHome()
            }
        } 
    })
    .disposed(by: rx.disposeBag)