ReactiveSwift 动作 observeResult 没有 return 像它应该的那样失败

Question

现在我对 ReactiveSwift 很感兴趣，并尝试将其添加到项目的网络操作中。但是有一些关于 action return type with observeResult 方法的问题。

查看模型：

final class TestViewModel: ViewModel {

    var getListAction: Action<Void, Void, APIError>!

    var arr = NSMutableArray()

    override init() {

        super.init()

        self.getListBuild()

    }

    func getListBuild() {

        getListAction = Action<Void, Void, APIError> { _ in
            let signalProducer = SignalProducer<Void, APIError> { observer, disposable in
                self.getList(observer)
            }
            return signalProducer
        }

        getListAction.apply().start()
    }


    func getList(_ observer: Observer<Void, APIError>) {

        Network<UserDetailInfo>().requestList(router: RegistrationRouter(endpoint:.Login())).take(during: lifetime).startWithResult { (result) in
            switch result {
            case let .success(value):
                self.arr = value as! NSMutableArray
                print("success")
                observer.sendCompleted()
            case let .failure(error):
                print("abort: \(String(describing: error.message))")
                observer.send(error: error)
            }
        }
    }
}

我尝试通过控制器来管理它：

final class ViewController: View {

    var viewModel: TestViewModel?

    func bindViewModel() {

        self.viewModel = TestViewModel()

        self.viewModel?.getListAction.events.take(during: lifetime).observeResult { (result) in
            switch result {
            case .success(_):
                print("success")
                print(self.viewModel?.arr.count as Any)
                break
            case let .failure(error):
                print(error.localizedDescription);
                break
            }
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        self.bindViewModel()
    }
}

尽管 viewModel 中的 getList 方法 returning 失败，情况如下：

方法 returned 成功，但事实并非如此。应该是失败。请让我了解一下这个主题的问题所在。

Answer 1

您观察到的 event 流永远不会 return 失败。请参阅其文档：

/// A signal of all events generated from applications of the Action.
///
/// In other words, this will send every `Event` from every signal generated
/// by each SignalProducer returned from apply() except `ActionError.disabled`.
public let events: Signal<Event<Output, Error>, NoError>

要观察成功的值，您需要订阅 values 并使用 observeValues:

self.viewModel?.getListAction
   .values
   .take(during: lifetime)
   .observeValues { [weak self] value in
      // always successful
   }

如果你想观察错误，你可以订阅errors并使用observeValues。

self.viewModel?.getListAction
   .errors
   .take(during: lifetime)
   .observeValues { [weak self] error in
      // error event
   }

ReactiveSwift 动作 observeResult 没有 return 像它应该的那样失败

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