ios - RxSwift - 订阅一个方法

Question

RxSwift 有没有办法订阅一个返回完成 block 的方法？

例如，让我们有这个对象:

struct Service {

    private var otherService = ...
    private var initSucceeded = PublishSubject<Bool>()

    var initSucceededObservale: Observable<Bool> {
        return initSucceeded.asObservable()
    }

    func init() {
        otherService.init {(success) in
            self.initSucceeded.onNext( success)
        }
    }
}

并且在不同的地方有一种方法可以在服务初始化时得到通知:

service.initSucceededObservable.subscribe(onNext: {
    [unowned self] (value) in
    ...
}).addDisposableTo(disposeBag)

service.init()

有没有更简单的解决方案？

Answer 1

我喜欢为这类事情使用变量。另外，我建议在这里使用类，因为您要跟踪独特的状态，而不仅仅是关心自己的值(value)。

class Service {
    private let bag = DisposeBag()
    public var otherService: Service?

    private var isInitializedVariable = Variable<Bool>(false)

    public var isInitialized: Observable<Bool> {
        return isInitializedVariable.asObservable()
    }

    public init(andRelyOn service: Service? = nil) {
        otherService = service

        otherService?.isInitialized
            .subscribe(onNext: { [unowned self] value in
                self.isInitializedVariable.value = value
            })
            .addDisposableTo(bag)
    }

    public func initialize() {
        isInitializedVariable.value = true
    }

}

var otherService = Service()
var dependentService = Service(andRelyOn: otherService)

dependentService.isInitialized
                .debug()
                .subscribe({
                    print($0)
                })

otherService.initialize() // "Initializes" the first service, causing the second to set it's variable to true.