RxSwift - subscribe to a method - ios

Question

Is there a way with RxSwift to subscribe to a method which returns a completion block?
Example, let's have this object:
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)
}
}
}
And in a different place have a way to be notified when the service has been initialised:
service.initSucceededObservable.subscribe(onNext: {
[unowned self] (value) in
...
}).addDisposableTo(disposeBag)
service.init()
Would be there a simpler solution?

Answer 1

I like to use Variables for this sort of thing. Also, I'd recommend using class here because you're tracking unique states and not just concerning yourself with values.
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.

Answer 2

You could use a lazy property:
lazy let initSucceededObservale: Observable<Bool> = {
return Observable.create { observer in
self.otherService.init {(success) in
observer.on(.next(success))
observer.on(.completed)
}
return Disposables.create()
}
}()
and then you can use:
service.init()
service.initSucceededObservable.subscribe(onNext: {
[unowned self] (value) in
...
}).addDisposableTo(disposeBag)
Let me know in the comments if you have problems before downvoting, thanks.