Simulate RxSwift

SimulateRxSwift.swift

class DisposeBag {
    var delegate: RxSimulator?
    deinit {
        print("test11 DisposeBag deinit")
        delegate = nil
    }
}

class RxSimulator {
    var action: ((Bool) -> Void)? = nil
    weak var disposeBag: DisposeBag?

    func createObservable(closure: ((Bool) -> Void)? = nil) -> RxSimulator {
        action = closure
        return self
    }

    func subscribe(callback: ((Bool) -> Void)? = nil) -> RxSimulator {
        action = callback
        return self
    }

    func onNext(val: Bool) {
        action?(val)
    }

    func disposed(by disposeBag: DisposeBag) {
        self.disposeBag = disposeBag
        self.disposeBag?.delegate = self
    }

    deinit {
        print("test11 RxSimulator deinit")
    }
}

class ViewController: UIViewController {
    var disposeBag: DisposeBag? = DisposeBag()
    override func viewDidLoad() {
        super.viewDidLoad()        
        if let disposeBag = disposeBag {
            let myClosure: ((Bool) -> Void)? =  { input in
                print("execute myClosure")
            }
            let observable = RxSimulator().createObservable(closure: myClosure)
            observable.subscribe { result in
                print("test11 In subscribe,  result is: \(result)")
            }.disposed(by: disposeBag)
            DispatchQueue.global().asyncAfter(deadline: .now() + 3) {
                print("test11 execute observable.onNext")
                observable.onNext(val: true)
            }
            DispatchQueue.global().asyncAfter(deadline: .now() + 5) {
                self.disposeBag = nil
            }
        }
    }
}