RXSwift simple async example? - swift

Question

I'm new in RXSwift, I just try to implement a simple async example
but subscribe will never be called.
What I miss ?
let disposeBag = DisposeBag()
Observable<Any>.create {
observer in
DispatchQueue.global(qos: .background).asyncAfter(deadline: .now() + 3) {
observer.onNext("done")
observer.onCompleted()
}
return Disposables.create()
}
.subscribe { print($0) }
.addDisposableTo(disposeBag)
================= UPDATE ======================
I'm trying to do something more advanced, a chain which allow pass value from previous, but the result was not expected. what I miss ?
output was
next(done 1 - done 2)
what I expected was
next(done 1)
next(done 1 - done 2)
completed
class AsyncObject {
func asyncTest1() -> Observable<String> {
return Observable<String>.create {
(o: AnyObserver<String>) -> Disposable in
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
o.onNext("done 1")
o.onCompleted()
}
return Disposables.create()
}
}
func asyncTest2(value: String) -> Observable<String> {
return Observable<String>.create {
(o: AnyObserver<String>) -> Disposable in
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
o.onNext("\(value) - done 2")
o.onCompleted()
}
return Disposables.create()
}
}
}
class ViewController: UIViewController {
let disposeBag = DisposeBag()
let observer = AsyncObject()
// MARK: Init Methods
override func viewDidLoad() {
super.viewDidLoad()
self.observer.asyncTest1()
.flatMap { self.observer.asyncTest2(value: $0) }
.subscribe { print($0) }
.addDisposableTo(disposeBag)
}
}

Answer 1

I think you can merge this with the original one, to achieve the expected result. So it should look something like this
let test1 = self.observer.asyncTest1()
let test2 = test1.flatMap { self.observer.asyncTest2() }
Observable
.of(test1, test2)
.merge()
.subscribe { print($0) }
.addDisposableTo(disposeBag)

Answer 2

got help from RxSwift Slack #sergdot,
let test1 = self.observer.asyncTest1().shareReplay(1)
let test2 = test1.flatMap { self.observer.asyncTest2(value: $0) }
Observable.of(test1, test2).merge().subscribe {
print($0)
}
or
let test1 = self.observer.asyncTest1().shareReplay(1)
let test2 = test1.flatMap { self.observer.asyncTest2(value: $0) }
test1.concat(test2).subscribe {
print($0)
}