Chaining Network Requests RxSwift - ios

Question

I am relatively new to RxSwift, and functional programming for that matter. I have an app where I need to make a sequential set of network calls, each call depends upon output of the other. How I have architected the app, these calls are not made anywhere close to the view or view controllers - they are handled by data provider classes which perform business logic on the response data. As I understand good Rx design, subscribers should stay at the top of chain, not in classes like these that purely perform business and functional logic on the data.
I am creating a contrived and simplified example for illustration from these requests that return Singles:
func loginRequest(_ data: LoginData) -> Single<LoginResponse> {
return Single.create { observer -> Disposable in
let request = LoginRequestWith(data)
networkClient.send(request) { result in
switch result {
case .success(let response):
observer(.success(response))
case .failure(let error):
observer(.error(error))
}
}
return Disposables.create {
networkClient.cancelRequest()
}
}
}
func userRequest(_ data: UserData) -> Single<UserResponse> {
return Single.create { observer -> Disposable in
let request = InfoRequestWith(data)
networkClient.send(request) { result in
switch result {
case .success(let response):
observer(.success(response))
case .failure(let error):
observer(.error(error))
}
}
return Disposables.create {
networkClient.cancelRequest()
}
}
}
func infoRequest(_ data: InfoData) -> Single<InfoResponse> {
return Single.create { observer -> Disposable in
let request = InfoRequestWith(data)
networkClient.send(request) { result in
switch result {
case .success(let response):
observer(.success(response))
case .failure(let error):
observer(.error(error))
}
}
return Disposables.create {
networkClient.cancelRequest()
}
}
}
These requests are working as intended, however I am calling and handling them improperly using subscriptions / dispose bags in the provider classes to get them to work. What I want to do is chain them together using a FlatMap or more appropriate chain of operators. And this is where I get stuck.
func login() -> Observable<InfoData> {
webServices.loginRequest(loginData)
// verify success?
.flatMap { result in
// Now call userRequest passing the response from the first
// and from that infoRequest passing the response from the second
// Which should return the Observable<InfoData>
}
}
Where I am messing up? I get errors around the FlatMap but I understand that these are best to use with Singles. My errors seem to revolve around not mapping the response correctly to a new observable:
webServices.loginRequest(loginData)
.flatMap { response -> PrimitiveSequence<SingleTrait, Result> in
return response
}
Xcode Error: Reference to generic type 'Result' requires arguments in
<...>
And then how do I chain call into the subsequent request after a previous one. Thank you very much for any assistance.