RxSwift - Use two observable to make a async call - ios

Question

Lets say I have a function that takes in two arguments - Observable<String?> and Observable<Person?> and returns Observable
This is my sample code below:
return Observable.combineLatest(self.id, personStream)
map { [weak self] (id,person) -> Person? in
guard let person = person as? Person else {
return nil
}
if let id = id {
// How do I return this updated person
self?.updatePersonDetails(for: person, completion: { (updatedPerson) in
return updatedPerson
})
} else {
return person
}
}
How do I return this updated person inside this mapping function?
Update:
public func updatePerson(personStream: Observable<Person>) -> Observable<Person> {
return Observable.combineLatest(
self.id,
personStream
).flatMap { [weak self] (id,person) -> Observable<Person?> in
guard let person = person as? Double else {
return Observable.just(nil)
}
if let id = id {
// How do I return this updated person
return Observable.create { [weak self] observer in
self?.updatePersonDetails(for: person, completion: { (updatedPerson) in
observer.on(.next(updatedPerson))
observer.on(.completed)
})
return Disposables.create()
}
} else {
return Observable.just(person)
}
}
}
The above function is called as below:
let personUpdateStream = personService.updatePerson(personStream: personDataStream)
Observable.combineLatest(personUpdateStream, nameStream,profileEnabledStream)
.subscribe(onNext: { [weak self] (person, name, isEnabled) in
print(name)
self?.updatePersonView(person: person, name: name, isLocked: !isEnabled)
})
.disposed(by: disposeBag)
Issue: The block inside combineLatest with the print(name) never runs. May I know whats the issue here?
Description of personUpdateStream
personUpdateStream RxSwift.FlatMap<(String?, Person?), RxSwift.Observable<Person?>> 0x0000604001e5af70

Answer 1

You should use flatMap instead of map and to integrate your non Rx call of updatePersonDetails you should use Observable.create.
Your final code should look something similar to:
return Observable.combineLatest(
self.id,
personStream
).flatMap { [weak self] (id,person) -> Observable<Person?> in
guard let person = person as? Double else {
return Observable.just(nil)
}
if let id = id {
// How do I return this updated person
return Observable.create { [weak self] observer in
self?.updatePersonDetails(for: person, completion: { (updatedPerson) in
observer.on(.next(updatedPerson))
observer.on(.completed)
})
return Disposables.create()
}
} else {
return Observable.just(person)
}
}