rx.swift

gistfile1.txt

//: Playground - noun: a place where people can play

import UIKit
import RxSwiftTest
import RxSwift

func api1() -> Observable<String> {
    return Observable.create{ (subscriber) -> Disposable in
        print("api1 called")
        subscriber.onNext("api1 #1")
        subscriber.onNext("api1 #2")
        subscriber.onCompleted()
        return Disposables.create()
    }
}

func api2() -> Observable<String> {
    return Observable.create{ (subscriber) -> Disposable in
        print("api2 called")
        subscriber.onNext("api2 #1")
        subscriber.onCompleted()
        return Disposables.create()
    }
}

func api3() -> Observable<String> {
    return Observable.create{ (subscriber) -> Disposable in
        print("api3 called")
        subscriber.onNext("api3 #3")
        subscriber.onCompleted()
        return Disposables.create()
    }
}

api1().flatMap { value -> Observable<String> in
        print("map 1 \(value)")
        return api2()
    }.flatMap { value -> Observable<String> in
        print("map 2 \(value)")
        return api3()
    }.subscribe(onNext: { (value) in
        print(value)
    })