RxSwift를 시작하며 감을 잡아보는 간단한 예제 코드

1. RxSwift 예제로 감잡기
RxSwift 시작을 위한 간단한 예제들
유용하
@inkyfox
github.com/inkyfox

2. ReactiveX
• 왜 쓰는가?
• 장점?
• 설치는?
• 비동기.. 함수형.. LINQ.. MVVM..?
• Observable? Observer?

3. ReactiveX
• 왜 쓰는가?
• 장점?
• 설치는?
• 비동기.. 함수형.. LINQ.. MVVM..?
• Observable? Observer?
일단 생략

4. ReactiveX
먼저 코드 예제를 보며 감을 잡아 보는 걸로

5. UI Event
func reload() { }
func setup() {
reloadButton.rx.tap // Observable<Void>
.subscribe(onNext: { [weak self] in self?.reload() })
.addDisposableTo(disposeBag)
}

6. UI Event
func reload() { }
func setup() {
reloadButton.rx.tap // Observable<Void>
.subscribe(onNext: { [weak self] in self?.reload() })
.addDisposableTo(disposeBag)
}

7. UI Event
func reload() { }
func setup() {
reloadButton.rx.tap // Observable<Void>
.bindNext(reload)
.addDisposableTo(disposeBag)
}

8. UI Event
func reload() { }
func setup() {
reloadButton.rx.tap // Observable<Void>
.do(onNext: {
print(“Reload Button Clicked.”)
Analytics.buttonReload.send()
})
.bindNext(reload)
.addDisposableTo(disposeBag)
}

9. UI Event
func reload() { }
func setup() {
reloadButton.rx.tap // Observable<Void>
.debounce(0.3, scheduler: MainScheduler.instance)
.do(onNext: {
print(“Reload Button Clicked.”)
Analytics.buttonReload.send()
})
.bindNext(reload)
.addDisposableTo(disposeBag)
}

10. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.map { json in Page(json: json) } // Observable<Page>
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] page in
self?.display(page: page)
})
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

11. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.map { json in Page(json: json) } // Observable<Page>
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] page in
self?.display(page: page)
})
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

12. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.map { json in Page(json: json) } // Observable<Page>
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] page in
self?.display(page: page)
})
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

13. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.map { json in Page(json: json) } // Observable<Page>
.observeOn(MainScheduler.instance)
.bindNext(display)
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

14. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.map { Page(json: $0) } // Observable<Page>
.observeOn(MainScheduler.instance)
.bindNext(display)
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

15. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.retry(2)
.map { Page(json: $0) } // Observable<Page>
.observeOn(MainScheduler.instance)
.bindNext(display)
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

16. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.subscribeOn(SerialDispatchQueueScheduler(qos: .background))
.retry(2)
.observeOn(ConcurrentDispatchQueueScheduler(qos: .background))
.map(Page.init) // Observable<Page>
.observeOn(MainScheduler.instance)
.bindNext(display)
.addDisposableTo(reloadDisposeBag)
}
func display(page: Page) { }

17. REST API
func reload() {
API.default.request(.getPage) // Observable<JSON>
.subscribeOn(SerialDispatchQueueScheduler(qos: .background))
.retry(2)
.observeOn(ConcurrentDispatchQueueScheduler(qos: .background))
.map(Page.init) // Observable<Page>
.observeOn(MainScheduler.instance)
.do(
onNext: { print("Reload success: ($0)") },
onError: { error in print("Reload failed! (error)") },
onCompleted: { print("Reload completed") }
)
.bindNext(display)
.addDisposableTo(reloadDisposeBag)
}

18. Property Binding
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] reloading in
self?.reloadButton.isEnabled = !reloading
})
.addDisposableTo(disposeBag)
}

19. Property Binding
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] reloading in
self?.reloadButton.isEnabled = !reloading
})
.addDisposableTo(disposeBag)
}

20. Property Binding
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.map { !$0 }
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] enabled in
self?.reloadButton.isEnabled = enabled
})
.addDisposableTo(disposeBag)
}

21. Property Binding
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.map { !$0 }
.observeOn(MainScheduler.instance)
.subscribe(onNext: { [weak self] enabled in
self?.reloadButton.isEnabled = enabled
})
.addDisposableTo(disposeBag)
}

22. Property Binding
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.map { !$0 }
.observeOn(MainScheduler.instance)
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
}

23. Merge Operator
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.map { !$0 }
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
reloadButton.rx.tap // Observable<Void>
.map { false } // Observable<Bool>
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
}

24. Merge Operator
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.map { !$0 }
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
reloadButton.rx.tap // Observable<Void>
.map { false } // Observable<Bool>
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
}

25. Merge Operator
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // Observable<Bool>
.map { !$0 }
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
reloadButton.rx.tap // Observable<Void>
.map { false } // Observable<Bool>
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
}

26. Merge Operator
let isReloading: Variable<Bool> = Variable(false)
func setup() {
Observable.from(
[isReloading.asObservable().map { !$0 },
reloadButton.rx.tap.map { false } ]
).merge() // Observable<Bool>
.bindTo(reloadButton.rx.isEnabled)
.addDisposableTo(disposeBag)
}

27. Operators
let isReloading: Variable<Bool> = Variable(false)
func setup() {
isReloading.asObservable() // |-F-T-F-T-F-
.filter { $0 == false } // |-F---F---F-
.skip(1) // |-----F---F-
.take(1) // |-----F|
.observeOn(MainScheduler.instance)
.bindTo(messageView.rx.isHidden)
.addDisposableTo(disposeBag)
}

28. 그 밖에
• NotificationCenter
• Animation
• 등의 모든 이벤트
• 예제: https://github.com/inkyfox/RxCurrency_iOS

29. ReactiveX
• Pulling이 아닌 Pushing Data (수동적)
• LINQ style 연산자 & 함수형 프로그래밍
• 비동기 (Async) 프로그래밍

30. ReactiveX
앞의 예제들을
Callback (Delegate pattern)으로 했으면
어땠을까 상상해봅시다

31. 공부
• http://www.introtorx.com
• http://reactivex.io/intro.html
• http://rxmarbles.com
• https://github.com/ReactiveX/RxSwift/tree/master/
Documentation