The introduction to RxSwift you've been missing @dtvd88 Kabukiza.tech#11

Who am I • Vu Nhat Minh (@dtvd88) • Author of RainbowStream • Scala/Swift engineer • Swift Monad: Proof of concept • The introduction to RxSwift you've been missing • JLPT Free Quiz (~10000 DL)

Agenda • RP(Reactive Programming) • RxSwift • The introduction to RxSwift you've been missing

Reactive Programming http://reactivex.io/

Programming with asynchronous data streams Observer pattern / Iterator pattern / Functional Programming

Functions to combine, create and filter streams • Stream is immutable • Function can be chained

ReactiveExtension(Rx) libraries Languages • Java: RxJava • JavaScript: RxJS • C#: Rx.NET • C#(Unity): UniRx • Scala: RxScala • Clojure: RxClojure • C++: RxCpp • Ruby: Rx.rb • Python: RxPY • Groovy: RxGroovy • JRuby: RxJRuby • Kotlin: RxKotlin • Swift: RxSwift • PHP: RxPHP Frameworks • RxNetty • RxAndroid • RxCocoa

RxSwift

Rx library for Swift • Member of ReactiveX: https://github.com/ ReactiveX/RxSwift • Communityɿhttps://github.com/RxSwiftCommunity • Learning RxSwift = Learning (RxSwift + RxCocoa + community libraries)

Realtime Github Search using RxSwift

Realtime Github Search using RxSwift let searchResults = searchBar.rx.text .throttle(0.3, scheduler: MainScheduler.instance) .distinctUntilChanged() .flatMapLatest { query -> Observable<[Repository]> in if query.isEmpty { return Observable.just([]) } return searchGitHub(query) .catchErrorJustReturn([]) } .observeOn(MainScheduler.instance)

Learning RxSwift

The introduction to Reactive Programming you've been missing • Incredibly well-written tutorial by @andrestaltz • Use Twitter’s "Who to follow" box to explain Reactive Programming

The introduction to RxSwift you've been missing • Use Twitter’s "Who to follow" box • Code in Swift (RxSwift + RxCocoa) • Use Moya/RxSwift for networking part • https://github.com/DTVD/The-introduction-to-RxSwift-you-have-been- missing

Call API and build responseStream let refreshStream = refresh.rx_tap.startWith(()) let requestStream: Observable = refreshStream.map { _ in let random = Array(1...1000).random() return “https://api.github.com/users/" + String(random) } let responseStream = requestStream.flatMap { url in return UserModel().findUsers(url) } refreshStream: --tap-------tap----------tap------------|-> requestStream: --url-------url----------url------------|-> responseStream: -----[User]-----[User]-----[User]-------|->

Call API and build responseStream let refreshStream = refresh.rx_tap.startWith(()) let requestStream: Observable = refreshStream.map { _ in let random = Array(1...1000).random() return “https://api.github.com/users/" + String(random)ɹ// String }ɹ// Observable let responseStream = requestStream.flatMap { url in return UserModel().findUsers(url) // Observable<[User]> }ɹ// Observable<[User]> refreshStream: --tap-------tap----------tap------------|-> requestStream: --url-------url----------url------------|-> responseStream: -----[User]-----[User]-----[User]-------|->

map vs flatMap let responseStream = requestStream.map { url in return UserModel().findUsers(url) // Observable<[User]> } // Observable>

map vs flatMap let responseStream = requestStream.flatMap { url in return UserModel().findUsers(url) // Observable<[User]> } // Observable<[User]>

Everything is a stream

Observable Stream type let closeStream = cell.cancel.rx_tap.startWith(()) let userStream: Observable = Observable.combineLatest(closeStream, responseStream){ (_, users) in guard users.count > 0 else {return nil} return users.random() } responseStream: --a-----------e--------i--------> closeStream: -----b----c--------d-------q----> vvvvvvvv combineLatest(f) vvvvvvv userStream: ----AB---AC--EC---ED--ID--IQ---->

Data binding for cell let nilOnRefreshTapStream: Observable = refresh.rx_tap.map {_ in return nil} let suggestionStream = Observable.of(userStream, nilOnRefreshTapStream) .merge() .startWith(.None) suggestionStream.subscribeNext{ op in guard let u = op else { return self.clearCell(cell) } return self.setCell(cell, user: u ) }.addDisposableTo(cell.disposeBagCell) nilOnRefreshTapStream: --n-----------n--------n--------> userStream: -----u----u--------u-------u----> vvvvvvvvvvvv merge() vvvvvvvvvvvv suggestionStream: --s--s----s---s----s---s-------->

See details in Github