Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Reactive thinking in Swift
Search
Ryo Aoyama
December 01, 2016
Programming
1
1.9k
Reactive thinking in Swift
presented at CA.swift #01
01 DEC. 2016
Ryo Aoyama
December 01, 2016
Tweet
Share
More Decks by Ryo Aoyama
See All by Ryo Aoyama
Micro Modular Architecture with Bazel
ra1028
9
1.7k
DifferenceKit in Action
ra1028
2
1.7k
Starting A11Y in iOS
ra1028
0
5k
Diffing inside SwiftUI List
ra1028
2
620
Integrate Combine into legacy frameworks
ra1028
2
620
Plasma - gRPC streamを利用したリアルタイムなユーザー体験
ra1028
3
1.4k
VueFlux - Flux inspired state managements
ra1028
3
1.5k
Optimizing Swift Collection
ra1028
2
3k
FRESH!配信アプリで採用した事・しなかった事
ra1028
8
4.9k
Other Decks in Programming
See All in Programming
生成AI時代のフルスタック開発
kenn
10
2.7k
Babylon.js 8.0のアプデ情報を 軽率にキャッチアップ / catch-up-babylonjs-8
drumath2237
0
110
RubyKaigi Hack Space in Tokyo & 函館最速 "予習" 会 / RubyKaigi Hack Space in Tokyo & The Fastest Briefing of RubyKaigi 2026 in Hakodate
moznion
1
120
Language Server と喋ろう – TSKaigi 2025
pizzacat83
2
660
當開發遇上包裝:AI 如何讓產品從想法變成商品
clonn
0
2.5k
AIエージェントによるテストフレームワーク Arbigent
takahirom
0
270
MLOps Japan 勉強会 #52 - 特徴量を言語を越えて一貫して管理する, 『特徴量ドリブン』な MLOps の実現への試み
taniiicom
2
570
TSConfigからTypeScriptの世界を覗く
planck16
2
1.3k
Reactive Thinking with Signals, Resource API, and httpResource @Devm.io Angular 20 Launch Party
manfredsteyer
PRO
0
130
ソフトウェア品質特性、意識してますか?AIの真の力を引き出す活用事例 / ai-and-software-quality
minodriven
19
6.6k
External SecretsのさくらProvider初期実装を担当しています
logica0419
0
230
iOSアプリ開発もLLMで自動運転する
hiragram
6
2.1k
Featured
See All Featured
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
PRO
180
53k
Put a Button on it: Removing Barriers to Going Fast.
kastner
60
3.9k
BBQ
matthewcrist
88
9.7k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
123
52k
Easily Structure & Communicate Ideas using Wireframe
afnizarnur
194
16k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
32
5.8k
Raft: Consensus for Rubyists
vanstee
137
7k
4 Signs Your Business is Dying
shpigford
183
22k
Build your cross-platform service in a week with App Engine
jlugia
231
18k
Java REST API Framework Comparison - PWX 2021
mraible
31
8.6k
Documentation Writing (for coders)
carmenintech
71
4.8k
Agile that works and the tools we love
rasmusluckow
329
21k
Transcript
Reactive thinking in Swift 2016/12/01 CA.swift Ryo Aoyama / ra1028
#ca_swift
None
ແྉͰߴը࣭ͳੜ์ૹಈըΛݟ์ ੜ์ૹ৴ϓϥοτϑΥʔϜαʔϏε
FRP Functional Reactive Programming
RxSwift RxCocoa ReactiveSwift ReactiveCocoa
ɾඇಉظσʔλϑϩʔΛநԽ͠ɺ ౷ҰతͳΠϯλʔϑΣʔεͰ ѻ͏͜ͱ͕Ͱ͖Δ ɾঢ়ଶཧΛݮΒͤΔ ɾએݴతͳهड़͕Ͱ͖Δ Why use…?
ɾDelegate methods ɾCallback blocks ɾNotifications ɾControl actions ɾResponder chain events
ɾKey-value observing (KVO) ɾFutures and promises
Event Stream Observable<T> Signal<T, E> SignalProducer<T, E>
Event Stream?
Event Stream = Water pipe
Event Observable Signal SignalProducer Observe
Transforming
Map Next(x) Next(x * 10) Eventͷ࣋ͭΛม͢Δ map
FlatMap Next(•) Next(▪) 2ͭͷΠϕϯτετϦʔϜ Λ1ͭʹฏୱԽ͢Δ flatMap
Filtering
Filter ݅ʹ߹க͢Δ͚ͩΛ ड͚औΔ filter Next(5)
Combining
Merge ෳͷΠϕϯτετϦʔϜ ͷΛҰຊʹͯ͠ड͚औΔ merge
Sample with RxSwift UISegmentedControl, UITextField ͦΕͧΕͷΠϕϯτͰAPIϦΫΤετΛߦ͍ɺ ͦͷϨεϙϯεʹԠͯ͡UITableViewΛදࣔߋ৽͢Δɻ
without RxSwift
final class NonRxViewController: UIViewController { @IBOutlet fileprivate weak var segmentedControl:
UISegmentedControl! @IBOutlet fileprivate weak var textField: UITextField! @IBOutlet fileprivate weak var tableView: UITableView! fileprivate var items = [Item]() override func viewDidLoad() { super.viewDidLoad() tableView.register(SampleCell.self, forCellReuseIdentifier: "SampleCell") tableView.delegate = self tableView.dataSource = self } }
private extension NonRxViewController { @IBAction func segmentedControlChanged(_ sender: UISegmentedControl) {
getItemsAndReload() } @IBAction func textFieldChanged(_ sender: UITextField) { getItemsAndReload() } func getItemsAndReload() { let text = textField.text ?? "" let index = segmentedControl.selectedSegmentIndex Api.getItems(segmentIndex: index, text: text) { [weak self] items in let reload = { self?.items = items self?.tableView.reloadData() } if Thread.isMainThread { reload() } else { DispatchQueue.main.async(execute: reload) } } } }
extension NonRxViewController: UITableViewDelegate, UITableViewDataSource { func numberOfSections(in tableView: UITableView) ->
Int { return 1 } func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return items.count } func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { let cell = tableView.dequeueReusableCell(withIdentifier: "SampleCell", for: indexPath) as! SampleCell let item = items[indexPath.item] cell.configure(with: item) return cell } }
ɾMutableͳม(ঢ়ଶ) ɾεϨουཧ ɾॲཧͷϑϩʔ͕ෳࡶ ɾ֦ு͕͍͠ ɾControl Actions ɾCallback blocks ɾDelegate methods
with RxSwift
final class RxViewController: UIViewController { @IBOutlet private weak var segmentedControl:
UISegmentedControl! @IBOutlet private weak var textField: UITextField! @IBOutlet private weak var tableView: UITableView! private let disposeBag = DisposeBag() override func viewDidLoad() { super.viewDidLoad() tableView.register(SampleCell.self, forCellReuseIdentifier: "SampleCell") Observable.combineLatest( segmentedControl.rx.value, textField.rx.text.orEmpty.distinctUntilChanged()) { ($0, $1) } .skip(1) .flatMap(Api.getItems) .asDriver(onErrorJustReturn: []) .drive(tableView.rx.items(cellIdentifier: "SampleCell", cellType: SampleCell.self)) { _, item, cell in cell.configure(with: item) } .addDisposableTo(disposeBag) } }
ɾMutableͳม(ঢ়ଶ) ɾεϨουཧ ɾॲཧͷϑϩʔ͕ෳࡶ ɾ֦ு͕͍͠ ɾControl Actions ɾCallback blocks ɾDelegate methods
Hot & Cold
Hot Observable Signal ɾߪಡऀͷ༗ແʹؔΘΒͣΠϕϯτ͕ྲྀΕΔ ɾෳߪಡ͞ΕΔͱετϦʔϜ͕ذ͢Δ
Subscribe Subscribe Subscribe Subscribe Hot
Hot let subject = PublishSubject<Int>() let observer = subject.asObserver() let
randomInt = { Int(arc4random_uniform(100)) } // PublishSubjectΛasObservable()͢ΔͱHot ObservableʹͳΔ let hot = subject.asObservable() hot.subscribe(onNext: { print("Hot 1: \($0)") }) hot.subscribe(onNext: { print("Hot 2: \($0)") }) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") ----- 1: 20 2: 20 ----- 1: 30 2: 30 ----- 1: 93 2: 93 ----- ग़ྗ ذͤͨ̎ͭ͞ͷߪಡͰ ͕ڞ༗͞Ε͍ͯΔࣄ͕Θ͔Δ
Observable SignalProducer Cold ɾߪಡ͢Δ·Ͱಈ࡞͠ͳ͍ ɾߪಡ͞Ε͚ͨͩετϦʔϜ͕࡞ΒΕΔ
Subscribe Subscribe Subscribe Subscribe Cold
Cold // RxSwiftͰHot ObservableΛmap͢ΔͱCold ObservableʹͳΔ let cold = hot.map {
$0 + randomInt() } cold.subscribe(onNext: { print("Cold 1: \($0)") }) cold.subscribe(onNext: { print("Cold 2: \($0)") }) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") ------ 1: 182 2: 117 ------ 1: 84 2: 139 ------ 1: 106 2: 64 ------ ग़ྗ ̎ͭͷߪಡͰผʑͷ ετϦʔϜʹͳ͍ͬͯΔ
ColdͰॏ͍ॲཧAPIϦΫΤετΛ͍ͯ͠Δͱ…
let cold = hot.map { i -> Int in sleep(1)
// <- ॏ͍ॲཧ return i } cold.subscribe(onNext: { print("Cold 1: \($0), seconds: \(currentTimeSeconds())") }) cold.subscribe(onNext: { print("Cold 2: \($0), seconds: \(currentTimeSeconds())") }) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") ----------------------- Cold 1: 21, seconds: 49 Cold 2: 21, seconds: 50 ----------------------- Cold 1: 62, seconds: 51 Cold 2: 62, seconds: 52 ----------------------- Cold 1: 65, seconds: 53 Cold 2: 65, seconds: 54 ----------------------- ग़ྗ ੩తͳΛฦ͍ͯͯ͠ݟ্͔͚͕ڞ༗Ͱ͖͍ͯͯɺ ॲཧߪಡ͍ͯ͠Δ͚ͩߦΘΕ͍ͯΔ Cold
Cold -> Hot
Subscribe Subscribe Subscribe Subscribe Cold -> Hot
Subscribe Subscribe Subscribe Subscribe Cold -> Hot
// Cold ObervableΛshareReplay͢Δ͜ͱͰHot ObservableʹͳΔ let coldToHot = cold.shareReplay(1) coldToHot.subscribe(onNext: {
print("ColdToHot 1: \($0)") }) coldToHot.subscribe(onNext: { print("ColdToHot 2: \($0)") }) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") ----- 1: 32 2: 32 ----- 1: 54 2: 54 ----- 1: 144 2: 144 ----- ग़ྗ Λڞ༗͢ΔΑ͏ʹͳͬͨ Cold -> Hot
Hotม͍ͯ͠ΕɺColdͰॏ͍ॲཧ͕ߦΘΕͯ…
let cold = hot.map { i -> Int in sleep(1)
// <- ॏ͍ॲཧ return i } .shareReplay(1) cold.subscribe(onNext: { print("Cold 1: \($0), seconds: \(currentTimeSeconds())") }) cold.subscribe(onNext: { print("Cold 2: \($0), seconds: \(currentTimeSeconds())") }) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") observer.onNext(randomInt()) print("-----") ---------------------- Cold 1: 6, seconds: 7 Cold 2: 6, seconds: 7 ---------------------- Cold 1: 74, seconds: 8 Cold 2: 74, seconds: 8 ---------------------- Cold 1: 77, seconds: 9 Cold 2: 77, seconds: 9 ---------------------- ग़ྗ ෳߪಡ͍ͯͯ͠ ॲཧ͕ߦΘΕΔͷҰճ͚ͩ Cold -> Hot
·ͱΊ
Event Stream ઃܭͷΠϯλʔϑΣʔε͕౷ҰԽɻ ࿈ଓతͳΛͲ͏ѻ͏͔͚ͩΛએݴతʹهड़͠ɺ ετϦʔϜಉ࢜Λଓ͢Δɻ = ඞવతʹMutableͳঢ়ଶཧݮΔɻ ίʔυྔͷݮ͕࠷େͷརͰͳ͍ɻ
Hot & Cold Hot or ColdͰετϦʔϜଓͷ͞Εํ͕ҟͳΔɻ ҙࣝ͠ͳ͍ͱϦιʔεͷແବɾҙਤ͠ͳ͍ڍಈɾόά ͷՄೳੑ͕͋Δɻ RxSwiftͰ҉తɻ ReactiveSwiftͰ໌ࣔతɻ
͝੩ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠