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
Simplifying State by partially introducing unid...
Search
Benedikt Terhechte
October 13, 2017
Programming
3
950
Simplifying State by partially introducing unidirectional data flow in your codebase
Benedikt Terhechte
October 13, 2017
Tweet
Share
More Decks by Benedikt Terhechte
See All by Benedikt Terhechte
Back to the Future: Let me tell you about the ACP protocol
terhechte
0
130
NSSpain 2023: An overview of different approaches to share code across platforms
terhechte
0
450
Dependency Management with Swift
terhechte
0
4
NSSpain 2020: GeometryReader, View Preferences and Anchors - SwiftUI tales from the Hyperdeck
terhechte
0
3
FrenchKit 2020: Hyperdeck. What can go wrong on a multiyear side project
terhechte
0
2
SwiftUI & UIKit, a match made in heaven or match made in hell?
terhechte
0
74
Learnings from building Design Systems at XING
terhechte
1
520
Introduction to Swift Keypaths
terhechte
15
20k
Sharing Code between iOS and Android with Rust
terhechte
8
2.4k
Other Decks in Programming
See All in Programming
2分台で1500examples完走!爆速CIを支える環境構築術 - Kaigi on Rails 2025
falcon8823
3
3k
そのpreloadは必要?見過ごされたpreloadが技術的負債として爆発した日
mugitti9
2
3k
iOSアプリの信頼性を向上させる取り組み/ios-app-improve-reliability
shino8rayu9
0
150
Go Conference 2025: Goで体感するMultipath TCP ― Go 1.24 時代の MPTCP Listener を理解する
takehaya
7
1.6k
overlayPreferenceValue で実現する ピュア SwiftUI な AdMob ネイティブ広告
uhucream
0
110
The Past, Present, and Future of Enterprise Java
ivargrimstad
0
130
階層構造を表現するデータ構造とリファクタリング 〜1年で10倍成長したプロダクトの変化と課題〜
yuhisatoxxx
3
910
ネイティブ製ガントチャートUIを作って学ぶUICollectionViewLayoutの威力
jrsaruo
0
130
Catch Up: Go Style Guide Update
andpad
0
170
詳しくない分野でのVibe Codingで困ったことと学び/vibe-coding-in-unfamiliar-area
shibayu36
3
4.4k
フロントエンド開発に役立つクライアントプログラム共通のノウハウ / Universal client-side programming best practices for frontend development
nrslib
7
3.9k
プログラミングどうやる? ~テスト駆動開発から学ぶ達人の型~
a_okui
0
190
Featured
See All Featured
Into the Great Unknown - MozCon
thekraken
40
2.1k
Distributed Sagas: A Protocol for Coordinating Microservices
caitiem20
333
22k
Build your cross-platform service in a week with App Engine
jlugia
232
18k
The Illustrated Children's Guide to Kubernetes
chrisshort
48
51k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
35
3.2k
GitHub's CSS Performance
jonrohan
1032
460k
Easily Structure & Communicate Ideas using Wireframe
afnizarnur
194
16k
Building Adaptive Systems
keathley
43
2.8k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
45
2.5k
Unsuck your backbone
ammeep
671
58k
GraphQLとの向き合い方2022年版
quramy
49
14k
The Web Performance Landscape in 2024 [PerfNow 2024]
tammyeverts
9
850
Transcript
1
2
3
4
5
6
7
8
9
None
10
11
12
13
14
None
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/// Model struct Cinnamon { let value: Int = 0
} enum Event { case increase } 45
/// Model struct Cinnamon { let value: Int = 0
} enum Event { case increase } func reducer(state: Cinnamon, event: Event) -> Cinnamon { var newState = state if event == .increase { newState.value += 1 } return newState } /// UI let builder = Form(state: Cinnamon(), reducer: reducer) 46
47
48
49
struct AddressBook { var contacts: [Person] var searchTerm: String var
scrollPosition: Int } 50
struct AddressBookApp { struct Data { var contacts: [Person] }
var data: Data struct UI { var searchTerm: String var scrollPosition: Int } var ui: UI } 51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
private var subscribers: [String: (State)->Void] = [:] public func subscribe(_
subscriber: @escaping (State)->Void) -> String { let token = UUID().uuidString subscribers[token] = subscriber subscriber(state) return token } 66
67
protocol FormComponent { associatedtype State func setup(with state: State) func
update(state: State) -> Void } public func subscribe<Component: FormComponent> (_ subscriber: Component) -> String where Component.State == State {... 68
69
func subscribe<Type: Equatable>( path: KeyPath<Data, Type>, action: @escaping (_ oldValue:
Type, _ newValue: Type) -> Void ) -> String struct Person { let name: String } form.subscribe(path: \Person.name) { (old, new) in ... } 70
private var history: [State] = [] func apply(_ change: (inout
State) -> Void) { states.append(state) change(&state) notifySubscribers() } func undo() { state = history.popLast() notifySubscribers() } 71
72
73
74
75
76
77
78
79
80