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
if 式と switch 式による SwiftUI のプレビューエラー対策
Search
ojun
November 14, 2023
Programming
1
980
if 式と switch 式による SwiftUI のプレビューエラー対策
ojun
November 14, 2023
Tweet
Share
More Decks by ojun
See All by ojun
Xcode 16のPreviewModifierと@Previewableを活用した効率的なプレビュー方法の考察
ojun9
2
160
Catch Up with Swift 5.10
ojun9
2
650
Overview: Swift OpenAPI Generator
ojun9
3
1.3k
楽しい夏休み!String Catalogs で新しい発見
ojun9
0
1.7k
ユニットテストを学んだ次に知りたかったApple標準APIに対するテストのやり方
ojun9
1
350
ハッカソンにおけるiOSアプリ開発での学びと楽しさ
ojun9
1
290
Other Decks in Programming
See All in Programming
GraphQL はいいぞ! ~Laravel で学ぶ GraphQL 入門~
azuki
1
160
Clean Architecture by TypeScript & NestJS
ryounasso
0
150
TiDB Serverless ~理想のServerless DBを考える~
soso_15315
1
160
実用的かつリーズナブルな 「Azure × Gemini × LINE」~キャラクターBot 実装ライブデモ~
tomodo_ysys
1
170
小さな開発会社を作った理由
polidog
0
1.9k
CSC307 Lecture 11
javiergs
PRO
0
240
Prompt FlowによるLLMアプリケーション開発
yuto2000
1
1k
Temporalを取り巻く仕様を整理する
sajikix
0
110
Product Management LT会_クアンド新家
shinshin
0
210
最近追加した型の紹介とその振り返り
aki19035vc
0
170
なぜ宣言的 UI は壊れにくいのか / Why declarative UI is less fragile
uenitty
29
13k
CSC307 Lecture 07
javiergs
PRO
0
220
Featured
See All Featured
Making the Leap to Tech Lead
cromwellryan
127
8.7k
Facilitating Awesome Meetings
lara
46
5.8k
Bash Introduction
62gerente
607
210k
Visualization
eitanlees
139
14k
The Cost Of JavaScript in 2023
addyosmani
31
4.7k
I Don’t Have Time: Getting Over the Fear to Launch Your Podcast
jcasabona
26
1.8k
A Tale of Four Properties
chriscoyier
155
22k
How To Stay Up To Date on Web Technology
chriscoyier
784
250k
Building Your Own Lightsaber
phodgson
101
5.9k
VelocityConf: Rendering Performance Case Studies
addyosmani
321
23k
Helping Users Find Their Own Way: Creating Modern Search Experiences
danielanewman
26
2.1k
Scaling GitHub
holman
458
140k
Transcript
potatotips #85 iOS/Android։ൃTipsڞ༗ձ 2023/11/14 @Voicy if ࣜͱ switch ࣜʹΑΔ SwiftUI
ͷϓϨϏϡʔΤϥʔରࡦ ojun - DeNA Co., Ltd.
ࣗݾհʢojunʣ • name: ojun • 2023৽ଔೖࣾ • iOSΤϯδχΞ @ojun_9
Xcode 15 ରԠਐΜͰ͍·͔͢ʁ
Xcode 15.0 Asset Catalogs / String Catalogs PreviewϚΫϩ Swift 5.9
ϒοΫϚʔΫػೳ ɾෳͷݴޠػೳͷՃ ɾσόοά࣌ʹมͷ༰Λग़ྗ͢ΔͨΊʹར༻͢ΔpίϚϯυͱpoίϚϯυ ʹΑΔग़ྗ͕࣌ؒେ෯ʹॖ ͦͷଞ͍Ζ͍Ζ
Xcode 15.0 Asset Catalogs / String Catalogs PreviewϚΫϩ Swift 5.9
ϒοΫϚʔΫػೳ ɾෳͷݴޠػೳͷՃ ͦͷଞ͍Ζ͍Ζ ɾσόοά࣌ʹมͷ༰Λग़ྗ͢ΔͨΊʹར༻ՄೳͳpίϚϯυͱpoίϚϯυ ʹΑΔग़ྗ͕࣌ؒେ෯ʹॖ
Swift 5.9: if ͱ switch ͷࣜදݱ
Swift 5.9: ifͱswitchͷࣜදݱ Swift 5.9͔ΒswitchͱifΛࣜͱͯ͠දݱͰ͖ΔΑ͏ʹͳͬͨ
Swift 5.9: ifͱswitchͷࣜදݱ Swift 5.9͔ΒswitchͱifΛࣜͱͯ͠දݱͰ͖ΔΑ͏ʹͳͬͨ
Swift 5.9: ifͱswitchͷࣜදݱ Swift 5.9͔ΒswitchͱifΛࣜͱͯ͠දݱͰ͖ΔΑ͏ʹͳͬͨ
Swift 5.9: ifͱswitchͷࣜදݱ Swift 5.9͔ΒswitchͱifΛࣜͱͯ͠දݱͰ͖ΔΑ͏ʹͳͬͨ
Swift 5.9: ifͱswitchͷࣜදݱ Swift 5.9͔ΒswitchͱifΛࣜͱͯ͠දݱͰ͖ΔΑ͏ʹͳͬͨ
Preview࣌ʹར༻͢Δ
Preview࣌ʹར༻͢Δ isSwiftͷBoolʹج͍ͮͯTextΛฦ͢
Preview࣌ʹར༻͢Δ isSwiftͷBoolʹج͍ͮͯTextΛฦ͢ ௨ৗͷϏϧυ 🎉 ͳ͘ޭ͢Δ
Preview࣌ʹར༻͢Δ isSwiftͷBoolʹج͍ͮͯTextΛฦ͢ ௨ৗͷϏϧυ 🎉 ͳ͘ޭ͢Δ Preview࣌ͷϏϧυ 😭 ίϯύΠϧΤϥʔ͕ൃੜ͢Δ
Preview࣌ʹར༻͢Δ isSwiftͷBoolʹج͍ͮͯTextΛฦ͢ ௨ৗͷϏϧυ 🎉 ͳ͘ޭ͢Δ Preview࣌ͷϏϧυ 😭 ίϯύΠϧΤϥʔ͕ൃੜ͢Δ Preview ProviderΛར༻ͯ͠ಉ༷
Preview࣌ʹར༻͢Δ 'if' may only be used as expression in return,
throw, or as the source of an assignment
ղܾํ๏
ղܾํ๏ 1. @ViewBuilderΩʔϫʔυΛ༩͢Δ 2. Opaque typeͰͳ͍໌֬ͳܕΛฦ͢ 3. Opaque Type Λ
Existential Type ʹஔ͖͑Δ
@ViewBuilderΩʔϫʔυΛ༩͢Δ @ViewBuilderΩʔϫʔυΛ༩͢Δ ͜ͱͰPreview࣌ͷΤϥʔΛճආͰ͖Δ ௨ৗͷϏϧυ 🎉 ͳ͘ޭ͢Δ Preview࣌ͷϏϧυ 🎉 ͳ͘ޭ͢Δ
໌֬ͳܕΛฦ͢ ௨ৗͷϏϧυ 🎉 ͳ͘ޭ͢Δ Preview࣌ͷϏϧυ 🎉 ͳ͘ޭ͢Δ `Text`ͷΑ͏ʹܕΛ໌֬ʹ͢Δ ͜ͱͰPreview࣌ͷΤϥʔΛճආͰ͖Δ
Opaque Type Λ Existential Type ʹஔ͖͑Δ ΓΛany Viewʹ͢Δํ๏ ͨͩ͠ɺݺͼग़͠ݩͰܕΩϟετΛ ߦ͏ඞཁ͕͋Δ
௨ৗͷϏϧυ 🎉 ͳ͘ޭ͢Δ Preview࣌ͷϏϧυ 🎉 ͳ͘ޭ͢Δ
ͷݪҼΛߟ͢Δ ʢࠜຊݪҼಥ͖ࢭΊΒΕ·ͤΜͰͨ͠😢ʣ
ͷݪҼΛߟ͢Δ ContentView.1.preview-thunk.swift ͱ͍͏ϑΝΠϧ͕ҎԼʹଘࡏ͢Δ ~/Library/Developer/Xcode/DerivedData/MakeViewFromSwitch- fghepcludbkyehbmhgmucvzdrxsk/Build/Intermediates.noindex/Previews/ MakeViewFromSwitch/Intermediates.noindex/MakeViewFromSwitch.build/ Debug-iphonesimulator/MakeViewFromSwitch.build/Objects-normal/arm64
ContentViewͷPreviewϏϧυ͕Δͱ͜ͷϑΝΠϧ͕ߋ৽͞ΕΔ
ྫ͑ɺany ErrorΛฦ͢Α͏ͳϝιουΛ࣮͢Δͱ
ContentView.1.preview-thunk.swift ߋ৽͞ΕΔ
ΓΛOpaque Typeʹ͢Δͱ ͨͩ͠
ContentView.1.preview-thunk.swift ͔ΒgetErrorͷॲཧ͕ফ͑Δ
ͷݪҼΛߟ͢Δ ίϯύΠϧΤϥʔʹͳ࣮ͬͨ Opaque Typeͩͬͨ తͳݪҼ͔Θ͔Βͳ͍͕͜Ε͕ ʹͳ͍ͬͯΔՄೳੑ͕͋Δ
·ͱΊ Swift 5.9͔Β if ͱ switch Λࣜͱͯ͠ѻ͑ΔΑ͏ʹͳͬͨ if / switch
ࣜΛ༻͍ͯSwiftUIͷViewΛʢopaque typeͱͯ͠ʣฦ͢ͱ Preview࣌ͷϏϧυͰͷΈίϯύΠϧΤϥʔ͕ൃੜ͢Δ ҎԼͷ͍ͣΕ͔ͷํ๏ͰͷରԠΛ͢Δ͜ͱ͕Ͱ͖Δ 1. @ViewBuilderΩʔϫʔυΛ༩͢Δ 2. Opaque typeͰͳ͍໌֬ͳܕΛฦ͢ʢText ͳͲʣ 3. Opaque Type Λ Existential Type ʹஔ͖͑Δ
͋Γ͕ͱ͏͍͟͝·ͨ͠ʂ