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
Property Wrapperで遊ぼう / Play with Property Wrapper
Search
Yutaro Muta
September 11, 2019
Programming
2
330
Property Wrapperで遊ぼう / Play with Property Wrapper
帰ってきた関西モバイルアプリ研究会#3
https://kanmoba.connpass.com/event/137475/
Yutaro Muta
September 11, 2019
Tweet
Share
More Decks by Yutaro Muta
See All by Yutaro Muta
猫と暮らす Google Nest Cam生活🐈 / WebRTC with Google Nest Cam
yutailang0119
0
210
Swiftの “private” を テストする / Testing Swift "private"
yutailang0119
0
250
Apple Vision Pro購入RTA 1泊3日弾丸ハワイツアー / RTA: Purchase Apple Vision Pro in Hawaii
yutailang0119
0
1.4k
個人開発のたのしみ / Enjoying personal development
yutailang0119
0
1k
バックポートして学ぶ新APIの仕組み
yutailang0119
0
2.9k
Backport AsyncImage
yutailang0119
0
740
xcrun Essentials
yutailang0119
6
1.3k
Let's Coding SwiftUI on iPad!
yutailang0119
1
530
Back of First Screen AB test of Hatena Bookmark iOS app with Firebase AB Testing
yutailang0119
0
320
Other Decks in Programming
See All in Programming
Updates on MLS on Ruby (and maybe more)
sylph01
1
180
概念モデル→論理モデルで気をつけていること
sunnyone
3
300
個人開発で徳島大学生60%以上の心を掴んだアプリ、そして手放した話
akidon0000
1
150
ファインディ株式会社におけるMCP活用とサービス開発
starfish719
0
2k
複雑なフォームに立ち向かう Next.js の技術選定
macchiitaka
2
230
奥深くて厄介な「改行」と仲良くなる20分
oguemon
1
560
ProxyによるWindow間RPC機構の構築
syumai
3
1.2k
Rancher と Terraform
fufuhu
2
550
Swift Updates - Learn Languages 2025
koher
2
510
そのAPI、誰のため? Androidライブラリ設計における利用者目線の実践テクニック
mkeeda
2
2.8k
プロパティベーステストによるUIテスト: LLMによるプロパティ定義生成でエッジケースを捉える
tetta_pdnt
0
4.3k
Deep Dive into Kotlin Flow
jmatsu
1
370
Featured
See All Featured
The Pragmatic Product Professional
lauravandoore
36
6.9k
Agile that works and the tools we love
rasmusluckow
330
21k
Improving Core Web Vitals using Speculation Rules API
sergeychernyshev
18
1.1k
Building Adaptive Systems
keathley
43
2.7k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
35
3.1k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
32
1.6k
It's Worth the Effort
3n
187
28k
Music & Morning Musume
bryan
46
6.8k
Java REST API Framework Comparison - PWX 2021
mraible
33
8.8k
What’s in a name? Adding method to the madness
productmarketing
PRO
23
3.7k
The World Runs on Bad Software
bkeepers
PRO
70
11k
Making the Leap to Tech Lead
cromwellryan
135
9.5k
Transcript
Property WrapperͰ༡΅͏ 2019/09/11 @ؼ͖ͬͯͨؔϞόΠϧΞϓϦݚڀձ#3 Yutaro Muta @yutailang0119
• Yutaro Muta @yutailang0119 • Hatena Co., Ltd. @Kyoto •
Conference Staff • builderscon 2017, 2018, 2019 • try! Swift Tokyo 2019, 2020 • try! Swift Tokyo 2020 νέοτൢച։࢝ • https://www.tryswift.co/events/2020/tokyo/en/ Who am I ?
⚠͝ҙ • ڥ • macOS Mojave Version 10.14.6 • Xcode
11.0 GM seed (11M419c)
Property Wrapper
Property Wrapper • https://github.com/apple/swift-evolution/blob/master/proposals/0258-property- wrappers.md • ࠷ॳͷPitchProperty Delegateͱͯ͠ɺMarch 3, 2019ʹొ
• https://forums.swift.org/t/returned-for-revision-se-0258-property-delegates/24080 • Swift 5.1 ~ • ొॳSwift 5.1ʹೖΒͳ͍ͩΖ͏ͱ͍͏ҹ͕ͩͬͨɺWWDCͰApple͕ൃදͨ͠ SwiftUIʹ༻͞Ε͍ͯΔ • Swift 5.1ͷfinal branchingMarch 18, 2019
Property Wrapper • https://github.com/apple/swift-evolution/blob/master/proposals/0258-property- wrappers.md • ࠷ॳͷPitchProperty Delegateͱͯ͠ɺMarch 3, 2019ʹొ
• https://forums.swift.org/t/returned-for-revision-se-0258-property-delegates/24080 • Swift 5.1 ~ • ొॳSwift 5.1ʹೖΒͳ͍ͩΖ͏ͱ͍͏ҹ͕ͩͬͨɺWWDCͰApple͕ൃදͨ͠ SwiftUIʹ༻͞Ε͍ͯΔ • Swift 5.1ͷfinal branchingMarch 18, 2019
https://github.com/apple/swift-evolution/blob/master/ proposals/0258-property-wrappers.md https://github.com/apple/swift-evolution/blob/master/proposals/0258-property-wrappers.md
https://github.com/apple/swift-evolution/blob/master/ proposals/0258-property-wrappers.md https://github.com/apple/swift-evolution/blob/master/proposals/0258-property-wrappers.md
OSS SwiftͰ࣮த
࣮ঢ়گ • େͰ͖͍ͯΔ • https://github.com/apple/swift/pulls?utf8=✓&q=is%3Apr+SE-+0258 • όάใࠂ͔ͳΓ͋Δ • https://bugs.swift.org/issues/?jql=labels+%3D+PropertyWrappers
BugΛ୳ͦ͏
Property WrapperͷΑ͋͘Δྫ
Property Wrapper x UserDefaults
Property Wrapper x UserDefaults • [WWDC 2019] What's New in
Swift • https://developer.apple.com/videos/play/wwdc2019/402 • UserDefaultsΛWrapͯ͠ɺϘΠϥʔϓϨʔτΛ௵͍ͯ͘͠
@propertyWrapper struct UserDefault<T> { let key: String let defaultValue: T
init(_ key: String, defaultValue: T) { self.key = key self.defaultValue = defaultValue UserDefaults.standard.register(defaults: [key: defaultValue]) } var wrappedValue: T { get { return UserDefaults.standard.object(forKey: key) as? T ?? defaultValue } set { UserDefaults.standard.set(newValue, forKey: key) } } } Property Wrapper x UserDefaults
@UserDefault("USES_TOUCH_ID", defaultValue: false) static var usesTouchID: Bool @UserDefault("LOGGED_IN", defaultValue: false)
static var isLoggedIn: Bool if !isLoggedIn && usesTouchID { !authenticateWithTouchID() } Property Wrapper x UserDefaults
defaultValue == nil Ͱ͖ͦ͏ͩͳ
@propertyWrapper struct UserDefault<T> { let key: String let defaultValue: T
init(_ key: String, defaultValue: T) { self.key = key self.defaultValue = defaultValue } var wrappedValue: T { get { return UserDefaults.standard.object(forKey: key) as? T ?? defaultValue } set { UserDefaults.standard.set(newValue, forKey: key) } } } Property Wrapper x UserDefaults x Optional
@UserDefault("USES_TOUCH_ID", defaultValue: nil) static var usesTouchID: Bool @UserDefault("LOGGED_IN", defaultValue: false)
static var isLoggedIn: Bool if !isLoggedIn && usesTouchID { !authenticateWithTouchID() } Property Wrapper x UserDefaults x Optional
@UserDefault("USES_TOUCH_ID", defaultValue: nil) static var usesTouchID: Bool @UserDefault("LOGGED_IN", defaultValue: false)
static var isLoggedIn: Bool if !isLoggedIn && usesTouchID { !authenticateWithTouchID() } Property Wrapper x UserDefaults x Optional
None
@UserDefault("USES_TOUCH_ID", defaultValue: nil) static var usesTouchID: Bool print(type(of: usesTouchID)) //
Optional<Bool> ܕΛݟͯΈΔ
None
ͱ͍͏͜ͱͰ
https://bugs.swift.org/browse/SR-11443
SR-11443 Property Wrapper overwrites type declaration • bugs swiftʹग़ͨ͠
Simple Case import Foundation var value: Any = "value" @propertyWrapper
struct Wrapper<Value> { private let defaultValue: Value init(defaultValue: Value) { self.defaultValue = defaultValue } var wrappedValue: Value { get { (value as? Value) ?? defaultValue } set { value = newValue } } } final class Playground { @Wrapper(defaultValue: nil) var explicitlyOptional: String? @Wrapper(defaultValue: nil) var implicitlyOptional: String @Wrapper(defaultValue: "NonOptional") var nonOptional: String func printExplicitlyOptionalType() { print(type(of: self.explicitlyOptional)) } func printImplicitlyOptionalType() { print(type(of: self.implicitlyOptional)) } func printNonOptionalType() { print(type(of: self.nonOptional)) } } let playground = Playground() playground.printExplicitlyOptionalType() // Optional<String> playground.printImplicitlyOptionalType() // Optional<String> playground.printNonOptionalType() // String
·ͱΊ
·ͱΊ • Property WrapperΛ͍ͯ͠ɺόάใࠂΛ͍ͯ͜͠͏
&OKPZ1SPQFSUZ8SBQQFS 5IBOLT w NVUBZVUBSP!HNBJMDPN w IUUQTUXJUUFSDPNZVUBJMBOH w IUUQTHJUIVCDPNZVUBJMBOH