TCA v0.19.0͔Βͷ SwitchStore/CaseLet͕ྑ͍ QPUBUPUJQT @yimajo ͞Β͹͢΂ͯͷ*G-FU4UPSFʹΑΔը໘දࣔ੾Γସ͑

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v0.19.0ͷ SwichStoreͱCaseLetʹ͍ͭͯ ExampleͷTicTacToeͰઆ໌

-PHJO 7JFX /FX (BNF 7JFX ىಈ ϩάΠϯ׬ྃ TicTacToeʢ3໨ฒ΂ʣήʔϜ

public enum AppState: Equatable { case login(LoginState) case newGame(NewGameState) public init() { self = .login(.init()) } } public struct AppState: Equatable { public var login: LoginState? = LoginState() public var newGame: NewGameState? public init() {} } public var body: some View { SwitchStore(self.store) { CaseLet( state: /AppState.login, action: AppAction.login ) { store in NavigationView { LoginView(store: store) } .navigationViewStyle(StackNavigationViewStyle()) } CaseLet( state: /AppState.newGame, action: AppAction.newGame ) { store in NavigationView { NewGameView(store: store) } .navigationViewStyle(StackNavigationViewStyle()) } } @ViewBuilder public var body: some View { IfLetStore( self.store.scope(state: \.login, action: AppAction.login) ) { store in NavigationView { LoginView(store: store) } .navigationViewStyle(StackNavigationViewStyle()) } IfLetStore( self.store.scope(state: \.newGame, action: AppAction.newGame) ) { store in NavigationView { NewGameView(store: store) } .navigationViewStyle(StackNavigationViewStyle()) } } Ҏલͷ΍Γํ 4XJUDI4UPSF$BTF-FUͰͷ΍Γํ 4XJGU6*7JFX 4XJGU6*7JFX 4UBUF 4UBUF

SwitchStore/CaseLet ͸ case͕໢ཏ͞Εͯͳ͚Ε͹ Τϥʔը໘Λදࣔͯ͘͠ΕΔ

SwitUI.View্Ͱ CaseLetͰ໢ཏͰ͖͍ͯ ͳ͍caseʹͳͬͨͱ͖ ਅͬ੺ͳը໘Ͱ $BTF-FUهࡌ͢Δ͔%FGBVMUΛ࢖͑ ͱܯࠂ͞ΕΔ

public var body: some View { SwitchStore(self.store) { CaseLet( state: /AppState.login, action: AppAction.login ) { store in NavigationView { LoginView(store: store) } .navigationViewStyle(StackNavigationViewStyle()) } CaseLet( state: /AppState.newGame, action: AppAction.newGame ) { store in NavigationView { NewGameView(store: store) } .navigationViewStyle(StackNavigationViewStyle()) } Default { Text(“ະ࣮૷: ͋ͱͰ͍͍ײ͡ʹCaseLetॻ͘”) } } 4XJGU6*7JFX DefaultΛ࢖ͬͯΈΔྫ %FGBVMU͸։ൃ࣌͘Β͍ʹ࢖ͬͯجຊతʹ͸$BTF-FUͰ໢ཏ͠Α͏ public enum AppState: Equatable { case login(LoginState) case newGame(NewGameState) case foo(FooState) public init() { self = .login(.init()) } } 4UBUF

SwitchStore/CaseLetͷ Ԡ༻Λߟ͑ͯΈΔ

લఏ ϩάΠϯը໘͸ ϩάΠϯࡁΈͳΒ දࣔ͠ͳ͍ -PHJO 7JFX /FX (BNF 7JFX ϩάΠϯ൑ఆ ͯ͠ ϩάΠϯͯͨ͠Β NewGameView ىಈ

-PHJO 7JFX /FX (BNF 7JFX ىಈ public enum AppState: Equatable { case launch(LaunchState) case login(LoginState) case newGame(NewGameState) public init() { self = .launch(.init()) } } -BVODI 7JFX ϩάΠϯ ͯ͠ͳ͚Ε͹ LoginView ϩάΠϯͯ͠Ε͹ NewGameView Ԡ༻ྫ1 LaunchViewͰΞχϝʔγϣϯͱ͔Ͱ͖Δ

ىಈ public struct AppState: Equatable { enum Scene: Equatable { case login(LoginState) case newGame(NewGameState) } var scene: Scene var flag: Bool // ڞ௨ͳԿ͔ public init( scene: Scene = .loginCore(.init()) flag: Bool = false ) { self.scene = scene self.flag = flag } } 4UBUF -PHJO 7JFX /FX (BNF 7JFX ϩάΠϯ൑ఆ ͯ͠ NewGameView Ԡ༻ྫ2 ୹ॴ: CathPathͷ࢓༷Λཧղ͠ͳ͍ͱೲಘͰ͖ͳ͍΍ΓํʹͳΔ

ىಈ public struct RootState: Equatable { var appCore: AppCoreState var flag: Bool // ڞ௨ͳԿ͔ public init( appCore: AppCoreState = .loginState(.init()) flag: Bool = false ) { self.appCore = appCore self.flag = flag } } let reducer = Reducer.combine( appCoreReducer( // … ), Reducer { // … } ) 4UBUF -PHJO 7JFX /FX (BNF 7JFX ϩάΠϯ൑ఆ ͯ͠ NewGameView Ԡ༻ྫ2.1 public enum AppCoreState: Equatable { case login(LoginState) case newGame(NewGameState) } public enum AppCoreAction: Equatable { case login(LoginAction) case newGame(NewGameAction) } $PSFͱͯ͠FOVN4UBUFʹ͢Δ͕3PPU͸TUSVDU

ൃද͸Ҏ্Ͱ͢🙇 ʮ͞Β͹͢΂ͯͷ*G-FU4UPSFʹΑΔը໘දࣔ੾Γସ͑ʯ ͱ͍͏αϒλΠτϧͰ͕ͨ͠ɺ $BTF-FUͷͳ͔Ͱ͸*G-FU4UPSF͕࢖ΘΕ͍ͯ·͢ɻ