SwiftUIにおける依存性逆転原則の戦略 / A strategy to import Dependency-Inversion-Principle in SwiftUI apps

Transcript

1. 4XJGU6*ʹ͓͚Δ
   ґଘੑٯసݪଇͷઓུ f o r
   ୈ   ճ

   
   ) " , "5"  T X J G U

2. } var employedBy = "YUMEMI Inc." var job = "iOS

   Tech Lead" var favoriteLanguage = "Swift" var twitter = "@lovee" var qiita = "lovee" var github = "el-hoshino" var additionalInfo = """ ݘ೿ͳͷʹೣΛอޢͯ͠͠·ͬͨ """ final class Me: Developable, Talkable {
3. None

4. struct LandmarkList: View { @EnvironmentObject var modelData: ModelData @State private

   var showFavoritesOnly = false var body: some View { // ... } } IUUQTEFWFMPQFSBQQMFDPNUVUPSJBMTTXJGUVJ

5. final class ModelData: ObservableObject { @Published var landmarks: [Landmark] =

   [ // ... ] } IUUQTEFWFMPQFSBQQMFDPNUVUPSJBMTTXJGUVJ

6. LandmarkList
   ͕ɺ
   ۩৅ܕͷ
   ModelData
   ʹґଘ͍ͯ͠Δɻ

7. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ final class SomeComponent { var p: Int = 0

   func f() {} // ... } final class SomeObject { let component: SomeComponent init(component: SomeComponent) { self.component = component } func doSomething() { component.f() } }

8. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ final class SomeComponent { var p: Int = 0

   func f() {} // ... } final class SomeObject { let component: SomeComponent init(component: SomeComponent) { self.component = component } func doSomething() { component.f() } } func test_doSomething() { final class MockComponent: SomeComponent { override init() { super.init() self.p = 100 } override func f() {} } let object = SomeObject(component: MockComponent()) object.doSomething() } Inheritance from a final class 'SomeComponent' Instance method overrides a 'final' instance method

9. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ class SomeComponent { var p: Int = 0 func

   f() {} // ... } final class SomeObject { let component: SomeComponent init(component: SomeComponent) { self.component = component } func doSomething() { component.f() } } func test_doSomething() { final class MockComponent: SomeComponent { override init() { super.init() self.p = 100 } override func f() {} } let object = SomeObject(component: MockComponent()) object.doSomething() } pOBM
   DMBTT
   ͰએݴͰ͖ͳ͍ͨΊ
   ύϑΥʔϚϯε͕ඍົʹྑ͘ͳ͍
   
   ܧঝ͕๷͛ͳ͍͔Β
   ࢓૊Έ্(PE
   $MBTT͕๷͛ͳ͍
   ͦ΋ͦ΋
   TUSVDU
   ͩͬͨΒͲ͏͢Δʁ ։ൃ࣌͸ΦʔόʔϥΠυશ෦Ͱ͖͚ͨͲ
   อक࣌ʹ௥Ճͨ͠΋ͷͷΦʔόʔϥΠυ
   ๨ΕͨΒͲ͏͢Δʁ

10. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ w ෦඼Λஔ͖׵͑ʹ͍͘ w ςετ͕ॻ͖ʹ͍͘

11. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ class SomeComponent { func a() {} func b() {}

    } final class ObjectA { let component: SomeComponent init(component: SomeComponent) { self.component = component } func doSomething() { component.a() } } final class ObjectB { let component: SomeComponent init(component: SomeComponent) { self.component = component } func doSomething() { component.b() } } 0CKFDU"
    ͕ࣗ෼ʹෆඞཁͳ
    4PNF$PNQPOFOUC
    Λ஌ͬͯΔ͠
    0CKFDU#
    ΋ࣗ෼ʹෆඞཁͳ
    4PNF$PNQPOFOUB
    Λ஌͍ͬͯΔ
    4PNF$PNQPOFOU
    ࣗମͷӨڹൣғ͕
    ඇৗʹ޿ͯ͘อकੑ͕Լ͕Δ
    0CKFDU"
    ͱ
    0CKFDU#
    ΋
    ࣗ෼ͨͪͲ͜·Ͱ஌Δඞཁ͕͋Δ͔
    Θ͔Γʹ͍͘ͷͰอकੑ͕Լ͕Δ

12. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ class SomeComponent { func a() {} func b() {}

    } final class ObjectA { let component: SomeComponent func doSomething() { component.a() } } final class ObjectB { } func test_doSomethingA() { final class MockComponent: SomeComponent { override func a() { // } override func b() { XCTFai() } } let object = ObjectA(component: MockComponent()) object.doSomething() } B
    ͚ͩΦʔόʔϥΠυ͢Ε͹͍͍͸ͣͳͷʹɺ
    C
    ΋ΦʔόʔϥΠυ͠ͳͪ͘Ό͍͚ͳ͍

13. ͳͥ۩৅ʹґଘ͢Δͷ͸ѱ͍จ໌͔ w ෦඼Λஔ͖׵͑ʹ͍͘
    w ςετ͕ॻ͖ʹ͍͘
    w ৘ใΛ஌Γ͗͢Δ
    w Өڹൣғ͕޿͘อकੑ͕௿͍

14. ґଘؔ܎ٯసͷݪଇ w ্ҐϨϕϧͷϞδϡʔϧ͸ԼҐϨϕϧͷϞδϡʔϧʹ ґଘ͢΂͖Ͱ͸ͳ͍ɻ
    ྆ํͱ΋ந৅ʹґଘ͢΂͖Ͱ͋Δɻ
    w ந৅͸ৄࡉʢ۩৅ʣʹґଘͯ͠͸ͳΒͳ͍ɻ
    ৄࡉʢ۩৅ʣ͕ந৅ʹґଘ͢΂͖Ͱ͋Δɻ

15. ۩৅ʁ
    ந৅ʁ

16. ந৅ protocol SomeProtocol { func add1(int: Int) -> Int }

    ۩৅ final class A: SomeProtocol { func add1(int: Int) -> Int { return int + 1 } } struct B: SomeProtocol { func add1(int: Int) -> Int { return int * 2 } } enum C: SomeProtocol { func add1(int: Int) -> Int { return 0 } }

17. Ԡ༻ͯ͠ΈΔͱ protocol ComponentProtocol { func f() } final class SomeObject

    { let component: ComponentProtocol init(component: ComponentProtocol) { self.component = component } func doSomething() { component.f() } } final class SomeComponent { var p: Int = 0 } extension SomeComponent: ComponentProtocol { func f() {} }

18. 4XJGU6*
    ʹద༻ͯ͠ΈΔͱ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct SomeView: View { @StateObject var object: SomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 }

19. ͜ͷΑ͏ʹ
    4XJGU6*
    Ͱ΋
    ґଘؔ܎Λٯసͯ͠
    อकੑΛߴΊ͍ͯ͜͏

20. ͜ͷΑ͏ʹ
    4XJGU6*
    Ͱ΋
    ґଘؔ܎Λٯసͯ͠
    อकੑΛߴΊ͍ͯ͜͏ ࢒೦ͳ͕Β
    ͜ΕͰऴΘΓʹͰ͖ͳ͔ͬͨ

21. 4XJGU6*
    ʹద༻ͯ͠ΈΔͱ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView: View { @StateObject var object: SomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } Property type 'SomeObject' does not ...

22. 4XJGU6*
    ʹద༻ͯ͠ΈΔͱ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView: View { @StateObject var object: SomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } Property type 'SomeObject' does not match that of the 'wrappedValue' property of its wrapper type 'StateObject'

23. ͳͥ
    @StateObject
    Ͱ
    protocol
    ͕
    ͦͷ··࢖͑ͳ͍ͷ͔ w StateObject
    ͷ
    wrappedValue: ObjectType
    ϓϩύςΟʔ ʹΑͬͯɺ಺แ͢Δܕ͕
    ObjectType
    ͷδΣωϦοΫܕͱͯ͠ ࢖͑Δඞཁ͕͋Δ
    w ObservableObject
    ʹ͸
    ObjectWillChangePublisher
    ͱ ͍͏ؔ࿈ܕ͕એݴ͞Ε͍ͯΔͨΊɺprotocol
    ͷଘࡏܕͱͯ͠

    δΣωϦοΫܕʹͳΕͳ͍
    w @StateObject
    ʹݶΒͣɺ@EnvironmentObject
    ΍
    @ObservedObject
    ΋ಉ͡

24. ͑ʁ͡Ό͋
    4XJGU6*
    Ͱ
    ґଘٯసͰ͖ͳ͍Μ͡ΌͶʁ

25. ͑ʁ͡Ό͋
    4XJGU6*
    Ͱ
    ґଘٯసͰ͖ͳ͍Μ͡ΌͶʁ ΋ͪΖΜͰ͖·͢Αʂ

26. ํ๏
    ɿδΣωϦΫεΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView: View { @StateObject var object: SomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } Property type 'SomeObject' does not ...

27. ํ๏
    ɿδΣωϦΫεΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView<Object: SomeObject>: View { @StateObject var object: Object var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } δΣωϦΫεΛೖΕͯ͋͛Ε͹
    4UBUF0CKFDU
    ʹ୅ೖͰ͖Δ

28. ํ๏
    ɿδΣωϦΫεΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView<Object: SomeObject>: View { @StateObject var object: Object var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } return MyView(object: Counter())

29. ํ๏
    ɿδΣωϦΫεΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView<Object: SomeObject>: View { @EnvironmentObject var object: Object var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } return MyView<Counter>() 4UBUF0CKFDU
    ΍
    0CTFSWFE0CKFDU
    ͷ
    ৔߹͸໰୊ͳ͍͕ɺ
    &OWJSPONFOU0CKFDU
    ͷ৔߹͸
    ΠχγϟϥΠβͰδΣωϦΫε͕
    ղܾͰ͖ͳ͍ͷͰɺ
    ໌ࣔతʹδΣωϦοΫܕΛ
    ॻ͘ඞཁ͕͋Δ

30. ํ๏
    ɿδΣωϦΫεΛ࢖͏ protocol ObjectA: ObservableObject { var int: Int { get

    } } protocol ObjectB: ObservableObject { var string: String { get } } struct MyView<A: ObjectA, B: ObjectB>: View { @EnvironmentObject var a: A @EnvironmentObject var b: B var body: some View { Text("\(a.int), \(b.string)") } } final class MyObjectA: ObjectA { @Published var int = 0 } final class MyObjectB: ObjectB { @Published var string = "" } return MyView<MyObjectA, MyObjectB>() &OWJSPONFOU0CKFDU
    ͷґଘ͕૿͑Δͱ
    δΣωϦοΫܕ΋૿͍͑ͯ͘

31. ํ๏
    ɿδΣωϦΫεΛ࢖͏ protocol ObjectA: ObservableObject { var int: Int { get

    } } protocol ObjectB: ObservableObject { var string: String { get } } struct MyView<A: ObjectA, B: ObjectB>: View { @EnvironmentObject var a: A @EnvironmentObject var b: B var body: some View { Text("\(a.int), \(b.string)") } } protocol ComponentA {} final class MyObjectA<A: ComponentA>: ObjectA { @ObservedObject var a: A @Published var int = 0 } protocol ComponentB {} final class MyObjectB<B: ComponentB>: ObjectB { @ObservedObject var b: B @Published var string = "" } struct Component: ComponentA, ComponentB {} return MyView<MyObjectA<Component>, MyObjectB<Component>>() &OWJSPONFOU0CKFDU
    ͷґଘʹ΋
    δΣωϦΫε͕࢖ΘΕΔͱ
    δΣωϦοΫܕͷωετͰ͞ΒʹΧΦε

32. ͦ΋ͦ΋
    @EnvironmentObject
    ͸
    ۩৅ΛӅ͢ͷʹ࢖͍͍ͨ͜ͱ΋ଟ͍ͷʹ
    δΣωϦΫεͰ۩৅ॻ͔͞ΕͨΒ
    ຊ຤స౗͡ΌΜʁ

33. ํ๏
    ɿܕফڈΛ࢖͏ w ܕফڈ͸ɺԿ͔ܕʹؚ·ΕΔܕม਺Λফڈ͢Δख๏
    w 4XJGU6*
    ΍
    $PNCJOF
    ͚ͩͰͳ͘ɺ4XJGU
    Ϟδϡʔϧ ࣗ਎Ͱ΋ྑ͘ݟ͔͚ΒΕΔ
    w 4XJGU6*ɿ
    AnyView
    w $PNCJOFɿ
    AnyPublisherɺAnySubscriber
    

    w 4XJGUɿ
    AnySequenceɺAnyCollectionʜ

34. ํ๏
    ɿܕফڈΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView<Object: SomeObject>: View { @EnvironmentObject var object: Object var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } return MyView<Counter>()

35. ํ๏
    ɿܕফڈΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView: View { @EnvironmentObject var object: AnySomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } return MyView() δΣωϦοΫܕ͕ͳ͘ͳͬͯεοΩϦ ܕফڈͨ͠ܕΛ࢖͏ͷͰ
    ۩৅Λ஌Δඞཁ͕ͳ͍··

36. ͰɺͲ͏΍ͬͯܕফڈͷܕΛ
    ࡞Δͷʁ

37. IUUQTRJJUBDPNPNPDIJNFUBSVJUFNTECFCFG

38. ํ๏
    ɿܕফڈΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } private class SomeObjectBox { var int: Int { fatalError() } var objectWillChange: ObservableObjectPublisher { fatalError() } } 4UFQ
    
    ܧঝͤ͞ΔͨΊͷμϛʔΫϥεΛ࡞Δɻ
    ͦͷࡍΦʔόʔϥΠυͤ͞ΔͨΊͷϓϩύςΟʔ ΍ϝιουΛ࡞ΓɺGBUBM&SSPS
    Λฦ͢ɻ
    ·ͨ͜͜Ͱফڈ͍ͨ͠ܕ΋༧Ίఆ͓ٛͯ͘͠ʢࠓ ճͷ৔߹͸
    PCKFDU8JMM$IBOHF
    ͷܕͰ͋Δ 0CTFSWBCMF0CKFDU0CKFDU8JMM$IBOHF1VCMJTIFS
    Λ
    0CTFSWBCMF0CKFDU1VCMJTIFS
    ʹݻఆ͢Δʣ

39. ํ๏
    ɿܕফڈΛ࢖͏ private final class AnySomeObjectBox<Object: SomeObject>: SomeObjectBox where Object.ObjectWillChangePublisher ==

    ObservableObjectPublisher { private let object: Object fileprivate init(_ object: Object) { self.object = object } override var int: Int { return object.int } override var objectWillChange: ObservableObjectPublisher { return object.objectWillChange } } 4UFQ
    
    μϛʔΫϥεΛܧঝͤ͞ɺܧঝͨ͠ࢠΫϥεʹ
    QSPUPDPM
    ४ڌͨ͠δΣωϦοΫܕΛೖΕɺফڈ ͍ͨ͠ܕͷ੍ݶΛೖΕ͓ͯ͘ɻ
    ͦͷࡍɺμϛʔΫϥεͷશͯͷϓϩύςΟʔͱ ϝιουΛΦʔόʔϥΠυ͠ɺೖΕͬࢠͷ֘౰ ϓϩύςΟʔ΍ϝιουΛฦ͢ɻ

40. ํ๏
    ɿܕফڈΛ࢖͏ final class AnySomeObject: SomeObject { private let object: SomeObjectBox

    fileprivate init<O: SomeObject>(_ object: O) where O.ObjectWillChangePublisher == ObservableObjectPublisher { self.object = AnySomeObjectBox(object) } var int: Int { return object.int } var objectWillChange: ObservableObjectPublisher { return object.objectWillChange } } 4UFQ
    
    QSPUPDPM
    ʹ४ڌͨ͠ܕফڈίϯςφΫϥεΛ࡞ Γɺ಺෦ͰμϛʔΫϥεΛ࣋ͨͤΔɻ
    ࣮ࡍͷੜ੒࣌͸δΣωϦοΫܕΛ࣋ͬͨࢠΫϥε Ͱੜ੒ͯ࣋ͨͤ͠Δɻ
    ͦͯ͠
    QSPUPDPM
    ͷ֤ϓϩύςΟʔ΍ϝιουΛ ೖΕͬ͜ͷͰฦ͢ɻ
    ͜͏͢Ε͹δΣωϦοΫܕΛ࣋ͨͳ͍μϛʔΫϥ ε͔͠ͳ͍ͷͰδΣωϦΫε͕ඞཁͳ͍ʀͰ΋Ϋ ϥεͷܧঝͱΦʔόʔϥΠυʹΑΓͪΌΜͱδΣ ωϦοΫܕΛ࣋ͬͨࢠΫϥεͷৼΔ෣͍Λ͢Δɻ

41. ํ๏
    ɿܕফڈΛ࢖͏ extension SomeObject where Self.ObjectWillChangePublisher == ObservableObjectPublisher { func eraseToAnySomeObject()

    -> AnySomeObject { return AnySomeObject(self) } } 4UFQ
    
    ར༻࣌ͷ࢖͍΍͢͞Λߟ͑ͯɺܕফڈͨ͠ίϯ ςφΫϥε΁ͷੜ੒ϝιουΛ࡞Δɻ

42. ํ๏
    ɿܕফڈΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView: View { @EnvironmentObject var object: AnySomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } return MyView()

43. ํ๏
    ɿܕফڈΛ࢖͏ protocol SomeObject: ObservableObject { var int: Int { get

    } } struct MyView: View { @EnvironmentObject var object: AnySomeObject var body: some View { Text("\(object.int)") } } final class Counter: SomeObject { @Published var int = 0 } return MyView() .environmentObject(Counter().eraseToAnySomeObject()) &OWJSPONFOU0CKFDU
    ͳͷͰɺ
    Ͳ͜Ͱ஫ೖͯ͠΋େৎ෉ʂ

44. ·ͱΊ w ॊೈͰςελϒϧͳઃܭʹґଘؔ܎ٯసͷݪଇ͸ඞਢ
    w 4XJGU6*
    Ͱ͸ґଘؔ܎ٯస͢Δͷʹ͸ͪΐͬͱେม
    w δΣωϦΫε΍ɺܕফڈͳͲͷख๏͕࢖͑Δ

45. δΣωϦΫε ܕফڈ ϝϦοτ ໘౗ͳ࢓૊͕ཁΒͳ͍ͷͰ ࣮૷ָ͕ ґଘͷ࣮ଶΛؾʹ͠ͳͯ͘ ࡁΉͷͰɺδΣωϦΫε͕ ཁΒͳ͍͔Βίʔυࣗମ͕ εοΩϦ͢Δ σϝϦοτ

    ґଘ͕૿͑ͨΓɺґଘࣗମ ΋ߋʹδΣωϦΫεΛ࢖͏ ͱॻ͖΋ಡΈ΋͠ʹ͍͘ ܕফڈͷ࢓૊ࣗମΛ࡞Δͷ ͕ඇৗʹ໘౗ ࢖͏৔໘ w 4UBUF0CKFDU
    ΍
    0CTFSWFE0CKFDU
    w ґଘ͕গͳ͍
    w δΣωϦΫεͷωετ͕ ਂ͘ͳ͍ w &OWJSPONFOU0CKFDU
    ͷ ґଘ͕ଟ͍
    w &OWJSPONFOU0CKFDU
    ͷ ґଘͷδΣωϦΫεͷω ετ͕ਂ͍

46. ͜ͷΑ͏ʹ
    4XJGU6*
    Ͱ΋
    ґଘؔ܎Λٯసͯ͠
    อकੑΛߴΊ͍ͯ͜͏

47. IUUQTZVNFNJDPOOQBTTDPNFWFOU ొஃ͓଴͓ͪͯ͠Γ·͢ʂ