Effective Multiplatform Architecture

Building multiplatform apps requires thinking about architecture a little differently than their single platform counterparts. Individually, each platform has their own norms and customs, filled with M's and V's and Promises, but they aren't alway a good fit to be shared with others. Often they have coupled relationships with the platforms for which they were designed that don't play nicely with others.

Over the past several months I've been migrating the Chicago Roboto app from a Kotlin first Android app to a multiplatform app, and have learned a lot about things that work well for one platform but not another, and how to make those feel a bit more native.

As I share the things I've learned with you, we'll discuss:

• Where to start the multiplatform conversion.
• Adapting native libraries
• Communicating between shared Kotlin code and native platforms
• Designing systems that non-Kotlin developers can get behind.

Transcript

1. #DCNYC19 @rharter Effective Multiplatform Architecture #DCNYC19 @rharter Ryan Harter
2. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
3. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
4. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
5. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API App App App
6. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API App App App
7. #DCNYC19 @rharter Multiplatform App App Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API
8. #DCNYC19 @rharter
9. #DCNYC19 @rharter Getting to Multiplatform #DCNYC19 @rharter Ryan Harter
10. #DCNYC19 @rharter Step 0 - Modularize
11. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time •
12. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time • “clean” architecture is important (MVI) •
13. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time • “clean” architecture is important (MVI) • Inversion of Control (Dependency Injection) •
14. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time • “clean” architecture is important (MVI) • Inversion of Control (Dependency Injection) • Minimal platform dependencies •
15. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time • “clean” architecture is important (MVI) • Inversion of Control (Dependency Injection) • Minimal platform dependencies • Limit to View and Repo dependencies •
16. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time • “clean” architecture is important (MVI) • Inversion of Control (Dependency Injection) • Minimal platform dependencies • Limit to View and Repo dependencies • LiveData
17. #DCNYC19 @rharter Modularize • Easier to migrate one module at a time • “clean” architecture is important (MVI) • Inversion of Control (Dependency Injection) • Minimal platform dependencies • Limit to View and Repo dependencies • LiveData
18. #DCNYC19 @rharter Modularize Auth API Database Login Feature User Repo App
19. #DCNYC19 @rharter Login Feature Auth API User Repo Modularize Database App
20. #DCNYC19 @rharter Modularize Auth API Database Login Feature User Repo App
21. #DCNYC19 @rharter Modularize Auth API Database Login Feature User Repo App
22. #DCNYC19 @rharter Modularize Auth API Database Login Feature User Repo App
23. #DCNYC19 @rharter Modularize Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
24. #DCNYC19 @rharter Multiplatform
25. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
26. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
27. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API App
28. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Multiple Similar Apps Single App Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
29. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
30. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API • All functionality needs to be replicated • Can start anywhere • Same approach as new app
31. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
32. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
33. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App
34. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App
35. #DCNYC19 @rharter Single App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App
36. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Multiple Similar Apps Single App Multiple Different Apps Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
37. #DCNYC19 @rharter Multiple Different Apps • Similar to modularization strategy • Convert to MPP as you modularize • Pick a feature to convert • Start from the bottom App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
38. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
39. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
40. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
41. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
42. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
43. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
44. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
45. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
46. #DCNYC19 @rharter Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
47. #DCNYC19 @rharter Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App Multiple Different Apps
48. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Multiple Similar Apps Single App Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
49. #DCNYC19 @rharter Multiple Similar Apps • Multiple Approaches • New Feature • Vertical Migration • Horizontal Migration • Choice depends on existing arch, teams, etc. • Can be done with many small PRs (i.e. reduce risk) Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
50. #DCNYC19 @rharter Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App Similar Apps - New Features
51. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Similar Apps - New Features Subscription Feature
52. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Similar Apps - New Features Subscription Feature
53. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Similar Apps - New Features Subscription Feature
54. #DCNYC19 @rharter Subscription Feature Common expect interface UserRepository { suspend fun getUser(): User suspend fun updateUser(user: User): User ... }
55. #DCNYC19 @rharter Subscription Feature Common expect interface UserRepository { suspend fun getUser(): User suspend fun updateUser(user: User): User ... }
56. #DCNYC19 @rharter Subscription Feature Common expect interface UserRepository { suspend fun getUser(): User suspend fun updateUser(user: User): User ... } iOS actual typealias UserRepository = backend.UserRepository JVM actual typealias UserRepository = com.example.myApp.backend.UserRepository
57. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Similar Apps - New Features Subscription Feature
58. #DCNYC19 @rharter Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API App Similar Apps - Vertical
59. #DCNYC19 @rharter Similar Apps - Vertical Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API
60. #DCNYC19 @rharter Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Similar Apps - Vertical
61. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Similar Apps - Vertical
62. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Similar Apps - Vertical
63. #DCNYC19 @rharter Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Similar Apps - Vertical
64. #DCNYC19 @rharter User Repo Login Feature App Account Feature Library Feature Social Repo Content Repo Activity API Content API Login Feature App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database User Repo Similar Apps - Vertical
65. #DCNYC19 @rharter Login Feature App Account Feature Library Feature Social Repo Content Repo Activity API Content API Login Feature App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database User Repo Similar Apps - Vertical
66. #DCNYC19 @rharter Login Feature App Account Feature Library Feature Social Repo Content Repo Activity API Content API App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database User Repo Login Feature Similar Apps - Vertical
67. #DCNYC19 @rharter Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Vertical
68. #DCNYC19 @rharter Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API App Auth API Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API App Similar Apps - Horizontal
69. #DCNYC19 @rharter Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal
70. #DCNYC19 @rharter Database Login Feature User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal
71. #DCNYC19 @rharter Database User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal
72. #DCNYC19 @rharter Database User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal Account Feature Account Feature Library Feature
73. #DCNYC19 @rharter Database User Repo Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal User Repo Social Repo Content Repo
74. #DCNYC19 @rharter Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo App Similar Apps - Horizontal Database Activity API Content API Auth API Database Activity API Content API Auth API Auth API Database Activity API Content API
75. #DCNYC19 @rharter Database User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal
76. #DCNYC19 @rharter Login Feature Feature Layer • Interface with platform implementations • Views • Repositories (or Use Cases) • Connected at both front and back • How to observe values?
77. #DCNYC19 @rharter Login Feature Feature Layer To Repositories
78. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View
79. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View
80. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ? ? ? ? ?
81. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ? ? ✆ ✆ ✆
82. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ? ? ☵ !☵ !☵
83. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ? ☵ !☵ !☵ ViewActions
84. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ☵ !☵ !☵ ViewActions ViewState
85. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ☵ !☵ !☵ ViewActions ViewState ☵
86. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ☵ !☵ !☵ ViewActions ViewState
87. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ☵ !☵ !☵ ViewActions ViewState !⚛
88. #DCNYC19 @rharter ⚛ Common package org.reactivestreams.mpp expect interface Subscriber<T> { fun onSubscribe(s: Subscription) fun onNext(t: T) fun onError(t: Throwable) fun onComplete() }
89. #DCNYC19 @rharter ⚛ Common JVM package org.reactivestreams.mpp actual typealias Subscriber<T> = org.reactivestreams.Subscriber<T> package org.reactivestreams.mpp expect interface Subscriber<T> { fun onSubscribe(s: Subscription) fun onNext(t: T) fun onError(t: Throwable) fun onComplete() }
90. #DCNYC19 @rharter ⚛ package org.reactivestreams.mpp actual interface Subscriber<T> { actual fun onSubscribe(s: Subscription) actual fun onNext(t: T) actual fun onError(t: Throwable) actual fun onComplete() } Common JVM iOS package org.reactivestreams.mpp actual typealias Subscriber<T> = org.reactivestreams.Subscriber<T> package org.reactivestreams.mpp expect interface Subscriber<T> { fun onSubscribe(s: Subscription) fun onNext(t: T) fun onError(t: Throwable) fun onComplete() }
91. #DCNYC19 @rharter ⚛ package org.reactivestreams.mpp actual interface Subscriber<T> { actual fun onSubscribe(s: Subscription) actual fun onNext(t: T) actual fun onError(t: Throwable) actual fun onComplete() } class BlockSubscriber<T>( private val onNextBlock: (T) -> Unit, private val onErrorBlock: (Throwable) -> Unit, private val onCompleteBlock: () -> Unit ) : Subscriber<T>, Disposable { ... } Common JVM iOS package org.reactivestreams.mpp actual typealias Subscriber<T> = org.reactivestreams.Subscriber<T> package org.reactivestreams.mpp expect interface Subscriber<T> { fun onSubscribe(s: Subscription) fun onNext(t: T) fun onError(t: Throwable) fun onComplete() }
92. #DCNYC19 @rharter ⚛ package org.reactivestreams.mpp actual interface Subscriber<T> { actual fun onSubscribe(s: Subscription) actual fun onNext(t: T) actual fun onError(t: Throwable) actual fun onComplete() } class BlockSubscriber<T>( private val onNextBlock: (T) -> Unit, private val onErrorBlock: (Throwable) -> Unit, private val onCompleteBlock: () -> Unit ) : Subscriber<T>, Disposable { ... } iOS extension Reactive_streams_mppPublisher { func subscribe<T: AnyObject>( onNext onNextBlock: @escaping (T) -> Void, onError onErrorBlock: @escaping (Error) -> Void, onComplete onCompleteBlock: @escaping () -> Void ) -> Disposable { let subscriber = BlockSubscriber<T>( onNextBlock: onNextBlock, onErrorBlock: onErrorBlock, onCompleteBlock: onCompleteBlock ) subscribe(s: subscriber) return subscriber } } iOS - Swift
93. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ☵ !☵ !☵ ViewActions ViewState !⚛
94. #DCNYC19 @rharter Login Feature ViewModel
95. #DCNYC19 @rharter Login Feature ViewModel Common package com.chicagoroboto.features.shared expect interface ViewModel<ViewState : Any> { val viewState: Flow<ViewState> }
96. #DCNYC19 @rharter Login Feature JVM ViewModel Common package com.chicagoroboto.features.shared expect interface ViewModel<ViewState : Any> { val viewState: Flow<ViewState> } package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> }
97. #DCNYC19 @rharter Login Feature Common JVM package com.chicagoroboto.features.shared expect interface ViewModel<ViewState : Any> { val viewState: Flow<ViewState> } ViewModel package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> } iOS package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> fun viewState(): Publisher<ViewState> = viewState.asPublisher() } fun viewState(): Publisher<ViewState> = viewState.asPublisher()
98. #DCNYC19 @rharter Login Feature ViewModel Common JVM package com.chicagoroboto.features.shared expect interface ViewModel<ViewState : Any> { val viewState: Flow<ViewState> } package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> } iOS package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> fun viewState(): Publisher<ViewState> = viewState.asPublisher() } fun viewState(): Publisher<ViewState> = viewState.asPublisher()
99. #DCNYC19 @rharter Login Feature SessionListViewModel class SessionListViewModel( private val sessionRepo: SessionRepository, speakerRepo SpeakerRepository, favoriteRepo: FavoriteRepository ) : ViewModel<SessionListViewState> { private val dateChannel = ConflatedBroadcastChannel<String>() private val sessionFlow: Flow<List<Session>> = dateChannel.asFlow() .flatMapConcat { sessionRepo.sessionsForDate(it) } private val speakerFlow: Flow<List<Speaker>> = speakerRepo.getSpeakers() private val favoriteFlow: Flow<Set<String>> = favoriteRepo.getFavorites() override val viewState = combine(sessionFlow, speakerFlow, favoriteFlow) { sessions, speakers, favorites -> SessionListViewState(date, viewSessions) } }
100. #DCNYC19 @rharter Login Feature SessionListViewModel override val viewState = combine(sessionFlow, speakerFlow, favoriteFlow) { sessions, speakers, favorites -> SessionListViewState(date, viewSessions) } class SessionListViewModel( private val sessionRepo: SessionRepository, speakerRepo SpeakerRepository, favoriteRepo: FavoriteRepository ) : ViewModel<SessionListViewState> { private val dateChannel = ConflatedBroadcastChannel<String>() private val sessionFlow: Flow<List<Session>> = dateChannel.asFlow() .flatMapConcat { sessionRepo.sessionsForDate(it) } private val speakerFlow: Flow<List<Speaker>> = speakerRepo.getSpeakers() private val favoriteFlow: Flow<Set<String>> = favoriteRepo.getFavorites() override val viewState = combine(sessionFlow, speakerFlow, favoriteFlow) { sessions, speakers, favorites -> SessionListViewState(date, viewSessions) } }
101. #DCNYC19 @rharter iOS App .subscribe( onNext: { [weak self] (state: SessionListViewState) in self?.sessions = state.sessions }, onError: { error in NSLog("Failed to load state.", error) }, onComplete: { NSLog("onComplete") } ) class SessionListViewController: UICollectionViewController { override func viewDidLoad() { super.viewDidLoad() disposables <= self.viewModel.viewState() .subscribe( onNext: { [weak self] (state: SessionListViewState) in self?.sessions = state.sessions }, onError: { error in NSLog("Failed to load state.", error) }, onComplete: { NSLog("onComplete") } ) self.viewModel.setDate(date: self.date) } }
102. #DCNYC19 @rharter iOS App .subscribe( onNext: { [weak self] (state: SessionListViewState) in self?.sessions = state.sessions }, onError: { error in NSLog("Failed to load state.", error) }, onComplete: { NSLog("onComplete") } ) class SessionListViewController: UICollectionViewController { override func viewDidLoad() { super.viewDidLoad() disposables <= self.viewModel.viewState() .subscribe( onNext: { [weak self] (state: SessionListViewState) in self?.sessions = state.sessions }, onError: { error in NSLog("Failed to load state.", error) }, onComplete: { NSLog("onComplete") } ) self.viewModel.setDate(date: self.date) } }
103. #DCNYC19 @rharter Login Feature Common JVM package com.chicagoroboto.features.shared expect interface ViewModel<ViewState : Any> { val viewState: Flow<ViewState> } ViewModel package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> } iOS package com.chicagoroboto.features.shared actual interface ViewModel<ViewState : Any> { actual val viewState: Flow<ViewState> fun viewState(): Publisher<ViewState> = viewState.asPublisher() } fun viewState(): Publisher<ViewState> = viewState.asPublisher()
104. #DCNYC19 @rharter Login Feature Feature Layer To Repositories To View ☵ !☵ !☵ ViewActions ViewState !⚛
105. #DCNYC19 @rharter Database User Repo Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API App Similar Apps - Horizontal
106. #DCNYC19 @rharter Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo App Similar Apps - Horizontal Auth API Database Activity API Content API
107. #DCNYC19 @rharter Multiplatform Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Multiple Similar Apps Single App Multiple Different Apps App Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API Auth API Database Login Feature User Repo App Account Feature Library Feature Social Repo Content Repo Activity API Content API
108. #DCNYC19 @rharter Effective Multiplatform Architecture #DCNYC19 @rharter Ryan Harter