flux with kotlin (Abema Dev Con 2016)

Presented at Abema developer conference 2016
Introduced flux architecture with Kotlin and RxJava.

conference page : http://developer.abema.io/
video in Japanese : https://abemafresh.tv/tech-conference/47693

Transcript

1. Flux with Kotlin Abema Dev Con 2016
2. About me @_a_akira AAkira a0akira Akira Aratani
3. About FRESH! • 生放送配信プラットフォーム • FRESH! ≒ AbemaTV
4. Released map M1 2012-04-12 M11 2015-03-19 M14 2015-10-01 1.0-beta4 2015-12-22 M13 2015-09-16 1.0 2016-02-16 1.0-RC 2016-02-04 2016-01-21 Release 2015-04 開発開始 kotlin FRESH
5. Architecture
6. https://facebook.github.io/flux/docs/overview.html Data in a Flux application flows in a single direction About Flux
7. About Flux
8. About Flux Observer pattern
9. https://speakerdeck.com/ogaclejapan/flux-de-relax
10. Architecture of FRESH IUUQTHJUIVCDPNBOESPJE"OESPJE$MFBO"SDIJUFDUVSF $MFBO
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11. Architecture of FRESH
12. View Action Dispatcher Store DB WEB view(flux) data Repository
13. View Action Dispatcher Store Repository DB WEB view(flux) data OKHttp(Retrofit) SQLBrite Observable<T> Subject Observable<T> Observable<T>
14. IUUQRJJUBDPNTBUPSVGVKJXBSBJUFNTDCGEBFDCBC
15. How to implement with kotlin
16. Using libraries • Dagger2 • RxJava(RxKotlin) • RxAndroid • RxBinding • SQLBrite • RxPreferences • RxLifecycle => DI => Reactive Extensions => RxJava bindings for Android => binding APIs for Android's UI widgets => introduces reactive stream to SQLite => introduces reactive stream to Preferences => handles Android LifeCycles
17. Archive List BSDIJWF BSDIJWF BSDIJWF BSDIJWF BSDIJWF
18. View Dispatcher Store DB WEB view(flux) data Repository Action
19. Action class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh(screenId) }) }) } }
20. Action class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh(screenId) }) }) } } *OKFDU
    %JTQBUDIFS
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21. Action class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh(screenId) }) }) } } $BMM
    3FQPTJUPSZ
22. View Action Dispatcher Store DB WEB view(flux) data Repository
23. Repository class ProgramRepository(private val programService: ProgramService) { fun getProgramsArchive(count: Int? = null, offset: Int? = null) = programService.getPrograms(count = count, offset = offset, status = "archive", orderBy = "endAt") .subscribeOn(Schedulers.io()) .map { it.data.nullSafeMap(::toProgram) } }
24. Repository class ProgramRepository(private val programService: ProgramService) { fun getProgramsArchive(count: Int? = null, offset: Int? = null) = programService.getPrograms(count = count, offset = offset, status = "archive", orderBy = "endAt") .subscribeOn(Schedulers.io()) .map { it.data.nullSafeMap(::toProgram) } } *OKFDU
    4FSWJDF
25. Repository class ProgramRepository(private val programService: ProgramService) { fun getProgramsArchive(count: Int? = null, offset: Int? = null) = programService.getPrograms(count = count, offset = offset, status = "archive", orderBy = "endAt") .subscribeOn(Schedulers.io()) .map { it.data.nullSafeMap(::toProgram) } } $BMM
    4FSWJDF
26. View Action Dispatcher Store view(flux) data Repository DB WEB
27. WEB (Service) interface ProgramService { @GET("/programs") fun getPrograms(@Query("channelId") channelId: String? = null, @Query("count") count: Int?, @Query("orderBy") orderBy: String? = null, @Query("status") status: String? = null, ……, ……, ): Observable<ApiResponse<List<ApiProgram>>> }
28. WEB (Service) 3FUVSO
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    0,)UUQ interface ProgramService { @GET("/programs") fun getPrograms(@Query("channelId") channelId: String? = null, @Query("count") count: Int?, @Query("orderBy") orderBy: String? = null, @Query("status") status: String? = null, ……, ……, ): Observable<ApiResponse<List<ApiProgram>>> }
29. View Action Store DB WEB view(flux) data Repository Dispatcher
30. Dispatcher class ArchiveDispatcher(provider: DispatcherProvider) { val archiveDao = provider.archiveDao() }
31. Action / Dispatcher class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh() }) }) } }
32. Action / Dispatcher class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh() }) }) } } 6QEBUF
    EBUBCBTF
33. View Action Dispatcher DB WEB view(flux) data Repository Store
34. Store class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun programs() = dispatcher.archiveDao.selectAll().subscribeOn(Schedulers.io()) }
35. Store *OKFDU
    %JTQBUDIFS class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun programs() = dispatcher.archiveDao.selectAll().subscribeOn(Schedulers.io()) }
36. Store 0CTFSWF
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    #SJUF class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun programs() = dispatcher.archiveDao.selectAll().subscribeOn(Schedulers.io()) }
37. Action Dispatcher Store DB WEB view(flux) data Repository View
38. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() }
39. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() } *OKFDU
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40. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() } $BMM
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41. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() } 0CTFSWF
    TUPSF
42. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() } 3Y"OESPJE
43. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() } 3Y-JGFDZDMF
44. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() }
45. View class ArchiveFragment { @Inject lateinit var archiveAction: ArchiveAction @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.programs() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { adapter.clear() it.forEach { … } // add to adapter adapter.notifyDataSetChanged() } savedInstanceState ?: archiveAction.refresh() } Why don’t you implement onError
46. Action / Dispatcher class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh() }) }) } } 4FOE
    FSSPS open class CommonDispatcher(val provider: DispatcherProvider) { fun errors() = provider.errorDispatcher.errorObservable fun onError(action: Any, cause: Throwable, extras: Any? = null, recoverAction: (() -> Unit)? = null) = provider.errorDispatcher.onError(action, cause, extras, recoverAction) }
47. Action / Dispatcher class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh() }) }) } } open class CommonDispatcher(val provider: DispatcherProvider) { fun errors() = provider.errorDispatcher.errorObservable fun onError(action: Any, cause: Throwable, extras: Any? = null, recoverAction: (() -> Unit)? = null) = provider.errorDispatcher.onError(action, cause, extras, recoverAction) } $PNNPO
    %JTQBUDIFS
48. Action / Dispatcher class ArchiveAction(private val dispatcher: ArchiveDispatcher, private val programRepository: ProgramRepository) { fun refresh() { programRepository.getProgramsArchive(count = 20, offset = 0) .subscribe({ dispatcher.archiveDao.replaceAll(it) }, { dispatcher.onError(this, it, recoverAction = { refresh() }) }) } } open class CommonDispatcher(val provider: DispatcherProvider) { fun errors() = provider.errorDispatcher.errorObservable fun onError(action: Any, cause: Throwable, extras: Any? = null, recoverAction: (() -> Unit)? = null) = provider.errorDispatcher.onError(action, cause, extras, recoverAction) } *OMJOF
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49. View class ArchiveFragment { @Inject lateinit var archiveStore: ArchiveStore override fun onResume() { super.onResume() onAirStore.errors() .filter { it.action is ArchiveAction } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { if (it.kind == ErrorEvent.Kind.NETWORK) { showSnackBar(){ it.recoverAction?.invoke() } } } } }
50. View class ArchiveFragment { @Inject lateinit var archiveStore: ArchiveStore override fun onResume() { super.onResume() onAirStore.errors() .filter { it.action is ArchiveAction } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { if (it.kind == ErrorEvent.Kind.NETWORK) { showSnackBar(){ it.recoverAction?.invoke() } } } } } 4VCTDSJCF
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51. View class ArchiveFragment { @Inject lateinit var archiveStore: ArchiveStore override fun onResume() { super.onResume() onAirStore.errors() .filter { it.action is ArchiveAction } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { if (it.kind == ErrorEvent.Kind.NETWORK) { showSnackBar(){ it.recoverAction?.invoke() } } } } } 'JMUFS
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52. View class ArchiveFragment { @Inject lateinit var archiveStore: ArchiveStore override fun onResume() { super.onResume() onAirStore.errors() .filter { it.action is ArchiveAction } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { if (it.kind == ErrorEvent.Kind.NETWORK) { showSnackBar(){ it.recoverAction?.invoke() } } } } } 3FUSZ
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53. Everything is a stream
54. DB WEB view(flux) data Repository Action Dispatcher Store View
55. Like event bus class ArchiveDispatcher(provider: DispatcherProvider) { val statusObservable = SerializedSubject(BehaviorSubject.create<Status>()) } class ArchiveAction(private val dispatcher: ArchiveDispatcher) { fun updateStatus(status: Status) { dispatcher.statusObservable.onNext(status) } } class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun status() = dispatcher.statusObservable }
56. Like event bus class ArchiveDispatcher(provider: DispatcherProvider) { val statusObservable = SerializedSubject(BehaviorSubject.create<Status>()) } class ArchiveAction(private val dispatcher: ArchiveDispatcher) { fun updateStatus(status: Status) { dispatcher.statusObservable.onNext(status) } } class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun status() = dispatcher.statusObservable }
57. Like event bus class ArchiveDispatcher(provider: DispatcherProvider) { val statusObservable = SerializedSubject(BehaviorSubject.create<Status>()) } class ArchiveAction(private val dispatcher: ArchiveDispatcher) { fun updateStatus(status: Status) { dispatcher.statusObservable.onNext(status) } } class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun status() = dispatcher.statusObservable }
58. Like event bus class ArchiveDispatcher(provider: DispatcherProvider) { val statusObservable = SerializedSubject(BehaviorSubject.create<Status>()) } class ArchiveAction(private val dispatcher: ArchiveDispatcher) { fun updateStatus(status: Status) { dispatcher.statusObservable.onNext(status) } } class ArchiveStore(private val dispatcher: ArchiveDispatcher) { fun status() = dispatcher.statusObservable }
59. Like event bus class ArchiveFragment { @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.status() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { when(it) { HOGE -> textView.text = "hoge" FOO -> textView.text = "foo" BAR -> textView.text = "bar" } } }
60. Like event bus class ArchiveFragment { @Inject lateinit var archiveStore: ArchiveStore override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) archiveStore.status() .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { when(it) { HOGE -> textView.text = "hoge" FOO -> textView.text = "foo" BAR -> textView.text = "bar" } } }
61. List MJTU MJTU MJTU MJTU MJTU refresh
62. Connect observables refreshButton.clicks() .mergeWith(recyclerView.pull()) .withLatestFrom(archiveStore.programs()) { void, programs -> programs } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { // add to adapter }
63. Connect observables 3Y#JOEJOH refreshButton.clicks() .mergeWith(recyclerView.pull()) .withLatestFrom(archiveStore.programs()) { void, programs -> programs } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { // add to adapter }
64. Connect observables .FSHF
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    PCTFSWBCMF refreshButton.clicks() .mergeWith(recyclerView.pull()) .withLatestFrom(archiveStore.programs()) { void, programs -> programs } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { // add to adapter }
65. Connect observables $POOFDU
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    refreshButton.clicks() .mergeWith(recyclerView.pull()) .withLatestFrom(archiveStore.programs()) { void, programs -> programs } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { // add to adapter }
66. Connect observables "EE
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    TVCTDSJCF refreshButton.clicks() .mergeWith(recyclerView.pull()) .withLatestFrom(archiveStore.programs()) { void, programs -> programs } .observeOn(AndroidSchedulers.mainThread()) .bindToLifecycle(this) .subscribe { // add to adapter }
67. • combineLatest, mergeWith, zipWith • map, switchMap, concatMap • scan, reduce • interval • filter, skip, distinctUntilChanged • etc… Other operators used in FRESH
68. Conclusion • Clarity ;-) • Beautiful :-) • Comfortable :-D
69. Flux with Kotlin @_a_akira