Reactive Architecture Boston Droidcon

Presentation given at Boston Droidcon about Reactive Architecture.

1. Reactive Architecture Daniel Leonardis @HIFILEO https://github.com/HIFILEO https://medium.com/@dan.leonardis
3. Kudos • Managing State with RxJava - Jack Wharton • The Rx Workflow Problem - Ray Ryan • Reactive Clean Architecture - Lucia Payo • Don’t Break The Chain - Dan Lew
4. Goal • Define it • History Lesson • Rx Problems & Solution • Think in Images, Dream in Code
5. Maximum Exposure
6. Reactive Architecture is simple but not easy.
7. Reactive Architecture • Responsive • Resilient • Elastic • Message Driven
8. Reactive Architecture
9. History Lesson
10. History Lesson
11. History Lesson • Death of MVP
12. History Lesson
13. History Lesson Clear Winner, MVVM!
14. MVVM Rx Problems Well… not quite
15. MVVM Rx Problem Unless you can model your entire system synchronously, a single asynchronous source breaks imperative programming. Jake Wharton - Managing State with Rx
16. MVVM Rx Problem .doOnNext(loadMoreCommand -> { loadMoreEnabledBehaviorSubject.onNext(false); if (loadMoreCommand.getLoadMoreType() == SCROLL) { adapterDataPublishSubject.onNext(AdapterUiCommand.createAddNull()); movieViewInfoList.add(null); } } }) .observeOn(Schedulers.computation()) .flatMap(loadMoreCommand -> serviceGateway.getNowPlaying(++pageNumber)) .delay(sleepSeconds, TimeUnit.SECONDS) .flatMap(new NowPlayingViewModel.MovieListFetcher()) .flatMap(new TranslateForUiFunction()) .doOnError(throwable -> pageNumber--;) .observeOn(AndroidSchedulers.mainThread()) .doOnNext(movieViewInfos -> { if (!firstLoad.get()) { movieViewInfoList.remove(movieViewInfoList.size() - 1); adapterDataPublishSubject.onNext(AdapterUiCommand.createRemoveNull()); } }) .onErrorResumeNext(movieViewInfos -> { showErrorPublishSubject.onNext(true); loadMorePublishSubject.onNext(new LoadMoreCommand(SCROLL)); }) .subscribe(movieViewInfos -> { movieViewInfoList.addAll(movieViewInfos); adapterDataPublishSubject.onNext( new AdapterUiCommand(AdapterUiCommand.CommandType.ADD, movieViewInfos)); //address first load //… //enable scroll }
17. MVVM Rx Problem < >
18. MVVM Rx Problem < >
19. Reactive Architecture
20. Reactive Architecture < > Observable<UiEvent>
21. Spinner Button Click Reactive Architecture RxBinding SubmitEvent LoadMoreEvent FilterEvent Scroll }Observable.merge<UiEvent>
22. Reactive Architecture < > Observable<UiEvent> Observable<Action>
23. Reactive Architecture
24. Reactive Architecture
25. Reactive Architecture < > Observable<UiEvent> Observable<Action>
26. Reactive Architecture Observable<UiEvent> TestObserver<UiEvent> Subject<?>
27. Reactive Architecture Observable<Action> Observable.Just<Action> TestObserver<?>
28. Reactive Architecture < > Observable<UiEvent> Observable<Action>
29. Reactive Architecture Observable<Action> Observable<UiEvent> Transformers Dan Lew - Don't break the chain: use RxJava's compose() operator ?
30. AutoCompleteEvent } Observable.merge<Action> Observable<Action> AutoCompleteAction SubmitAction Reactive Architecture Observable<UiEvent> { Observable.publish() SubmitEvent
31. Reactive Architecture < > Observable<UiEvent> Observable<Action> Observable<Result>
32. Reactive Architecture Observable<Result> Observable<Action> Transformers
33. } Observable.merge<Result> Observable<Result> Reactive Architecture Observable<Action> { Observable.publish() SubmitAction FilterAction Data Set Data Set SubmitResult FilterResult
34. Reactive Architecture < > Observable<UiEvent> Observable<Action> Observable<Result> Observable<UiModel>
35. Reactive Architecture
36. Reactive Architecture Observable<Result> Observable<UiModel> Observable.scan() ?
37. Observable<UiModel> Reactive Architecture Observable<Result> Observable.scan(initialState, Function())
38. Reactive Architecture < > Observable<UiEvent> Observable<Action> Observable<Result> Observable<UiModel> WEB => REDUX
39. Reactive Architecture ViewModel View View Controller Controller <I> Controller Impl Entity Entity API
40. Reactive Architecture ViewModel View View Controller Controller <I> Controller Impl Entity Entity API Interactor
41. Deep Dive
42. Deep Dive • As a user, show a list of "Now Playing" movies. Poster, Title, Release Date, & Rating. • As a user, any rating at eight or above should be stared. • As a user, I only want to see ratings rounded to the nearest whole digit. • As a user, while scrolling, keep loading "Now Playing" movies until you hit the last page. • Example #1
43. Deep Dive
44. Deeper Dive • New requirement • As a user, restore the last page I was on when the "Now Playing" screen restarts. • Example #2
45. Deeper Dive
46. Deeper Dive
47. Deeper Dive
48. We Need To Go Deeper • New Requirement • As a user, I want to filter my results based on Rating. • Note - Filter at any moment.
49. We Need To Go Deeper }Observable.merge<UiEvent> ScrollListener FilterSpinner FilterEvent LoadMoreEvent
50. }Observable.merge<UiEvent> We Need To Go Deeper
51. Observable.merge<UiEvent> We Need To Go Deeper Action
52. We Need To Go Deeper { Action Observable.Publish
53. We Need To Go Deeper { Action Observable.Publish FilterAction LoadMoreResult
54. We Need To Go Deeper FilterAction LoadMoreResult }Observable.merge<Object>
55. We Need To Go Deeper }Observable.merge<Object> { Concat + Publish
56. { We Need To Go Deeper Concat + Publish Filter Result Filter On / Off }Observable.merge<Result>
57. We Need To Go Deeper Result Observable.scan() Observable<UiModel>
58. We Need To Go Deeper • So let’s look at code for the: New Requirement • Example #3
59. Summary • Read, Watch, Repeat… • Remember (Like Redux) • Save State using UiModel • Don’t break the stream • Do you need a subject? • Speed Increase + Quality Increase
60. Summary