Reactive Architecture Android Meetup

Reactive Architecture is nothing more than the combination of reactive programming and software architectures. Also known as reactive systems, the goal is to make the system responsive, resilient, elastic, and message driven. Reactive Architecture is simple but not easy.

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1. Reactive Architecture Daniel Leonardis @HIFILEO medium.com/@dan.leonardis
2. 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
3. Goal • Define it • History Lesson • Rx Problems & Solution • Think in Images, Dream in Code
4. Reactive Architecture is simple but not easy.
5. Reactive Architecture • Responsive • Resilient • Elastic • Message Driven
6. Reactive Architecture
7. History Lesson
8. History Lesson
9. History Lesson • Death of MVP
10. History Lesson
11. History Lesson Clear Winner, MVVM!
12. MVVM Rx Problems Well… not quite
13. MVVM Rx Problem Unless you can model your entire system synchronously, a single asynchronous source breaks imperative programming. Jake Wharton - Managing State with Rx
14. 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 }
15. MVVM Rx Problem < >
16. MVVM Rx Problem < >
17. Reactive Architecture
18. Reactive Architecture < > Observable<UiEvent>
19. Spinner Button Click Reactive Architecture RxBinding SubmitEvent LoadMoreEvent FilterEvent Scroll }Observable.merge<UiEvent>
20. Reactive Architecture < > Observable<UiEvent> Observable<Action>
21. Reactive Architecture
22. Reactive Architecture
23. Reactive Architecture < > Observable<UiEvent> Observable<Action>
24. Reactive Architecture Observable<UiEvent> TestObserver<UiEvent> Subject<?>
25. Reactive Architecture Observable<Action> Observable.Just<Action> TestObserver<?>
26. Reactive Architecture < > Observable<UiEvent> Observable<Action>
27. Reactive Architecture Observable<Action> Observable<UiEvent> Transformers Dan Lew - Don't break the chain: use RxJava's compose() operator ?
28. AutoCompleteEvent } Observable.merge<Action> Observable<Action> AutoCompleteAction SubmitAction Reactive Architecture Observable<UiEvent> { Observable.publish() SubmitEvent
29. Reactive Architecture < > Observable<UiEvent> Observable<Action> Observable<Result>
30. Reactive Architecture Observable<Result> Observable<Action> Transformers
31. } Observable.merge<Result> Observable<Result> Reactive Architecture Observable<Action> { Observable.publish() SubmitAction FilterAction Data Set Data Set SubmitResult FilterResult
32. Reactive Architecture < > Observable<UiEvent> Observable<Action> Observable<Result> Observable<UiModel>
33. Reactive Architecture
34. Reactive Architecture Observable<Result> Observable<UiModel> Observable.scan() ?
35. Observable<UiModel> Reactive Architecture Observable<Result> Observable.scan(initialState, Function())
36. Reactive Architecture < > Observable<UiEvent> Observable<Action> Observable<Result> Observable<UiModel> WEB => REDUX
37. Reactive Architecture ViewModel View View Controller Controller <I> Controller Impl Entity Entity API
38. Reactive Architecture ViewModel View View Controller Controller <I> Controller Impl Entity Entity API Interactor
39. Deep Dive
40. 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
41. Deep Dive
42. Deeper Dive • New requirement • As a user, restore the last page I was on when the "Now Playing" screen restarts. • Example #2
43. Deeper Dive
44. Deeper Dive
45. Deeper Dive
46. We Need To Go Deeper • New Requirement • As a user, I want to filter my results based on Rating. • Note - Filter at any moment.
47. We Need To Go Deeper }Observable.merge<UiEvent> ScrollListener FilterSpinner FilterEvent LoadMoreEvent
48. }Observable.merge<UiEvent> We Need To Go Deeper
49. Observable.merge<UiEvent> We Need To Go Deeper Action
50. We Need To Go Deeper { Action Observable.Publish
51. We Need To Go Deeper { Action Observable.Publish FilterAction LoadMoreResult
52. We Need To Go Deeper FilterAction LoadMoreResult }Observable.merge<Object>
53. We Need To Go Deeper }Observable.merge<Object> { Concat + Publish
54. { We Need To Go Deeper Concat + Publish Filter Result Filter On / Off }Observable.merge<Result>
55. We Need To Go Deeper Result Observable.scan() Observable<UiModel>
56. We Need To Go Deeper • So let’s look at code for the: New Requirement • Example #3
57. Summary • Managing State with Rx • Remember (Like Redux) • Save State using UiModel • Don’t break the stream • Do you need a subject? • Speed Increase + Quality Increase
58. Summary