Reactive way on Android

Presentation at ReactiveX meetup first in Bangkok, Thailand

Transcript

1. @werockstar @werockstar Kotchaphan Muangsan Software Developer @ODDS
2. @werockstar Interested - Fundamental - OOP, FP, RP - Design Pattern, Refactoring - Software Design
3. medium.com/@werockstar
6. Reactively way on Android @werockstar
7. @werockstar The Land of Reactive
8. @werockstar
9. @werockstar Before we start I gonna sharing some story about Rx on Mobile Development
10. @werockstar We know the first implementation of Rx is Rx.NET
11. @werockstar And which is the first mobile OS uses Rx?
12. @werockstar And Android RxJava RxKotlin RxBinding Agera iOS RxSwift ReactiveCocoa ReactiveSwift
13. Solve the same problem with Rx
14. @werockstar Zero to One Basic Rx on UI
15. @werockstar 'io.reactivex.rxjava2:rxjava:2.2.11' 'io.reactivex.rxjava2:rxkotlin:2.4.0' 'com.jakewharton.rxbinding3:rxbinding-core:3.0.0'
16. @werockstar click click click click
17. @werockstar click click click click click Time
18. @werockstar button.clicks() .subscribe() click click click click Button as an producer(observable) Emitter of event() value over time Time
19. @werockstar button.clicks() .subscribe( { data -> println(data) }, { error -> } ) Observer or subscriber Observer doesn't know anything about the data come from and when, or how many times
20. @werockstar button.clicks() .subscribe( { data -> println(data) }, { error -> } ) Why <- Producer (Observable) <- Observer
21. @werockstar .subscribe( { data -> println(data) }, { error -> } ) button.clicks() Why Decoupling the relationship Know little about each other
22. @werockstar click click click click Duplicate pages?
23. @werockstar button.clicks() .debounce(150, MILLISECONDS) .subscribe()
24. @werockstar click click click debounce(150, MILLISECONDS) 150 ms 150 ms 150 ms ✅
25. @werockstar Auto search editText.afterTextChangeEvents() .debounce(150, MILLISECONDS) .subscribe()
26. @werockstar editText.afterTextChangeEvents() .debounce(150, MILLISECONDS) .subscribe() A A B “A” and “A” are duplicates?
27. @werockstar editText.afterTextChangeEvents() .debounce(150, MILLISECONDS) .distinctUntilChanged() ✅ .subscribe() A A B “A” and “A” are duplicates?
28. @werockstar Sample Window Buffer Throttle
29. @werockstar ————
30. @werockstar
31. @werockstar A A B API?
32. @werockstar editText.afterTextChangeEvents() .debounce(200, MILLISECONDS) .distinctUntilChanged() .flatMap { api.getResult(it) } .subscribe() A A B
33. @werockstar A A B API
34. @werockstar
35. @werockstar editText.afterTextChangeEvents() .debounce(200, MILLISECONDS) .distinctUntilChanged() .map { it.editable.toString() } .switchMap { api.getResult(it) } .subscribe() A A B
36. @werockstar Retry Patterns
37. @werockstar editText.afterTextChangeEvents() .debounce(200, MILLISECONDS) .distinctUntilChanged() .map { it.editable.toString() } .switchMap { api.getResult(it) } .subscribe() A A B ก้าวแรกไม่เป็นไร ก้าวต่อไปไฟเริ่มไหม้ getResult
38. @werockstar editText.afterTextChangeEvents() .debounce(200, TimeUnit.MILLISECONDS) .distinctUntilChanged() .map { it.editable.toString() } .switchMap { api.getResult(it) .retry(2) } .subscribe() A A B ✅
39. @werockstar But We shouldn't use retry in every situation
40. @werockstar editText.afterTextChangeEvents() .debounce(200, TimeUnit.MILLISECONDS) .distinctUntilChanged() .map { it.editable.toString() } .switchMap { api.getResult(it) .retry { attempt, throwable -> throwable is TimeoutException && attempt <= 2 } }.subscribe()
41. @werockstar editText.afterTextChangeEvents() .debounce(200, TimeUnit.MILLISECONDS) .distinctUntilChanged() .map { it.editable.toString() } .switchMap { api.getResult(it) .retry { attempt, throwable -> throwable is TimeoutException && attempt <= 2 } }.subscribe() .onErrorReturnItem("WeRockStar") ✅
42. @werockstar Reactively on precondition
43. @werockstar editText.afterTextChangeEvents() ... .switchMap { api.getResult(it) .retryWhen { it.flatMap { throwable -> when (throwable.code()) { 401 -> api.getSomeToken("refresh_token") else -> Observable.error(throwable) } } } }.subscribe() 1 2
44. @werockstar And finally Delay error notification
45. @werockstar Observable.mergeDelayError( api.delete1(), api.delete2(), api.delete3() ).subscribe()
46. @werockstar And then
47. @werockstar Build in solutions
48. @werockstar Complex solution for complex problem
49. @werockstar Reactive Data Flow Back Pressure Flow Control Subject Push/Pull Hot/Cold Messaging Responsive Elastic Publish/Subscribe Resilience Stream
50. @werockstar 80 Years of Life 5 ปีหมดไปการลองใช้ Rx 10 ปีหมดไปกับ Observable 25 ปีหมดไปกับ FlatMap ส่วน 40 ปีที่เหลือหมดไปกับการทำความเข้าใจ และอธิบาย Reactive
51. @werockstar Questions and Answers @werockstar Thank you