Android Reactive Programming

Reactive Android at Geeky base (29/04/2017)

Transcript

1. REACTIVE PROGRAMMING (ANDROID)
2. REACTIVE PROGRAMMING (ANDROID) KOTCHAPHAN MUANGSAN ▸ Software Developer Facebook: @werockstar Github: @werockstar Medium: @werockstar
3. REACTIVE PROGRAMMING (ANDROID) COURSE OUTLINE ▸ What is Reactive Programming ▸ What is Rx ▸ Reactive manifesto ▸ History of Rx ▸ RxJava1, RxJava 2 ▸ Key types ▸ Operators ▸ RxBinding ▸ Retrofit ▸ Concurrency ▸ Multiple source ▸ Error handling ▸ Backpressure
4. Reactive programming is a general programming term that is focused on reacting to changes, such as data values or events Ben Christensen REACTIVE PROGRAMMING (ANDROID) @werockstar
5. Reactive programming is an asynchronous programming paradigm oriented around data streams and the propagation of change. Wikipedia REACTIVE PROGRAMMING (ANDROID) @werockstar
6. ReactiveX (Rx) is a library for composing asynchronous and event-based programs by using observable sequences. ReactiveX REACTIVE PROGRAMMING (ANDROID) @werockstar
7. Reactive Programming It hard to definition of What is Reactive Programming Characteristics of Reactive programming - Propagate for change - Data streams (Everything is Stream) - React to change
8. @werockstar
9. ▸ Responsive - timely react to user ▸ Resilient - recover from failure or error ▸ Elastic - react by increasing or decreasing the resources allocate ▸ Message Driven - react to events or messages REACTIVE PROGRAMMING (ANDROID) REACTIVE MANIFESTO @werockstar
10. REACTIVE PROGRAMMING (ANDROID) REACTIVE MANIFESTO @werockstar
11. REACTIVE PROGRAMMING (ANDROID) REACTIVE MANIFESTO @werockstar
12. Reactive Programming Functional Reactive Programming Reactive Stream ReactiveX Reactive System Reactive Manifesto Reactive Extension
13. Reactive Programming (RP) Functional Reactive Programming (FRP) != REACTIVE PROGRAMMING (ANDROID) @werockstar
14. Reactive Programming (RP) = Over time Functional Reactive Programming (FRP) = Continuous time REACTIVE PROGRAMMING (ANDROID) @werockstar
15. Reactive Programming (RP) = Productivity for Developer at component level, internal level and data flow management. Reactive System = Productivity for DevOps at system level REACTIVE PROGRAMMING (ANDROID) @werockstar
16. HISTORY ▸ Original by Microsoft - Erik Meijer ▸ 2009 - Rx.NET v.1.0.0 ▸ 2010 - RxJS ▸ 2012 - Ported from Rx.Net to RxJava by Netflix ▸ 2014 - Release RxJava 1.0 ▸ 2016 - Release RxJava 2.0 on top of the Reactive-Streams specification REACTIVE PROGRAMMING (ANDROID) @werockstar
17. REACTIVE WORLD REACTIVE PROGRAMMING (ANDROID) @werockstar
18. RxJava REACTIVE PROGRAMMING (ANDROID) ▸ Just Library, not a framework @werockstar
19. RxJava1 REACTIVE PROGRAMMING (ANDROID) ▸ June 1, 2017 - feature freeze (no new operators), only bug fixes ▸ March 31, 2018 - end of life, no further development @werockstar
20. RxJava2 - Major changes REACTIVE PROGRAMMING (ANDROID) ▸ Reactive Streams ▸ Changing package from rx. to io.reactivex ▸ Backpressure (Flowable) ▸ * Bye. Nulls @werockstar
21. Key Types REACTIVE PROGRAMMING (ANDROID) ▸ Observable, Observer ▸ Flowable, Subscriber ▸ Single, Completable, Maybe ▸ Disposable (Subscription) ▸ Subject @werockstar
22. REACTIVE PROGRAMMING (ANDROID) @werockstar
23. REACTIVE PROGRAMMING (ANDROID) Observable / Observer @werockstar Push style
24. REACTIVE PROGRAMMING (ANDROID) Observable is represents the stream of data and can be subscribed to by an Observer @werockstar
25. REACTIVE PROGRAMMING (ANDROID) Observable<String> someObs; @werockstar Stream of String
26. REACTIVE PROGRAMMING (ANDROID) Observable.just("Reactive Android") .subscribeOn(Schedulers.io()) .subscribe(observer()); @werockstar Observable Schedule Observer
27. REACTIVE PROGRAMMING (ANDROID) Observable.just(“Reactive Android") .subscribe(new Observer<String>() { @Override public void onSubscribe(Disposable d) { } @Override public void onNext(String s) { } @Override public void onError(Throwable e) { } @Override public void onComplete() { } }) @werockstar Observer
28. REACTIVE PROGRAMMING (ANDROID) subscribe/unsubscribe @werockstar Avoiding Memory Leaks in Activities
29. REACTIVE PROGRAMMING (ANDROID) Disposable (subscription) @werockstar
30. REACTIVE PROGRAMMING (ANDROID) RxLint @werockstar - RxSubscribeOnError - RxLeakedSubscription
31. REACTIVE PROGRAMMING (ANDROID) Operators @werockstar
32. REACTIVE PROGRAMMING (ANDROID) Merge Map First SwitchMap Filter Concat FlatMap Zip CombineLast Last @werockstar
33. REACTIVE PROGRAMMING (ANDROID) @werockstar Example
34. REACTIVE PROGRAMMING (ANDROID) RxBinding @werockstar
35. REACTIVE PROGRAMMING (ANDROID) CompositeDisposable @werockstar
36. REACTIVE PROGRAMMING (ANDROID) Form validation @werockstar
37. REACTIVE PROGRAMMING (ANDROID) Retrofit @werockstar
38. Concurrency ▸ subscribeOn() - Specify the Scheduler on which an Observable will operate ▸ observeOn() - Observable to send notifications to observers on a specified Scheduler REACTIVE PROGRAMMING (ANDROID) @werockstar
39. REACTIVE PROGRAMMING (ANDROID) @werockstar
40. Multiple source ▸ flatMap - transform the items emitted by an Observable into Observables, then flatten this into a single Observable ▸ concatMap - transform the items emitted by an Observable into Observables, then flatten this into a single Observable (sequentially) REACTIVE PROGRAMMING (ANDROID) @werockstar
41. FlatMap REACTIVE PROGRAMMING (ANDROID) @werockstar
42. FlatMap REACTIVE PROGRAMMING (ANDROID) @werockstar
43. FlatMap REACTIVE PROGRAMMING (ANDROID) @werockstar
44. FlatMap REACTIVE PROGRAMMING (ANDROID) @werockstar
45. FlatMap REACTIVE PROGRAMMING (ANDROID) @werockstar
46. Error handling ▸ onErrorReturn() - discards it and replaces it with a fixed value. ▸ onErrorResumeNext() - replaces error notification with another stream. ▸ onErrorReturnItem() - discards it and replaces it with a fixed value. ▸ retry() - resubscribe to it if it calls onError, hoping that it will keep producing normal events rather than failures. ▸ retryWhen() - if Observable emits an error, pass that error to another Observable to determine whether to resubscribe to the source. REACTIVE PROGRAMMING (ANDROID) @werockstar
47. Backpressure ▸ RxJava1 late for design support ▸ RxJava2 fully support (Flowable) REACTIVE PROGRAMMING (ANDROID) @werockstar
48. REACTIVE PROGRAMMING (ANDROID) @werockstar Good / Bad / Try