The document discusses Reactive Xamarin, which combines Rx (Reactive Extensions) and Xamarin. It introduces key Rx concepts like Observables, LINQ, and Schedulers. Observables represent asynchronous push-based collections and address concurrency using Schedulers. LINQ allows querying Observables. Reactive UI and RxLite provide UI frameworks that integrate these Rx concepts into Xamarin apps through bindings and commands. In summary, Reactive Xamarin leverages Rx to build responsive and concurrent Xamarin apps in a reactive and declarative manner.

1. Reactive Xamarin
Olexandr Leuschenko
uamobile 2016

2. Everything
is an
object
Alan Kay

3. Everything
is a stream
of objects!

4. Streams
are
observable

5. represent data as streams with observables
!
query with LINQ
!
rule the concurrency with schedulers

6. Observables + LINQ +
Schedulers

7. Rx =
Observables + LINQ + Schedulers

8. Reactive Xamarin =
Rx + Xamarin

9. Q & A

10. Agenda
• What is Observable?
• What about LINQ?
• Master time with Schedulers
• Why bother?

11. Agenda
• What is Observable?
• What about LINQ?
• Master time with Schedulers
• Why bother?

14. stream is a collection
collection is a stream

15. IEnumerator
• object Current { get; }
• bool MoveNext ();
• void Reset ();

17. PULL

18. PULL

19. PUSH

20. IObserver
• void OnNext (T value);
• void OnCompeted ();
• void OnError (Exception exception);

21. PULL vs PUSH

22. SYNC vs ASYNC

23. I have TPL

24. Single Value Multiple Values
SYNC T IEnumerable<T>
ASYNC Task<T> IObservable<T>

25. How to create Observables?
• Factory Methods
◦ Observable.Return
◦ Observable.Empty
◦ Observable.Never
◦ Observable.Throw
◦ Observable.Create
• Unfold methods
◦ Observable.Range
◦ Observable.Interval
◦ Observable.Timer
◦ Observable.Generate
• Paradigm Transition
◦ Observable.Start
◦ Observable.FromEventPattern
◦ Task.ToObservable
◦ Task<T>.ToObservable
◦ IEnumerable<T>.ToObservable
◦ Observable.FromAsyncPattern

26. Tiny demo

27. Agenda
• What is Observable?
• What about LINQ?
• Master time with Schedulers
• Why bother?

28. Reactive LINQ is like
LINQ, but Reactive

29. LINQ & Observables

30. RxMarbles
http://rxmarbles.com

31. Agenda
• What is Observable?
• What about LINQ?
• Master time with Schedulers
• Why bother?

32. Events are single-
thread

33. Rx is single-thread

34. Schedulers
• ImmediateScheduler — will start the specified
action immediately
• CurrentThreadScheduler — will schedule action to
be performed on the thread that makes the original
call
• DispatcherScheduler — will scheduler action on the
current Dispatcher
• …

35. TimeScheduler

36. Teeny-weeny Demo

37. Agenda
• What is Observable?
• What about LINQ?
• Master time with Schedulers
• Why bother?

38. Reactive UI
• UI-friendly extension methods
• Base ViewModel
• Base View
• DI
• Logging
• Supports Xamarin.iOS, Xamarin.Android, Xamarin.Mac,
Xamarin Forms, WPF, Windows Forms, Windows Phone 8,
Windows Store and Universal Windows Platform (UWP)

39. Reactive UI
• UI-friendly extension methods
• Base ViewModel
• Base View
• DI
• Logging
• Supports Xamarin.iOS, Xamarin.Android, Xamarin.Mac,
Xamarin Forms, WPF, Windows Forms, Windows Phone 8,
Windows Store and Universal Windows Platform (UWP)

40. Reactive UI
• UI-friendly extension methods
• Base ViewModel
• Base View
• DI
• Logging
• Supports Xamarin.iOS, Xamarin.Android, Xamarin.Mac,
Xamarin Forms, WPF, Windows Forms, Windows Phone 8,
Windows Store and Universal Windows Platform (UWP)

44. RxLite
• UI-friendly extension methods
• Optional base ViewModel

45. RxLite Simple Rules
• One-Way binding — ObservableAsProperty
• Two-Way binding — property with RaiseAndSetIfChanged
• Command — ReactiveCommand

46. Reactive UI
RxLite
So?

47. Playground demo
https://github.com/OlexaLe/RxLite

48. Thanks!
• olexa.le@gmail.com
• http://twitter.com/olexale

49. Q&A
olexa.le@gmail.com http://twitter.com/olexale