1. Reactive Extensions
“democratize cloud”
Dima Pasko

2. about me
Kharkov – Ciklum (Scale Point) - .NET – podcasts – open source

3. Erik Meijer
Professor at Utrecht
University
One of the designers of
Haskell
Microsoft Architect
LINQ
Volta
Rx

4. Rx mission
“Rx is a library for composing asynchronous
and event-based programs using observable
collections.”

5. Rx current version
• Base interfaces in BCL .NET 4 and WP7
• Stable version: v1.0.10621
Experimental Release: v1.1.11011
Last update: October 12, 2011
• http://msdn.microsoft.com/en-
us/data/gg577609

6. Rx for
.NET
 .NET 3.5 SP1
 .NET 4
 .NET Framework 4.5 (with Metro support on
Windows 8 Developer Preview)
Silverlight
 Silverlight 4
 Silverlight 5
 Windows Phone
Java script

7. “asynchronous”

8. “observable”
interface IObservable out
interface IEnumerable out
IDisposable Subscribe IObserver
IEnumerator Get
interface IEnumerator out IDisposable
interface IObserver in
bool Move
void On
get
void On Exception
void
void On

9. Application
MoveNext
Got next?
Interactive
Reactive
OnNext
Have next!
IEnumerable<T> IObservable<T>
IEnumerator<T> IObserver<T>
Environment

10. IDisposable
interface IObservable out
IDisposable Subscribe IObserver
interface IObserver in
void On
void On Exception
void On

11. demo #1
Simple example

12. exception handling
Observable.Catch()
Observable.Throw()
Observable.Retry()
Observable.Timeout()

13. demo #2
Exception handling

14. “composing”
• Linq(Where, Take, Skip, Sum, Max, Any, …)
• Statements(If, Case, For, While, DoWhile)
• Combinators(Merge, Zip, Amb, …)
• Exceptions(Catch, Retry, ..)
• Rx(Delay, Throttle, Interval, Publish, …)

15. “event-based”
Observable.FromEventPattern()
Observable.FromAsyncEventPattern()

16. IScheduler
Observable.OnserveOn()
Observable.SubscribeOn(Scheduler.TaskPool)

17. demo #3
Big demo!!!

18. Rx unit testing

19. more Rx
Rx Contrib
http://rxcontrib.codeplex.com/
Reactive Extensions - Extensions (Rxx)
http://rxx.codeplex.com/
Rx Power Toys
http://rxpowertoys.codeplex.com/

20. examples

21. ReactiveUI
http://www.reactiveui.net/

22. “Anna”
http://github.com/jfromaniello/Anna

23. domain events
http://chaliy.name/archive/2010/1/business_logic_rx_example

24. TweetSharp.Rx
https://github.com/jhollingworth/TweetSharp.Rx

25. Rx in books
Programming Reactive Extensions and LINQ
Jesse Liberty, Paul Betts
http://www.amazon.com/Programming-Reactive-Extensions-Jesse-Liberty/dp/1430237473/

26. out of scope
• Hot&Cold
• Marble diagrams
• IQbservable<T>
(IQueryable<T> + IObservable<T>)
• ISubject, Subject<T>
• ReactiveJS
• ….

27. information
Rx team blog
http://blogs.msdn.com/rxteam
DevLabs
http://msdn.microsoft.com/en-us/data/gg577609
MSDN forums
http://social.msdn.microsoft.com/Forums/en-US/rx
Channel9
http://channel9.msdn.com/Tags/Rx
Wiki
http://rxwiki.wikidot.com
Examples
http://rxworkshop.codeplex.com/

28. summary

29. questions
dimapasko@gmail.com
pad@ciklum.net
31337
@dimapasko