SignalR. Code, not toothpaste. (or: Using SignalR for realtime client/server communication) Today’s users are interested in a rich experience where the terms client and server don’t mean a thing. They expect real-time action between both, no matter if the technology used is HTML5 websockets or something else. This session will cover SignalR and show you how it can be used to communicate in real time between the client and server, using HTML5 or not. Combine SignalR with ASP.NET MVC, jQuery and perhaps a sprinkle of Windows Azure and you’ll have an interesting, reliable and fast stack to build your real-time client-server and server-client communications. Join me on this journey between web, cloud and user. No toothpaste. Just code.

1. JANUARY 23, 2012 | SLIDE 1

2. www.realdolmen.com
USING SIGNALR FOR REALTIME CLIENT/SERVER
COMMUNICATION
JANUARY 23, 2012 | SLIDE 2

3. WHO AM I?
 Maarten Balliauw
 Antwerp, Belgium
 www.realdolmen.com
 Focus on web
 ASP.NET MVC, PHP, Azure, SignalR, …
 MVP Windows Azure (formerly ASP.NET)
 Co-founder of AZUG
 http://blog.maartenballiauw.be
 @maartenballiauw
JANUARY 23, 2012 | SLIDE 4

4. AGENDA
 Why real-time & how?
 Meet SignalR
 Connections and Hubs
 Clients
 Q&A
JANUARY 23, 2012 | SLIDE 5

5. WHY REAL-TIME & HOW?
JANUARY 23, 2012 | SLIDE 6

6. USERS WANT THE LATEST INFORMATION, NOW!
 Twitter – live searches/updates
 Stock streamers
 Auctions
 Live scores
 New e-mail
 Real-time notifications
 Interactive games
 Collaborative apps
 Analytics of users
 …
JANUARY 23, 2012 | SLIDE 7

7. HTTP IS AN OLD BEAST…
 Never designed for real-time communications
 Web is request-response
 Web is stateless
 But…
 HTML5 WebSockets to the rescue,
right?
JANUARY 23, 2012 | SLIDE 8

8. HTML5 WEBSOCKETS
 Extension to HTTP
 Provide raw sockets over HTTP
 Full-duplex
 Traverses proxies
 It’s still a draft…
 Not every proxy server supports it 
 Not every webserver supports it 
 Not every browser supports it 
 They are raw sockets!
JANUARY 23, 2012 | SLIDE 9

9. PERIODIC POLLING Fiddler
hootsuite.com
 Bottom line:
 Poll from time to time using Ajax
 Delay in communications due to polling interval
 Wastes bandwidth & latency 
JANUARY 23, 2012 | SLIDE 10

10. LONG POLLING Fiddler
facebook.com
 Bottom line:
 Poll but don’t respond untill there’s data
 Poll again after data received or after the connection times out
 Consumes server threads & connection resources 
JANUARY 23, 2012 | SLIDE 11

11. WHICH LEAVES US WITH 3 OPTIONS FOR REAL-TIME
 Periodic polling
 Long polling
 HTML5 WebSockets
JANUARY 23, 2012 | SLIDE 12

12. ARRR!
MEET SIGNALR
JANUARY 23, 2012 | SLIDE 13

13. SIGNALR?
 Three-in-one!
 “Persistent” client/server connection over best transport
 Abstracts away the transport
 Provides just one programming model
 David Fowler and Damian Edwards
(two guys on the ASP.NET team)
 Not an official Microsoft project (yet?)
 OSS project on Github, MIT licensed
http://github.com/signalr/signalr
 Simple to setup & just works
 Depends on C# (not VB.NET), .NET 4+ and jQuery
JANUARY 23, 2012 | SLIDE 15

14. WHERE DO I GET IT?
*
* where else!
JANUARY 23, 2012 | SLIDE 16

15. HELLO, SIGNALR!
JANUARY 23, 2012 | SLIDE 17

16. WHAT JUST HAPPENED?
 The server is broadcasting a message every few seconds
 Clients are receiving messages
 Code looks easy
 No polling or whatsoever (at least in my code)
JANUARY 23, 2012 | SLIDE 18

17. CONNECTIONS AND HUBS
JANUARY 23, 2012 | SLIDE 19

18. TWO CONNECTION MODELS
PersistentConnection Hubs
 Can communicate with  Can communicate with
1..N clients 1..N clients
 Is an IHttpHandler  Abstraction over
 Requires a route to be PersistentConnection
defined  Route automatically
 Limited to sending mapped (/signalr/hubs)
messages  Can send messages and
 You define the call methods
“protocol”  SignalR defines the
protocol
JANUARY 23, 2012 | SLIDE 20

19. HELLO, SIGNALR HUBS!
JANUARY 23, 2012 | SLIDE 21

20. HUBS
 Hub methods can be called from client
 Client methods can be called from hub
 Target individual client
 Target all clients
 Target group of clients
 http://jabbr.net
JANUARY 23, 2012 | SLIDE 22

21. CLIENTS
JANUARY 23, 2012 | SLIDE 23

22. SO FAR WE’VE USED…
 On the server side:
 Host in any ASP.NET application (SignalR.Server)
 On the client side:
 JavaScript (SignalR.JS)
 But there’s more…
JANUARY 23, 2012 | SLIDE 24

23. DECKCAST
JANUARY 23, 2012 | SLIDE 25

24. THAT’S A LOT MORE!
 On the server side:
 Host in any ASP.NET application (SignalR.Server)
 Use “SelfHost”
https://github.com/SignalR/SignalR/tree/master/SignalR.SelfHost
 On the client side:
 JavaScript (SignalR.JS)
 Any .NET client (SignalR.Client)
 Any WP7 device (SignalR.Client.WP7)
 iOS
 Android
 Is this becoming a replacement for WCF?
JANUARY 23, 2012 | SLIDE 26

25. CONCLUSION
 SignalR is three-in-one!
 “Persistent” client/server connection over best transport
 Abstracts away the transport
 Provides just one programming model
 Connections & Hubs
 Connect various clients
 Make the web real-time!
JANUARY 23, 2012 | SLIDE 27

26. RESOURCES
 My blog:
http://blog.maartenballiauw.be
 SignalR on Github:
http://github.com/signalr/signalr
 SignalR on NuGet:
http://www.nuget.org/packages?q=signalr
 Websockets:
http://github.com/signalr/signalr.websockets
 Scale-out on Windows Azure:
http://github.com/signalr/signalr.azure
 Objective C client:
https://github.com/DyKnow/SignalR-ObjC
 Android client (using MonoDroid):
https://github.com/SignalR/SignalR/pull/127
JANUARY 23, 2012 | SLIDE 28

27. Q&A
JANUARY 23, 2012 | SLIDE 29

28. THANK YOU FOR JOINING
JANUARY 23, 2012 | SLIDE 30