Realtime Web Applications wit ExpressJS

Hüseyin BABALSoftware Developer, CSM

@Sony Eurasia

A Scenario...

Plane status board…

Updating board on every flight

Check flight status for every second?

Let’s code that board software...

Good Code, but this is something like...

Yeah, client side server bombing...

It would be better if server side inform client on any update...

What is SocketIO?

● Care-Free realtime 100% Javascript● Cross-Browser and mobile device● Wrapper for the Websocket● Learnboost

Go back to origin...

Websocket?● Full-duplex comm. channels over TCP● Only its handshake interpreted by HTTP servers● Push server data to client browser● 80 port and no firewall prevent

Handshake

Clients sends base64 encoded string

Server appends a magic string to it and encrypt SHA-1 after then base64

Example...

Client: x3JJHMbDL1EzLkh9GBhXDw==

Server: x3JJHMbDL1EzLkh9GBhXDw==258EAFA5-E914-47DA-95CA-C5AB0DC85B11 then SHA-1.

base64(above appended string) = HSmrc0sMlYUkAGmm5OPpG2HaGWk=

In SocketIO, you don’t need to know all this

stuffs

Send / Receive Events

Store client data

Namespace

Volatile Messaging

Acknowledgement

Broadcasting

QuickiesExpressJS https://github.com/visionmedia/express

SocketIO https://github.com/LearnBoost/socket.io

Learnboost https://github.com/LearnBoost

Websockets http://en.wikipedia.org/wiki/WebSocket

Button Click Game http://btnclick.herokuapp.com/signin

Heroku Websockets https://blog.heroku.com/archives/2013/10/8/websockets-public-beta

Mobile?Will Be Demonstrated

on Next BBS

Thanks