node conf - building realtime webapps

Building Realtime Singlepage Apps

@HenrikJoreteg(hurray for Twitter)

Friday, May 6, 2011

The web is in DIRECT

competition with native apps

Friday, May 6, 2011

Stop supporting crappy browsers.

Just STOP!

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focus on providing compelling experiences

(with the latest technologies)

Friday, May 6, 2011

Adoption is directly related to how easy it is to tinker with.

Friday, May 6, 2011

Socket.io is to realtime what jQuery is to AJAX

Friday, May 6, 2011

Quick look at Socket.io

Friday, May 6, 2011

Servervar http = require('http'),      io = require('socket.io');

server = http.createServer(function(req, res){  // your normal server code  res.writeHead(200, {'Content-Type': 'text/html'});  res.end('<h1>Hello world</h1>'); });server.listen(80);  // socket.io var socket = io.listen(server); socket.on('connection', function(client){   // new client is here!   client.on('message', function(){ … })   client.on('disconnect', function(){ … }) });

Friday, May 6, 2011

Client<script src="http://{node_server_url}/socket.io/socket.io.js"></script> <script>   var socket = new io.Socket({node_server_url});   socket.connect();  socket.on('connect', function(){ … })   socket.on('message', function(){ … })   socket.on('disconnect', function(){ … }) </script>

Friday, May 6, 2011

It’s all about state

Friday, May 6, 2011

Quick Look at Backbone.js

Friday, May 6, 2011

Backbone gives you Observable Models & Collections

var App = Backbone.Model.extend({ initialize: function () { this.bind(‘change:myProperty’, _(this.writeIt).bind(this)); }, writeIt: function () { console.log(“my prop is: “ + this.get(‘myProperty’)); }});

app = new App();app.set({myProperty: true}); // outputs: “my prop is: true”

Friday, May 6, 2011

Views just listen to model changesvar AppView = Backbone.Model.extend({ initialize: function () { this.model.bind(‘change’, _(this.render).bind(this)); }, render: function () { this.el.html(ich.app(this.model.toJSON())); return this; }});

var app = new App(); // init our modelvar appView = new AppView({ model: app, el: document.body }); // init our view

appView.render();app.set({myProperty: true}); // will re-render the whole app

Friday, May 6, 2011

Quick look at Capsule

Friday, May 6, 2011

Backbone.js +

model nesting +

serialization+

event bubblingFriday, May 6, 2011

Models shared by Server + Client(function () { ... detect and set up environment for CommonJS or browser here // Main app model exports.AppModel = Capsule.Model.extend({ type: 'app', initialize: function (spec) { this.register(); this.addChildCollection('members', exports.Members); this.addChildModel('activityLog', exports.ActivityLogPage); } }); // other models exports.Members = ...})();

Friday, May 6, 2011

Server-sidesocket.on('connection', function (client) { var app, sessionId;

// this is split out so we have a reference to it function sendClientChanges(changes) { client.send(changes); } client.on('message', function(message){ var model, collection;

switch (message.event) { case 'session': ... // Here you'd fetch your user from DB based on sessionid // you'd also get the corresponding app state that they should have access to. // `require` your shared models file and inflate or instantiate your root app model // Then grab whatever else you need and send the intial state to the client. client.send({ event: 'initial', app: app.xport() });

// bind to the root `publish` events to send any changes to this client app.bind('publish', sendClientChanges); ...

Friday, May 6, 2011

Clientside$(function () { var app = window.app = new AppModel(); window.socket = new io.Socket();

// get and send our session cookie socket.on('connect', function() { socket.send({ event: 'session', cookie: $.cookie('&!') }); }); socket.on(‘message’, ...});

Friday, May 6, 2011

Clientside cont...socket.on('message', function (msg) { switch (msg.event) { case 'initial': //import app state app.mport(msg.app); // init and render our root view view = window.view = new AppView({ el: $('body'), model: app }).render(); break; case 'change': app.modelGetter(msg.id).set(msg.data); break;

... other cases for `add`, `remove` etc. }});

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Challenges

• Partially shared stateHint, sync everything, have your view render what’s relevant

• Scaling• Providing external APIs

Friday, May 6, 2011

Thank you!

me on twitter: @HenrikJoreteg (hit me up for early invite to &!)

Backbone.js: http://documentcloud.github.com/backbone/

Capsule.js: https://github.com/andyet/capsule

App Testing: http://funcunit.com,

http://mwbrooks.github.com/dominator.js/

Helpful Resources:

Friday, May 6, 2011