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<div id="sidebar" class="interface">

<a class="toc_title" href="#">

Backbone.js <span class="version">(1.0.0)</span>

</a>

<ul class="toc_section">

<li>&raquo; <a href="http://github.com/documentcloud/backbone">GitHub Repository</a></li>

<li>&raquo; <a href="docs/backbone.html">Annotated Source</a></li>

</ul>

<a class="toc_title" href="#introduction">

Introduction

</a>

<a class="toc_title" href="#upgrading">

Upgrading

</a>

<a class="toc_title" href="#Events">

Events

</a>

<ul class="toc_section">

<li>– <a href="#Events-on">on</a></li>

<li>– <a href="#Events-off">off</a></li>

<li>– <a href="#Events-trigger">trigger</a></li>

<li>– <a href="#Events-once">once</a></li>

<li>– <a href="#Events-listenTo">listenTo</a></li>

<li>– <a href="#Events-stopListening">stopListening</a></li>

<li>– <a href="#Events-listenToOnce">listenToOnce</a></li>

<li>- <a href="#Events-catalog"><b>Catalog of Built-in Events</b></a></li>

</ul>

<a class="toc_title" href="#Model">

Model

</a>

<ul class="toc_section">

<li>– <a href="#Model-extend">extend</a></li>

<li>– <a href="#Model-constructor">constructor / initialize</a></li>

<li>– <a href="#Model-get">get</a></li>

<li>– <a href="#Model-set">set</a></li>

<li>– <a href="#Model-escape">escape</a></li>

<li>– <a href="#Model-has">has</a></li>

<li>– <a href="#Model-unset">unset</a></li>

<li>– <a href="#Model-clear">clear</a></li>

<li>– <a href="#Model-id">id</a></li>

<li>– <a href="#Model-idAttribute">idAttribute</a></li>

<li>– <a href="#Model-cid">cid</a></li>

<li>– <a href="#Model-attributes">attributes</a></li>

<li>– <a href="#Model-changed">changed</a></li>

<li>– <a href="#Model-defaults">defaults</a></li>

<li>– <a href="#Model-toJSON">toJSON</a></li>

<li>– <a href="#Model-sync">sync</a></li>

<li>– <a href="#Model-fetch">fetch</a></li>

<li>– <a href="#Model-save">save</a></li>

<li>– <a href="#Model-destroy">destroy</a></li>

<li>– <a href="#Model-Underscore-Methods"><b>Underscore Methods (6)</b></a></li>

<li>– <a href="#Model-validate">validate</a></li>

<li>– <a href="#Model-validationError">validationError</a></li>

<li>– <a href="#Model-isValid">isValid</a></li>

<li>– <a href="#Model-url">url</a></li>

<li>– <a href="#Model-urlRoot">urlRoot</a></li>

<li>– <a href="#Model-parse">parse</a></li>

<li>– <a href="#Model-clone">clone</a></li>

<li>– <a href="#Model-isNew">isNew</a></li>

<li>– <a href="#Model-hasChanged">hasChanged</a></li>

<li>– <a href="#Model-changedAttributes">changedAttributes</a></li>

<li>– <a href="#Model-previous">previous</a></li>

<li>– <a href="#Model-previousAttributes">previousAttributes</a></li>

</ul>

<a class="toc_title" href="#Collection">

Collection

</a>

<ul class="toc_section">

<li>– <a href="#Collection-extend">extend</a></li>

<li>– <a href="#Collection-model">model</a></li>

<li>– <a href="#Collection-constructor">constructor / initialize</a></li>

<li>– <a href="#Collection-models">models</a></li>

<li>– <a href="#Collection-toJSON">toJSON</a></li>

<li>– <a href="#Collection-sync">sync</a></li>

<li>– <a href="#Collection-Underscore-Methods"><b>Underscore Methods (28)</b></a></li>

<li>– <a href="#Collection-add">add</a></li>

<li>– <a href="#Collection-remove">remove</a></li>

<li>– <a href="#Collection-reset">reset</a></li>

<li>– <a href="#Collection-set">set</a></li>

<li>– <a href="#Collection-get">get</a></li>

<li>– <a href="#Collection-at">at</a></li>

<li>– <a href="#Collection-push">push</a></li>

<li>– <a href="#Collection-pop">pop</a></li>

<li>– <a href="#Collection-unshift">unshift</a></li>

<li>– <a href="#Collection-shift">shift</a></li>

<li>– <a href="#Collection-slice">slice</a></li>

<li>– <a href="#Collection-length">length</a></li>

<li>– <a href="#Collection-comparator">comparator</a></li>

<li>– <a href="#Collection-sort">sort</a></li>

<li>– <a href="#Collection-pluck">pluck</a></li>

<li>– <a href="#Collection-where">where</a></li>

<li>– <a href="#Collection-findWhere">findWhere</a></li>

<li>– <a href="#Collection-url">url</a></li>

<li>– <a href="#Collection-parse">parse</a></li>

<li>– <a href="#Collection-clone">clone</a></li>

<li>– <a href="#Collection-fetch">fetch</a></li>

<li>– <a href="#Collection-create">create</a></li>

</ul>

<a class="toc_title" href="#Router">

Router

</a>

<ul class="toc_section">

<li>– <a href="#Router-extend">extend</a></li>

<li>– <a href="#Router-routes">routes</a></li>

<li>– <a href="#Router-constructor">constructor / initialize</a></li>

<li>– <a href="#Router-route">route</a></li>

<li>– <a href="#Router-navigate">navigate</a></li>

</ul>

<a class="toc_title" href="#History">

History

</a>

<ul class="toc_section">

<li>– <a href="#History-start">start</a></li>

</ul>

<a class="toc_title" href="#Sync">

Sync

</a>

<ul class="toc_section">

<li>– <a href="#Sync">Backbone.sync</a></li>

<li>– <a href="#Sync-ajax">Backbone.ajax</a></li>

<li>– <a href="#Sync-emulateHTTP">Backbone.emulateHTTP</a></li>

<li>– <a href="#Sync-emulateJSON">Backbone.emulateJSON</a></li>

</ul>

<a class="toc_title" href="#View">

View

</a>

<ul class="toc_section">

<li>– <a href="#View-extend">extend</a></li>

<li>– <a href="#View-constructor">constructor / initialize</a></li>

<li>– <a href="#View-el">el</a></li>

<li>– <a href="#View-$el">$el</a></li>

<li>– <a href="#View-setElement">setElement</a></li>

<li>– <a href="#View-attributes">attributes</a></li>

<li>– <a href="#View-dollar">$ (jQuery)</a></li>

<li>– <a href="#View-render">render</a></li>

<li>– <a href="#View-remove">remove</a></li>

<li>– <a href="#View-delegateEvents">delegateEvents</a></li>

<li>– <a href="#View-undelegateEvents">undelegateEvents</a></li>

</ul>

<a class="toc_title" href="#Utility">

Utility

</a>

<ul class="toc_section">

<li>– <a href="#Utility-Backbone-noConflict">Backbone.noConflict</a></li>

<li>– <a href="#Utility-Backbone-$">Backbone.$</a></li>

</ul>

<a class="toc_title" href="#examples">

Examples

</a>

<ul class="toc_section">

<li>– <a href="#examples-todos">Todos</a></li>

<li>– <a href="#examples-documentcloud">DocumentCloud</a></li>

<li>– <a href="#examples-usa-today">USA Today</a></li>

<li>– <a href="#examples-rdio">Rdio</a></li>

<li>– <a href="#examples-linkedin">LinkedIn Mobile</a></li>

<li>– <a href="#examples-hulu">Hulu</a></li>

<li>– <a href="#examples-quartz">Quartz</a></li>

<li>– <a href="#examples-flow">Flow</a></li>

<li>– <a href="#examples-gilt">Gilt Groupe</a></li>

<li>– <a href="#examples-newsblur">NewsBlur</a></li>

<li>– <a href="#examples-wordpress">WordPress.com</a></li>

<li>– <a href="#examples-foursquare">Foursquare</a></li>

<li>– <a href="#examples-bitbucket">Bitbucket</a></li>

<li>– <a href="#examples-disqus">Disqus</a></li>

<li>– <a href="#examples-khan-academy">Khan Academy</a></li>

<li>– <a href="#examples-do">Do</a></li>

<li>– <a href="#examples-irccloud">IRCCloud</a></li>

<li>– <a href="#examples-pitchfork">Pitchfork</a></li>

<li>– <a href="#examples-spin">Spin</a></li>

<li>– <a href="#examples-walmart">Walmart Mobile</a></li>

<li>– <a href="#examples-groupon">Groupon Now!</a></li>

<li>– <a href="#examples-basecamp">Basecamp</a></li>

<li>– <a href="#examples-slavery-footprint">Slavery Footprint</a></li>

<li>– <a href="#examples-stripe">Stripe</a></li>

<li>– <a href="#examples-airbnb">Airbnb</a></li>

<li>– <a href="#examples-diaspora">Diaspora</a></li>

<li>– <a href="#examples-soundcloud">SoundCloud Mobile</a></li>

<li>- <a href="#examples-artsy">Art.sy</a></li>

<li>– <a href="#examples-pandora">Pandora</a></li>

<li>– <a href="#examples-inkling">Inkling</a></li>

<li>– <a href="#examples-code-school">Code School</a></li>

<li>– <a href="#examples-cloudapp">CloudApp</a></li>

<li>– <a href="#examples-seatgeek">SeatGeek</a></li>

<li>– <a href="#examples-easel">Easel</a></li>

<li>– <a href="#examples-prose">Prose</a></li>

<li>- <a href="#examples-jolicloud">Jolicloud</a></li>

<li>– <a href="#examples-battlefield">Battlefield Play4Free</a></li>

<li>– <a href="#examples-syllabus">Syllabus</a></li>

<li>– <a href="#examples-salon">Salon.io</a></li>

<li>– <a href="#examples-tilemill">TileMill</a></li>

<li>– <a href="#examples-blossom">Blossom</a></li>

<li>– <a href="#examples-trello">Trello</a></li>

<li>– <a href="#examples-tzigla">Tzigla</a></li>

</ul>

<a class="toc_title" href="#faq">

F.A.Q.

</a>

<ul class="toc_section">

<li>– <a href="#FAQ-why-backbone">Why Backbone?</a></li>

<li>– <a href="#FAQ-tim-toady">More Than One Way To Do It</a></li>

<li>– <a href="#FAQ-nested">Nested Models &amp; Collections</a></li>

<li>– <a href="#FAQ-bootstrap">Loading Bootstrapped Models</a></li>

<li>– <a href="#FAQ-extending">Extending Backbone</a></li>

<li>– <a href="#FAQ-mvc">Traditional MVC</a></li>

<li>– <a href="#FAQ-this">Binding "this"</a></li>

<li>– <a href="#FAQ-rails">Working with Rails</a></li>

</ul>

<a class="toc_title" href="#changelog">

Change Log

</a>

</div>

<div class="container">

<p>

<img id="logo" src="docs/images/backbone.png" alt="Backbone.js" />

</p>

<p>

Backbone.js gives structure to web applications

by providing <b>models</b> with key-value binding and custom events,

<b>collections</b> with a rich API of enumerable functions,

<b>views</b> with declarative event handling, and connects it all to your

existing API over a RESTful JSON interface.

</p>

<p>

The project is <a href="http://github.com/documentcloud/backbone/">hosted on GitHub</a>,

and the <a href="docs/backbone.html">annotated source code</a> is available,

as well as an online <a href="test/">test suite</a>,

an <a href="examples/todos/index.html">example application</a>,

a <a href="https://github.com/documentcloud/backbone/wiki/Tutorials%2C-blog-posts-and-example-sites">list of tutorials</a>

and a <a href="#examples">long list of real-world projects</a> that use Backbone.

Backbone is available for use under the <a href="http://github.com/documentcloud/backbone/blob/master/LICENSE">MIT software license</a>.

</p>

<p>

You can report bugs and discuss features on the

<a href="http://github.com/documentcloud/backbone/issues">GitHub issues page</a>,

on Freenode IRC in the <tt>#documentcloud</tt> channel, post questions to the

<a href="https://groups.google.com/forum/#!forum/backbonejs">Google Group</a>,

add pages to the <a href="https://github.com/documentcloud/backbone/wiki">wiki</a>

or send tweets to <a href="http://twitter.com/documentcloud">@documentcloud</a>.

</p>

<p>

<i>

Backbone is an open-source component of

<a href="http://documentcloud.org/">DocumentCloud</a>.

</i>

</p>

<h2 id="downloads">

Downloads &amp; Dependencies

<span style="padding-left: 7px; font-size:11px; font-weight: normal;" class="interface">(Right-click, and use "Save As")</span>

</h2>

<table>

<tr>

<td><a class="punch" href="backbone.js">Development Version (1.0.0)</a></td>

<td class="text"><i>58kb, Full source, tons of comments</i></td>

</tr>

<tr>

<td><a class="punch" href="backbone-min.js">Production Version (1.0.0)</a></td>

<td class="text" style="line-height: 16px;">

<i>6.3kb, Packed and gzipped</i><br />

<small>(<a href="backbone-min.map">Source Map</a>)</small>

</td>

</tr>

<tr>

<td><a class="punch" href="https://raw.github.com/documentcloud/backbone/master/backbone.js">Edge Version (master)</a></td>

<td>

<i>Unreleased, use at your own risk</i>

<a class="travis-badge" href="https://travis-ci.org/documentcloud/backbone">

<img src="https://travis-ci.org/documentcloud/backbone.png" />

</a>

</td>

</tr>

</table>

<p>

Backbone's only hard dependency is

<a href="http://underscorejs.org/">Underscore.js</a> <small>( >= 1.4.3)</small>.

For RESTful persistence, history support via <a href="#Router">Backbone.Router</a>

and DOM manipulation with <a href="#View">Backbone.View</a>, include

<a href="https://github.com/douglascrockford/JSON-js">json2.js</a>, and either

<a href="http://jquery.com">jQuery</a> <small>( >= 1.7.0)</small> or

<a href="http://zeptojs.com/">Zepto</a>.

</p>

<h2 id="introduction">Introduction</h2>

<p>

When working on a web application that involves a lot of JavaScript, one

of the first things you learn is to stop tying your data to the DOM. It's all

too easy to create JavaScript applications that end up as tangled piles of

jQuery selectors and callbacks, all trying frantically to keep data in

sync between the HTML UI, your JavaScript logic, and the database on your

server. For rich client-side applications, a more structured approach

is often helpful.

</p>

<p>

With Backbone, you represent your data as

<a href="#Model">Models</a>, which can be created, validated, destroyed,

and saved to the server. Whenever a UI action causes an attribute of

a model to change, the model triggers a <i>"change"</i> event; all

the <a href="#View">Views</a> that display the model's state can be notified of the

change, so that they are able to respond accordingly, re-rendering themselves with

the new information. In a finished Backbone app, you don't have to write the glue

code that looks into the DOM to find an element with a specific <i>id</i>,

and update the HTML manually

&mdash; when the model changes, the views simply update themselves.

</p>

<p>

If you're new here, and aren't yet quite sure what Backbone is for, start by

browsing the <a href="#examples">list of Backbone-based projects</a>.

</p>

<p>

Many of the examples that follow are runnable. Click the <i>play</i> button

to execute them.

</p>

<h2 id="upgrading">Upgrading to 1.0</h2>

<p>

Backbone <b>1.0</b> should be a fairly painless upgrade from the <b>0.9</b>

series. If you're upgrading from an older version, be sure to check out the

<a href="#changelog">change log</a>. In brief, a few of the larger breaking

changes are:

</p>

<ul>

<li>

If you want to smartly update the contents of a Collection,

adding new models, removing missing ones, and merging those already present,

you now call <a href="#Collection-set">set</a> (previously named "update"),

a similar operation to calling <tt>set</tt> on a Model. This is now the

default when you call <a href="#Collection-fetch">fetch</a> on a collection.

To get the old behavior, pass <tt>{reset: true}</tt>.

</li>

<li>

If you have characters in your URL segments that require URL encoding,

Backbone will now decode them for you (normalizing the behavior

cross-browser) before your route handlers receive them as arguments.

</li>

<li>

In <b>0.9.x</b>, Backbone events gained two new methods:

<a href="#Events-listenTo">listenTo</a> and

<a href="#Events-stopListening">stopListening</a>, which make it easier

to create Views that have all of their observers unbound when you

want to <a href="#View-remove">remove</a> the view.

</li>

<li>

Model validation is now only enforced by default in

<a href="#Model-save">save</a> &mdash; not in

<a href="#Model-set">set</a> unless the <tt>{validate:true}</tt>

option is passed. Model validation now fires an <tt>"invalid"</tt> event instead of

<tt>"error"</tt>.

</li>

</ul>

<h2 id="Events">Backbone.Events</h2>

<p>

<b>Events</b> is a module that can be mixed in to any object, giving the

object the ability to bind and trigger custom named events. Events do not

have to be declared before they are bound, and may take passed arguments.

For example:

</p>

<pre class="runnable">

var object = {};

_.extend(object, Backbone.Events);

object.on("alert", function(msg) {

alert("Triggered " + msg);

});

object.trigger("alert", "an event");

<p>

For example, to make a handy event dispatcher that can coordinate events

among different areas of your application: <tt>var dispatcher = _.clone(Backbone.Events)</tt>

</p>

<p id="Events-on">

<b class="header">on</b><code>object.on(event, callback, [context])</code><span class="alias">Alias: bind</span>

<br />

Bind a <b>callback</b> function to an object. The callback will be invoked

whenever the <b>event</b> is fired.

If you have a large number of different events on a page, the convention is to use colons to

namespace them: <tt>"poll:start"</tt>, or <tt>"change:selection"</tt>.

The event string may also be a space-delimited list of several events...

</p>

book.on("change:title change:author", ...);

<p>

To supply a <b>context</b> value for <tt>this</tt> when the callback is invoked,

pass the optional third argument: <tt>model.on('change', this.render, this)</tt>

</p>

<p>

Callbacks bound to the special

<tt>"all"</tt> event will be triggered when any event occurs, and are passed

the name of the event as the first argument. For example, to proxy all events

from one object to another:

</p>

proxy.on("all", function(eventName) {

object.trigger(eventName);

});

<p>

All Backbone event methods also support an event map syntax, as an alternative

to positional arguments:

</p>

book.on({

"change:title": titleView.update,

"change:author": authorPane.update,

"destroy": bookView.remove

});

<p id="Events-off">

<b class="header">off</b><code>object.off([event], [callback], [context])</code><span class="alias">Alias: unbind</span>