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<body>
<div id="sidebar" class="interface">
<a class="toc_title" href="#">
Backbone.js <span class="version">(0.9.2)</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>
</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-fetch">fetch</a></li>
<li>– <a href="#Model-save">save</a></li>
<li>– <a href="#Model-destroy">destroy</a></li>
<li>– <a href="#Model-validate">validate</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-change">change</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-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-get">get</a></li>
<li>– <a href="#Collection-getByCid">getByCid</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-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-url">url</a></li>
<li>– <a href="#Collection-parse">parse</a></li>
<li>– <a href="#Collection-fetch">fetch</a></li>
<li>– <a href="#Collection-reset">reset</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-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 or Zepto)</a></li>
<li>– <a href="#View-render">render</a></li>
<li>– <a href="#View-remove">remove</a></li>
<li>– <a href="#View-make">make</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-noConflict">noConflict</a></li>
<li>– <a href="#Utility-setDomLibrary">setDomLibrary</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-linkedin">LinkedIn Mobile</a></li>
<li>– <a href="#examples-flow">Flow</a></li>
<li>– <a href="#examples-audiovroom">AudioVroom</a></li>
<li>– <a href="#examples-foursquare">Foursquare</a></li>
<li>– <a href="#examples-wunderkit">Wunderkit</a></li>
<li>– <a href="#examples-khan-academy">Khan Academy</a></li>
<li>– <a href="#examples-do">Do</a></li>
<li>– <a href="#examples-posterous">Posterous Spaces</a></li>
<li>– <a href="#examples-groupon">Groupon Now!</a></li>
<li>– <a href="#examples-basecamp">Basecamp Mobile</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 Mobile</a></li>
<li>– <a href="#examples-diaspora">Diaspora</a></li>
<li>– <a href="#examples-soundcloud">SoundCloud Mobile</a></li>
<li>– <a href="#examples-pandora">Pandora</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-grove">Grove.io</a></li>
<li>– <a href="#examples-kicksend">Kicksend</a></li>
<li>– <a href="#examples-shortmail">Shortmail</a></li>
<li>– <a href="#examples-battlefield">Battlefield Play4Free</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-animoto">Animoto</a></li>
<li>– <a href="#examples-chaincal">ChainCal</a></li>
<li>– <a href="#examples-attictv">AtticTV</a></li>
<li>– <a href="#examples-decide">Decide</a></li>
<li>– <a href="#examples-editd">EDITD</a></li>
<li>– <a href="#examples-trello">Trello</a></li>
<li>– <a href="#examples-ducksboard">Ducksboard</a></li>
<li>– <a href="#examples-quietwrite">QuietWrite</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-events">Catalog of Events</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 style="width: 451px; height: 80px;" 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.html">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 (0.9.2)</a></td>
<td><i>52kb, Full source, lots of comments</i></td>
</tr>
<tr>
<td><a class="punch" href="backbone-min.js">Production Version (0.9.2)</a></td>
<td><i>5.6kb, Packed and gzipped</i></td>
</tr>
</table>
<p>
Backbone's only hard dependency is
<a href="http://documentcloud.github.com/underscore/">Underscore.js</a> <small>( > 1.3.1)</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>( > 1.4.2)</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 0.9</h2>
<p>
Backbone's <b>0.9</b> series should be considered as a release candidate
for an upcoming <b>1.0</b>. Some APIs have changed, and while there is a
<a href="#changelog">change log</a> available, and many new features to
take advantage of, there are a few specific changes where you'll need
to take care:
</p>
<ul>
<li>
If you've ever manually set <tt>this.el</tt> in a Backbone View to be a
particular DOM element, you'll want to use
<a href="#View-setElement">setElement</a> instead.
</li>
<li>
Creating and destroying models is now optimistic. Pass <tt>{wait: true}</tt>
if you need the previous behavior of waiting for the server to acknowledge
success. You can now also pass <tt>{wait: true}</tt> to <a href="#Model-save">save</a> calls.
</li>
<li>
If you have been writing a fair amount of <tt>$(view.el)</tt>, there's now
a cached reference for that jQuery object: <a href="#View-$el">$el</a>.
</li>
<li>
If you're upgrading, make sure you also upgrade your version of Underscore.js
to the latest &mdash; 1.3.1 or greater.
</li>
<li>
<tt>model.set</tt> will no longer trigger change events when setting a value
with <tt>{silent: true}</tt> then setting it back to its original value.
Similarly, after changing an attribute silently, that <tt>change:attribute</tt>
event <i>will</i> fire during the next change.
</li>
<li>
Since <tt>view.$(selector)</tt> is now equivalent to <tt>view.$el.find(selector)</tt>
rather than <tt>$(selector, view.el)</tt> it can no longer be used when
<tt>selector</tt> is an HTML string or DOM element.
</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");
</pre>
<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>
<pre>
book.on("change:title change:author", ...);
</pre>
<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>
<pre>
proxy.on("all", function(eventName) {
object.trigger(eventName);
});
</pre>
<p id="Events-off">
<b class="header">off</b><code>object.off([event], [callback], [context])</code><span class="alias">Alias: unbind</span>
<br />
Remove a previously-bound <b>callback</b> function from an object. If no
<b>context</b> is specified, all of the versions of the callback with
different contexts will be removed. If no
callback is specified, all callbacks for the <b>event</b> will be
removed. If no event is specified, <i>all</i> event callbacks on the object
will be removed.
</p>
<pre>
// Removes just the `onChange` callback.
object.off("change", onChange);
// Removes all "change" callbacks.
object.off("change");
// Removes the `onChange` callback for all events.
object.off(null, onChange);
// Removes all callbacks for `context` for all events.
object.off(null, null, context);
// Removes all callbacks on `object`.
object.off();
</pre>
<p id="Events-trigger">
<b class="header">trigger</b><code>object.trigger(event, [*args])</code>
<br />
Trigger callbacks for the given <b>event</b>, or space-delimited list of events.
Subsequent arguments to <b>trigger</b> will be passed along to the
event callbacks.
</p>
<h2 id="Model">Backbone.Model</h2>
<p>
<b>Models</b> are the heart of any JavaScript application, containing
the interactive data as well as a large part of the logic surrounding it:
conversions, validations, computed properties, and access control. You
extend <b>Backbone.Model</b> with your domain-specific methods, and
<b>Model</b> provides a basic set of functionality for managing changes.
</p>
<p>
The following is a contrived example, but it demonstrates defining a model
with a custom method, setting an attribute, and firing an event keyed
to changes in that specific attribute.
After running this code once, <tt>sidebar</tt> will be
available in your browser's console, so you can play around with it.
</p>
<pre class="runnable">
var Sidebar = Backbone.Model.extend({
promptColor: function() {
var cssColor = prompt("Please enter a CSS color:");
this.set({color: cssColor});
}
});
window.sidebar = new Sidebar;
sidebar.on('change:color', function(model, color) {
$('#sidebar').css({background: color});
});
sidebar.set({color: 'white'});
sidebar.promptColor();
</pre>
<p id="Model-extend">
<b class="header">extend</b><code>Backbone.Model.extend(properties, [classProperties])</code>
<br />
To create a <b>Model</b> class of your own, you extend <b>Backbone.Model</b>
and provide instance <b>properties</b>, as well as optional
<b>classProperties</b> to be attached directly to the constructor function.
</p>
<p>
<b>extend</b> correctly sets up the prototype chain, so subclasses created
with <b>extend</b> can be further extended and subclassed as far as you like.
</p>
<pre>
var Note = Backbone.Model.extend({
initialize: function() { ... },
author: function() { ... },
coordinates: function() { ... },
allowedToEdit: function(account) {
return true;
}
});
var PrivateNote = Note.extend({
allowedToEdit: function(account) {
return account.owns(this);
}
});
</pre>
<p class="warning">
Brief aside on <tt>super</tt>: JavaScript does not provide
a simple way to call super &mdash; the function of the same name defined
higher on the prototype chain. If you override a core function like
<tt>set</tt>, or <tt>save</tt>, and you want to invoke the
parent object's implementation, you'll have to explicitly call it, along these lines:
</p>
<pre>
var Note = Backbone.Model.extend({
set: function(attributes, options) {
Backbone.Model.prototype.set.call(this, attributes, options);
...
}
});
</pre>
<p id="Model-constructor">
<b class="header">constructor / initialize</b><code>new Model([attributes])</code>
<br />
When creating an instance of a model, you can pass in the initial values
of the <b>attributes</b>, which will be <a href="#Model-set">set</a> on the
model. If you define an <b>initialize</b> function, it will be invoked when
the model is created.
</p>
<pre>
new Book({
title: "One Thousand and One Nights",
author: "Scheherazade"
});
</pre>
<p>
In rare cases, if you're looking to get fancy,
you may want to override <b>constructor</b>, which allows
you to replace the actual constructor function for your model.
</p>
<p id="Model-get">
<b class="header">get</b><code>model.get(attribute)</code>
<br />
Get the current value of an attribute from the model. For example:
<tt>note.get("title")</tt>
</p>
<p id="Model-set">
<b class="header">set</b><code>model.set(attributes, [options])</code>
<br />
Set a hash of attributes (one or many) on the model. If any of the attributes
change the models state, a <tt>"change"</tt> event will be triggered, unless
<tt>{silent: true}</tt> is passed as an option. Change events for specific
attributes are also triggered, and you can bind to those as well, for example:
<tt>change:title</tt>, and <tt>change:content</tt>. You may also pass
individual keys and values.
</p>
<pre>
note.set({title: "March 20", content: "In his eyes she eclipses..."});
book.set("title", "A Scandal in Bohemia");
</pre>
<p>
If the model has a <a href="#Model-validate">validate</a> method,
it will be validated before the attributes are set, no changes will
occur if the validation fails, and <b>set</b> will return <tt>false</tt>.
Otherwise, <b>set</b> returns a reference to the model.
You may also pass an <tt>error</tt>
callback in the options, which will be invoked instead of triggering an
<tt>"error"</tt> event, should validation fail.
If <tt>{silent: true}</tt> is passed as an option, the validation is deferred
until the next change.
</p>
<p id="Model-escape">
<b class="header">escape</b><code>model.escape(attribute)</code>
<br />
Similar to <a href="#Model-get">get</a>, but returns the HTML-escaped version
of a model's attribute. If you're interpolating data from the model into
HTML, using <b>escape</b> to retrieve attributes will prevent
<a href="http://en.wikipedia.org/wiki/Cross-site_scripting">XSS</a> attacks.
</p>
<pre class="runnable">
var hacker = new Backbone.Model({
name: "&lt;script&gt;alert('xss')&lt;/script&gt;"
});
alert(hacker.escape('name'));
</pre>
<p id="Model-has">
<b class="header">has</b><code>model.has(attribute)</code>
<br />
Returns <tt>true</tt> if the attribute is set to a non-null or non-undefined
value.
</p>
<pre>
if (note.has("title")) {
...
}
</pre>
<p id="Model-unset">
<b class="header">unset</b><code>model.unset(attribute, [options])</code>
<br />
Remove an attribute by deleting it from the internal attributes hash.
Fires a <tt>"change"</tt> event unless <tt>silent</tt> is passed as an option.
</p>
<p id="Model-clear">
<b class="header">clear</b><code>model.clear([options])</code>
<br />
Removes all attributes from the model. Fires a <tt>"change"</tt> event unless
<tt>silent</tt> is passed as an option.
</p>
<p id="Model-id">
<b class="header">id</b><code>model.id</code>
<br />
A special property of models, the <b>id</b> is an arbitrary string
(integer id or UUID). If you set the <b>id</b> in the
attributes hash, it will be copied onto the model as a direct property.
Models can be retrieved by id from collections, and the id is used to generate
model URLs by default.
</p>
<p id="Model-idAttribute">
<b class="header">idAttribute</b><code>model.idAttribute</code>
<br />
A model's unique identifier is stored under the <tt>id</tt> attribute.
If you're directly communicating with a backend (CouchDB, MongoDB) that uses
a different unique key, you may set a Model's <tt>idAttribute</tt> to
transparently map from that key to <tt>id</tt>.
<pre class="runnable">
var Meal = Backbone.Model.extend({
idAttribute: "_id"
});
var cake = new Meal({ _id: 1, name: "Cake" });
alert("Cake id: " + cake.id);
</pre>
</p>
<p id="Model-cid">
<b class="header">cid</b><code>model.cid</code>
<br />
A special property of models, the <b>cid</b> or client id is a unique identifier
automatically assigned to all models when they're first created. Client ids
are handy when the model has not yet been saved to the server, and does not
yet have its eventual true <b>id</b>, but already needs to be visible in the UI.
Client ids take the form: <tt>c1, c2, c3 ...</tt>
</p>
<p id="Model-attributes">
<b class="header">attributes</b><code>model.attributes</code>
<br />
The <b>attributes</b> property is the internal hash containing the model's
state. Please use <a href="#Model-set">set</a> to update the attributes instead of modifying
them directly. If you'd like to retrieve and munge a copy of the model's
attributes, use <a href="#Model-toJSON">toJSON</a> instead.
</p>
<p id="Model-changed">
<b class="header">changed</b><code>model.changed</code>
<br />
The <b>changed</b> property is the internal hash containing all the attributes
that have changed since the last <tt>"change"</tt> event was triggered.
Please do not update <b>changed</b> directly. Its state is maintained internally
by <a href="#Model-set">set</a> and <a href="#Model-change">change</a>.
A copy of <b>changed</b> can be acquired from
<a href="#Model-changedAttributes">changedAttributes</a>.
</p>
<p id="Model-defaults">
<b class="header">defaults</b><code>model.defaults or model.defaults()</code>
<br />
The <b>defaults</b> hash (or function) can be used to specify the default
attributes for your model. When creating an instance of the model,
any unspecified attributes will be set to their default value.
</p>
<pre class="runnable">
var Meal = Backbone.Model.extend({
defaults: {
"appetizer": "caesar salad",
"entree": "ravioli",
"dessert": "cheesecake"
}
});
alert("Dessert will be " + (new Meal).get('dessert'));
</pre>
<p class="warning">
Remember that in JavaScript, objects are passed by reference, so if you
include an object as a default value, it will be shared among all instances.
</p>
<p id="Model-toJSON">
<b class="header">toJSON</b><code>model.toJSON()</code>
<br />
Return a copy of the model's <a href="#Model-attributes">attributes</a> for JSON stringification.
This can be used for persistence, serialization, or for augmentation before
being handed off to a view. The name of this method is a bit confusing, as
it doesn't actually return a JSON string &mdash; but I'm afraid that it's
the way that the <a href="https://developer.mozilla.org/en/JSON#toJSON()_method">JavaScript API for <b>JSON.stringify</b> works</a>.
</p>
<pre class="runnable">
var artist = new Backbone.Model({
firstName: "Wassily",
lastName: "Kandinsky"
});
artist.set({birthday: "December 16, 1866"});
alert(JSON.stringify(artist));
</pre>
<p id="Model-fetch">
<b class="header">fetch</b><code>model.fetch([options])</code>
<br />
Resets the model's state from the server by delegating to
<a href="#Sync">Backbone.sync</a>. Returns a
<a href="http://api.jquery.com/jQuery.ajax/#jqXHR">jqXHR</a>.
Useful if the model has never
been populated with data, or if you'd like to ensure that you have the
latest server state. A <tt>"change"</tt> event will be triggered if the
server's state differs from the current attributes. Accepts
<tt>success</tt> and <tt>error</tt> callbacks in the options hash, which
are passed <tt>(model, response)</tt> as arguments.
</p>
<pre>
// Poll every 10 seconds to keep the channel model up-to-date.
setInterval(function() {
channel.fetch();
}, 10000);
</pre>
<p id="Model-save">
<b class="header">save</b><code>model.save([attributes], [options])</code>
<br />
Save a model to your database (or alternative persistence layer),
by delegating to <a href="#Sync">Backbone.sync</a>. Returns a
<a href="http://api.jquery.com/jQuery.ajax/#jqXHR">jqXHR</a> if
validation is successful and <tt>false</tt> otherwise. The <b>attributes</b>
hash (as in <a href="#Model-set">set</a>) should contain the attributes
you'd like to change &mdash; keys that aren't mentioned won't be altered &mdash; but,
a <i>complete representation</i> of the resource will be sent to the server.
As with <tt>set</tt>, you may pass individual keys and values instead of a hash.
If the model has a <a href="#Model-validate">validate</a>
method, and validation fails, the model will not be saved. If the model
<a href="#Model-isNew">isNew</a>, the save will be a <tt>"create"</tt>
(HTTP <tt>POST</tt>), if the model already
exists on the server, the save will be an <tt>"update"</tt> (HTTP <tt>PUT</tt>).
</p>
<p>
Calling <tt>save</tt> with new attributes will cause a <tt>"change"</tt>
event immediately, and a <tt>"sync"</tt> event after the server has acknowledged
the successful change. Pass <tt>{wait: true}</tt> if you'd like to wait
for the server before setting the new attributes on the model.
</p>
<p>
In the following example, notice how our overridden version
of <tt>Backbone.sync</tt> receives a <tt>"create"</tt> request
the first time the model is saved and an <tt>"update"</tt>
request the second time.
</p>
<pre class="runnable">
Backbone.sync = function(method, model) {
alert(method + ": " + JSON.stringify(model));
model.id = 1;
};
var book = new Backbone.Model({
title: "The Rough Riders",
author: "Theodore Roosevelt"
});
book.save();
book.save({author: "Teddy"});
</pre>
<p>
<b>save</b> accepts <tt>success</tt> and <tt>error</tt> callbacks in the
options hash, which are passed <tt>(model, response)</tt> as arguments.
The <tt>error</tt> callback will also be invoked if the model has a
<tt>validate</tt> method, and validation fails. If a server-side
validation fails, return a non-<tt>200</tt> HTTP response code, along with
an error response in text or JSON.
</p>
<pre>
book.save("author", "F.D.R.", {error: function(){ ... }});
</pre>
<p id="Model-destroy">
<b class="header">destroy</b><code>model.destroy([options])</code>
<br />
Destroys the model on the server by delegating an HTTP <tt>DELETE</tt>
request to <a href="#Sync">Backbone.sync</a>. Returns a
<a href="http://api.jquery.com/jQuery.ajax/#jqXHR">jqXHR</a> object, or
<tt>false</tt> if the model <a href="#Model-isNew">isNew</a>. Accepts
<tt>success</tt> and <tt>error</tt> callbacks in the options hash.
Triggers a <tt>"destroy"</tt> event on the model, which will bubble up
through any collections that contain it, and a <tt>"sync"</tt> event, after
the server has successfully acknowledged the model's deletion. Pass
<tt>{wait: true}</tt> if you'd like to wait for the server to respond
before removing the model from the collection.
</p>
<pre>
book.destroy({success: function(model, response) {
...
}});
</pre>
<p id="Model-validate">
<b class="header">validate</b><code>model.validate(attributes)</code>
<br />
This method is left undefined, and you're encouraged to override it with
your custom validation logic, if you have any that can be performed
in JavaScript. <b>validate</b> is called before <tt>set</tt> and
<tt>save</tt>, and is passed the model attributes updated with the values
from <tt>set</tt> or <tt>save</tt>.
If the attributes are valid, don't return anything from <b>validate</b>;
if they are invalid, return an error of your choosing. It
can be as simple as a string error message to be displayed, or a complete
error object that describes the error programmatically. If <b>validate</b>
returns an error, <tt>set</tt> and <tt>save</tt> will not continue, and the
model attributes will not be modified.
Failed validations trigger an <tt>"error"</tt> event.
</p>
<pre class="runnable">
var Chapter = Backbone.Model.extend({
validate: function(attrs) {
if (attrs.end < attrs.start) {
return "can't end before it starts";
}
}
});
var one = new Chapter({
title : "Chapter One: The Beginning"
});
one.on("error", function(model, error) {
alert(model.get("title") + " " + error);
});
one.set({
start: 15,
end: 10
});
</pre>
<p>
<tt>"error"</tt> events are useful for providing coarse-grained error
messages at the model or collection level, but if you have a specific view
that can better handle the error, you may override and suppress the event
by passing an <tt>error</tt> callback directly:
</p>
<pre>
account.set({access: "unlimited"}, {
error: function(model, error) {
alert(error);
}
});
</pre>
<p id="Model-isValid">
<b class="header">isValid</b><code>model.isValid()</code>
<br />
Models may enter an invalid state if you make changes to them silently
... useful when dealing with form input. Call <tt>model.isValid()</tt>
to check if the model is currently in a valid state, according to your
<tt>validate</tt> function.
</p>
<p id="Model-url">
<b class="header">url</b><code>model.url()</code>
<br />
Returns the relative URL where the model's resource would be located on
the server. If your models are located somewhere else, override this method
with the correct logic. Generates URLs of the form: <tt>"/[collection.url]/[id]"</tt>,
falling back to <tt>"/[urlRoot]/id"</tt> if the model is not part of a collection.
</p>
<p>
Delegates to <a href="#Collection-url">Collection#url</a> to generate the
URL, so make sure that you have it defined, or a <a href="#Model-urlRoot">urlRoot</a>
property, if all models of this class share a common root URL.
A model with an id of <tt>101</tt>, stored in a
<a href="#Collection">Backbone.Collection</a> with a <tt>url</tt> of <tt>"/documents/7/notes"</tt>,
would have this URL: <tt>"/documents/7/notes/101"</tt>
</p>
<p id="Model-urlRoot">
<b class="header">urlRoot</b><code>model.urlRoot or model.urlRoot()</code>
<br />
Specify a <tt>urlRoot</tt> if you're using a model outside of a collection,
to enable the default <a href="#Model-url">url</a> function to generate
URLs based on the model id. <tt>"/[urlRoot]/id"</tt><br />
Note that <tt>urlRoot</tt> may also be defined as a function.
</p>
<pre class="runnable">
var Book = Backbone.Model.extend({urlRoot : '/books'});
var solaris = new Book({id: "1083-lem-solaris"});
alert(solaris.url());
</pre>
<p id="Model-parse">
<b class="header">parse</b><code>model.parse(response)</code>
<br />
<b>parse</b> is called whenever a model's data is returned by the
server, in <a href="#Model-fetch">fetch</a>, and <a href="#Model-save">save</a>.
The function is passed the raw <tt>response</tt> object, and should return
the attributes hash to be <a href="#Model-set">set</a> on the model. The
default implementation is a no-op, simply passing through the JSON response.
Override this if you need to work with a preexisting API, or better namespace
your responses.
</p>
<p>
If you're working with a Rails backend, you'll notice that Rails' default
<tt>to_json</tt> implementation includes a model's attributes under a
namespace. To disable this behavior for seamless Backbone integration, set:
</p>
<pre>
ActiveRecord::Base.include_root_in_json = false
</pre>
<p id="Model-clone">
<b class="header">clone</b><code>model.clone()</code>
<br />
Returns a new instance of the model with identical attributes.
</p>
<p id="Model-isNew">
<b class="header">isNew</b><code>model.isNew()</code>
<br />
Has this model been saved to the server yet? If the model does not yet have
an <tt>id</tt>, it is considered to be new.
</p>
<p id="Model-change">
<b class="header">change</b><code>model.change()</code>
<br />
Manually trigger the <tt>"change"</tt> event and a <tt>"change:attribute"</tt>
event for each attribute that has changed. If you've been passing
<tt>{silent: true}</tt> to the <a href="#Model-set">set</a> function in order to
aggregate rapid changes to a model, you'll want to call <tt>model.change()</tt>
when you're all finished.
</p>
<p id="Model-hasChanged">
<b class="header">hasChanged</b><code>model.hasChanged([attribute])</code>
<br />
Has the model changed since the last <tt>"change"</tt> event? If an <b>attribute</b>
is passed, returns <tt>true</tt> if that specific attribute has changed.
</p>
<p class="warning">
Note that this method, and the following change-related ones,
are only useful during the course of a <tt>"change"</tt> event.
</p>
<pre>
book.on("change", function() {
if (book.hasChanged("title")) {
...
}
});
</pre>
<p id="Model-changedAttributes">
<b class="header">changedAttributes</b><code>model.changedAttributes([attributes])</code>
<br />
Retrieve a hash of only the model's attributes that have changed. Optionally,
an external <b>attributes</b> hash can be passed in, returning
the attributes in that hash which differ from the model. This can be used
to figure out which portions of a view should be updated, or what calls
need to be made to sync the changes to the server.
</p>
<p id="Model-previous">
<b class="header">previous</b><code>model.previous(attribute)</code>
<br />
During a <tt>"change"</tt> event, this method can be used to get the
previous value of a changed attribute.
</p>
<pre class="runnable">
var bill = new Backbone.Model({
name: "Bill Smith"
});
bill.on("change:name", function(model, name) {
alert("Changed name from " + bill.previous("name") + " to " + name);
});
bill.set({name : "Bill Jones"});
</pre>
<p id="Model-previousAttributes">
<b class="header">previousAttributes</b><code>model.previousAttributes()</code>
<br />
Return a copy of the model's previous attributes. Useful for getting a
diff between versions of a model, or getting back to a valid state after
an error occurs.
</p>
<h2 id="Collection">Backbone.Collection</h2>
<p>
Collections are ordered sets of models. You can bind <tt>"change"</tt> events
to be notified when any model in the collection has been modified,
listen for <tt>"add"</tt> and <tt>"remove"</tt> events, <tt>fetch</tt>
the collection from the server, and use a full suite of
<a href="#Collection-Underscore-Methods">Underscore.js methods</a>.
</p>
<p>
Any event that is triggered on a model in a collection will also be
triggered on the collection directly, for convenience.
This allows you to listen for changes to specific attributes in any
model in a collection, for example:
<tt>Documents.on("change:selected", ...)</tt>
</p>
<p id="Collection-extend">
<b class="header">extend</b><code>Backbone.Collection.extend(properties, [classProperties])</code>
<br />
To create a <b>Collection</b> class of your own, extend <b>Backbone.Collection</b>,
providing instance <b>properties</b>, as well as optional <b>classProperties</b> to be attached
directly to the collection's constructor function.
</p>
<p id="Collection-model">
<b class="header">model</b><code>collection.model</code>
<br />
Override this property to specify the model class that the collection
contains. If defined, you can pass raw attributes objects (and arrays) to
<a href="#Collection-add">add</a>, <a href="#Collection-create">create</a>,
and <a href="#Collection-reset">reset</a>, and the attributes will be
converted into a model of the proper type.
</p>
<pre>
var Library = Backbone.Collection.extend({
model: Book
});
</pre>
<p id="Collection-constructor">
<b class="header">constructor / initialize</b><code>new Collection([models], [options])</code>
<br />
When creating a Collection, you may choose to pass in the initial array of <b>models</b>.
The collection's <a href="#Collection-comparator">comparator</a> function
may be included as an option. If you define an <b>initialize</b> function, it will be
invoked when the collection is created.
</p>
<pre>
var tabs = new TabSet([tab1, tab2, tab3]);
</pre>
<p id="Collection-models">
<b class="header">models</b><code>collection.models</code>
<br />
Raw access to the JavaScript array of models inside of the collection. Usually you'll
want to use <tt>get</tt>, <tt>at</tt>, or the <b>Underscore methods</b>
to access model objects, but occasionally a direct reference to the array
is desired.
</p>
<p id="Collection-toJSON">
<b class="header">toJSON</b><code>collection.toJSON()</code>
<br />
Return an array containing the attributes hash of each model in the
collection. This can be used to serialize and persist the
collection as a whole. The name of this method is a bit confusing, because
it conforms to
<a href="https://developer.mozilla.org/en/JSON#toJSON()_method">JavaScript's JSON API</a>.
</p>
<pre class="runnable">
var collection = new Backbone.Collection([
{name: "Tim", age: 5},
{name: "Ida", age: 26},
{name: "Rob", age: 55}
]);
alert(JSON.stringify(collection));
</pre>
<p id="Collection-Underscore-Methods">
<b class="header">Underscore Methods (28)</b>
<br />
Backbone proxies to <b>Underscore.js</b> to provide 28 iteration functions
on <b>Backbone.Collection</b>. They aren't all documented here, but
you can take a look at the Underscore documentation for the full details&hellip;
</p>
<ul class="small">
<li><a href="http://documentcloud.github.com/underscore/#each">forEach (each)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#map">map</a></li>
<li><a href="http://documentcloud.github.com/underscore/#reduce">reduce (foldl, inject)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#reduceRight">reduceRight (foldr)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#detect">find (detect)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#select">filter (select)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#reject">reject</a></li>
<li><a href="http://documentcloud.github.com/underscore/#all">every (all)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#any">some (any)</a></li>
<li><a href="http://documentcloud.github.com/underscore/#include">include</a></li>
<li><a href="http://documentcloud.github.com/underscore/#invoke">invoke</a></li>
<li><a href="http://documentcloud.github.com/underscore/#max">max</a></li>
<li><a href="http://documentcloud.github.com/underscore/#min">min</a></li>
<li><a href="http://documentcloud.github.com/underscore/#sortBy">sortBy</a></li>
<li><a href="http://documentcloud.github.com/underscore/#groupBy">groupBy</a></li>
<li><a href="http://documentcloud.github.com/underscore/#sortedIndex">sortedIndex</a></li>
<li><a href="http://documentcloud.github.com/underscore/#shuffle">shuffle</a></li>
<li><a href="http://documentcloud.github.com/underscore/#toArray">toArray</a></li>
<li><a href="http://documentcloud.github.com/underscore/#size">size</a></li>
<li><a href="http://documentcloud.github.com/underscore/#first">first</a></li>
<li><a href="http://documentcloud.github.com/underscore/#initial">initial</a></li>
<li><a href="http://documentcloud.github.com/underscore/#rest">rest</a></li>
<li><a href="http://documentcloud.github.com/underscore/#last">last</a></li>
<li><a href="http://documentcloud.github.com/underscore/#without">without</a></li>
<li><a href="http://documentcloud.github.com/underscore/#indexOf">indexOf</a></li>
<li><a href="http://documentcloud.github.com/underscore/#lastIndexOf">lastIndexOf</a></li>
<li><a href="http://documentcloud.github.com/underscore/#isEmpty">isEmpty</a></li>
<li><a href="http://documentcloud.github.com/underscore/#chain">chain</a></li>
</ul>
<pre>
Books.each(function(book) {
book.publish();
});
var titles = Books.map(function(book) {
return book.get("title");
});
var publishedBooks = Books.filter(function(book) {
return book.get("published") === true;
});
var alphabetical = Books.sortBy(function(book) {
return book.author.get("name").toLowerCase();
});
</pre>
<p id="Collection-add">
<b class="header">add</b><code>collection.add(models, [options])</code>
<br />
Add a model (or an array of models) to the collection. Fires an <tt>"add"</tt>
event, which you can pass <tt>{silent: true}</tt> to suppress. If a
<a href="#Collection-model">model</a> property is defined, you may also pass
raw attributes objects, and have them be vivified as instances of the model.
Pass <tt>{at: index}</tt> to splice the model into the collection at the
specified <tt>index</tt>. Likewise, if you're a callback listening to a
collection's <tt>"add"</tt> event, <tt>options.index</tt> will tell you the
index at which the model is being added to the collection.
</p>
<pre class="runnable">
var ships = new Backbone.Collection;
ships.on("add", function(ship) {
alert("Ahoy " + ship.get("name") + "!");
});
ships.add([
{name: "Flying Dutchman"},
{name: "Black Pearl"}
]);
</pre>
<p id="Collection-remove">
<b class="header">remove</b><code>collection.remove(models, [options])</code>
<br />
Remove a model (or an array of models) from the collection. Fires a
<tt>"remove"</tt> event, which you can use <tt>silent</tt>
to suppress. If you're a callback listening to the <tt>"remove"</tt> event,
the index at which the model is being removed from the collection is available
as <tt>options.index</tt>.
</p>
<p id="Collection-get">
<b class="header">get</b><code>collection.get(id)</code>
<br />
Get a model from a collection, specified by <b>id</b>.
</p>
<pre>
var book = Library.get(110);
</pre>
<p id="Collection-getByCid">
<b class="header">getByCid</b><code>collection.getByCid(cid)</code>
<br />
Get a model from a collection, specified by client id. The client id
is the <tt>.cid</tt> property of the model, automatically assigned whenever
a model is created. Useful for models which have not yet been saved to
the server, and do not yet have true ids.
</p>
<p id="Collection-at">
<b class="header">at</b><code>collection.at(index)</code>
<br />
Get a model from a collection, specified by index. Useful if your collection
is sorted, and if your collection isn't sorted, <b>at</b> will still
retrieve models in insertion order.
</p>
<p id="Collection-push">
<b class="header">push</b><code>collection.push(model, [options])</code>
<br />
Add a model at the end of a collection. Takes the same options as
<a href="#Collection-add">add</a>.
</p>
<p id="Collection-pop">
<b class="header">pop</b><code>collection.pop([options])</code>
<br />
Remove and return the last model from a collection. Takes the same options as
<a href="#Collection-remove">remove</a>.
</p>
<p id="Collection-unshift">
<b class="header">unshift</b><code>collection.unshift(model, [options])</code>
<br />
Add a model at the beginning of a collection. Takes the same options as
<a href="#Collection-add">add</a>.
</p>
<p id="Collection-shift">
<b class="header">shift</b><code>collection.shift([options])</code>
<br />
Remove and return the first model from a collection. Takes the same options as
<a href="#Collection-remove">remove</a>.
</p>
<p id="Collection-length">
<b class="header">length</b><code>collection.length</code>
<br />
Like an array, a Collection maintains a <tt>length</tt> property, counting
the number of models it contains.
</p>
<p id="Collection-comparator">
<b class="header">comparator</b><code>collection.comparator</code>
<br />
By default there is no <b>comparator</b> function on a collection.
If you define a comparator, it will be used to maintain
the collection in sorted order. This means that as models are added,
they are inserted at the correct index in <tt>collection.models</tt>.
Comparator function can be defined as either a
<a href="http://underscorejs.org/#sortBy">sortBy</a>
(pass a function that takes a single argument),
or as a
<a href="https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/sort">sort</a>
(pass a comparator function that expects two arguments).
</p>
<p>
"sortBy" comparator functions take a model and return a numeric or string
value by which the model should be ordered relative to others.
"sort" comparator functions take two models, and return <tt>-1</tt> if
the first model should come before the second, <tt>0</tt> if they are of
the same rank and <tt>1</tt> if the first model should come after.
</p>
<p>
Note how even though all of the chapters in this example are added backwards,
they come out in the proper order:
</p>
<pre class="runnable">
var Chapter = Backbone.Model;
var chapters = new Backbone.Collection;
chapters.comparator = function(chapter) {
return chapter.get("page");
};
chapters.add(new Chapter({page: 9, title: "The End"}));
chapters.add(new Chapter({page: 5, title: "The Middle"}));
chapters.add(new Chapter({page: 1, title: "The Beginning"}));
alert(chapters.pluck('title'));
</pre>
<p class="warning">
Collections with comparator functions will not automatically re-sort if you
later change model attributes, so you may wish to call <tt>sort</tt> after
changing model attributes that would affect the order.
</p>
<p id="Collection-sort">
<b class="header">sort</b><code>collection.sort([options])</code>
<br />
Force a collection to re-sort itself. You don't need to call this under
normal circumstances, as a collection with a <a href="#Collection-comparator">comparator</a> function
will maintain itself in proper sort order at all times. Calling <b>sort</b>
triggers the collection's <tt>"reset"</tt> event, unless silenced by passing
<tt>{silent: true}</tt>
</p>
<p id="Collection-pluck">
<b class="header">pluck</b><code>collection.pluck(attribute)</code>
<br />
Pluck an attribute from each model in the collection. Equivalent to calling
<tt>map</tt>, and returning a single attribute from the iterator.
</p>
<pre class="runnable">
var stooges = new Backbone.Collection([
{name: "Curly"},
{name: "Larry"},
{name: "Moe"}
]);
var names = stooges.pluck("name");
alert(JSON.stringify(names));
</pre>
<p id="Collection-where">
<b class="header">where</b><code>collection.where(attributes)</code>
<br />
Return an array of all the models in a collection that match the
passed <b>attributes</b>. Useful for simple cases of <tt>filter</tt>.
</p>
<pre class="runnable">
var friends = new Backbone.Collection([
{name: "Athos", job: "Musketeer"},
{name: "Porthos", job: "Musketeer"},
{name: "Aramis", job: "Musketeer"},
{name: "d'Artagnan", job: "Guard"},
]);
var musketeers = friends.where({job: "Musketeer"});
alert(musketeers.length);
</pre>
<p id="Collection-url">
<b class="header">url</b><code>collection.url or collection.url()</code>
<br />
Set the <b>url</b> property (or function) on a collection to reference
its location on the server. Models within the collection will use <b>url</b>
to construct URLs of their own.
</p>
<pre>
var Notes = Backbone.Collection.extend({
url: '/notes'
});
// Or, something more sophisticated:
var Notes = Backbone.Collection.extend({
url: function() {
return this.document.url() + '/notes';
}
});
</pre>
<p id="Collection-parse">
<b class="header">parse</b><code>collection.parse(response)</code>
<br />
<b>parse</b> is called by Backbone whenever a collection's models are
returned by the server, in <a href="#Collection-fetch">fetch</a>.
The function is passed the raw <tt>response</tt> object, and should return
the array of model attributes to be <a href="#Collection-add">added</a>
to the collection. The default implementation is a no-op, simply passing
through the JSON response. Override this if you need to work with a
preexisting API, or better namespace your responses. Note that afterwards,
if your model class already has a <tt>parse</tt> function, it will be
run against each fetched model.
</p>
<pre>
var Tweets = Backbone.Collection.extend({
// The Twitter Search API returns tweets under "results".
parse: function(response) {
return response.results;
}
});
</pre>
<p id="Collection-fetch">
<b class="header">fetch</b><code>collection.fetch([options])</code>
<br />
Fetch the default set of models for this collection from the server,
resetting the collection when they arrive. The <b>options</b> hash takes
<tt>success</tt> and <tt>error</tt>
callbacks which will be passed <tt>(collection, response)</tt> as arguments.
When the model data returns from the server, the collection will
<a href="#Collection-reset">reset</a>.
Delegates to <a href="#Sync">Backbone.sync</a>
under the covers for custom persistence strategies and returns a
<a href="http://api.jquery.com/jQuery.ajax/#jqXHR">jqXHR</a>.
The server handler for <b>fetch</b> requests should return a JSON array of
models.
</p>
<pre class="runnable">
Backbone.sync = function(method, model) {
alert(method + ": " + model.url);
};
var Accounts = new Backbone.Collection;
Accounts.url = '/accounts';
Accounts.fetch();
</pre>
<p>
If you'd like to add the incoming models to the current collection, instead
of replacing the collection's contents, pass <tt>{add: true}</tt> as an
option to <b>fetch</b>.
</p>
<p>
<b>jQuery.ajax</b> options can also be passed directly as <b>fetch</b> options,
so to fetch a specific page of a paginated collection:
<tt>Documents.fetch({data: {page: 3}})</tt>
</p>
<p>
Note that <b>fetch</b> should not be used to populate collections on
page load &mdash; all models needed at load time should already be
<a href="#FAQ-bootstrap">bootstrapped</a> in to place. <b>fetch</b> is
intended for lazily-loading models for interfaces that are not needed
immediately: for example, documents with collections of notes that may be
toggled open and closed.
</p>
<p id="Collection-reset">
<b class="header">reset</b><code>collection.reset(models, [options])</code>
<br />
Adding and removing models one at a time is all well and good, but sometimes
you have so many models to change that you'd rather just update the collection
in bulk. Use <b>reset</b> to replace a collection with a new list
of models (or attribute hashes), triggering a single <tt>"reset"</tt> event
at the end. Pass <tt>{silent: true}</tt> to suppress the <tt>"reset"</tt> event.
Using reset with no arguments is useful as a way to empty the collection.
</p>
<p>
Here's an example using <b>reset</b> to bootstrap a collection during initial page load,
in a Rails application.
</p>
<pre>
&lt;script&gt;
var Accounts = new Backbone.Collection;
Accounts.reset(&lt;%= @accounts.to_json %&gt;);
&lt;/script&gt;
</pre>
<p>
Calling <tt>collection.reset()</tt> without passing any models as arguments
will empty the entire collection.
</p>
<p id="Collection-create">
<b class="header">create</b><code>collection.create(attributes, [options])</code>
<br />
Convenience to create a new instance of a model within a collection.
Delegates to <a href="#Sync">Backbone.sync</a> and returns a
<a href="http://api.jquery.com/jQuery.ajax/#jqXHR">jqXHR</a> if validation
is successful, and <tt>false</tt> otherwise.
Equivalent to instantiating a model with a hash of attributes,
saving the model to the server, and adding the model to the set after being
successfully created. Returns
the model, or <tt>false</tt> if a validation error prevented the
model from being created. In order for this to work, you should set the
<a href="#Collection-model">model</a> property of the collection.
The <b>create</b> method can accept either an attributes hash or an
existing, unsaved model object.
</p>
<p>
Creating a model will cause an immediate <tt>"add"</tt> event to be
triggered on the collection, as well as a <tt>"sync"</tt> event, once the
model has been successfully created on the server. Pass <tt>{wait: true}</tt>
if you'd like to wait for the server before adding the new model to the collection.
</p>
<pre>
var Library = Backbone.Collection.extend({
model: Book
});
var NYPL = new Library;
var othello = NYPL.create({
title: "Othello",
author: "William Shakespeare"
});
</pre>
<h2 id="Router">Backbone.Router</h2>
<p>
Web applications often provide linkable, bookmarkable, shareable URLs for
important locations in the app. Until recently, hash fragments
(<tt>#page</tt>) were used to provide these permalinks, but with the
arrival of the History API, it's now possible to use standard URLs (<tt>/page</tt>).
<b>Backbone.Router</b> provides methods for routing client-side pages, and
connecting them to actions and events. For browsers which don't yet support
the History API, the Router handles graceful fallback and transparent
translation to the fragment version of the URL.
</p>
<p>
During page load, after your application has finished creating all of its routers,
be sure to call <tt>Backbone.history.start()</tt>, or
<tt>Backbone.history.start({pushState: true})</tt> to route the initial URL.
</p>
<p id="Router-extend">
<b class="header">extend</b><code>Backbone.Router.extend(properties, [classProperties])</code>
<br />
Get started by creating a custom router class. Define actions that are
triggered when certain URL fragments are
matched, and provide a <a href="#Router-routes">routes</a> hash
that pairs routes to actions. Note that you'll want to avoid using a
leading slash in your route definitions:
</p>
<pre>
var Workspace = Backbone.Router.extend({
routes: {
"help": "help", // #help
"search/:query": "search", // #search/kiwis
"search/:query/p:page": "search" // #search/kiwis/p7
},
help: function() {
...
},
search: function(query, page) {
...
}
});
</pre>
<p id="Router-routes">
<b class="header">routes</b><code>router.routes</code>
<br />
The routes hash maps URLs with parameters to functions on your router,
similar to the <a href="#View">View</a>'s <a href="#View-delegateEvents">events hash</a>.
Routes can contain parameter parts, <tt>:param</tt>, which match a single URL
component between slashes; and splat parts <tt>*splat</tt>, which can match
any number of URL components.
</p>
<p>
For example, a route of <tt>"search/:query/p:page"</tt> will match
a fragment of <tt>#search/obama/p2</tt>, passing <tt>"obama"</tt>
and <tt>"2"</tt> to the action. A route of <tt>"file/*path"</tt> will
match <tt>#file/nested/folder/file.txt</tt>,
passing <tt>"nested/folder/file.txt"</tt> to the action.
</p>
<p>
When the visitor presses the back button, or enters a URL, and a particular
route is matched, the name of the action will be fired as an
<a href="#Events">event</a>, so that other objects can listen to the router,
and be notified. In the following example, visiting <tt>#help/uploading</tt>
will fire a <tt>route:help</tt> event from the router.
</p>
<pre>
routes: {
"help/:page": "help",
"download/*path": "download",
"folder/:name": "openFolder",
"folder/:name-:mode": "openFolder"
}
</pre>
<pre>
router.on("route:help", function(page) {
...
});
</pre>
<p id="Router-constructor">
<b class="header">constructor / initialize</b><code>new Router([options])</code>
<br />
When creating a new router, you may pass its
<a href="#Router-routes">routes</a> hash directly as an option, if you
choose. All <tt>options</tt> will also be passed to your <tt>initialize</tt>
function, if defined.
</p>
<p id="Router-route">
<b class="header">route</b><code>router.route(route, name, [callback])</code>
<br />
Manually create a route for the router, The <tt>route</tt> argument may
be a <a href="#Router-routes">routing string</a> or regular expression.
Each matching capture from the route or regular expression will be passed as
an argument to the callback. The <tt>name</tt> argument will be triggered as
a <tt>"route:name"</tt> event whenever the route is matched. If the
<tt>callback</tt> argument is omitted <tt>router[name]</tt> will be used
instead.
</p>
<pre>
initialize: function(options) {
// Matches #page/10, passing "10"
this.route("page/:number", "page", function(number){ ... });
// Matches /117-a/b/c/open, passing "117-a/b/c" to this.open
this.route(/^(.*?)\/open$/, "open");
},
open: function(id) { ... }
</pre>
<p id="Router-navigate">
<b class="header">navigate</b><code>router.navigate(fragment, [options])</code>
<br />
Whenever you reach a point in your application that you'd like to save
as a URL, call <b>navigate</b> in order to update the URL.
If you wish to also call the route function, set the <b>trigger</b>
option to <tt>true</tt>.
To update the URL without creating an entry in the browser's history,
set the <b>replace</b> option to <tt>true</tt>.
</p>
<pre>
openPage: function(pageNumber) {
this.document.pages.at(pageNumber).open();
this.navigate("page/" + pageNumber);
}
# Or ...
app.navigate("help/troubleshooting", {trigger: true});
# Or ...
app.navigate("help/troubleshooting", {trigger: true, replace: true});
</pre>
<h2 id="History">Backbone.history</h2>
<p>
<b>History</b> serves as a global router (per frame) to handle <tt>hashchange</tt>
events or <tt>pushState</tt>, match the appropriate route, and trigger callbacks. You shouldn't
ever have to create one of these yourself &mdash; you should use the reference
to <tt>Backbone.history</tt> that will be created for you automatically if you make use
of <a href="#Router">Routers</a> with <a href="#Router-routes">routes</a>.
</p>
<p>
<b>pushState</b> support exists on a purely opt-in basis in Backbone.
Older browsers that don't support <tt>pushState</tt> will continue to use
hash-based URL fragments, and if a hash URL is visited by a
<tt>pushState</tt>-capable browser, it will be transparently upgraded to
the true URL. Note that using real URLs requires your web server to be
able to correctly render those pages, so back-end changes are required
as well. For example, if you have a route of <tt>/documents/100</tt>,
your web server must be able to serve that page, if the browser
visits that URL directly. For full search-engine crawlability, it's best to
have the server generate the complete HTML for the page ... but if it's a web
application, just rendering the same content you would have for the root URL,
and filling in the rest with Backbone Views and JavaScript works fine.
</p>
<p id="History-start">
<b class="header">start</b><code>Backbone.history.start([options])</code>
<br />
When all of your <a href="#Router">Routers</a> have been created,
and all of the routes are set up properly, call <tt>Backbone.history.start()</tt>
to begin monitoring <tt>hashchange</tt> events, and dispatching routes.
</p>
<p>
To indicate that you'd like to use HTML5 <tt>pushState</tt> support in
your application, use <tt>Backbone.history.start({pushState: true})</tt>.
</p>
<p>
If your application is not being served from the root url <tt>/</tt> of your
domain, be sure to tell History where the root really is, as an option:
<tt>Backbone.history.start({pushState: true, root: "/public/search/"})</tt>
</p>
<p>
When called, if a route succeeds with a match for the current URL,
<tt>Backbone.history.start()</tt> returns <tt>true</tt>. If no defined
route matches the current URL, it returns <tt>false</tt>.
</p>
<p>
If the server has already rendered the entire page, and you don't want the
initial route to trigger when starting History, pass <tt>silent: true</tt>.
</p>
<p>
Because hash-based history in Internet Explorer relies on an
<tt>&lt;iframe&gt;</tt>, be sure to only call <tt>start()</tt> after the DOM
is ready.
</p>
<pre>
$(function(){
new WorkspaceRouter();
new HelpPaneRouter();
Backbone.history.start({pushState: true});
});
</pre>
<h2 id="Sync">Backbone.sync</h2>
<p>
<b>Backbone.sync</b> is the function that Backbone calls every time it
attempts to read or save a model to the server. By default, it uses
<tt>(jQuery/Zepto).ajax</tt> to make a RESTful JSON request and returns a
<a href="http://api.jquery.com/jQuery.ajax/#jqXHR">jqXHR</a>. You can override
it in order to use a different persistence strategy, such as WebSockets,
XML transport, or Local Storage.
</p>
<p>
The method signature of <b>Backbone.sync</b> is <tt>sync(method, model, [options])</tt>
</p>
<ul>
<li><b>method</b> – the CRUD method (<tt>"create"</tt>, <tt>"read"</tt>, <tt>"update"</tt>, or <tt>"delete"</tt>)</li>
<li><b>model</b> – the model to be saved (or collection to be read)</li>
<li><b>options</b> – success and error callbacks, and all other jQuery request options</li>
</ul>
<p>
With the default implementation, when <b>Backbone.sync</b> sends up a request to save
a model, its attributes will be passed, serialized as JSON, and sent in the HTTP body
with content-type <tt>application/json</tt>. When returning a JSON response,
send down the attributes of the model that have been changed by the server, and need
to be updated on the client. When responding to a <tt>"read"</tt> request from a collection
(<a href="#Collection#fetch">Collection#fetch</a>), send down an array
of model attribute objects.
</p>
<p>
The <b>sync</b> function may be overriden globally as <tt>Backbone.sync</tt>,
or at a finer-grained level, by adding a <tt>sync</tt> function to a Backbone
collection or to an individual model.
</p>
<p>
The default <b>sync</b> handler maps CRUD to REST like so:
</p>
<ul>
<li><b>create &rarr; POST &nbsp; </b><tt>/collection</tt></li>
<li><b>read &rarr; GET &nbsp; </b><tt>/collection[/id]</tt></li>
<li><b>update &rarr; PUT &nbsp; </b><tt>/collection/id</tt></li>
<li><b>delete &rarr; DELETE &nbsp; </b><tt>/collection/id</tt></li>
</ul>
<p>
As an example, a Rails handler responding to an <tt>"update"</tt> call from
<tt>Backbone</tt> might look like this: <i>(In real code, never use
</i><tt>update_attributes</tt><i> blindly, and always whitelist the attributes
you allow to be changed.)</i>
</p>
<pre>
def update
account = Account.find params[:id]
account.update_attributes params
render :json => account
end
</pre>
<p>
One more tip for Rails integration is to disable the default namespacing for
<tt>to_json</tt> calls on models by setting <tt>ActiveRecord::Base.include_root_in_json = false</tt>
</p>
<p id="Sync-emulateHTTP">
<b class="header">emulateHTTP</b><code>Backbone.emulateHTTP = true</code>
<br />
If you want to work with a legacy web server that doesn't support Backbones's
default REST/HTTP approach, you may choose to turn on <tt>Backbone.emulateHTTP</tt>.
Setting this option will fake <tt>PUT</tt> and <tt>DELETE</tt> requests with
a HTTP <tt>POST</tt>, setting the <tt>X-HTTP-Method-Override</tt> header
with the true method. If <tt>emulateJSON</tt> is also on, the true method
will be passed as an additional <tt>_method</tt> parameter.
</p>
<pre>
Backbone.emulateHTTP = true;
model.save(); // POST to "/collection/id", with "_method=PUT" + header.
</pre>
<p id="Sync-emulateJSON">
<b class="header">emulateJSON</b><code>Backbone.emulateJSON = true</code>
<br />
If you're working with a legacy web server that can't handle requests
encoded as <tt>application/json</tt>, setting <tt>Backbone.emulateJSON = true;</tt>
will cause the JSON to be serialized under a <tt>model</tt> parameter, and
the request to be made with a <tt>application/x-www-form-urlencoded</tt>
mime type, as if from an HTML form.
</p>
<h2 id="View">Backbone.View</h2>
<p>
Backbone views are almost more convention than they are code &mdash; they
don't determine anything about your HTML or CSS for you, and can be used
with any JavaScript templating library.
The general idea is to organize your interface into logical views,
backed by models, each of which can be updated independently when the
model changes, without having to redraw the page. Instead of digging into
a JSON object, looking up an element in the DOM, and updating the HTML by hand,
you can bind your view's <tt>render</tt> function to the model's <tt>"change"</tt>
event &mdash; and now everywhere that
model data is displayed in the UI, it is always immediately up to date.
</p>
<p id="View-extend">
<b class="header">extend</b><code>Backbone.View.extend(properties, [classProperties])</code>
<br />
Get started with views by creating a custom view class. You'll want to
override the <a href="#View-render">render</a> function, specify your
declarative <a href="#View-delegateEvents">events</a>, and perhaps the
<tt>tagName</tt>, <tt>className</tt>, or <tt>id</tt> of the View's root
element.
</p>
<pre>
var DocumentRow = Backbone.View.extend({
tagName: "li",
className: "document-row",
events: {
"click .icon": "open",
"click .button.edit": "openEditDialog",
"click .button.delete": "destroy"
},
render: function() {
...
}
});
</pre>
<p id="View-constructor">
<b class="header">constructor / initialize</b><code>new View([options])</code>
<br />
When creating a new View, the options you pass are attached to the view
as <tt>this.options</tt>, for future reference. There are several special
options that, if passed, will be attached directly to the view:
<tt>model</tt>, <tt>collection</tt>,
<tt>el</tt>, <tt>id</tt>, <tt>className</tt>, <tt>tagName</tt> and <tt>attributes</tt>.
If the view defines an <b>initialize</b> function, it will be called when
the view is first created. If you'd like to create a view that references
an element <i>already</i> in the DOM, pass in the element as an option:
<tt>new View({el: existingElement})</tt>
</p>
<pre>
var doc = Documents.first();
new DocumentRow({
model: doc,
id: "document-row-" + doc.id
});
</pre>
<p id="View-el">
<b class="header">el</b><code>view.el</code>
<br />
All views have a DOM element at all times (the <b>el</b> property),
whether they've already been inserted into the page or not. In this
fashion, views can be rendered at any time, and inserted into the DOM all
at once, in order to get high-performance UI rendering with as few
reflows and repaints as possible. <tt>this.el</tt> is created from the
view's <tt>tagName</tt>, <tt>className</tt>, <tt>id</tt> and <tt>attributes</tt> properties,
if specified. If not, <b>el</b> is an empty <tt>div</tt>.
</p>
<pre class="runnable">
var ItemView = Backbone.View.extend({
tagName: 'li'
});
var BodyView = Backbone.View.extend({
el: 'body'
});
var item = new ItemView();
var body = new BodyView();
alert(item.el + ' ' + body.el);
</pre>
<p id="View-$el">
<b class="header">$el</b><code>view.$el</code>
<br />
A cached jQuery (or Zepto) object for the view's element. A handy
reference instead of re-wrapping the DOM element all the time.
</p>
<pre>
view.$el.show();
listView.$el.append(itemView.el);
</pre>
<p id="View-setElement">
<b class="header">setElement</b><code>view.setElement(element)</code>
<br />
If you'd like to apply a Backbone view to a different DOM element, use
<b>setElement</b>, which will also create the cached <tt>$el</tt> reference
and move the view's delegated events from the old element to the new one.
</p>
<p id="View-attributes">
<b class="header">attributes</b><code>view.attributes</code>
<br />
A hash of attributes that will be set as HTML DOM element attributes on the
view's <tt>el</tt> (id, class, data-properties, etc.), or a function that
returns such a hash.
</p>
<p id="View-dollar">
<b class="header">$ (jQuery or Zepto)</b><code>view.$(selector)</code>
<br />
If jQuery or Zepto is included on the page, each view has a
<b>$</b> function that runs queries scoped within the view's element. If you use this
scoped jQuery function, you don't have to use model ids as part of your query
to pull out specific elements in a list, and can rely much more on HTML class
attributes. It's equivalent to running: <tt>view.$el.find(selector)</tt>
</p>
<pre>
ui.Chapter = Backbone.View.extend({
serialize : function() {
return {
title: this.$(".title").text(),
start: this.$(".start-page").text(),
end: this.$(".end-page").text()
};
}
});
</pre>
<p id="View-render">
<b class="header">render</b><code>view.render()</code>
<br />
The default implementation of <b>render</b> is a no-op. Override this
function with your code that renders the view template from model data,
and updates <tt>this.el</tt> with the new HTML. A good
convention is to <tt>return this</tt> at the end of <b>render</b> to
enable chained calls.
</p>
<pre>
var Bookmark = Backbone.View.extend({
render: function() {
$(this.el).html(this.template(this.model.toJSON()));
return this;
}
});
</pre>
<p>
Backbone is agnostic with respect to your preferred method of HTML templating.
Your <b>render</b> function could even munge together an HTML string, or use
<tt>document.createElement</tt> to generate a DOM tree. However, we suggest
choosing a nice JavaScript templating library.
<a href="http://github.com/janl/mustache.js">Mustache.js</a>,
<a href="http://github.com/creationix/haml-js">Haml-js</a>, and
<a href="http://github.com/sstephenson/eco">Eco</a> are all fine alternatives.
Because <a href="http://documentcloud.github.com/underscore/">Underscore.js</a> is already on the page,
<a href="http://documentcloud.github.com/underscore/#template">_.template</a>
is available, and is an excellent choice if you've already XSS-sanitized
your interpolated data.
</p>
<p>
Whatever templating strategy you end up with, it's nice if you <i>never</i>
have to put strings of HTML in your JavaScript. At DocumentCloud, we
use <a href="http://documentcloud.github.com/jammit/">Jammit</a> in order
to package up JavaScript templates stored in <tt>/app/views</tt> as part
of our main <tt>core.js</tt> asset package.
</p>
<p id="View-remove">
<b class="header">remove</b><code>view.remove()</code>
<br />
Convenience function for removing the view from the DOM. Equivalent to calling
<tt>$(view.el).remove();</tt>
</p>
<p id="View-make">
<b class="header">make</b><code>view.make(tagName, [attributes], [content])</code>
<br />
Convenience function for creating a DOM element of the given type (<b>tagName</b>),
with optional attributes and HTML content. Used internally to create the
initial <tt>view.el</tt>.
</p>
<pre class="runnable">
var view = new Backbone.View;
var el = view.make("b", {"class": "bold"}, "Bold! ");
$("#make-demo").append(el);
</pre>
<div id="make-demo"></div>
<p id="View-delegateEvents">
<b class="header">delegateEvents</b><code>delegateEvents([events])</code>
<br />
Uses jQuery's <tt>delegate</tt> function to provide declarative callbacks
for DOM events within a view.
If an <b>events</b> hash is not passed directly, uses <tt>this.events</tt>
as the source. Events are written in the format <tt>{"event selector": "callback"}</tt>.
The callback may be either the name of a method on the view, or a direct
function body.
Omitting the <tt>selector</tt> causes the event to be bound to the view's
root element (<tt>this.el</tt>). By default, <tt>delegateEvents</tt> is called
within the View's constructor for you, so if you have a simple <tt>events</tt>
hash, all of your DOM events will always already be connected, and you will
never have to call this function yourself.
</p>
<p>
The <tt>events</tt> property may also be defined as a function that returns
an <b>events</b> hash, to make it easier to programmatically define your
events, as well as inherit them from parent views.
</p>
<p>
Using <b>delegateEvents</b> provides a number of advantages over manually
using jQuery to bind events to child elements during <a href="#View-render">render</a>. All attached
callbacks are bound to the view before being handed off to jQuery, so when
the callbacks are invoked, <tt>this</tt> continues to refer to the view object. When
<b>delegateEvents</b> is run again, perhaps with a different <tt>events</tt>
hash, all callbacks are removed and delegated afresh &mdash; useful for
views which need to behave differently when in different modes.
</p>
<p>
A view that displays a document in a search result might look
something like this:
</p>
<pre>
var DocumentView = Backbone.View.extend({
events: {
"dblclick" : "open",
"click .icon.doc" : "select",
"contextmenu .icon.doc" : "showMenu",
"click .show_notes" : "toggleNotes",
"click .title .lock" : "editAccessLevel",
"mouseover .title .date" : "showTooltip"
},
render: function() {
$(this.el).html(this.template(this.model.toJSON()));
return this;
},
open: function() {
window.open(this.model.get("viewer_url"));
},
select: function() {
this.model.set({selected: true});
},
...
});
</pre>
<p id="View-undelegateEvents">
<b class="header">undelegateEvents</b><code>undelegateEvents()</code>
<br />
Removes all of the view's delegated events. Useful if you want to disable
or remove a view from the DOM temporarily.
</p>
<h2 id="Utility">Utility Functions</h2>
<p id="Utility-noConflict">
<b class="header">noConflict</b><code>var backbone = Backbone.noConflict();</code>
<br />
Returns the <tt>Backbone</tt> object back to its original value. You can
use the return value of <tt>Backbone.noConflict()</tt> to keep a local
reference to Backbone. Useful for embedding Backbone on third-party
websites, where you don't want to clobber the existing Backbone.
</p>
<pre>
var localBackbone = Backbone.noConflict();
var model = localBackbone.Model.extend(...);
</pre>
<p id="Utility-setDomLibrary">
<b class="header">setDomLibrary</b><code>Backbone.setDomLibrary(jQueryNew);</code>
<br />
If you have multiple copies of <tt>jQuery</tt> on the page, or simply want
to tell Backbone to use a particular object as its DOM / Ajax library,
this is the function for you.
</p>
<h2 id="examples">Examples</h2>
<p>
The list of examples that follows, while long, is not exhaustive. If you've
worked on an app that uses Backbone, please add it to the
<a href="https://github.com/documentcloud/backbone/wiki/Projects-and-Companies-using-Backbone">wiki page of Backbone apps</a>.
</p>
<p id="examples-todos">
<a href="http://jgn.me/">Jérôme Gravel-Niquet</a> has contributed a
<a href="examples/todos/index.html">Todo List application</a>
that is bundled in the repository as Backbone example. If you're wondering
where to get started with Backbone in general, take a moment to
<a href="docs/todos.html">read through the annotated source</a>. The app uses a
<a href="docs/backbone-localstorage.html">LocalStorage adapter</a>
to transparently save all of your todos within your browser, instead of
sending them to a server. Jérôme also has a version hosted at
<a href="http://localtodos.com/">localtodos.com</a> that uses a
<a href="http://github.com/jeromegn/backbone-mootools">MooTools-backed version of Backbone</a>
instead of jQuery.
</p>
<div style="text-align: center;">
<a href="examples/todos/index.html">
<img src="docs/images/todos.png" alt="Todos" class="example_image" />
</a>
</div>
<h2 id="examples-documentcloud">DocumentCloud</h2>
<p>
The <a href="http://www.documentcloud.org/public/#search/">DocumentCloud workspace</a>
is built on Backbone.js, with <i>Documents</i>, <i>Projects</i>,
<i>Notes</i>, and <i>Accounts</i> all as Backbone models and collections.
If you're interested in history &mdash; both Underscore.js and Backbone.js
were originally extracted from the DocumentCloud codebase, and packaged
into standalone JS libraries.
</p>
<div style="text-align: center;">
<a href="http://www.documentcloud.org/public/#search/">
<img src="docs/images/dc-workspace.png" alt="DocumentCloud Workspace" class="example_image" />
</a>
</div>
<h2 id="examples-linkedin">LinkedIn Mobile</h2>
<p>
<a href="http://www.linkedin.com/">LinkedIn</a> used Backbone.js to create
its <a href="http://www.linkedin.com/static?key=mobile">next-generation HTML5 mobile web app</a>.
Backbone made it easy to keep the app modular, organized and extensible so
that it was possible to program the complexities of LinkedIn's user experience.
The app also uses <a href="http://zeptojs.com/">Zepto</a>,
<a href="http://documentcloud.github.com/underscore/">Underscore.js</a>,
<a href="http://sass-lang.com/">SASS</a>, <a href="http://cubiq.org/iscroll">iScroll</a>,
HTML5 LocalStorage and Canvas.
</p>
<div style="text-align: center;">
<a href="http://www.linkedin.com/static?key=mobile">
<img src="docs/images/linkedin-mobile.png" alt="LinkedIn Mobile" class="example_image" />
</a>
</div>
<h2 id="examples-flow">Flow</h2>
<p>
<a href="http://www.metalabdesign.com/">MetaLab</a> used Backbone.js to create
<a href="http://www.getflow.com/">Flow</a>, a task management app for teams. The
workspace relies on Backbone.js to construct task views, activities, accounts,
folders, projects, and tags. You can see the internals under <tt>window.Flow</tt>.
</p>
<div style="text-align: center;">
<a href="http://www.getflow.com/">
<img src="docs/images/flow.png" alt="Flow" class="example_image" />
</a>
</div>
<h2 id="examples-audiovroom">AudioVroom</h2>
<p>
<a href="http://www.audiovroom.com/">AudioVroom</a> is a free music
streaming app that allows you to listen to your Facebook friends like
radio stations. It relies heavily on Backbone (views and song management)
and also features a responsive grid-based design (using CSS3 media-queries)
to deliver a unified user experience on desktops, mobiles, and tablets alike.
Being a pure Backbone app, AudioVroom is only 60kb compressed, and can be
entirely hosted on the CDN.
</p>
<div style="text-align: center;">
<a href="http://www.audiovroom.com/">
<img src="docs/images/audiovroom.png" alt="AudioVroom" class="example_image" />
</a>
</div>
<h2 id="examples-foursquare">Foursquare</h2>
<p>
Foursquare is a fun little startup that helps you meet up with friends,
discover new places, and save money. Backbone Models are heavily used in
the core JavaScript API layer and Views power many popular features like
the <a href="https://foursquare.com">homepage map</a> and
<a href="https://foursquare.com/seriouseats/list/the-best-doughnuts-in-ny">lists</a>.
</p>
<div style="text-align: center;">
<a href="http://foursquare.com">
<img src="docs/images/foursquare.png" alt="Foursquare" class="example_image" />
</a>
</div>
<h2 id="examples-wunderkit">Wunderkit</h2>
<p>
<a href="http://get.wunderkit.com/">Wunderkit</a> is a productivity and
social collaboration platform. It
uses Backbone.js as the foundation for the single-page application,
which is backed by a RESTful Rails API.
The freedom and agility that Backbone gives to developers
made it possible to build Wunderkit in a very short time and
extend it with custom features: a write-through cache using HTML5
localStorage, and a view hierarchy extension to easily manage trees of
sub-views. Aside from Backbone, Wunderkit also
depends on <a href="http://jquery.com/">jQuery</a>, <a href="http://underscorejs.org/">Underscore</a>, <a href="http://requirejs.org/">Require.js</a>, <a href="http://lesscss.org/">LESS</a> and doT.js templates.
</p>
<div style="text-align: center;">
<a href="http://get.wunderkit.com/">
<img src="docs/images/wunderkit.png" alt="Wunderkit" class="example_image" />
</a>
</div>
<h2 id="examples-khan-academy">Khan Academy</h2>
<p>
<a href="http://www.khanacademy.org">Khan Academy</a> is on a mission to
provide a free world-class education to anyone anywhere. With thousands of
videos, hundreds of JavaScript-driven exercises, and big plans for the
future, Khan Academy uses Backbone to keep frontend code modular and organized.
<a href="https://khanacademy.kilnhg.com/Code/Website/Group/stable/Files/javascript/profile-package?rev=tip">User profiles</a>
and <a href="https://khanacademy.kilnhg.com/Code/Website/Group/stable/File/javascript/shared-package/goals.js?rev=tip">goal setting</a>
are implemented with Backbone, <a href="http://jquery.com/">jQuery</a> and <a href="http://handlebarsjs.com/">Handlebars</a>, and most new feature
work is being pushed to the client side, greatly increasing the quality of
<a href="https://github.com/Khan/khan-api/">the API</a>.
</p>
<div style="text-align: center;">
<a href="http://www.khanacademy.org">
<img src="docs/images/khan-academy.png" alt="Khan Academy" class="example_image" />
</a>
</div>
<h2 id="examples-do">Do</h2>
<p>
<a href="http://do.com">Do</a> is a social productivity app that makes it
easy to work on tasks, track projects, and take notes with your team.
The <a href="http://do.com">Do.com</a> web application was built from the
ground up to work seamlessly on your smartphone, tablet and computer. The
team used Backbone, <a href="http://coffeescript.org/">CoffeeScript</a> and <a href="http://handlebarsjs.com/">Handlebars</a> to build a full-featured
app in record time and rolled their own extensions for complex navigation
and model sync support.
</p>
<div style="text-align: center;">
<a href="http://do.com">
<img src="docs/images/do.png" alt="Do" class="example_image" />
</a>
</div>
<h2 id="examples-posterous">Posterous</h2>
<p>
<a href="https://posterous.com/">Posterous Spaces</a> is
<a href="http://technology.posterous.com/posterous-spaces-is-built-on-backbonejs">built on Backbone</a>.
The models and collections mirror the public
<a href="http://posterous.com/api">Posterous API</a>. Backbone made it easy
for the team to create a JavaScript-heavy application with complex
interactions and state maintenance. Spaces also uses <a href="http://coffeescript.org/">CoffeeScript</a>,
<a href="http://underscorejs.org/">Underscore.js</a>, <a href="https://github.com/creationix/haml-js">Haml.js</a>, <a href="http://sass-lang.com/">Sass</a>, <a href="http://compass-style.org/">Compass</a>, and of course <a href="http://jquery.com">jQuery</a>.
</p>
<div style="text-align: center;">
<a href="https://posterous.com/">
<img src="docs/images/posterous-spaces.png" alt="Posterous Spaces" class="example_image" />
</a>
</div>
<h2 id="examples-groupon">Groupon Now!</h2>
<p>
<a href="http://www.groupon.com/now">Groupon Now!</a> helps you find
local deals that you can buy and use right now. When first developing
the product, the team decided it would be AJAX heavy with smooth transitions
between sections instead of full refreshes, but still needed to be fully
linkable and shareable. Despite never having used Backbone before, the
learning curve was incredibly quick &mdash; a prototype was hacked out in an
afternoon, and the team was able to ship the product in two weeks.
Because the source is minimal and understandable, it was easy to
add several Backbone extensions for Groupon Now!: changing the router
to handle URLs with querystring parameters, and adding a simple
in-memory store for caching repeated requests for the same data.
</p>
<div style="text-align: center;">
<a href="http://www.groupon.com/now">
<img src="docs/images/groupon.png" alt="Groupon Now!" class="example_image" />
</a>
</div>
<h2 id="examples-basecamp">Basecamp Mobile</h2>
<p>
<a href="http://37signals.com/">37Signals</a> used Backbone.js to create
<a href="http://basecamphq.com/mobile">Basecamp Mobile</a>, the mobile version
of their popular project management software. You can access all your Basecamp
projects, post new messages, and comment on milestones (all represented
internally as Backbone.js models).
</p>
<div style="text-align: center;">
<a href="http://basecamphq.com/mobile">
<img src="docs/images/basecamp-mobile.png" alt="Basecamp Mobile" class="example_image" />
</a>
</div>
<h2 id="examples-slavery-footprint">Slavery Footprint</h2>
<p>
<a href="http://slaveryfootprint.org/survey">Slavery Footprint</a>
allows consumers to visualize how their consumption habits are
connected to modern-day slavery and provides them with an opportunity
to have a deeper conversation with the companies that manufacture the
goods they purchased.
Based in Oakland, California, the Slavery Footprint team works to engage
individuals, groups, and businesses to build awareness for and create
deployable action against forced labor, human trafficking, and modern-day
slavery through online tools, as well as off-line community education and
mobilization programs.
</p>
<div style="text-align: center;">
<a href="http://slaveryfootprint.org/survey">
<img src="docs/images/slavery-footprint.png" alt="Slavery Footprint" class="example_image" />
</a>
</div>
<h2 id="examples-stripe">Stripe</h2>
<p>
<a href="https://stripe.com">Stripe</a> provides an API for accepting
credit cards on the web. Stripe's
<a href="https://manage.stripe.com">management interface</a> was recently
rewritten from scratch in Coffeescript using Backbone.js as the primary
framework, <a href="https://github.com/sstephenson/eco">Eco</a> for templates, <a href="http://sass-lang.com/">Sass</a> for stylesheets, and <a href="https://github.com/sstephenson/stitch">Stitch</a> to package
everything together as <a href="http://commonjs.org/">CommonJS</a> modulas. The new app uses
<a href="https://stripe.com/docs/api">Stripe's API</a> directly for the
majority of its actions; Backbone.js models made it simple to map
client-side models to their corresponding RESTful resources.
</p>
<div style="text-align: center;">
<a href="https://stripe.com">
<img src="docs/images/stripe.png" alt="Stripe" class="example_image" />
</a>
</div>
<h2 id="examples-airbnb">Airbnb Mobile</h2>
<p>
<a href="http://airbnb.com">Airbnb</a> used Backbone.js and
<a href="http://coffeescript.org">CoffeeScript</a> to quickly build
<a href="http://m.airbnb.com">Airbnb Mobile</a>
in six weeks with a team of three. The mobile version of Airbnb lets you
discover and book rental spaces directly from your phone: from a private
apartment to a private island...
</p>
<div style="text-align: center;">
<a href="http://m.airbnb.com/">
<img src="docs/images/airbnb-mobile.png" alt="Airbnb-Mobile" class="example_image" />
</a>
</div>
<h2 id="examples-diaspora">Diaspora</h2>
<p>
<a href="http://www.joindiaspora.com/">Diaspora</a> is a distributed social
network, formed from a number of independently operated <i>pods</i>.
You own your personal data, and control with whom you share.
All of Diaspora is <a href="https://github.com/diaspora/diaspora">open-source</a>
code, built with <a href="http://rubyonrails.org/">Rails</a> and Backbone.js.
</p>
<div style="text-align: center;">
<a href="http://www.joindiaspora.com/">
<img src="docs/images/diaspora.png" alt="Diaspora" class="example_image" />
</a>
</div>
<h2 id="examples-soundcloud">SoundCloud Mobile</h2>
<p>
<a href="http://soundcloud.com">SoundCloud</a> is the leading sound sharing
platform on the internet, and Backbone.js provides the foundation for
<a href="http://m.soundcloud.com">SoundCloud Mobile</a>. The project uses
the public SoundCloud <a href="http://soundcloud.com/developers">API</a>
as a data source (channeled through a nginx proxy),
<a href="http://api.jquery.com/category/plugins/templates/">jQuery templates</a>
for the rendering, <a href="http://docs.jquery.com/Qunit">Qunit
</a> and <a href="http://www.phantomjs.org/">PhantomJS</a> for
the testing suite. The JS code, templates and CSS are built for the
production deployment with various Node.js tools like
<a href="https://github.com/dsimard/ready.js">ready.js</a>,
<a href="https://github.com/mde/jake">Jake</a>,
<a href="https://github.com/tmpvar/jsdom">jsdom</a>.
The <b>Backbone.History</b> was modified to support the HTML5 <tt>history.pushState</tt>.
<b>Backbone.sync</b> was extended with an additional SessionStorage based cache
layer.
</p>
<div style="text-align: center;">
<a href="http://m.soundcloud.com">
<img src="docs/images/soundcloud.png" alt="SoundCloud" class="example_image" />
</a>
</div>
<h2 id="examples-pandora">Pandora</h2>
<p>
When <a href="http://www.pandora.com/newpandora">Pandora</a> redesigned
their site in HTML5, they chose Backbone.js to help
manage the user interface and interactions. For example, there's a model
that represents the "currently playing track", and multiple views that
automatically update when the current track changes. The station list is a
collection, so that when stations are added or changed, the UI stays up to date.
</p>
<div style="text-align: center;">
<a href="http://www.pandora.com/newpandora">
<img src="docs/images/pandora.png" alt="Pandora" class="example_image" />
</a>
</div>
<h2 id="examples-code-school">Code School</h2>
<p>
<a href="http://www.codeschool.com">Code School</a> courses teach people
about various programming topics like <a href="http://coffeescript.org">CoffeeScript</a>, CSS, Ruby on Rails,
and more. The new Code School course
<a href="http://coffeescript.codeschool.com/levels/1/challenges/1">challenge page</a>
is built from the ground up on Backbone.js, using
everything it has to offer: the router, collections, models, and complex
event handling. Before, the page was a mess of <a href="http://jquery.com/">jQuery</a> DOM manipulation
and manual Ajax calls. Backbone.js helped introduce a new way to
think about developing an organized front-end application in Javascript.
</p>
<div style="text-align: center;">
<a href="http://www.codeschool.com">
<img src="docs/images/code-school.png" alt="Code School" class="example_image" />
</a>
</div>
<h2 id="examples-cloudapp">CloudApp</h2>
<p>
<a href="http://getcloudapp.com">CloudApp</a> is simple file and link
sharing for the Mac. Backbone.js powers the web tools
which consume the <a href="http://developer.getcloudapp.com">documented API</a>
to manage Drops. Data is either pulled manually or pushed by
<a href="http://pusher.com">Pusher</a> and fed to
<a href="http://github.com/janl/mustache.js">Mustache</a> templates for
rendering. Check out the <a href="http://cloudapp.github.com/engine">annotated source code</a>
to see the magic.
</p>
<div style="text-align: center;">
<a href="http://getcloudapp.com">
<img src="docs/images/cloudapp.png" alt="CloudApp" class="example_image" />
</a>
</div>
<h2 id="examples-seatgeek">SeatGeek</h2>
<p>
<a href="http://seatgeek.com">SeatGeek</a>'s stadium ticket maps were originally
developed with <a href="http://prototypejs.org/">Prototype.js</a>. Moving to Backbone.js and <a href="http://jquery.com/">jQuery</a> helped organize
a lot of the UI code, and the increased structure has made adding features
a lot easier. SeatGeek is also in the process of building a mobile
interface that will be Backbone.js from top to bottom.
</p>
<div style="text-align: center;">
<a href="http://seatgeek.com">
<img src="docs/images/seatgeek.png" alt="SeatGeek" class="example_image" />
</a>
</div>
<h2 id="examples-grove">Grove.io</h2>
<p>
<a href="http://grove.io">Grove.io</a> provides hosted IRC for teams.
Backbone.js powers Grove's web client together with <a href="http://handlebarsjs.com/">Handlebars.js templating</a>.
Updates to chat stream are pulled in realtime using long-polling.
</p>
<div style="text-align: center;">
<a href="http://grove.io">
<img src="docs/images/grove.png" alt="Grove.io" class="example_image" />
</a>
</div>
<h2 id="examples-kicksend">Kicksend</h2>
<p>
<a href="http://kicksend.com">Kicksend</a> is a real-time file sharing
platform that helps everyday people send and receive files of any size
with their friends and family. Kicksend's web application makes extensive
use of Backbone.js to model files, friends, lists and activity streams.
</p>
<div style="text-align: center;">
<a href="http://kicksend.com">
<img src="docs/images/kicksend.png" alt="Kicksend" class="example_image" />
</a>
</div>
<h2 id="examples-shortmail">Shortmail</h2>
<p>
<a href="http://410labs.com/">410 Labs</a> uses Backbone.js at
<a href="http://shortmail.com/">Shortmail.com</a> to build a
fast and responsive inbox, driven by the <a href="#Router">Router</a>.
Backbone works with a <a href="http://rubyonrails.org/">Rails</a> backend to provide inbox rendering, archiving,
replying, composing, and even a changes feed. Using Backbone's event-driven
model and pushing the rendering and interaction logic to the front-end
has not only simplified the view code, it has also drastically reduced the
load on Shortmail's servers.
</p>
<div style="text-align: center;">
<a href="http://shortmail.com">
<img src="docs/images/shortmail.png" alt="Shortmail" class="example_image" />
</a>
</div>
<h2 id="examples-battlefield">Battlefield Play4Free</h2>
<p>
<a href="http://battlefield.play4free.com/">Battlefield Play4Free</a> is
the latest free-to-play first person shooter from the same team that
created Battlefield Heroes. The in-game HTML5 front-end for makes heavy use of
Backbone's views, models and collections to help keep the code modular
and structured.
</p>
<div style="text-align: center;">
<a href="http://battlefield.play4free.com/">
<img src="docs/images/battlefield.png" alt="Battlefield Play4Free" class="example_image" />
</a>
</div>
<h2 id="examples-salon">Salon.io</h2>
<p>
<a href="http://salon.io">Salon.io</a> provides a space where photographers,
artists and designers freely arrange their visual art on virtual walls.
<a href="http://salon.io">Salon.io</a> runs on <a href="http://rubyonrails.org/">Rails</a>, but does not use
much of the traditional stack, as the entire frontend is designed as a
single page web app, using Backbone.js and
<a href="http://coffeescript.org">CoffeeScript</a>.
</p>
<div style="text-align: center;">
<a href="http://salon.io">
<img src="docs/images/salon.png" alt="Salon.io" class="example_image" />
</a>
</div>
<h2 id="examples-tilemill">TileMill</h2>
<p>
Our fellow
<a href="http://www.newschallenge.org/">Knight Foundation News Challenge</a>
winners, <a href="http://mapbox.com/">MapBox</a>, created an open-source
map design studio with Backbone.js:
<a href="http://mapbox.github.com/tilemill/">TileMill</a>.
TileMill lets you manage map layers based on shapefiles and rasters, and
edit their appearance directly in the browser with the
<a href="https://github.com/mapbox/carto">Carto styling language</a>.
Note that the gorgeous <a href="http://mapbox.com/">MapBox</a> homepage
is also a Backbone.js app.
</p>
<div style="text-align: center;">
<a href="http://mapbox.github.com/tilemill/">
<img src="docs/images/tilemill.png" alt="TileMill" class="example_image" />
</a>
</div>
<h2 id="examples-blossom">Blossom</h2>
<p>
<a href="http://blossom.io">Blossom</a> is a lightweight project management
tool for lean teams. Backbone.js is heavily used in combination with
<a href="http://coffeescript.org">CoffeeScript</a> to provide a smooth
interaction experience. The RESTful backend is built
with <a href="http://flask.pocoo.org/">Flask</a> on Google App Engine.
</p>
<div style="text-align: center;">
<a href="http://blossom.io">
<img src="docs/images/blossom.png" alt="Blossom" class="example_image" />
</a>
</div>
<h2 id="examples-animoto">Animoto</h2>
<p>
<a href="http://animoto.com">Animoto</a> is a web-based video creation
platform, where users can upload their own photos, video clips and music
and create beautifully orchestrated slideshows. The video editor app is
built with Backbone.js and <a href="http://jquery.com">jQuery</a> and interfaces with a <a href="http://rubyonrails.org/">Ruby on Rails</a>
backend. Backbone has provided structure which helps the Animoto team
iterate quickly on the codebase while reducing the risk of regressions.
</p>
<div style="text-align: center;">
<a href="http://www.animoto.com/">
<img src="docs/images/animoto.png" alt="Tzigla" class="Animoto Video Editor" />
</a>
</div>
<h2 id="examples-chaincal">ChainCal</h2>
<p>
<a href="http://chaincalapp.com/">ChainCal</a>
is an iPhone app that helps you to track your daily goals in a
minimalist, visual way. The app is written almost entirely in <a href="http://coffeescript.org/">CoffeeScript</a>,
Backbone handles the models, collections and views, and persistence is
done with a Backbone.sync localStorage adapter. Templates are written in
<a href="https://github.com/sstephenson/eco">Eco</a> and the app is packaged with <a href="http://brunch.io/">Brunch</a> and deployed with <a href="http://phonegap.com/">Phonegap</a>.
</p>
<div style="text-align: center;">
<a href="http://chaincalapp.com/">
<img src="docs/images/chaincal.png" alt="ChainCal" class="example_image" />
</a>
</div>
<h2 id="examples-attictv">AtticTV</h2>
<p>
<a href="http://attictv.com/">AtticTV</a> is MTV for the Youtube Generation:
kick back and relax while watching the best
music videos of your favorite genre. The videos are synced across the
world, so, you're never watching alone on AtticTV. AtticTV is served by
<a href="http://nodejs.org/">NodeJS</a> written in <a href="http://coffeescript.org/">CoffeeScript</a> with <a href="http://socket.io/">Socket.IO</a> as data transport. The
frontend is built with Backbone.js with pushstate support, <a href="http://jquery.com/">jQuery</a>, and
<a href="http://jade-lang.com/">Jade templates</a>.
</p>
<div style="text-align: center;">
<a href="http://attictv.com/">
<img src="docs/images/attictv.png" alt="AtticTV" class="example_image" />
</a>
</div>
<h2 id="examples-decide">Decide</h2>
<p>
<a href="http://decide.com">Decide.com</a> helps people decide when to buy
consumer electronics. It relies heavily on Backbone.js to render and
update its Search Results Page. An "infinite scroll" feature takes
advantage of a SearchResults model containing a collection of
Product models to fetch more results and render them on the fly
with <a href="http://mustache.github.com">Mustache</a>. A SearchController keeps everything in sync and
maintains page state in the URL. Backbone also powers the user
accounts and settings management.
</p>
<div style="text-align: center;">
<a href="http://decide.com">
<img src="docs/images/decide.png" alt="Decide" class="example_image" />
</a>
</div>
<h2 id="examples-editd">EDITD</h2>
<p>
<a href="http://editd.com">EDITD</a> aims to disrupt the fashion
industry with big data. The next generation of their web application
is based on a custom JavaScript framework that builds on top of
Backbone. The back end is
<a href="https://www.djangoproject.com/">Django</a> +
<a href="http://www.elasticsearch.org/">Elastic Search</a>,
<a href="http://handlebarsjs.com/">Handlebars.js</a> is used for templating,
<a href="http://code.google.com/p/js-test-driver/">jsTestDriver</a> for testing, and
<a href="http://jashkenas.github.com/docco/">Docco</a> for quick documentation.
</p>
<div style="text-align: center;">
<a href="http://editd.com">
<img src="docs/images/editd.png" alt="EDITD" class="example_image" />
</a>
</div>
<h2 id="examples-trello">Trello</h2>
<p>
<a href="http://trello.com">Trello</a> is a collaboration tool that
organizes your projects into boards. A Trello board holds many lists of
cards, which can contain checklists, files and conversations, and may be
voted on and organized with labels. Updates on the board happen in
real time. The site was built ground up using Backbone.js for all the
models, views, and routes.
</p>
<div style="text-align: center;">
<a href="http://trello.com">
<img src="docs/images/trello.png" alt="Trello" class="example_image" />
</a>
</div>
<h2 id="examples-ducksboard">Ducksboard</h2>
<p>
<a href="http://ducksboard.com/">Ducksboard</a> is an online dashboard
for your SaaS and business metrics, built with
<a href="http://twistedmatrix.com/">Twisted</a> and
<a href="http://www.djangoproject.com/">Django</a> and using WebSockets.
It can fetch data from popular providers or accept input through
a simple API.
Backbone is used throughout Ducksboard's interface, every widget,
dashboard and SaaS account is a Backbone model with several views
(data display, configuration view). A
<a href="https://public.ducksboard.com/BFVzKVPeOoWRsL0VZ8MZ/">live demo</a>
is available.
</p>
<div style="text-align: center;">
<a href="http://ducksboard.com/">
<img src="docs/images/ducksboard.png" alt="Ducksboard" class="example_image" />
</a>
</div>
<h2 id="examples-quietwrite">QuietWrite</h2>
<p>
<a href="http://www.twitter.com/jamesjyu">James Yu</a> used Backbone.js to
create <a href="http://www.quietwrite.com/">QuietWrite</a>, an app
that gives writers a clean and quiet interface to concentrate on the text itself.
The editor relies on Backbone to persist document data to the server. He
followed up with a Backbone.js + <a href="http://rubyonrails.org/">Rails</a> tutorial that describes how to implement
<a href="http://www.jamesyu.org/2011/01/27/cloudedit-a-backbone-js-tutorial-by-example/">CloudEdit, a simple document editing app</a>.
</p>
<div style="text-align: center;">
<a href="http://www.quietwrite.com/">
<img src="docs/images/quietwrite.png" alt="QuietWrite" class="example_image" />
</a>
</div>
<h2 id="examples-tzigla">Tzigla</h2>
<p>
<a href="http://twitter.com/evilchelu">Cristi Balan</a> and
<a href="http://dira.ro">Irina Dumitrascu</a> created
<a href="http://tzigla.com">Tzigla</a>, a collaborative drawing
application where artists make tiles that connect to each other to
create <a href="http://tzigla.com/boards/1">surreal drawings</a>.
Backbone models help organize the code, routers provide
<a href="http://tzigla.com/boards/1#!/tiles/2-2">bookmarkable deep links</a>,
and the views are rendered with
<a href="https://github.com/creationix/haml-js">haml.js</a> and
<a href="http://zeptojs.com/">Zepto</a>.
Tzigla is written in Ruby (<a href="http://rubyonrails.org/">Rails</a>) on the backend, and
<a href="http://coffeescript.org">CoffeeScript</a> on the frontend, with
<a href="http://documentcloud.github.com/jammit/">Jammit</a>
prepackaging the static assets.
</p>
<div style="text-align: center;">
<a href="http://www.tzigla.com/">
<img src="docs/images/tzigla.png" alt="Tzigla" class="example_image" />
</a>
</div>
<h2 id="faq">F.A.Q.</h2>
<p id="FAQ-events">
<b class="header">Catalog of Events</b>
<br />
Here's a list of all of the built-in events that Backbone.js can fire.
You're also free to trigger your own events on Models and Views as you
see fit.
</p>
<ul class="small">
<li><b>"add"</b> (model, collection) &mdash; when a model is added to a collection. </li>
<li><b>"remove"</b> (model, collection) &mdash; when a model is removed from a collection. </li>
<li><b>"reset"</b> (collection) &mdash; when the collection's entire contents have been replaced. </li>
<li><b>"change"</b> (model, options) &mdash; when a model's attributes have changed. </li>
<li><b>"change:[attribute]"</b> (model, value, options) &mdash; when a specific attribute has been updated. </li>
<li><b>"destroy"</b> (model, collection) &mdash; when a model is <a href="#Model-destroy">destroyed</a>. </li>
<li><b>"sync"</b> (model, collection) &mdash; triggers whenever a model has been successfully synced to the server. </li>
<li><b>"error"</b> (model, collection) &mdash; when a model's validation fails, or a <a href="#Model-save">save</a> call fails on the server. </li>
<li><b>"route:[name]"</b> (router) &mdash; when one of a router's routes has matched. </li>
<li><b>"all"</b> &mdash; this special event fires for <i>any</i> triggered event, passing the event name as the first argument. </li>
</ul>
<p id="FAQ-tim-toady">
<b class="header">There's More Than One Way To Do It</b>
<br />
It's common for folks just getting started to treat the examples listed
on this page as some sort of gospel truth. In fact, Backbone.js is intended
to be fairly agnostic about many common patterns in client-side code.
For example...
</p>
<p>
<b>References between Models and Views</b> can be handled several ways.
Some people like to have direct pointers, where views correspond 1:1 with
models (<tt>model.view</tt> and <tt>view.model</tt>). Others prefer to have intermediate
"controller" objects that orchestrate the creation and organization of
views into a hierarchy. Others still prefer the evented approach, and always
fire events instead of calling methods directly. All of these styles work well.
</p>
<p>
<b>Batch operations</b> on Models are common, but often best handled differently
depending on your server-side setup. Some folks don't mind making individual
Ajax requests. Others create explicit resources for RESTful batch operations:
<tt>/notes/batch/destroy?ids=1,2,3,4</tt>. Others tunnel REST over JSON, with the
creation of "changeset" requests:
</p>
<pre>
{
"create": [array of models to create]
"update": [array of models to update]
"destroy": [array of model ids to destroy]
}
</pre>
<p>
<b>Feel free to define your own events.</b> <a href="#Events">Backbone.Events</a>
is designed so that you can mix it in to any JavaScript object or prototype.
Since you can use any string as an event, it's often handy to bind
and trigger your own custom events: <tt>model.on("selected:true")</tt> or
<tt>model.on("editing")</tt>
</p>
<p>
<b>Render the UI</b> as you see fit. Backbone is agnostic as to whether you
use <a href="http://documentcloud.github.com/underscore/#template">Underscore templates</a>,
<a href="https://github.com/janl/mustache.js">Mustache.js</a>, direct DOM
manipulation, server-side rendered snippets of HTML, or
<a href="http://jqueryui.com/">jQuery UI</a> in your <tt>render</tt> function.
Sometimes you'll create a view for each model ... sometimes you'll have a
view that renders thousands of models at once, in a tight loop. Both can be
appropriate in the same app, depending on the quantity of data involved,
and the complexity of the UI.
</p>
<p id="FAQ-nested">
<b class="header">Nested Models &amp; Collections</b>
<br />
It's common to nest collections inside of models with Backbone. For example,
consider a <tt>Mailbox</tt> model that contains many <tt>Message</tt> models.
One nice pattern for handling this is have a <tt>this.messages</tt> collection
for each mailbox, enabling the lazy-loading of messages, when the mailbox
is first opened ... perhaps with <tt>MessageList</tt> views listening for
<tt>"add"</tt> and <tt>"remove"</tt> events.
</p>
<pre>
var Mailbox = Backbone.Model.extend({
initialize: function() {
this.messages = new Messages;
this.messages.url = '/mailbox/' + this.id + '/messages';
this.messages.on("reset", this.updateCounts);
},
...
});
var Inbox = new Mailbox;
// And then, when the Inbox is opened:
Inbox.messages.fetch();
</pre>
<p>
If you're looking for something more opinionated, there are a number of
Backbone plugins that add sophisticated associations among models,
<a href="https://github.com/documentcloud/backbone/wiki/Extensions%2C-Plugins%2C-Resources">available on the wiki</a>.
</p>
<p>
Backbone doesn't include direct support for nested models and collections
or "has many" associations because there are a number
of good patterns for modeling structured data on the client side, and
<i>Backbone should provide the foundation for implementing any of them.</i>
You may want to&hellip;
</p>
<ul>
<li>
Mirror an SQL database's structure, or the structure of a NoSQL database.
</li>
<li>
Use models with arrays of "foreign key" ids, and join to top level
collections (a-la tables).
</li>
<li>
For associations that are numerous, use a range of ids instead of an
explicit list.
</li>
<li>
Avoid ids, and use direct references, creating a partial object graph
representing your data set.
</li>
<li>
Lazily load joined models from the server, or lazily deserialize nested
models from JSON documents.
</li>
</ul>
<p id="FAQ-bootstrap">
<b class="header">Loading Bootstrapped Models</b>
<br />
When your app first loads, it's common to have a set of initial models that
you know you're going to need, in order to render the page. Instead of
firing an extra AJAX request to <a href="#Collection-fetch">fetch</a> them,
a nicer pattern is to have their data already bootstrapped into the page.
You can then use <a href="#Collection-reset">reset</a> to populate your
collections with the initial data. At DocumentCloud, in the
<a href="http://en.wikipedia.org/wiki/ERuby">ERB</a> template for the
workspace, we do something along these lines:
</p>
<pre>
&lt;script&gt;
var Accounts = new Backbone.Collection;
Accounts.reset(&lt;%= @accounts.to_json %&gt;);
var Projects = new Backbone.Collection;
Projects.reset(&lt;%= @projects.to_json(:collaborators => true) %&gt;);
&lt;/script&gt;
</pre>
<p>You have to <a href="http://mathiasbynens.be/notes/etago">escape</a>
<tt>&lt;/</tt> within the JSON string, to prevent javascript injection
attacks.
<p id="FAQ-extending">
<b class="header">Extending Backbone</b>
<br />
Many JavaScript libraries are meant to be insular and self-enclosed,
where you interact with them by calling their public API, but never peek
inside at the guts. Backbone.js is <i>not</i> that kind of library.
</p>
<p>
Because it serves as a foundation for your application, you're meant to
extend and enhance it in the ways you see fit &mdash; the entire source
code is <a href="docs/backbone.html">annotated</a> to make this easier
for you. You'll find that there's very little there apart from core
functions, and most of those can be overriden or augmented should you find
the need. If you catch yourself adding methods to <tt>Backbone.Model.prototype</tt>,
or creating your own base subclass, don't worry &mdash; that's how things are
supposed to work.
</p>
<p id="FAQ-mvc">
<b class="header">How does Backbone relate to "traditional" MVC?</b>
<br />
Different implementations of the
<a href="http://en.wikipedia.org/wiki/Model–View–Controller">Model-View-Controller</a>
pattern tend to disagree about the definition of a controller. If it helps any, in
Backbone, the <a href="#View">View</a> class can also be thought of as a
kind of controller, dispatching events that originate from the UI, with
the HTML template serving as the true view. We call it a View because it
represents a logical chunk of UI, responsible for the contents of a single
DOM element.
</p>
<p>
Comparing the overall structure of Backbone to a server-side MVC framework
like <b>Rails</b>, the pieces line up like so:
</p>
<ul>
<li>
<b>Backbone.Model</b> &ndash; Like a Rails model minus the class
methods. Wraps a row of data in business logic.
</li>
<li>
<b>Backbone.Collection</b> &ndash; A group of models on the client-side,
with sorting/filtering/aggregation logic.
</li>
<li>
<b>Backbone.Router</b> &ndash; Rails <tt>routes.rb</tt> + Rails controller
actions. Maps URLs to functions.
</li>
<li>
<b>Backbone.View</b> &ndash; A logical, re-usable piece of UI. Often,
but not always, associated with a model.
</li>
<li>
<b>Client-side Templates</b> &ndash; Rails <tt>.html.erb</tt> views,
rendering a chunk of HTML.
</li>
</ul>
<p id="FAQ-this">
<b class="header">Binding "this"</b>
<br />
Perhaps the single most common JavaScript "gotcha" is the fact that when
you pass a function as a callback, its value for <tt>this</tt> is lost. With
Backbone, when dealing with <a href="#Events">events</a> and callbacks,
you'll often find it useful to rely on
<a href="http://documentcloud.github.com/underscore/#bind">_.bind</a> and
<a href="http://documentcloud.github.com/underscore/#bindAll">_.bindAll</a>
from Underscore.js.
</p>
<p>
When binding callbacks to Backbone events, you can choose to pass an optional
third argument to specify the <tt>this</tt> that will be used when the
callback is later invoked:
</p>
<pre>
var MessageList = Backbone.View.extend({
initialize: function() {
var messages = this.collection;
messages.on("reset", this.render, this);
messages.on("add", this.addMessage, this);
messages.on("remove", this.removeMessage, this);
}
});
// Later, in the app...
Inbox.messages.add(newMessage);
</pre>
<p id="FAQ-rails">
<b class="header">Working with Rails</b>
<br />
Backbone.js was originally extracted from
<a href="http://www.documentcloud.org">a Rails application</a>; getting
your client-side (Backbone) Models to sync correctly with your server-side
(Rails) Models is painless, but there are still a few things to be aware of.
</p>
<p>
By default, Rails adds an extra layer of wrapping around the JSON representation
of models. You can disable this wrapping by setting:
</p>
<pre>
ActiveRecord::Base.include_root_in_json = false
</pre>
<p>
... in your configuration. Otherwise, override
<a href="#Model-parse">parse</a> to pull model attributes out of the
wrapper. Similarly, Backbone PUTs and POSTs direct JSON representations
of models, where by default Rails expects namespaced attributes. You can
have your controllers filter attributes directly from <tt>params</tt>, or
you can override <a href="#Model-toJSON">toJSON</a> in Backbone to add
the extra wrapping Rails expects.
</p>
<h2 id="changelog">Change Log</h2>
<b class="header">0.9.2</b> &mdash; <small><i>March 21, 2012</i></small> &mdash; <a href="https://github.com/documentcloud/backbone/compare/0.9.1...0.9.2">Diff</a><br />
<ul style="margin-top: 5px;">
<li>
Instead of throwing an error when adding duplicate models to a collection,
Backbone will now silently skip them instead.
</li>
<li>
Added <a href="#Collection-push">push</a>,
<a href="#Collection-pop">pop</a>,
<a href="#Collection-unshift">unshift</a>, and
<a href="#Collection-shift">shift</a> to collections.
</li>
<li>
A model's <a href="#Model-changed">changed</a> hash is now exposed for
easy reading of the changed attribute delta, since the model's last
<tt>"change"</tt> event.
</li>
<li>
Added <a href="#Collection-where">where</a> to collections for simple
filtering.
</li>
<li>
You can now use a single <a href="#Events-off">off</a> call
to remove all callbacks bound to a specific object.
</li>
<li>
Bug fixes for nested individual change events, some of which may be
"silent".
</li>
<li>
Bug fixes for URL encoding in <tt>location.hash</tt> fragments.
</li>
<li>
Bug fix for client-side validation in advance of a <tt>save</tt> call
with