<!DOCTYPE HTML> <html> <head> <meta http-equiv="content-type" content="text/html;charset=UTF-8" /> <meta http-equiv="X-UA-Compatible" content="chrome=1"> <title>Backbone.js</title> <style> body { font-size: 14px; line-height: 22px; font-family: Helvetica Neue, Helvetica, Arial; background: #f4f4f4 url(docs/images/background.png); } .interface { font-family: "Lucida Grande", "Lucida Sans Unicode", Helvetica, Arial, sans-serif !important; } div#sidebar { background: #fff; position: fixed; top: 0; left: 0; bottom: 0; width: 200px; overflow-y: auto; overflow-x: hidden; padding: 15px 0 30px 30px; border-right: 1px solid #ddd; box-shadow: 0 0 20px #ccc; -webkit-box-shadow: 0 0 20px #ccc; -moz-box-shadow: 0 0 20px #ccc; } a.toc_title, a.toc_title:visited { display: block; color: black; font-weight: bold; margin-top: 15px; } a.toc_title:hover { text-decoration: underline; } #sidebar .version { font-size: 10px; font-weight: normal; } ul.toc_section { font-size: 11px; line-height: 14px; margin: 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margin: 15px 0 0; padding: 0; } tr, td { margin: 0; padding: 0; } td { padding: 0px 15px 5px 0; } code, pre, tt { font-family: Monaco, Consolas, "Lucida Console", monospace; font-size: 12px; line-height: 18px; font-style: normal; } tt { padding: 0px 3px; background: #fff; border: 1px solid #ddd; zoom: 1; } code { margin-left: 20px; } pre { font-size: 12px; padding: 2px 0 2px 15px; border: 4px solid #bbb; border-top: 0; border-bottom: 0; margin: 0px 0 30px; } img.example_image { margin: 0px auto; } </style> </head> <body> <div id="sidebar" class="interface"> <a class="toc_title" href="#"> Backbone.js <span class="version">(0.5.3)</span> </a> <a class="toc_title" href="#Introduction"> Introduction </a> <a class="toc_title" href="#Events"> Events </a> <ul class="toc_section"> <li>– <a href="#Events-bind">bind</a></li> <li>– <a href="#Events-unbind">unbind</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-cid">cid</a></li> <li>– <a href="#Model-attributes">attributes</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-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 (26)</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-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-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-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> </ul> <a class="toc_title" href="#Utility"> Utility </a> <ul class="toc_section"> <li>– <a href="#Utility-noConflict">noConflict</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-basecamp">Basecamp Mobile</a></li> <li>– <a href="#examples-groupon">Groupon Now!</a></li> <li>– <a href="#examples-trajectory">Trajectory</a></li> <li>– <a href="#examples-soundcloud">SoundCloud Mobile</a></li> <li>– <a href="#examples-pandora">Pandora</a></li> <li>– <a href="#examples-cloudapp">CloudApp</a></li> <li>– <a href="#examples-seatgeek">SeatGeek</a></li> <li>– <a href="#examples-tpm">Talking Points Memo</a></li> <li>– <a href="#examples-shortmail">Shortmail</a></li> <li>– <a href="#examples-hotel-tonight">Hotel Tonight</a></li> <li>– <a href="#examples-salon">Salon.io</a></li> <li>– <a href="#examples-quoteroller">Quote Roller</a></li> <li>– <a href="#examples-tilemill">TileMill</a></li> <li>– <a href="#examples-rround">rround.me</a></li> <li>- <a href="#examples-blossom">Blossom</a></li> <li>- <a href="#examples-instagreat">Insta-great!</a></li> <li>- <a href="#examples-decide">Decide</a></li> <li>- <a href="#examples-bittorrent">BitTorrent</a></li> <li>- <a href="#examples-trapit">Trapit</a></li> <li>- <a href="#examples-fluxiom">Fluxiom</a></li> <li>- <a href="#examples-chop">Chop</a></li> <li>- <a href="#examples-blackcomb">Blackcomb</a></li> <li>- <a href="#examples-test-kitchen">America’s Test Kitchen</a></li> <li>- <a href="#examples-quietwrite">QuietWrite</a></li> <li>- <a href="#examples-tzigla">Tzigla</a></li> <li>- <a href="#examples-substance">Substance</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 & Collections</a></li> <li>– <a href="#FAQ-bootstrap">Loading Bootstrapped Models</a></li> <li>– <a href="#FAQ-mvc">Traditional MVC</a></li> <li>– <a href="#FAQ-this">Binding "this"</a></li> </ul> <a class="toc_title" href="#changelog"> Change Log </a> </div> <div class="container"> <p> <img style="width: 385px; height: 126px;" src="docs/images/backbone.png" alt="Backbone.js" /> </p> <p> <a href="http://github.com/documentcloud/backbone/">Backbone</a> supplies structure to JavaScript-heavy 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 application 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> and a <a href="https://github.com/documentcloud/backbone/wiki/Tutorials%2C-blog-posts-and-example-sites">list of tutorials</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>, 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 & 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 href="backbone.js">Development Version (0.5.3)</a></td> <td><i>41kb, Full Source with Comments</i></td> </tr> <tr> <td><a href="backbone-min.js">Production Version (0.5.3)</a></td> <td><i>4.6kb, Packed and Gzipped</i></td> </tr> </table> <p> Backbone's only hard dependency is <a href="http://documentcloud.github.com/underscore/">Underscore.js</a>. 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="Upgrading">Upgrading to 0.5.0+</h2> <p> We've taken the opportunity to clarify some naming with the <b>0.5.0</b> release. <tt>Controller</tt> is now <a href="#Router">Router</a>, and <tt>refresh</tt> is now <a href="#Collection-reset">reset</a>. The previous <tt>saveLocation</tt> and <tt>setLocation</tt> functions have been replaced by <a href="#Router-navigate">navigate</a>. <tt>Backbone.sync</tt>'s method signature has changed to allow the passing of arbitrary options to <tt>jQuery.ajax</tt>. Be sure to <a href="#History-start">opt-in</a> to <tt>pushState</tt> support, if you want to use it. </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 data are notified of the event, causing them to re-render. 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 — when the model changes, the views simply update themselves. </p> <p> Many of the examples that follow are runnable. Click the <i>play</i> button to execute them. </p> <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.bind("alert", function(msg) { alert("Triggered " + msg); }); object.trigger("alert", "an event"); </pre> <p id="Events-bind"> <b class="header">bind</b><code>object.bind(event, callback, [context])</code> <br /> Bind a <b>callback</b> function to an object. The callback will be invoked whenever the <b>event</b> (specified by an arbitrary string identifier) 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> </p> <p> To supply a <b>context</b> value for <tt>this</tt> when the callback is invoked, pass the optional third argument: <tt>model.bind('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.bind("all", function(eventName) { object.trigger(eventName); }); </pre> <p id="Events-unbind"> <b class="header">unbind</b><code>object.unbind([event], [callback])</code> <br /> Remove a previously-bound <b>callback</b> function from an object. 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> object.unbind("change", onChange); // Removes just the onChange callback. object.unbind("change"); // Removes all "change" callbacks. object.unbind(); // Removes all callbacks on object. </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>. 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.bind('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 — 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 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>. </p> <pre> note.set({title: "October 12", content: "Lorem Ipsum Dolor Sit Amet..."}); </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>. 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. </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: "<script>alert('xss')</script>" }); 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-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-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 — 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. 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>. The <b>attributes</b> hash (as in <a href="#Model-set">set</a>) should contain the attributes you'd like to change -- keys that aren't mentioned won't be altered. 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> 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>. 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. </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 attributes that are about to be updated. If the model and attributes are valid, don't return anything from <b>validate</b>; if the attributes 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. <tt>set</tt> and <tt>save</tt> will not continue if <b>validate</b> returns an error. 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.bind("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-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</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> </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. 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.bind("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.bind("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 to 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.bind("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 (26)</b> <br /> Backbone proxies to <b>Underscore.js</b> to provide 26 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… </p> <ul> <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/#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/#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>. </p> <pre class="runnable"> var ships = new Backbone.Collection; ships.bind("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. </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-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 functions take a model and return a numeric or string value by which the model should be ordered relative to others. </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"> Brief aside: This comparator function is different than JavaScript's regular "sort", which must return <tt>0</tt>, <tt>1</tt>, or <tt>-1</tt>, and is more similar to a <tt>sortBy</tt> — a much nicer API. </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([ new Backbone.Model({name: "Curly"}), new Backbone.Model({name: "Larry"}), new Backbone.Model({name: "Moe"}) ]); var names = stooges.pluck("name"); alert(JSON.stringify(names)); </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. </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. 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 — 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> <script> Accounts.reset(<%= @accounts.to_json %>); </script> </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. 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> <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 imporant 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. You'll want to 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. </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.bind("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. </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" this.route(/^(.*?)\/open$/, "open", function(id){ ... }); } </pre> <p id="Router-navigate"> <b class="header">navigate</b><code>router.navigate(fragment, [triggerRoute])</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, pass <b>triggerRoute</b>. </p> <pre> openPage: function(pageNumber) { this.document.pages.at(pageNumber).open(); this.navigate("page/" + pageNumber); } # Or ... app.navigate("help/troubleshooting", 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 — 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> <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. 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 default <b>sync</b> handler maps CRUD to REST like so: </p> <ul> <li><b>create → POST </b><tt>/collection</tt></li> <li><b>read → GET </b><tt>/collection[/id]</tt></li> <li><b>update → PUT </b><tt>/collection/id</tt></li> <li><b>delete → DELETE </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>, and pass them under the <tt>_method</tt> parameter. Setting this option will also set an <tt>X-HTTP-Method-Override</tt> header with the true method. </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 — 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 — 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>, and <tt>tagName</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>, and <tt>id</tt> properties, if specified. If not, <b>el</b> is an empty <tt>div</tt>. </p> <p> You may assign <b>el</b> directly if the view is being created for an element that already exists in the DOM. Use either a reference to a real DOM element, or a css selector string. </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-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>$(selector, this.el)</tt> </p> <pre> ui.Chapter = Backbone.View.extend({ serialize : function() { return { title: this.$(".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", {className: "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>. 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 — 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> <h2 id="Utility">Utility Functions</h2> <p> </p> <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> <h2 id="examples">Examples</h2> <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 — 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-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-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 — 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-trajectory">Trajectory</h2> <p> <a href="https://www.apptrajectory.com/">Trajectory</a> is an agile software planning tool used to discuss wireframes, record decisions made, relate user stories and bugs to discussions, and track your progress and plan the future. With Rails on the backend, Trajectory uses Backbone.js heavily to provide a fluid story planning interface that even updates in real-time based on the actions of other users. </p> <div style="text-align: center;"> <a href="http://www.apptrajectory.com/"> <img src="docs/images/trajectory.png" alt="Trajectory" 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://code.google.com/p/phantomjs/">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/node-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-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 Prototype.js. Moving to Backbone.js and jQuery 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-tpm">Talking Points Memo: Baroque</h2> <p> <a href="http://labs.talkingpointsmemo.com/2011/08/the-baroque-era.php">Baroque</a> is the editor currently powering the homepage of <a href="http://talkingpointsmemo.com/">Talking Points Memo</a>. With a Sinatra backend for publishing, Baroque uses Backbone.js to provide real-time story and asset dropping, complex reordering actions and copy editing, making web layout feel much more like print layout. </p> <div style="text-align: center;"> <a href="http://labs.talkingpointsmemo.com/2011/08/the-baroque-era.php"> <img src="docs/images/baroque.jpg" alt="Baroque" 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 Rails 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-hotel-tonight">Hotel Tonight</h2> <p> <a href="http://www.hoteltonight.com/">Hotel Tonight</a> used Backbone.js, <a href="http://coffeescript.org">CoffeeScript</a>, <a href="http://documentcloud.github.com/jammit/">Jammit</a> and more to create the <a href="https://market.android.com/details?id=com.hoteltonight.android.prod">Android version</a> of their app; a last-minute, mobile, hotel booking application. The app leverages Backbone for the bulk of its architecture, with jQuery Mobile coming in for visual presentation. </p> <div style="text-align: center;"> <a href="http://www.hoteltonight.com"> <img src="docs/images/hotel-tonight.png" alt="Hotel Tonight" 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 Rails, 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-quoteroller">Quote Roller</h2> <p> <a href="http://www.codingstaff.com">Coding Staff</a> used Backbone.js to create <a href="http://www.quoteroller.com">Quote Roller</a>, an application that helps to create, send, organize and track business proposals with ease. Backbone.js has been used to implement interactive parts of the application like template builder, pricing table, file attachments manager. </p> <div style="text-align: center;"> <a href="http://www.quoteroller.com"> <img src="docs/images/quoteroller.png" alt="Quote Roller" 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-rround">rround.me</h2> <p> <a href="http://rround.me">rround.me</a> uses the HTML <a href="http://diveintohtml5.org/geolocation.html">Geolocation API</a> to discover tweets, YouTube videos, Instagram photos, Foursquare spots, and other happenings posted by people close to you. The site is a single-page app built on Backbone.js, with people, locations and events all represented by Backbone Models. Backbone Views listen for changes in the underlying data as you adjust the range (distance) of your search. </p> <div style="text-align: center;"> <a href="http://rround.me/"> <img src="docs/images/rround.png" alt="rround.me" 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-instagreat">Insta-great!</h2> <p> <a href="http://twitter.com/elliottkember">Elliott Kember</a> and <a href="http://twitter.com/dizzyup">Hector Simpson</a> built <a href="http://instagre.at">Insta-great!</a> - a fun way to explore popular photos and interact with <a href="http://instagram.com/">Instagram</a> on the web. Elliott says, "Backbone.js and Coffeescript were insanely useful for writing clean, consistent UI code and keeping everything modular and readable, even through several code refactors. I'm in love." </p> <div style="text-align: center;"> <a href="http://instagre.at"> <img src="docs/images/instagreat.png" alt="instagre.at" 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 Mustache. 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-bittorrent">BitTorrent</h2> <p> <a href="http://www.bittorrent.com">BitTorrent</a> used Backbone to completely rework an existing Win32 UI. Models normalize access to the client's data and views rely heavily on the <tt>change</tt> events to keep the UI state current. Using Backbone and SCSS, <a href="http://www.bittorrent.com/chrysalis/">our new design</a> and UX prototypes are considerably easier to iterate, test and work with than the original Win32 UI. </p> <div style="text-align: center;"> <a href="http://www.bittorrent.com/chrysalis/"> <img src="docs/images/bittorrent.jpg" alt="BitTorrent" class="example_image" /> </a> </div> <h2 id="examples-trapit">Trapit</h2> <p> <a href="http://trap.it">Trapit</a> brings the web to you, scouring the web on your behalf, 24/7. The product, currently in private beta, uses Backbone to organize the best, most relevant content into individual "traps" on your favorite topics and interests. </p> <div style="text-align: center;"> <a href="http://trap.it"> <img src="docs/images/trapit.png" alt="Trapit" class="example_image" /> </a> </div> <h2 id="examples-fluxiom">Fluxiom</h2> <p> <a href="http://fluxiom.com">Fluxiom</a> uses Backbone.js and HTML5 to deliver a seamless upload experience from the desktop to the cloud, including drag and drop, live previews, partial uploads, and one-click sharing. <p> <p> The upload queue is a single collection and each file is it’s own model. The UI is divided into several views for efficient event handling, and uses <a href="http://documentcloud.github.com/underscore/">Underscore.js</a> templates for fast rendering, even when handling hundreds of uploads. </p> <div style="text-align: center;"> <a href="http://fluxiom.com/"> <img src="docs/images/fluxiom.png" alt="Fluxiom" class="example_image" /> </a> </div> <h2 id="examples-chop">Chop</h2> <p> <a href="http://chopapp.com/">Chop</a> is a little app from <a href="http://www.zurb.com/">ZURB</a> that lets people slice up bad code and share their feedback to help put it back together. Chop was built to demonstrate how easy it is to build pageless apps using Backbone.js and Rails. Chop makes extensive use of Backbone <b>Views</b>, <b>Controllers</b>, and <b>Models</b>. </p> <div style="text-align: center;"> <a href="http://chopapp.com/"> <img src="docs/images/chop.png" alt="Chop" class="example_image" /> </a> </div> <h2 id="examples-blackcomb">Blackcomb</h2> <p> <a href="http://www.opzi.com/">Opzi</a> used Backbone.js to create <a href="http://www.opzi.com/">Blackcomb</a>, a web-based platform for collaboration applications. Apps can be installed through a simple app store or added in custom configurations by editing a simple YAML file. The project relied heavily on Backbone.js for the creation of reusable view components. </p> <div style="text-align: center;"> <a href="http://www.opzi.com/"> <img src="docs/images/blackcomb.png" alt="Blackcomb" class="example_image" /> </a> </div> <h2 id="examples-test-kitchen">America’s Test Kitchen</h2> <p> <a href="http://www.testkitchenschool.com/">America’s Test Kitchen</a>, an online cooking school, uses Backbone.js to manage quizzes, polls, kitchen assignments, recipe tutorials and a hybrid HTML5/Flash video player. The whole Backbone codebase is about 5k SLOC, with Mustache.js for templating, and Rails on the back end. <a href="http://wir35.com/">Max Lord</a> writes: “Working with Backbone made this one of the most pleasurable large scale client-side projects I have ever worked on, and I am definitely planning on continuing to work with it.” </p> <div style="text-align: center;"> <a href="http://www.testkitchenschool.com/"> <img src="docs/images/test-kitchen.png" alt="America's Test Kitchen" 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 + Rails 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 (Rails) 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="examples-substance">Substance</h2> <p> Michael Aufreiter is building an open source document authoring and publishing engine: <a href="http://substance.io">Substance</a>. Substance makes use of Backbone.View and Backbone.Router, while Backbone plays well together with <a href="http://github.com/michael/data">Data.js</a>, which is used for data persistence. </p> <div style="text-align: center;"> <a href="http://substance.io/"> <img src="docs/images/substance.png" alt="Substance" 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> <li><b>"add"</b> (model, collection) — when a model is added to a collection. </li> <li><b>"remove"</b> (model, collection) — when a model is removed from a collection. </li> <li><b>"reset"</b> (collection) — when the collection's entire contents have been replaced. </li> <li><b>"change"</b> (model, collection) — when a model's attributes have changed. </li> <li><b>"change:[attribute]"</b> (model, collection) — when a specific attribute has been updated. </li> <li><b>"destroy"</b> (model, collection) — when a model is <a href="#Model-destroy">destroyed</a>. </li> <li><b>"error"</b> (model, collection) — 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) — when one of a router's routes has matched. </li> <li><b>"all"</b> — 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.bind("selected:true")</tt> or <tt>model.bind("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 & 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.bind("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 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> <script> Accounts.reset(<%= @accounts.to_json %>); Projects.reset(<%= @projects.to_json(:collaborators => true) %>); </script> </pre> <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> – Like a Rails model minus the class methods. Wraps a row of data in business logic. </li> <li> <b>Backbone.Collection</b> – A group of models on the client-side, with sorting/filtering/aggregation logic. </li> <li> <b>Backbone.Router</b> – Rails <tt>routes.rb</tt> + Rails controller actions. Maps URLs to functions. </li> <li> <b>Backbone.View</b> – A logical, re-usable piece of UI. Often, but not always, associated with a model. </li> <li> <b>Client-side Templates</b> – 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.bind("reset", this.render, this); messages.bind("add", this.addMessage, this); messages.bind("remove", this.removeMessage, this); } }); // Later, in the app... Inbox.messages.add(newMessage); </pre> <h2 id="changelog">Change Log</h2> <p> <b class="header">0.5.3</b> — <small><i>August 9, 2011</i></small><br /> A View's <tt>events</tt> property may now be defined as a function, as well as an object literal, making it easier to programmatically define and inherit events. <tt>groupBy</tt> is now proxied from Underscore as a method on Collections. If the server has already rendered everything on page load, pass <tt>Backbone.history.start({silent: true})</tt> to prevent the initial route from triggering. Bugfix for pushState with encoded URLs. </p> <p> <b class="header">0.5.2</b> — <small><i>July 26, 2011</i></small><br /> The <tt>bind</tt> function, can now take an optional third argument, to specify the <tt>this</tt> of the callback function. Multiple models with the same <tt>id</tt> are now allowed in a collection. Fixed a bug where calling <tt>.fetch(jQueryOptions)</tt> could cause an incorrect URL to be serialized. Fixed a brief extra route fire before redirect, when degrading from <tt>pushState</tt>. </p> <p> <b class="header">0.5.1</b> — <small><i>July 5, 2011</i></small><br /> Cleanups from the 0.5.0 release, to wit: improved transparent upgrades from hash-based URLs to pushState, and vice-versa. Fixed inconsistency with non-modified attributes being passed to <tt>Model#initialize</tt>. Reverted a <b>0.5.0</b> change that would strip leading hashbangs from routes. Added <tt>contains</tt> as an alias for <tt>includes</tt>. </p> <p> <b class="header">0.5.0</b> — <small><i>July 1, 2011</i></small><br /> A large number of tiny tweaks and micro bugfixes, best viewed by looking at <a href="https://github.com/documentcloud/backbone/compare/0.3.3...0.5.0">the commit diff</a>. HTML5 <tt>pushState</tt> support, enabled by opting-in with: <tt>Backbone.history.start({pushState: true})</tt>. <tt>Controller</tt> was renamed to <tt>Router</tt>, for clarity. <tt>Collection#refresh</tt> was renamed to <tt>Collection#reset</tt> to emphasize its ability to both reset the collection with new models, as well as empty out the collection when used with no parameters. <tt>saveLocation</tt> was replaced with <tt>navigate</tt>. RESTful persistence methods (save, fetch, etc.) now return the jQuery deferred object for further success/error chaining and general convenience. Improved XSS escaping for <tt>Model#escape</tt>. Added a <tt>urlRoot</tt> option to allow specifying RESTful urls without the use of a collection. An error is thrown if <tt>Backbone.history.start</tt> is called multiple times. <tt>Collection#create</tt> now validates before initializing the new model. <tt>view.el</tt> can now be a jQuery string lookup. Backbone Views can now also take an <tt>attributes</tt> parameter. <tt>Model#defaults</tt> can now be a function as well as a literal attributes object. </p> <p> <b class="header">0.3.3</b> — <small><i>Dec 1, 2010</i></small><br /> Backbone.js now supports <a href="http://zeptojs.com">Zepto</a>, alongside jQuery, as a framework for DOM manipulation and Ajax support. Implemented <a href="#Model-escape">Model#escape</a>, to efficiently handle attributes intended for HTML interpolation. When trying to persist a model, failed requests will now trigger an <tt>"error"</tt> event. The ubiquitous <tt>options</tt> argument is now passed as the final argument to all <tt>"change"</tt> events. </p> <p> <b class="header">0.3.2</b> — <small><i>Nov 23, 2010</i></small><br /> Bugfix for IE7 + iframe-based "hashchange" events. <tt>sync</tt> may now be overridden on a per-model, or per-collection basis. Fixed recursion error when calling <tt>save</tt> with no changed attributes, within a <tt>"change"</tt> event. </p> <p> <b class="header">0.3.1</b> — <small><i>Nov 15, 2010</i></small><br /> All <tt>"add"</tt> and <tt>"remove"</tt> events are now sent through the model, so that views can listen for them without having to know about the collection. Added a <tt>remove</tt> method to <a href="#View">Backbone.View</a>. <tt>toJSON</tt> is no longer called at all for <tt>'read'</tt> and <tt>'delete'</tt> requests. Backbone routes are now able to load empty URL fragments. </p> <p> <b class="header">0.3.0</b> — <small><i>Nov 9, 2010</i></small><br /> Backbone now has <a href="#Controller">Controllers</a> and <a href="#History">History</a>, for doing client-side routing based on URL fragments. Added <tt>emulateHTTP</tt> to provide support for legacy servers that don't do <tt>PUT</tt> and <tt>DELETE</tt>. Added <tt>emulateJSON</tt> for servers that can't accept <tt>application/json</tt> encoded requests. Added <a href="#Model-clear">Model#clear</a>, which removes all attributes from a model. All Backbone classes may now be seamlessly inherited by CoffeeScript classes. </p> <p> <b class="header">0.2.0</b> — <small><i>Oct 25, 2010</i></small><br /> Instead of requiring server responses to be namespaced under a <tt>model</tt> key, now you can define your own <a href="#Model-parse">parse</a> method to convert responses into attributes for Models and Collections. The old <tt>handleEvents</tt> function is now named <a href="#View-delegateEvents">delegateEvents</a>, and is automatically called as part of the View's constructor. Added a <a href="#Collection-toJSON">toJSON</a> function to Collections. Added <a href="#Collection-chain">Underscore's chain</a> to Collections. </p> <p> <b class="header">0.1.2</b> — <small><i>Oct 19, 2010</i></small><br /> Added a <a href="#Model-fetch">Model#fetch</a> method for refreshing the attributes of single model from the server. An <tt>error</tt> callback may now be passed to <tt>set</tt> and <tt>save</tt> as an option, which will be invoked if validation fails, overriding the <tt>"error"</tt> event. You can now tell backbone to use the <tt>_method</tt> hack instead of HTTP methods by setting <tt>Backbone.emulateHTTP = true</tt>. Existing Model and Collection data is no longer sent up unnecessarily with <tt>GET</tt> and <tt>DELETE</tt> requests. Added a <tt>rake lint</tt> task. Backbone is now published as an <a href="http://npmjs.org">NPM</a> module. </p> <p> <b class="header">0.1.1</b> — <small><i>Oct 14, 2010</i></small><br /> Added a convention for <tt>initialize</tt> functions to be called upon instance construction, if defined. Documentation tweaks. </p> <p> <b class="header">0.1.0</b> — <small><i>Oct 13, 2010</i></small><br /> Initial Backbone release. </p> <p> <br /> <a href="http://documentcloud.org/" title="A DocumentCloud Project" style="background:none;"> <img src="http://jashkenas.s3.amazonaws.com/images/a_documentcloud_project.png" alt="A DocumentCloud Project" style="position:relative;left:-10px;" /> </a> </p> </div> <script src="test/vendor/underscore-1.1.6.js"></script> <script src="test/vendor/jquery-1.5.js"></script> <script src="test/vendor/json2.js"></script> <script src="backbone.js"></script> <script> // Set up the "play" buttons for each runnable code example. $(function() { $('.runnable').each(function() { var code = this; var button = $('<div class="run" title="Run"></div>'); $(button).insertBefore(code).bind('click', function(){ eval($(code).text()); }); }); }); </script> </body> </html>