backbone.js

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  1. //     Backbone.js 1.1.2
  2.  
  3. //     (c) 2010-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
  4. //     Backbone may be freely distributed under the MIT license.
  5. //     For all details and documentation:
  6. //     http://backbonejs.org
  7.  
  8. (function(root, factory) {
  9.  
  10.   // Set up Backbone appropriately for the environment. Start with AMD.
  11.   if (typeof define === 'function' && define.amd) {
  12.     define('backbone',['underscore', 'jquery', 'exports'], function(_, $, exports) {
  13.       // Export global even in AMD case in case this script is loaded with
  14.       // others that may still expect a global Backbone.
  15.       root.Backbone = factory(root, exports, _, $);
  16.     });
  17.  
  18.   // Next for Node.js or CommonJS. jQuery may not be needed as a module.
  19.   } else if (typeof exports !== 'undefined') {
  20.     var _ = require('underscore');
  21.     factory(root, exports, _);
  22.  
  23.   // Finally, as a browser global.
  24.   } else {
  25.     root.Backbone = factory(root, {}, root._, (root.jQuery || root.Zepto || root.ender || root.$));
  26.   }
  27.  
  28. }(this, function(root, Backbone, _, $) {
  29.  
  30.   // Initial Setup
  31.   // -------------
  32.  
  33.   // Save the previous value of the `Backbone` variable, so that it can be
  34.   // restored later on, if `noConflict` is used.
  35.   var previousBackbone = root.Backbone;
  36.  
  37.   // Create local references to array methods we'll want to use later.
  38.   var array = [];
  39.   var push = array.push;
  40.   var slice = array.slice;
  41.   var splice = array.splice;
  42.  
  43.   // Current version of the library. Keep in sync with `package.json`.
  44.   Backbone.VERSION = '1.1.2';
  45.  
  46.   // For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
  47.   // the `$` variable.
  48.   Backbone.$ = $;
  49.  
  50.   // Runs Backbone.js in *noConflict* mode, returning the `Backbone` variable
  51.   // to its previous owner. Returns a reference to this Backbone object.
  52.   Backbone.noConflict = function() {
  53.     root.Backbone = previousBackbone;
  54.     return this;
  55.   };
  56.  
  57.   // Turn on `emulateHTTP` to support legacy HTTP servers. Setting this option
  58.   // will fake `"PATCH"`, `"PUT"` and `"DELETE"` requests via the `_method` parameter and
  59.   // set a `X-Http-Method-Override` header.
  60.   Backbone.emulateHTTP = false;
  61.  
  62.   // Turn on `emulateJSON` to support legacy servers that can't deal with direct
  63.   // `application/json` requests ... will encode the body as
  64.   // `application/x-www-form-urlencoded` instead and will send the model in a
  65.   // form param named `model`.
  66.   Backbone.emulateJSON = false;
  67.  
  68.   // Backbone.Events
  69.   // ---------------
  70.  
  71.   // A module that can be mixed in to *any object* in order to provide it with
  72.   // custom events. You may bind with `on` or remove with `off` callback
  73.   // functions to an event; `trigger`-ing an event fires all callbacks in
  74.   // succession.
  75.   //
  76.   //     var object = {};
  77.   //     _.extend(object, Backbone.Events);
  78.   //     object.on('expand', function(){ alert('expanded'); });
  79.   //     object.trigger('expand');
  80.   //
  81.   var Events = Backbone.Events = {
  82.  
  83.     // Bind an event to a `callback` function. Passing `"all"` will bind
  84.     // the callback to all events fired.
  85.     on: function(name, callback, context) {
  86.       if (!eventsApi(this, 'on', name, [callback, context]) || !callback) return this;
  87.       this._events || (this._events = {});
  88.       var events = this._events[name] || (this._events[name] = []);
  89.       events.push({callback: callback, context: context, ctx: context || this});
  90.       return this;
  91.     },
  92.  
  93.     // Bind an event to only be triggered a single time. After the first time
  94.     // the callback is invoked, it will be removed.
  95.     once: function(name, callback, context) {
  96.       if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
  97.       var self = this;
  98.       var once = _.once(function() {
  99.         self.off(name, once);
  100.         callback.apply(this, arguments);
  101.       });
  102.       once._callback = callback;
  103.       return this.on(name, once, context);
  104.     },
  105.  
  106.     // Remove one or many callbacks. If `context` is null, removes all
  107.     // callbacks with that function. If `callback` is null, removes all
  108.     // callbacks for the event. If `name` is null, removes all bound
  109.     // callbacks for all events.
  110.     off: function(name, callback, context) {
  111.       var retain, ev, events, names, i, l, j, k;
  112.       if (!this._events || !eventsApi(this, 'off', name, [callback, context])) return this;
  113.       if (!name && !callback && !context) {
  114.         this._events = void 0;
  115.         return this;
  116.       }
  117.       names = name ? [name] : _.keys(this._events);
  118.       for (i = 0, l = names.length; i < l; i++) {
  119.         name = names[i];
  120.         if (events = this._events[name]) {
  121.           this._events[name] = retain = [];
  122.           if (callback || context) {
  123.             for (j = 0, k = events.length; j < k; j++) {
  124.               ev = events[j];
  125.               if ((callback && callback !== ev.callback && callback !== ev.callback._callback) ||
  126.                   (context && context !== ev.context)) {
  127.                 retain.push(ev);
  128.               }
  129.             }
  130.           }
  131.           if (!retain.length) delete this._events[name];
  132.         }
  133.       }
  134.  
  135.       return this;
  136.     },
  137.  
  138.     // Trigger one or many events, firing all bound callbacks. Callbacks are
  139.     // passed the same arguments as `trigger` is, apart from the event name
  140.     // (unless you're listening on `"all"`, which will cause your callback to
  141.     // receive the true name of the event as the first argument).
  142.     trigger: function(name) {
  143.       if (!this._events) return this;
  144.       var args = slice.call(arguments, 1);
  145.       if (!eventsApi(this, 'trigger', name, args)) return this;
  146.       var events = this._events[name];
  147.       var allEvents = this._events.all;
  148.       if (events) triggerEvents(events, args);
  149.       if (allEvents) triggerEvents(allEvents, arguments);
  150.       return this;
  151.     },
  152.  
  153.     // Tell this object to stop listening to either specific events ... or
  154.     // to every object it's currently listening to.
  155.     stopListening: function(obj, name, callback) {
  156.       var listeningTo = this._listeningTo;
  157.       if (!listeningTo) return this;
  158.       var remove = !name && !callback;
  159.       if (!callback && typeof name === 'object') callback = this;
  160.       if (obj) (listeningTo = {})[obj._listenId] = obj;
  161.       for (var id in listeningTo) {
  162.         obj = listeningTo[id];
  163.         obj.off(name, callback, this);
  164.         if (remove || _.isEmpty(obj._events)) delete this._listeningTo[id];
  165.       }
  166.       return this;
  167.     }
  168.  
  169.   };
  170.  
  171.   // Regular expression used to split event strings.
  172.   var eventSplitter = /\s+/;
  173.  
  174.   // Implement fancy features of the Events API such as multiple event
  175.   // names `"change blur"` and jQuery-style event maps `{change: action}`
  176.   // in terms of the existing API.
  177.   var eventsApi = function(obj, action, name, rest) {
  178.     if (!name) return true;
  179.  
  180.     // Handle event maps.
  181.     if (typeof name === 'object') {
  182.       for (var key in name) {
  183.         obj[action].apply(obj, [key, name[key]].concat(rest));
  184.       }
  185.       return false;
  186.     }
  187.  
  188.     // Handle space separated event names.
  189.     if (eventSplitter.test(name)) {
  190.       var names = name.split(eventSplitter);
  191.       for (var i = 0, l = names.length; i < l; i++) {
  192.         obj[action].apply(obj, [names[i]].concat(rest));
  193.       }
  194.       return false;
  195.     }
  196.  
  197.     return true;
  198.   };
  199.  
  200.   // A difficult-to-believe, but optimized internal dispatch function for
  201.   // triggering events. Tries to keep the usual cases speedy (most internal
  202.   // Backbone events have 3 arguments).
  203.   var triggerEvents = function(events, args) {
  204.     var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];
  205.     switch (args.length) {
  206.       case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;
  207.       case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;
  208.       case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;
  209.       case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;
  210.       default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args); return;
  211.     }
  212.   };
  213.  
  214.   var listenMethods = {listenTo: 'on', listenToOnce: 'once'};
  215.  
  216.   // Inversion-of-control versions of `on` and `once`. Tell *this* object to
  217.   // listen to an event in another object ... keeping track of what it's
  218.   // listening to.
  219.   _.each(listenMethods, function(implementation, method) {
  220.     Events[method] = function(obj, name, callback) {
  221.       var listeningTo = this._listeningTo || (this._listeningTo = {});
  222.       var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
  223.       listeningTo[id] = obj;
  224.       if (!callback && typeof name === 'object') callback = this;
  225.       obj[implementation](name, callback, this);
  226.       return this;
  227.     };
  228.   });
  229.  
  230.   // Aliases for backwards compatibility.
  231.   Events.bind   = Events.on;
  232.   Events.unbind = Events.off;
  233.  
  234.   // Allow the `Backbone` object to serve as a global event bus, for folks who
  235.   // want global "pubsub" in a convenient place.
  236.   _.extend(Backbone, Events);
  237.  
  238.   // Backbone.Model
  239.   // --------------
  240.  
  241.   // Backbone **Models** are the basic data object in the framework --
  242.   // frequently representing a row in a table in a database on your server.
  243.   // A discrete chunk of data and a bunch of useful, related methods for
  244.   // performing computations and transformations on that data.
  245.  
  246.   // Create a new model with the specified attributes. A client id (`cid`)
  247.   // is automatically generated and assigned for you.
  248.   var Model = Backbone.Model = function(attributes, options) {
  249.     var attrs = attributes || {};
  250.     options || (options = {});
  251.     this.cid = _.uniqueId('c');
  252.     this.attributes = {};
  253.     if (options.collection) this.collection = options.collection;
  254.     if (options.parse) attrs = this.parse(attrs, options) || {};
  255.     attrs = _.defaults({}, attrs, _.result(this, 'defaults'));
  256.     this.set(attrs, options);
  257.     this.changed = {};
  258.     this.initialize.apply(this, arguments);
  259.   };
  260.  
  261.   // Attach all inheritable methods to the Model prototype.
  262.   _.extend(Model.prototype, Events, {
  263.  
  264.     // A hash of attributes whose current and previous value differ.
  265.     changed: null,
  266.  
  267.     // The value returned during the last failed validation.
  268.     validationError: null,
  269.  
  270.     // The default name for the JSON `id` attribute is `"id"`. MongoDB and
  271.     // CouchDB users may want to set this to `"_id"`.
  272.     idAttribute: 'id',
  273.  
  274.     // Initialize is an empty function by default. Override it with your own
  275.     // initialization logic.
  276.     initialize: function(){},
  277.  
  278.     // Return a copy of the model's `attributes` object.
  279.     toJSON: function(options) {
  280.       return _.clone(this.attributes);
  281.     },
  282.  
  283.     // Proxy `Backbone.sync` by default -- but override this if you need
  284.     // custom syncing semantics for *this* particular model.
  285.     sync: function() {
  286.       return Backbone.sync.apply(this, arguments);
  287.     },
  288.  
  289.     // Get the value of an attribute.
  290.     get: function(attr) {
  291.       return this.attributes[attr];
  292.     },
  293.  
  294.     // Get the HTML-escaped value of an attribute.
  295.     escape: function(attr) {
  296.       return _.escape(this.get(attr));
  297.     },
  298.  
  299.     // Returns `true` if the attribute contains a value that is not null
  300.     // or undefined.
  301.     has: function(attr) {
  302.       return this.get(attr) != null;
  303.     },
  304.  
  305.     // Set a hash of model attributes on the object, firing `"change"`. This is
  306.     // the core primitive operation of a model, updating the data and notifying
  307.     // anyone who needs to know about the change in state. The heart of the beast.
  308.     set: function(key, val, options) {
  309.       var attr, attrs, unset, changes, silent, changing, prev, current;
  310.       if (key == null) return this;
  311.  
  312.       // Handle both `"key", value` and `{key: value}` -style arguments.
  313.       if (typeof key === 'object') {
  314.         attrs = key;
  315.         options = val;
  316.       } else {
  317.         (attrs = {})[key] = val;
  318.       }
  319.  
  320.       options || (options = {});
  321.  
  322.       // Run validation.
  323.       if (!this._validate(attrs, options)) return false;
  324.  
  325.       // Extract attributes and options.
  326.       unset           = options.unset;
  327.       silent          = options.silent;
  328.       changes         = [];
  329.       changing        = this._changing;
  330.       this._changing  = true;
  331.  
  332.       if (!changing) {
  333.         this._previousAttributes = _.clone(this.attributes);
  334.         this.changed = {};
  335.       }
  336.       current = this.attributes, prev = this._previousAttributes;
  337.  
  338.       // Check for changes of `id`.
  339.       if (this.idAttribute in attrs) this.id = attrs[this.idAttribute];
  340.  
  341.       // For each `set` attribute, update or delete the current value.
  342.       for (attr in attrs) {
  343.         val = attrs[attr];
  344.         if (!_.isEqual(current[attr], val)) changes.push(attr);
  345.         if (!_.isEqual(prev[attr], val)) {
  346.           this.changed[attr] = val;
  347.         } else {
  348.           delete this.changed[attr];
  349.         }
  350.         unset ? delete current[attr] : current[attr] = val;
  351.       }
  352.  
  353.       // Trigger all relevant attribute changes.
  354.       if (!silent) {
  355.         if (changes.length) this._pending = options;
  356.         for (var i = 0, l = changes.length; i < l; i++) {
  357.           this.trigger('change:' + changes[i], this, current[changes[i]], options);
  358.         }
  359.       }
  360.  
  361.       // You might be wondering why there's a `while` loop here. Changes can
  362.       // be recursively nested within `"change"` events.
  363.       if (changing) return this;
  364.       if (!silent) {
  365.         while (this._pending) {
  366.           options = this._pending;
  367.           this._pending = false;
  368.           this.trigger('change', this, options);
  369.         }
  370.       }
  371.       this._pending = false;
  372.       this._changing = false;
  373.       return this;
  374.     },
  375.  
  376.     // Remove an attribute from the model, firing `"change"`. `unset` is a noop
  377.     // if the attribute doesn't exist.
  378.     unset: function(attr, options) {
  379.       return this.set(attr, void 0, _.extend({}, options, {unset: true}));
  380.     },
  381.  
  382.     // Clear all attributes on the model, firing `"change"`.
  383.     clear: function(options) {
  384.       var attrs = {};
  385.       for (var key in this.attributes) attrs[key] = void 0;
  386.       return this.set(attrs, _.extend({}, options, {unset: true}));
  387.     },
  388.  
  389.     // Determine if the model has changed since the last `"change"` event.
  390.     // If you specify an attribute name, determine if that attribute has changed.
  391.     hasChanged: function(attr) {
  392.       if (attr == null) return !_.isEmpty(this.changed);
  393.       return _.has(this.changed, attr);
  394.     },
  395.  
  396.     // Return an object containing all the attributes that have changed, or
  397.     // false if there are no changed attributes. Useful for determining what
  398.     // parts of a view need to be updated and/or what attributes need to be
  399.     // persisted to the server. Unset attributes will be set to undefined.
  400.     // You can also pass an attributes object to diff against the model,
  401.     // determining if there *would be* a change.
  402.     changedAttributes: function(diff) {
  403.       if (!diff) return this.hasChanged() ? _.clone(this.changed) : false;
  404.       var val, changed = false;
  405.       var old = this._changing ? this._previousAttributes : this.attributes;
  406.       for (var attr in diff) {
  407.         if (_.isEqual(old[attr], (val = diff[attr]))) continue;
  408.         (changed || (changed = {}))[attr] = val;
  409.       }
  410.       return changed;
  411.     },
  412.  
  413.     // Get the previous value of an attribute, recorded at the time the last
  414.     // `"change"` event was fired.
  415.     previous: function(attr) {
  416.       if (attr == null || !this._previousAttributes) return null;
  417.       return this._previousAttributes[attr];
  418.     },
  419.  
  420.     // Get all of the attributes of the model at the time of the previous
  421.     // `"change"` event.
  422.     previousAttributes: function() {
  423.       return _.clone(this._previousAttributes);
  424.     },
  425.  
  426.     // Fetch the model from the server. If the server's representation of the
  427.     // model differs from its current attributes, they will be overridden,
  428.     // triggering a `"change"` event.
  429.     fetch: function(options) {
  430.       options = options ? _.clone(options) : {};
  431.       if (options.parse === void 0) options.parse = true;
  432.       var model = this;
  433.       var success = options.success;
  434.       options.success = function(resp) {
  435.         if (!model.set(model.parse(resp, options), options)) return false;
  436.         if (success) success(model, resp, options);
  437.         model.trigger('sync', model, resp, options);
  438.       };
  439.       wrapError(this, options);
  440.       return this.sync('read', this, options);
  441.     },
  442.  
  443.     // Set a hash of model attributes, and sync the model to the server.
  444.     // If the server returns an attributes hash that differs, the model's
  445.     // state will be `set` again.
  446.     save: function(key, val, options) {
  447.       var attrs, method, xhr, attributes = this.attributes;
  448.  
  449.       // Handle both `"key", value` and `{key: value}` -style arguments.
  450.       if (key == null || typeof key === 'object') {
  451.         attrs = key;
  452.         options = val;
  453.       } else {
  454.         (attrs = {})[key] = val;
  455.       }
  456.  
  457.       options = _.extend({validate: true}, options);
  458.  
  459.       // If we're not waiting and attributes exist, save acts as
  460.       // `set(attr).save(null, opts)` with validation. Otherwise, check if
  461.       // the model will be valid when the attributes, if any, are set.
  462.       if (attrs && !options.wait) {
  463.         if (!this.set(attrs, options)) return false;
  464.       } else {
  465.         if (!this._validate(attrs, options)) return false;
  466.       }
  467.  
  468.       // Set temporary attributes if `{wait: true}`.
  469.       if (attrs && options.wait) {
  470.         this.attributes = _.extend({}, attributes, attrs);
  471.       }
  472.  
  473.       // After a successful server-side save, the client is (optionally)
  474.       // updated with the server-side state.
  475.       if (options.parse === void 0) options.parse = true;
  476.       var model = this;
  477.       var success = options.success;
  478.       options.success = function(resp) {
  479.         // Ensure attributes are restored during synchronous saves.
  480.         model.attributes = attributes;
  481.         var serverAttrs = model.parse(resp, options);
  482.         if (options.wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
  483.         if (_.isObject(serverAttrs) && !model.set(serverAttrs, options)) {
  484.           return false;
  485.         }
  486.         if (success) success(model, resp, options);
  487.         model.trigger('sync', model, resp, options);
  488.       };
  489.       wrapError(this, options);
  490.  
  491.       method = this.isNew() ? 'create' : (options.patch ? 'patch' : 'update');
  492.       if (method === 'patch') options.attrs = attrs;
  493.       xhr = this.sync(method, this, options);
  494.  
  495.       // Restore attributes.
  496.       if (attrs && options.wait) this.attributes = attributes;
  497.  
  498.       return xhr;
  499.     },
  500.  
  501.     // Destroy this model on the server if it was already persisted.
  502.     // Optimistically removes the model from its collection, if it has one.
  503.     // If `wait: true` is passed, waits for the server to respond before removal.
  504.     destroy: function(options) {
  505.       options = options ? _.clone(options) : {};
  506.       var model = this;
  507.       var success = options.success;
  508.  
  509.       var destroy = function() {
  510.         model.trigger('destroy', model, model.collection, options);
  511.       };
  512.  
  513.       options.success = function(resp) {
  514.         if (options.wait || model.isNew()) destroy();
  515.         if (success) success(model, resp, options);
  516.         if (!model.isNew()) model.trigger('sync', model, resp, options);
  517.       };
  518.  
  519.       if (this.isNew()) {
  520.         options.success();
  521.         return false;
  522.       }
  523.       wrapError(this, options);
  524.  
  525.       var xhr = this.sync('delete', this, options);
  526.       if (!options.wait) destroy();
  527.       return xhr;
  528.     },
  529.  
  530.     // Default URL for the model's representation on the server -- if you're
  531.     // using Backbone's restful methods, override this to change the endpoint
  532.     // that will be called.
  533.     url: function() {
  534.       var base =
  535.         _.result(this, 'urlRoot') ||
  536.         _.result(this.collection, 'url') ||
  537.         urlError();
  538.       if (this.isNew()) return base;
  539.       return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(this.id);
  540.     },
  541.  
  542.     // **parse** converts a response into the hash of attributes to be `set` on
  543.     // the model. The default implementation is just to pass the response along.
  544.     parse: function(resp, options) {
  545.       return resp;
  546.     },
  547.  
  548.     // Create a new model with identical attributes to this one.
  549.     clone: function() {
  550.       return new this.constructor(this.attributes);
  551.     },
  552.  
  553.     // A model is new if it has never been saved to the server, and lacks an id.
  554.     isNew: function() {
  555.       return !this.has(this.idAttribute);
  556.     },
  557.  
  558.     // Check if the model is currently in a valid state.
  559.     isValid: function(options) {
  560.       return this._validate({}, _.extend(options || {}, { validate: true }));
  561.     },
  562.  
  563.     // Run validation against the next complete set of model attributes,
  564.     // returning `true` if all is well. Otherwise, fire an `"invalid"` event.
  565.     _validate: function(attrs, options) {
  566.       if (!options.validate || !this.validate) return true;
  567.       attrs = _.extend({}, this.attributes, attrs);
  568.       var error = this.validationError = this.validate(attrs, options) || null;
  569.       if (!error) return true;
  570.       this.trigger('invalid', this, error, _.extend(options, {validationError: error}));
  571.       return false;
  572.     }
  573.  
  574.   });
  575.  
  576.   // Underscore methods that we want to implement on the Model.
  577.   var modelMethods = ['keys', 'values', 'pairs', 'invert', 'pick', 'omit'];
  578.  
  579.   // Mix in each Underscore method as a proxy to `Model#attributes`.
  580.   _.each(modelMethods, function(method) {
  581.     Model.prototype[method] = function() {
  582.       var args = slice.call(arguments);
  583.       args.unshift(this.attributes);
  584.       return _[method].apply(_, args);
  585.     };
  586.   });
  587.  
  588.   // Backbone.Collection
  589.   // -------------------
  590.  
  591.   // If models tend to represent a single row of data, a Backbone Collection is
  592.   // more analagous to a table full of data ... or a small slice or page of that
  593.   // table, or a collection of rows that belong together for a particular reason
  594.   // -- all of the messages in this particular folder, all of the documents
  595.   // belonging to this particular author, and so on. Collections maintain
  596.   // indexes of their models, both in order, and for lookup by `id`.
  597.  
  598.   // Create a new **Collection**, perhaps to contain a specific type of `model`.
  599.   // If a `comparator` is specified, the Collection will maintain
  600.   // its models in sort order, as they're added and removed.
  601.   var Collection = Backbone.Collection = function(models, options) {
  602.     options || (options = {});
  603.     if (options.model) this.model = options.model;
  604.     if (options.comparator !== void 0) this.comparator = options.comparator;
  605.     this._reset();
  606.     this.initialize.apply(this, arguments);
  607.     if (models) this.reset(models, _.extend({silent: true}, options));
  608.   };
  609.  
  610.   // Default options for `Collection#set`.
  611.   var setOptions = {add: true, remove: true, merge: true};
  612.   var addOptions = {add: true, remove: false};
  613.  
  614.   // Define the Collection's inheritable methods.
  615.   _.extend(Collection.prototype, Events, {
  616.  
  617.     // The default model for a collection is just a **Backbone.Model**.
  618.     // This should be overridden in most cases.
  619.     model: Model,
  620.  
  621.     // Initialize is an empty function by default. Override it with your own
  622.     // initialization logic.
  623.     initialize: function(){},
  624.  
  625.     // The JSON representation of a Collection is an array of the
  626.     // models' attributes.
  627.     toJSON: function(options) {
  628.       return this.map(function(model){ return model.toJSON(options); });
  629.     },
  630.  
  631.     // Proxy `Backbone.sync` by default.
  632.     sync: function() {
  633.       return Backbone.sync.apply(this, arguments);
  634.     },
  635.  
  636.     // Add a model, or list of models to the set.
  637.     add: function(models, options) {
  638.       return this.set(models, _.extend({merge: false}, options, addOptions));
  639.     },
  640.  
  641.     // Remove a model, or a list of models from the set.
  642.     remove: function(models, options) {
  643.       var singular = !_.isArray(models);
  644.       models = singular ? [models] : _.clone(models);
  645.       options || (options = {});
  646.       var i, l, index, model;
  647.       for (i = 0, l = models.length; i < l; i++) {
  648.         model = models[i] = this.get(models[i]);
  649.         if (!model) continue;
  650.         delete this._byId[model.id];
  651.         delete this._byId[model.cid];
  652.         index = this.indexOf(model);
  653.         this.models.splice(index, 1);
  654.         this.length--;
  655.         if (!options.silent) {
  656.           options.index = index;
  657.           model.trigger('remove', model, this, options);
  658.         }
  659.         this._removeReference(model, options);
  660.       }
  661.       return singular ? models[0] : models;
  662.     },
  663.  
  664.     // Update a collection by `set`-ing a new list of models, adding new ones,
  665.     // removing models that are no longer present, and merging models that
  666.     // already exist in the collection, as necessary. Similar to **Model#set**,
  667.     // the core operation for updating the data contained by the collection.
  668.     set: function(models, options) {
  669.       options = _.defaults({}, options, setOptions);
  670.       if (options.parse) models = this.parse(models, options);
  671.       var singular = !_.isArray(models);
  672.       models = singular ? (models ? [models] : []) : _.clone(models);
  673.       var i, l, id, model, attrs, existing, sort;
  674.       var at = options.at;
  675.       var targetModel = this.model;
  676.       var sortable = this.comparator && (at == null) && options.sort !== false;
  677.       var sortAttr = _.isString(this.comparator) ? this.comparator : null;
  678.       var toAdd = [], toRemove = [], modelMap = {};
  679.       var add = options.add, merge = options.merge, remove = options.remove;
  680.       var order = !sortable && add && remove ? [] : false;
  681.  
  682.       // Turn bare objects into model references, and prevent invalid models
  683.       // from being added.
  684.       for (i = 0, l = models.length; i < l; i++) {
  685.         attrs = models[i] || {};
  686.         if (attrs instanceof Model) {
  687.           id = model = attrs;
  688.         } else {
  689.           id = attrs[targetModel.prototype.idAttribute || 'id'];
  690.         }
  691.  
  692.         // If a duplicate is found, prevent it from being added and
  693.         // optionally merge it into the existing model.
  694.         if (existing = this.get(id)) {
  695.           if (remove) modelMap[existing.cid] = true;
  696.           if (merge) {
  697.             attrs = attrs === model ? model.attributes : attrs;
  698.             if (options.parse) attrs = existing.parse(attrs, options);
  699.             existing.set(attrs, options);
  700.             if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
  701.           }
  702.           models[i] = existing;
  703.  
  704.         // If this is a new, valid model, push it to the `toAdd` list.
  705.         } else if (add) {
  706.           model = models[i] = this._prepareModel(attrs, options);
  707.           if (!model) continue;
  708.           toAdd.push(model);
  709.           this._addReference(model, options);
  710.         }
  711.  
  712.         // Do not add multiple models with the same `id`.
  713.         model = existing || model;
  714.         if (order && (model.isNew() || !modelMap[model.id])) order.push(model);
  715.         modelMap[model.id] = true;
  716.       }
  717.  
  718.       // Remove nonexistent models if appropriate.
  719.       if (remove) {
  720.         for (i = 0, l = this.length; i < l; ++i) {
  721.           if (!modelMap[(model = this.models[i]).cid]) toRemove.push(model);
  722.         }
  723.         if (toRemove.length) this.remove(toRemove, options);
  724.       }
  725.  
  726.       // See if sorting is needed, update `length` and splice in new models.
  727.       if (toAdd.length || (order && order.length)) {
  728.         if (sortable) sort = true;
  729.         this.length += toAdd.length;
  730.         if (at != null) {
  731.           for (i = 0, l = toAdd.length; i < l; i++) {
  732.             this.models.splice(at + i, 0, toAdd[i]);
  733.           }
  734.         } else {
  735.           if (order) this.models.length = 0;
  736.           var orderedModels = order || toAdd;
  737.           for (i = 0, l = orderedModels.length; i < l; i++) {
  738.             this.models.push(orderedModels[i]);
  739.           }
  740.         }
  741.       }
  742.  
  743.       // Silently sort the collection if appropriate.
  744.       if (sort) this.sort({silent: true});
  745.  
  746.       // Unless silenced, it's time to fire all appropriate add/sort events.
  747.       if (!options.silent) {
  748.         for (i = 0, l = toAdd.length; i < l; i++) {
  749.           (model = toAdd[i]).trigger('add', model, this, options);
  750.         }
  751.         if (sort || (order && order.length)) this.trigger('sort', this, options);
  752.       }
  753.  
  754.       // Return the added (or merged) model (or models).
  755.       return singular ? models[0] : models;
  756.     },
  757.  
  758.     // When you have more items than you want to add or remove individually,
  759.     // you can reset the entire set with a new list of models, without firing
  760.     // any granular `add` or `remove` events. Fires `reset` when finished.
  761.     // Useful for bulk operations and optimizations.
  762.     reset: function(models, options) {
  763.       options || (options = {});
  764.       for (var i = 0, l = this.models.length; i < l; i++) {
  765.         this._removeReference(this.models[i], options);
  766.       }
  767.       options.previousModels = this.models;
  768.       this._reset();
  769.       models = this.add(models, _.extend({silent: true}, options));
  770.       if (!options.silent) this.trigger('reset', this, options);
  771.       return models;
  772.     },
  773.  
  774.     // Add a model to the end of the collection.
  775.     push: function(model, options) {
  776.       return this.add(model, _.extend({at: this.length}, options));
  777.     },
  778.  
  779.     // Remove a model from the end of the collection.
  780.     pop: function(options) {
  781.       var model = this.at(this.length - 1);
  782.       this.remove(model, options);
  783.       return model;
  784.     },
  785.  
  786.     // Add a model to the beginning of the collection.
  787.     unshift: function(model, options) {
  788.       return this.add(model, _.extend({at: 0}, options));
  789.     },
  790.  
  791.     // Remove a model from the beginning of the collection.
  792.     shift: function(options) {
  793.       var model = this.at(0);
  794.       this.remove(model, options);
  795.       return model;
  796.     },
  797.  
  798.     // Slice out a sub-array of models from the collection.
  799.     slice: function() {
  800.       return slice.apply(this.models, arguments);
  801.     },
  802.  
  803.     // Get a model from the set by id.
  804.     get: function(obj) {
  805.       if (obj == null) return void 0;
  806.       return this._byId[obj] || this._byId[obj.id] || this._byId[obj.cid];
  807.     },
  808.  
  809.     // Get the model at the given index.
  810.     at: function(index) {
  811.       return this.models[index];
  812.     },
  813.  
  814.     // Return models with matching attributes. Useful for simple cases of
  815.     // `filter`.
  816.     where: function(attrs, first) {
  817.       if (_.isEmpty(attrs)) return first ? void 0 : [];
  818.       return this[first ? 'find' : 'filter'](function(model) {
  819.         for (var key in attrs) {
  820.           if (attrs[key] !== model.get(key)) return false;
  821.         }
  822.         return true;
  823.       });
  824.     },
  825.  
  826.     // Return the first model with matching attributes. Useful for simple cases
  827.     // of `find`.
  828.     findWhere: function(attrs) {
  829.       return this.where(attrs, true);
  830.     },
  831.  
  832.     // Force the collection to re-sort itself. You don't need to call this under
  833.     // normal circumstances, as the set will maintain sort order as each item
  834.     // is added.
  835.     sort: function(options) {
  836.       if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
  837.       options || (options = {});
  838.  
  839.       // Run sort based on type of `comparator`.
  840.       if (_.isString(this.comparator) || this.comparator.length === 1) {
  841.         this.models = this.sortBy(this.comparator, this);
  842.       } else {
  843.         this.models.sort(_.bind(this.comparator, this));
  844.       }
  845.  
  846.       if (!options.silent) this.trigger('sort', this, options);
  847.       return this;
  848.     },
  849.  
  850.     // Pluck an attribute from each model in the collection.
  851.     pluck: function(attr) {
  852.       return _.invoke(this.models, 'get', attr);
  853.     },
  854.  
  855.     // Fetch the default set of models for this collection, resetting the
  856.     // collection when they arrive. If `reset: true` is passed, the response
  857.     // data will be passed through the `reset` method instead of `set`.
  858.     fetch: function(options) {
  859.       options = options ? _.clone(options) : {};
  860.       if (options.parse === void 0) options.parse = true;
  861.       var success = options.success;
  862.       var collection = this;
  863.       options.success = function(resp) {
  864.         var method = options.reset ? 'reset' : 'set';
  865.         collection[method](resp, options);
  866.         if (success) success(collection, resp, options);
  867.         collection.trigger('sync', collection, resp, options);
  868.       };
  869.       wrapError(this, options);
  870.       return this.sync('read', this, options);
  871.     },
  872.  
  873.     // Create a new instance of a model in this collection. Add the model to the
  874.     // collection immediately, unless `wait: true` is passed, in which case we
  875.     // wait for the server to agree.
  876.     create: function(model, options) {
  877.       options = options ? _.clone(options) : {};
  878.       if (!(model = this._prepareModel(model, options))) return false;
  879.       if (!options.wait) this.add(model, options);
  880.       var collection = this;
  881.       var success = options.success;
  882.       options.success = function(model, resp) {
  883.         if (options.wait) collection.add(model, options);
  884.         if (success) success(model, resp, options);
  885.       };
  886.       model.save(null, options);
  887.       return model;
  888.     },
  889.  
  890.     // **parse** converts a response into a list of models to be added to the
  891.     // collection. The default implementation is just to pass it through.
  892.     parse: function(resp, options) {
  893.       return resp;
  894.     },
  895.  
  896.     // Create a new collection with an identical list of models as this one.
  897.     clone: function() {
  898.       return new this.constructor(this.models);
  899.     },
  900.  
  901.     // Private method to reset all internal state. Called when the collection
  902.     // is first initialized or reset.
  903.     _reset: function() {
  904.       this.length = 0;
  905.       this.models = [];
  906.       this._byId  = {};
  907.     },
  908.  
  909.     // Prepare a hash of attributes (or other model) to be added to this
  910.     // collection.
  911.     _prepareModel: function(attrs, options) {
  912.       if (attrs instanceof Model) return attrs;
  913.       options = options ? _.clone(options) : {};
  914.       options.collection = this;
  915.       var model = new this.model(attrs, options);
  916.       if (!model.validationError) return model;
  917.       this.trigger('invalid', this, model.validationError, options);
  918.       return false;
  919.     },
  920.  
  921.     // Internal method to create a model's ties to a collection.
  922.     _addReference: function(model, options) {
  923.       this._byId[model.cid] = model;
  924.       if (model.id != null) this._byId[model.id] = model;
  925.       if (!model.collection) model.collection = this;
  926.       model.on('all', this._onModelEvent, this);
  927.     },
  928.  
  929.     // Internal method to sever a model's ties to a collection.
  930.     _removeReference: function(model, options) {
  931.       if (this === model.collection) delete model.collection;
  932.       model.off('all', this._onModelEvent, this);
  933.     },
  934.  
  935.     // Internal method called every time a model in the set fires an event.
  936.     // Sets need to update their indexes when models change ids. All other
  937.     // events simply proxy through. "add" and "remove" events that originate
  938.     // in other collections are ignored.
  939.     _onModelEvent: function(event, model, collection, options) {
  940.       if ((event === 'add' || event === 'remove') && collection !== this) return;
  941.       if (event === 'destroy') this.remove(model, options);
  942.       if (model && event === 'change:' + model.idAttribute) {
  943.         delete this._byId[model.previous(model.idAttribute)];
  944.         if (model.id != null) this._byId[model.id] = model;
  945.       }
  946.       this.trigger.apply(this, arguments);
  947.     }
  948.  
  949.   });
  950.  
  951.   // Underscore methods that we want to implement on the Collection.
  952.   // 90% of the core usefulness of Backbone Collections is actually implemented
  953.   // right here:
  954.   var methods = ['forEach', 'each', 'map', 'collect', 'reduce', 'foldl',
  955.     'inject', 'reduceRight', 'foldr', 'find', 'detect', 'filter', 'select',
  956.     'reject', 'every', 'all', 'some', 'any', 'include', 'contains', 'invoke',
  957.     'max', 'min', 'toArray', 'size', 'first', 'head', 'take', 'initial', 'rest',
  958.     'tail', 'drop', 'last', 'without', 'difference', 'indexOf', 'shuffle',
  959.     'lastIndexOf', 'isEmpty', 'chain', 'sample'];
  960.  
  961.   // Mix in each Underscore method as a proxy to `Collection#models`.
  962.   _.each(methods, function(method) {
  963.     Collection.prototype[method] = function() {
  964.       var args = slice.call(arguments);
  965.       args.unshift(this.models);
  966.       return _[method].apply(_, args);
  967.     };
  968.   });
  969.  
  970.   // Underscore methods that take a property name as an argument.
  971.   var attributeMethods = ['groupBy', 'countBy', 'sortBy', 'indexBy'];
  972.  
  973.   // Use attributes instead of properties.
  974.   _.each(attributeMethods, function(method) {
  975.     Collection.prototype[method] = function(value, context) {
  976.       var iterator = _.isFunction(value) ? value : function(model) {
  977.         return model.get(value);
  978.       };
  979.       return _[method](this.models, iterator, context);
  980.     };
  981.   });
  982.  
  983.   // Backbone.View
  984.   // -------------
  985.  
  986.   // Backbone Views are almost more convention than they are actual code. A View
  987.   // is simply a JavaScript object that represents a logical chunk of UI in the
  988.   // DOM. This might be a single item, an entire list, a sidebar or panel, or
  989.   // even the surrounding frame which wraps your whole app. Defining a chunk of
  990.   // UI as a **View** allows you to define your DOM events declaratively, without
  991.   // having to worry about render order ... and makes it easy for the view to
  992.   // react to specific changes in the state of your models.
  993.  
  994.   // Creating a Backbone.View creates its initial element outside of the DOM,
  995.   // if an existing element is not provided...
  996.   var View = Backbone.View = function(options) {
  997.     this.cid = _.uniqueId('view');
  998.     options || (options = {});
  999.     _.extend(this, _.pick(options, viewOptions));
  1000.     this._ensureElement();
  1001.     this.initialize.apply(this, arguments);
  1002.     this.delegateEvents();
  1003.   };
  1004.  
  1005.   // Cached regex to split keys for `delegate`.
  1006.   var delegateEventSplitter = /^(\S+)\s*(.*)$/;
  1007.  
  1008.   // List of view options to be merged as properties.
  1009.   var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
  1010.  
  1011.   // Set up all inheritable **Backbone.View** properties and methods.
  1012.   _.extend(View.prototype, Events, {
  1013.  
  1014.     // The default `tagName` of a View's element is `"div"`.
  1015.     tagName: 'div',
  1016.  
  1017.     // jQuery delegate for element lookup, scoped to DOM elements within the
  1018.     // current view. This should be preferred to global lookups where possible.
  1019.     $: function(selector) {
  1020.       return this.$el.find(selector);
  1021.     },
  1022.  
  1023.     // Initialize is an empty function by default. Override it with your own
  1024.     // initialization logic.
  1025.     initialize: function(){},
  1026.  
  1027.     // **render** is the core function that your view should override, in order
  1028.     // to populate its element (`this.el`), with the appropriate HTML. The
  1029.     // convention is for **render** to always return `this`.
  1030.     render: function() {
  1031.       return this;
  1032.     },
  1033.  
  1034.     // Remove this view by taking the element out of the DOM, and removing any
  1035.     // applicable Backbone.Events listeners.
  1036.     remove: function() {
  1037.       this.$el.remove();
  1038.       this.stopListening();
  1039.       return this;
  1040.     },
  1041.  
  1042.     // Change the view's element (`this.el` property), including event
  1043.     // re-delegation.
  1044.     setElement: function(element, delegate) {
  1045.       if (this.$el) this.undelegateEvents();
  1046.       this.$el = element instanceof Backbone.$ ? element : Backbone.$(element);
  1047.       this.el = this.$el[0];
  1048.       if (delegate !== false) this.delegateEvents();
  1049.       return this;
  1050.     },
  1051.  
  1052.     // Set callbacks, where `this.events` is a hash of
  1053.     //
  1054.     // *{"event selector": "callback"}*
  1055.     //
  1056.     //     {
  1057.     //       'mousedown .title':  'edit',
  1058.     //       'click .button':     'save',
  1059.     //       'click .open':       function(e) { ... }
  1060.     //     }
  1061.     //
  1062.     // pairs. Callbacks will be bound to the view, with `this` set properly.
  1063.     // Uses event delegation for efficiency.
  1064.     // Omitting the selector binds the event to `this.el`.
  1065.     // This only works for delegate-able events: not `focus`, `blur`, and
  1066.     // not `change`, `submit`, and `reset` in Internet Explorer.
  1067.     delegateEvents: function(events) {
  1068.       if (!(events || (events = _.result(this, 'events')))) return this;
  1069.       this.undelegateEvents();
  1070.       for (var key in events) {
  1071.         var method = events[key];
  1072.         if (!_.isFunction(method)) method = this[events[key]];
  1073.         if (!method) continue;
  1074.  
  1075.         var match = key.match(delegateEventSplitter);
  1076.         var eventName = match[1], selector = match[2];
  1077.         method = _.bind(method, this);
  1078.         eventName += '.delegateEvents' + this.cid;
  1079.         if (selector === '') {
  1080.           this.$el.on(eventName, method);
  1081.         } else {
  1082.           this.$el.on(eventName, selector, method);
  1083.         }
  1084.       }
  1085.       return this;
  1086.     },
  1087.  
  1088.     // Clears all callbacks previously bound to the view with `delegateEvents`.
  1089.     // You usually don't need to use this, but may wish to if you have multiple
  1090.     // Backbone views attached to the same DOM element.
  1091.     undelegateEvents: function() {
  1092.       this.$el.off('.delegateEvents' + this.cid);
  1093.       return this;
  1094.     },
  1095.  
  1096.     // Ensure that the View has a DOM element to render into.
  1097.     // If `this.el` is a string, pass it through `$()`, take the first
  1098.     // matching element, and re-assign it to `el`. Otherwise, create
  1099.     // an element from the `id`, `className` and `tagName` properties.
  1100.     _ensureElement: function() {
  1101.       if (!this.el) {
  1102.         var attrs = _.extend({}, _.result(this, 'attributes'));
  1103.         if (this.id) attrs.id = _.result(this, 'id');
  1104.         if (this.className) attrs['class'] = _.result(this, 'className');
  1105.         var $el = Backbone.$('<' + _.result(this, 'tagName') + '>').attr(attrs);
  1106.         this.setElement($el, false);
  1107.       } else {
  1108.         this.setElement(_.result(this, 'el'), false);
  1109.       }
  1110.     }
  1111.  
  1112.   });
  1113.  
  1114.   // Backbone.sync
  1115.   // -------------
  1116.  
  1117.   // Override this function to change the manner in which Backbone persists
  1118.   // models to the server. You will be passed the type of request, and the
  1119.   // model in question. By default, makes a RESTful Ajax request
  1120.   // to the model's `url()`. Some possible customizations could be:
  1121.   //
  1122.   // * Use `setTimeout` to batch rapid-fire updates into a single request.
  1123.   // * Send up the models as XML instead of JSON.
  1124.   // * Persist models via WebSockets instead of Ajax.
  1125.   //
  1126.   // Turn on `Backbone.emulateHTTP` in order to send `PUT` and `DELETE` requests
  1127.   // as `POST`, with a `_method` parameter containing the true HTTP method,
  1128.   // as well as all requests with the body as `application/x-www-form-urlencoded`
  1129.   // instead of `application/json` with the model in a param named `model`.
  1130.   // Useful when interfacing with server-side languages like **PHP** that make
  1131.   // it difficult to read the body of `PUT` requests.
  1132.   Backbone.sync = function(method, model, options) {
  1133.     var type = methodMap[method];
  1134.  
  1135.     // Default options, unless specified.
  1136.     _.defaults(options || (options = {}), {
  1137.       emulateHTTP: Backbone.emulateHTTP,
  1138.       emulateJSON: Backbone.emulateJSON
  1139.     });
  1140.  
  1141.     // Default JSON-request options.
  1142.     var params = {type: type, dataType: 'json'};
  1143.  
  1144.     // Ensure that we have a URL.
  1145.     if (!options.url) {
  1146.       params.url = _.result(model, 'url') || urlError();
  1147.     }
  1148.  
  1149.     // Ensure that we have the appropriate request data.
  1150.     if (options.data == null && model && (method === 'create' || method === 'update' || method === 'patch')) {
  1151.       params.contentType = 'application/json';
  1152.       params.data = JSON.stringify(options.attrs || model.toJSON(options));
  1153.     }
  1154.  
  1155.     // For older servers, emulate JSON by encoding the request into an HTML-form.
  1156.     if (options.emulateJSON) {
  1157.       params.contentType = 'application/x-www-form-urlencoded';
  1158.       params.data = params.data ? {model: params.data} : {};
  1159.     }
  1160.  
  1161.     // For older servers, emulate HTTP by mimicking the HTTP method with `_method`
  1162.     // And an `X-HTTP-Method-Override` header.
  1163.     if (options.emulateHTTP && (type === 'PUT' || type === 'DELETE' || type === 'PATCH')) {
  1164.       params.type = 'POST';
  1165.       if (options.emulateJSON) params.data._method = type;
  1166.       var beforeSend = options.beforeSend;
  1167.       options.beforeSend = function(xhr) {
  1168.         xhr.setRequestHeader('X-HTTP-Method-Override', type);
  1169.         if (beforeSend) return beforeSend.apply(this, arguments);
  1170.       };
  1171.     }
  1172.  
  1173.     // Don't process data on a non-GET request.
  1174.     if (params.type !== 'GET' && !options.emulateJSON) {
  1175.       params.processData = false;
  1176.     }
  1177.  
  1178.     // If we're sending a `PATCH` request, and we're in an old Internet Explorer
  1179.     // that still has ActiveX enabled by default, override jQuery to use that
  1180.     // for XHR instead. Remove this line when jQuery supports `PATCH` on IE8.
  1181.     if (params.type === 'PATCH' && noXhrPatch) {
  1182.       params.xhr = function() {
  1183.         return new ActiveXObject("Microsoft.XMLHTTP");
  1184.       };
  1185.     }
  1186.  
  1187.     // Make the request, allowing the user to override any Ajax options.
  1188.     var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
  1189.     model.trigger('request', model, xhr, options);
  1190.     return xhr;
  1191.   };
  1192.  
  1193.   var noXhrPatch =
  1194.     typeof window !== 'undefined' && !!window.ActiveXObject &&
  1195.       !(window.XMLHttpRequest && (new XMLHttpRequest).dispatchEvent);
  1196.  
  1197.   // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
  1198.   var methodMap = {
  1199.     'create': 'POST',
  1200.     'update': 'PUT',
  1201.     'patch':  'PATCH',
  1202.     'delete': 'DELETE',
  1203.     'read':   'GET'
  1204.   };
  1205.  
  1206.   // Set the default implementation of `Backbone.ajax` to proxy through to `$`.
  1207.   // Override this if you'd like to use a different library.
  1208.   Backbone.ajax = function() {
  1209.     return Backbone.$.ajax.apply(Backbone.$, arguments);
  1210.   };
  1211.  
  1212.   // Backbone.Router
  1213.   // ---------------
  1214.  
  1215.   // Routers map faux-URLs to actions, and fire events when routes are
  1216.   // matched. Creating a new one sets its `routes` hash, if not set statically.
  1217.   var Router = Backbone.Router = function(options) {
  1218.     options || (options = {});
  1219.     if (options.routes) this.routes = options.routes;
  1220.     this._bindRoutes();
  1221.     this.initialize.apply(this, arguments);
  1222.   };
  1223.  
  1224.   // Cached regular expressions for matching named param parts and splatted
  1225.   // parts of route strings.
  1226.   var optionalParam = /\((.*?)\)/g;
  1227.   var namedParam    = /(\(\?)?:\w+/g;
  1228.   var splatParam    = /\*\w+/g;
  1229.   var escapeRegExp  = /[\-{}\[\]+?.,\\\^$|#\s]/g;
  1230.  
  1231.   // Set up all inheritable **Backbone.Router** properties and methods.
  1232.   _.extend(Router.prototype, Events, {
  1233.  
  1234.     // Initialize is an empty function by default. Override it with your own
  1235.     // initialization logic.
  1236.     initialize: function(){},
  1237.  
  1238.     // Manually bind a single named route to a callback. For example:
  1239.     //
  1240.     //     this.route('search/:query/p:num', 'search', function(query, num) {
  1241.     //       ...
  1242.     //     });
  1243.     //
  1244.     route: function(route, name, callback) {
  1245.       if (!_.isRegExp(route)) route = this._routeToRegExp(route);
  1246.       if (_.isFunction(name)) {
  1247.         callback = name;
  1248.         name = '';
  1249.       }
  1250.       if (!callback) callback = this[name];
  1251.       var router = this;
  1252.       Backbone.history.route(route, function(fragment) {
  1253.         var args = router._extractParameters(route, fragment);
  1254.         router.execute(callback, args);
  1255.         router.trigger.apply(router, ['route:' + name].concat(args));
  1256.         router.trigger('route', name, args);
  1257.         Backbone.history.trigger('route', router, name, args);
  1258.       });
  1259.       return this;
  1260.     },
  1261.  
  1262.     // Execute a route handler with the provided parameters.  This is an
  1263.     // excellent place to do pre-route setup or post-route cleanup.
  1264.     execute: function(callback, args) {
  1265.       if (callback) callback.apply(this, args);
  1266.     },
  1267.  
  1268.     // Simple proxy to `Backbone.history` to save a fragment into the history.
  1269.     navigate: function(fragment, options) {
  1270.       Backbone.history.navigate(fragment, options);
  1271.       return this;
  1272.     },
  1273.  
  1274.     // Bind all defined routes to `Backbone.history`. We have to reverse the
  1275.     // order of the routes here to support behavior where the most general
  1276.     // routes can be defined at the bottom of the route map.
  1277.     _bindRoutes: function() {
  1278.       if (!this.routes) return;
  1279.       this.routes = _.result(this, 'routes');
  1280.       var route, routes = _.keys(this.routes);
  1281.       while ((route = routes.pop()) != null) {
  1282.         this.route(route, this.routes[route]);
  1283.       }
  1284.     },
  1285.  
  1286.     // Convert a route string into a regular expression, suitable for matching
  1287.     // against the current location hash.
  1288.     _routeToRegExp: function(route) {
  1289.       route = route.replace(escapeRegExp, '\\$&')
  1290.                    .replace(optionalParam, '(?:$1)?')
  1291.                    .replace(namedParam, function(match, optional) {
  1292.                      return optional ? match : '([^/?]+)';
  1293.                    })
  1294.                    .replace(splatParam, '([^?]*?)');
  1295.       return new RegExp('^' + route + '(?:\\?([\\s\\S]*))?$');
  1296.     },
  1297.  
  1298.     // Given a route, and a URL fragment that it matches, return the array of
  1299.     // extracted decoded parameters. Empty or unmatched parameters will be
  1300.     // treated as `null` to normalize cross-browser behavior.
  1301.     _extractParameters: function(route, fragment) {
  1302.       var params = route.exec(fragment).slice(1);
  1303.       return _.map(params, function(param, i) {
  1304.         // Don't decode the search params.
  1305.         if (i === params.length - 1) return param || null;
  1306.         return param ? decodeURIComponent(param) : null;
  1307.       });
  1308.     }
  1309.  
  1310.   });
  1311.  
  1312.   // Backbone.History
  1313.   // ----------------
  1314.  
  1315.   // Handles cross-browser history management, based on either
  1316.   // [pushState](http://diveintohtml5.info/history.html) and real URLs, or
  1317.   // [onhashchange](https://developer.mozilla.org/en-US/docs/DOM/window.onhashchange)
  1318.   // and URL fragments. If the browser supports neither (old IE, natch),
  1319.   // falls back to polling.
  1320.   var History = Backbone.History = function() {
  1321.     this.handlers = [];
  1322.     _.bindAll(this, 'checkUrl');
  1323.  
  1324.     // Ensure that `History` can be used outside of the browser.
  1325.     if (typeof window !== 'undefined') {
  1326.       this.location = window.location;
  1327.       this.history = window.history;
  1328.     }
  1329.   };
  1330.  
  1331.   // Cached regex for stripping a leading hash/slash and trailing space.
  1332.   var routeStripper = /^[#\/]|\s+$/g;
  1333.  
  1334.   // Cached regex for stripping leading and trailing slashes.
  1335.   var rootStripper = /^\/+|\/+$/g;
  1336.  
  1337.   // Cached regex for detecting MSIE.
  1338.   var isExplorer = /msie [\w.]+/;
  1339.  
  1340.   // Cached regex for removing a trailing slash.
  1341.   var trailingSlash = /\/$/;
  1342.  
  1343.   // Cached regex for stripping urls of hash.
  1344.   var pathStripper = /#.*$/;
  1345.  
  1346.   // Has the history handling already been started?
  1347.   History.started = false;
  1348.  
  1349.   // Set up all inheritable **Backbone.History** properties and methods.
  1350.   _.extend(History.prototype, Events, {
  1351.  
  1352.     // The default interval to poll for hash changes, if necessary, is
  1353.     // twenty times a second.
  1354.     interval: 50,
  1355.  
  1356.     // Are we at the app root?
  1357.     atRoot: function() {
  1358.       return this.location.pathname.replace(/[^\/]$/, '$&/') === this.root;
  1359.     },
  1360.  
  1361.     // Gets the true hash value. Cannot use location.hash directly due to bug
  1362.     // in Firefox where location.hash will always be decoded.
  1363.     getHash: function(window) {
  1364.       var match = (window || this).location.href.match(/#(.*)$/);
  1365.       return match ? match[1] : '';
  1366.     },
  1367.  
  1368.     // Get the cross-browser normalized URL fragment, either from the URL,
  1369.     // the hash, or the override.
  1370.     getFragment: function(fragment, forcePushState) {
  1371.       if (fragment == null) {
  1372.         if (this._hasPushState || !this._wantsHashChange || forcePushState) {
  1373.           fragment = decodeURI(this.location.pathname + this.location.search);
  1374.           var root = this.root.replace(trailingSlash, '');
  1375.           if (!fragment.indexOf(root)) fragment = fragment.slice(root.length);
  1376.         } else {
  1377.           fragment = this.getHash();
  1378.         }
  1379.       }
  1380.       return fragment.replace(routeStripper, '');
  1381.     },
  1382.  
  1383.     // Start the hash change handling, returning `true` if the current URL matches
  1384.     // an existing route, and `false` otherwise.
  1385.     start: function(options) {
  1386.       if (History.started) throw new Error("Backbone.history has already been started");
  1387.       History.started = true;
  1388.  
  1389.       // Figure out the initial configuration. Do we need an iframe?
  1390.       // Is pushState desired ... is it available?
  1391.       this.options          = _.extend({root: '/'}, this.options, options);
  1392.       this.root             = this.options.root;
  1393.       this._wantsHashChange = this.options.hashChange !== false;
  1394.       this._wantsPushState  = !!this.options.pushState;
  1395.       this._hasPushState    = !!(this.options.pushState && this.history && this.history.pushState);
  1396.       var fragment          = this.getFragment();
  1397.       var docMode           = document.documentMode;
  1398.       var oldIE             = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
  1399.  
  1400.       // Normalize root to always include a leading and trailing slash.
  1401.       this.root = ('/' + this.root + '/').replace(rootStripper, '/');
  1402.  
  1403.       if (oldIE && this._wantsHashChange) {
  1404.         var frame = Backbone.$('<iframe src="javascript:0" tabindex="-1">');
  1405.         this.iframe = frame.hide().appendTo('body')[0].contentWindow;
  1406.         this.navigate(fragment);
  1407.       }
  1408.  
  1409.       // Depending on whether we're using pushState or hashes, and whether
  1410.       // 'onhashchange' is supported, determine how we check the URL state.
  1411.       if (this._hasPushState) {
  1412.         Backbone.$(window).on('popstate', this.checkUrl);
  1413.       } else if (this._wantsHashChange && ('onhashchange' in window) && !oldIE) {
  1414.         Backbone.$(window).on('hashchange', this.checkUrl);
  1415.       } else if (this._wantsHashChange) {
  1416.         this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
  1417.       }
  1418.  
  1419.       // Determine if we need to change the base url, for a pushState link
  1420.       // opened by a non-pushState browser.
  1421.       this.fragment = fragment;
  1422.       var loc = this.location;
  1423.  
  1424.       // Transition from hashChange to pushState or vice versa if both are
  1425.       // requested.
  1426.       if (this._wantsHashChange && this._wantsPushState) {
  1427.  
  1428.         // If we've started off with a route from a `pushState`-enabled
  1429.         // browser, but we're currently in a browser that doesn't support it...
  1430.         if (!this._hasPushState && !this.atRoot()) {
  1431.           this.fragment = this.getFragment(null, true);
  1432.           this.location.replace(this.root + '#' + this.fragment);
  1433.           // Return immediately as browser will do redirect to new url
  1434.           return true;
  1435.  
  1436.         // Or if we've started out with a hash-based route, but we're currently
  1437.         // in a browser where it could be `pushState`-based instead...
  1438.         } else if (this._hasPushState && this.atRoot() && loc.hash) {
  1439.           this.fragment = this.getHash().replace(routeStripper, '');
  1440.           this.history.replaceState({}, document.title, this.root + this.fragment);
  1441.         }
  1442.  
  1443.       }
  1444.  
  1445.       if (!this.options.silent) return this.loadUrl();
  1446.     },
  1447.  
  1448.     // Disable Backbone.history, perhaps temporarily. Not useful in a real app,
  1449.     // but possibly useful for unit testing Routers.
  1450.     stop: function() {
  1451.       Backbone.$(window).off('popstate', this.checkUrl).off('hashchange', this.checkUrl);
  1452.       if (this._checkUrlInterval) clearInterval(this._checkUrlInterval);
  1453.       History.started = false;
  1454.     },
  1455.  
  1456.     // Add a route to be tested when the fragment changes. Routes added later
  1457.     // may override previous routes.
  1458.     route: function(route, callback) {
  1459.       this.handlers.unshift({route: route, callback: callback});
  1460.     },
  1461.  
  1462.     // Checks the current URL to see if it has changed, and if it has,
  1463.     // calls `loadUrl`, normalizing across the hidden iframe.
  1464.     checkUrl: function(e) {
  1465.       var current = this.getFragment();
  1466.       if (current === this.fragment && this.iframe) {
  1467.         current = this.getFragment(this.getHash(this.iframe));
  1468.       }
  1469.       if (current === this.fragment) return false;
  1470.       if (this.iframe) this.navigate(current);
  1471.       this.loadUrl();
  1472.     },
  1473.  
  1474.     // Attempt to load the current URL fragment. If a route succeeds with a
  1475.     // match, returns `true`. If no defined routes matches the fragment,
  1476.     // returns `false`.
  1477.     loadUrl: function(fragment) {
  1478.       fragment = this.fragment = this.getFragment(fragment);
  1479.       return _.any(this.handlers, function(handler) {
  1480.         if (handler.route.test(fragment)) {
  1481.           handler.callback(fragment);
  1482.           return true;
  1483.         }
  1484.       });
  1485.     },
  1486.  
  1487.     // Save a fragment into the hash history, or replace the URL state if the
  1488.     // 'replace' option is passed. You are responsible for properly URL-encoding
  1489.     // the fragment in advance.
  1490.     //
  1491.     // The options object can contain `trigger: true` if you wish to have the
  1492.     // route callback be fired (not usually desirable), or `replace: true`, if
  1493.     // you wish to modify the current URL without adding an entry to the history.
  1494.     navigate: function(fragment, options) {
  1495.       if (!History.started) return false;
  1496.       if (!options || options === true) options = {trigger: !!options};
  1497.  
  1498.       var url = this.root + (fragment = this.getFragment(fragment || ''));
  1499.  
  1500.       // Strip the hash for matching.
  1501.       fragment = fragment.replace(pathStripper, '');
  1502.  
  1503.       if (this.fragment === fragment) return;
  1504.       this.fragment = fragment;
  1505.  
  1506.       // Don't include a trailing slash on the root.
  1507.       if (fragment === '' && url !== '/') url = url.slice(0, -1);
  1508.  
  1509.       // If pushState is available, we use it to set the fragment as a real URL.
  1510.       if (this._hasPushState) {
  1511.         this.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, url);
  1512.  
  1513.       // If hash changes haven't been explicitly disabled, update the hash
  1514.       // fragment to store history.
  1515.       } else if (this._wantsHashChange) {
  1516.         this._updateHash(this.location, fragment, options.replace);
  1517.         if (this.iframe && (fragment !== this.getFragment(this.getHash(this.iframe)))) {
  1518.           // Opening and closing the iframe tricks IE7 and earlier to push a
  1519.           // history entry on hash-tag change.  When replace is true, we don't
  1520.           // want this.
  1521.           if(!options.replace) this.iframe.document.open().close();
  1522.           this._updateHash(this.iframe.location, fragment, options.replace);
  1523.         }
  1524.  
  1525.       // If you've told us that you explicitly don't want fallback hashchange-
  1526.       // based history, then `navigate` becomes a page refresh.
  1527.       } else {
  1528.         return this.location.assign(url);
  1529.       }
  1530.       if (options.trigger) return this.loadUrl(fragment);
  1531.     },
  1532.  
  1533.     // Update the hash location, either replacing the current entry, or adding
  1534.     // a new one to the browser history.
  1535.     _updateHash: function(location, fragment, replace) {
  1536.       if (replace) {
  1537.         var href = location.href.replace(/(javascript:|#).*$/, '');
  1538.         location.replace(href + '#' + fragment);
  1539.       } else {
  1540.         // Some browsers require that `hash` contains a leading #.
  1541.         location.hash = '#' + fragment;
  1542.       }
  1543.     }
  1544.  
  1545.   });
  1546.  
  1547.   // Create the default Backbone.history.
  1548.   Backbone.history = new History;
  1549.  
  1550.   // Helpers
  1551.   // -------
  1552.  
  1553.   // Helper function to correctly set up the prototype chain, for subclasses.
  1554.   // Similar to `goog.inherits`, but uses a hash of prototype properties and
  1555.   // class properties to be extended.
  1556.   var extend = function(protoProps, staticProps) {
  1557.     var parent = this;
  1558.     var child;
  1559.  
  1560.     // The constructor function for the new subclass is either defined by you
  1561.     // (the "constructor" property in your `extend` definition), or defaulted
  1562.     // by us to simply call the parent's constructor.
  1563.     if (protoProps && _.has(protoProps, 'constructor')) {
  1564.       child = protoProps.constructor;
  1565.     } else {
  1566.       child = function(){ return parent.apply(this, arguments); };
  1567.     }
  1568.  
  1569.     // Add static properties to the constructor function, if supplied.
  1570.     _.extend(child, parent, staticProps);
  1571.  
  1572.     // Set the prototype chain to inherit from `parent`, without calling
  1573.     // `parent`'s constructor function.
  1574.     var Surrogate = function(){ this.constructor = child; };
  1575.     Surrogate.prototype = parent.prototype;
  1576.     child.prototype = new Surrogate;
  1577.  
  1578.     // Add prototype properties (instance properties) to the subclass,
  1579.     // if supplied.
  1580.     if (protoProps) _.extend(child.prototype, protoProps);
  1581.  
  1582.     // Set a convenience property in case the parent's prototype is needed
  1583.     // later.
  1584.     child.__super__ = parent.prototype;
  1585.  
  1586.     return child;
  1587.   };
  1588.  
  1589.   // Set up inheritance for the model, collection, router, view and history.
  1590.   Model.extend = Collection.extend = Router.extend = View.extend = History.extend = extend;
  1591.  
  1592.   // Throw an error when a URL is needed, and none is supplied.
  1593.   var urlError = function() {
  1594.     throw new Error('A "url" property or function must be specified');
  1595.   };
  1596.  
  1597.   // Wrap an optional error callback with a fallback error event.
  1598.   var wrapError = function(model, options) {
  1599.     var error = options.error;
  1600.     options.error = function(resp) {
  1601.       if (error) error(model, resp, options);
  1602.       model.trigger('error', model, resp, options);
  1603.     };
  1604.   };
  1605.  
  1606.   return Backbone;
  1607.  
  1608. }));
  1609.  
  1610. // https://c.disquscdn.com/next/node_modules/backbone/backbone.js

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