comparison src/DML/VendorAssetsBundle/Resources/assets/backbone/1.1.2_modif/backbone.js @ 0:493bcb69166c

added public content

+//     Backbone.js 1.1.2
+
+//     (c) 2010-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+//     Backbone may be freely distributed under the MIT license.
+//     For all details and documentation:
+//     http://backbonejs.org
+
+(function(root, factory) {
+
+  // Set up Backbone appropriately for the environment. Start with AMD.
+  if (typeof define === 'function' && define.amd) {
+    define(['underscore', 'jquery', 'exports'], function(_, $, exports) {
+      // Export global even in AMD case in case this script is loaded with
+      // others that may still expect a global Backbone.
+      root.Backbone = factory(root, exports, _, $);
+    });
+
+  // Next for Node.js or CommonJS. jQuery may not be needed as a module.
+  } else if (typeof exports !== 'undefined') {
+    var _ = require('underscore');
+    factory(root, exports, _);
+
+  // Finally, as a browser global.
+  } else {
+    root.Backbone = factory(root, {}, root._, (root.jQuery || root.Zepto || root.ender || root.$));
+  }
+
+}(this, function(root, Backbone, _, $) {
+
+  // Initial Setup
+  // -------------
+
+  // Save the previous value of the `Backbone` variable, so that it can be
+  // restored later on, if `noConflict` is used.
+  var previousBackbone = root.Backbone;
+
+  // Create local references to array methods we'll want to use later.
+  var array = [];
+  var push = array.push;
+  var slice = array.slice;
+  var splice = array.splice;
+
+  // Current version of the library. Keep in sync with `package.json`.
+  Backbone.VERSION = '1.1.2';
+
+  // For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
+  // the `$` variable.
+  Backbone.$ = $;
+
+  // Runs Backbone.js in *noConflict* mode, returning the `Backbone` variable
+  // to its previous owner. Returns a reference to this Backbone object.
+  Backbone.noConflict = function() {
+    root.Backbone = previousBackbone;
+    return this;
+  };
+
+  // Turn on `emulateHTTP` to support legacy HTTP servers. Setting this option
+  // will fake `"PATCH"`, `"PUT"` and `"DELETE"` requests via the `_method` parameter and
+  // set a `X-Http-Method-Override` header.
+  Backbone.emulateHTTP = false;
+
+  // Turn on `emulateJSON` to support legacy servers that can't deal with direct
+  // `application/json` requests ... will encode the body as
+  // `application/x-www-form-urlencoded` instead and will send the model in a
+  // form param named `model`.
+  Backbone.emulateJSON = false;
+
+  // Backbone.Events
+  // ---------------
+
+  // A module that can be mixed in to *any object* in order to provide it with
+  // custom events. You may bind with `on` or remove with `off` callback
+  // functions to an event; `trigger`-ing an event fires all callbacks in
+  // succession.
+  //
+  //     var object = {};
+  //     _.extend(object, Backbone.Events);
+  //     object.on('expand', function(){ alert('expanded'); });
+  //     object.trigger('expand');
+  //
+  var Events = Backbone.Events = {
+
+    // Bind an event to a `callback` function. Passing `"all"` will bind
+    // the callback to all events fired.
+    on: function(name, callback, context) {
+      if (!eventsApi(this, 'on', name, [callback, context]) || !callback) return this;
+      this._events || (this._events = {});
+      var events = this._events[name] || (this._events[name] = []);
+      events.push({callback: callback, context: context, ctx: context || this});
+      return this;
+    },
+
+    // Bind an event to only be triggered a single time. After the first time
+    // the callback is invoked, it will be removed.
+    once: function(name, callback, context) {
+      if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
+      var self = this;
+      var once = _.once(function() {
+        self.off(name, once);
+        callback.apply(this, arguments);
+      });
+      once._callback = callback;
+      return this.on(name, once, context);
+    },
+
+    // Remove one or many callbacks. If `context` is null, removes all
+    // callbacks with that function. If `callback` is null, removes all
+    // callbacks for the event. If `name` is null, removes all bound
+    // callbacks for all events.
+    off: function(name, callback, context) {
+      var retain, ev, events, names, i, l, j, k;
+      if (!this._events || !eventsApi(this, 'off', name, [callback, context])) return this;
+      if (!name && !callback && !context) {
+        this._events = void 0;
+        return this;
+      }
+      names = name ? [name] : _.keys(this._events);
+      for (i = 0, l = names.length; i < l; i++) {
+        name = names[i];
+        if (events = this._events[name]) {
+          this._events[name] = retain = [];
+          if (callback || context) {
+            for (j = 0, k = events.length; j < k; j++) {
+              ev = events[j];
+              if ((callback && callback !== ev.callback && callback !== ev.callback._callback) ||
+                  (context && context !== ev.context)) {
+                retain.push(ev);
+              }
+            }
+          }
+          if (!retain.length) delete this._events[name];
+        }
+      }
+
+      return this;
+    },
+
+    // Trigger one or many events, firing all bound callbacks. Callbacks are
+    // passed the same arguments as `trigger` is, apart from the event name
+    // (unless you're listening on `"all"`, which will cause your callback to
+    // receive the true name of the event as the first argument).
+    trigger: function(name) {
+      if (!this._events) return this;
+      var args = slice.call(arguments, 1);
+      if (!eventsApi(this, 'trigger', name, args)) return this;
+      var events = this._events[name];
+      var allEvents = this._events.all;
+      if (events) triggerEvents(events, args);
+      if (allEvents) triggerEvents(allEvents, arguments);
+      return this;
+    },
+
+    // Tell this object to stop listening to either specific events ... or
+    // to every object it's currently listening to.
+    stopListening: function(obj, name, callback) {
+      var listeningTo = this._listeningTo;
+      if (!listeningTo) return this;
+      var remove = !name && !callback;
+      if (!callback && typeof name === 'object') callback = this;
+      if (obj) (listeningTo = {})[obj._listenId] = obj;
+      for (var id in listeningTo) {
+        obj = listeningTo[id];
+        obj.off(name, callback, this);
+        if (remove || _.isEmpty(obj._events)) delete this._listeningTo[id];
+      }
+      return this;
+    }
+
+  };
+
+  // Regular expression used to split event strings.
+  var eventSplitter = /\s+/;
+
+  // Implement fancy features of the Events API such as multiple event
+  // names `"change blur"` and jQuery-style event maps `{change: action}`
+  // in terms of the existing API.
+  var eventsApi = function(obj, action, name, rest) {
+    if (!name) return true;
+
+    // Handle event maps.
+    if (typeof name === 'object') {
+      for (var key in name) {
+        obj[action].apply(obj, [key, name[key]].concat(rest));
+      }
+      return false;
+    }
+
+    // Handle space separated event names.
+    if (eventSplitter.test(name)) {
+      var names = name.split(eventSplitter);
+      for (var i = 0, l = names.length; i < l; i++) {
+        obj[action].apply(obj, [names[i]].concat(rest));
+      }
+      return false;
+    }
+
+    return true;
+  };
+
+  // A difficult-to-believe, but optimized internal dispatch function for
+  // triggering events. Tries to keep the usual cases speedy (most internal
+  // Backbone events have 3 arguments).
+  var triggerEvents = function(events, args) {
+    var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];
+    switch (args.length) {
+      case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;
+      case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;
+      case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;
+      case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;
+      default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args); return;
+    }
+  };
+
+  var listenMethods = {listenTo: 'on', listenToOnce: 'once'};
+
+  // Inversion-of-control versions of `on` and `once`. Tell *this* object to
+  // listen to an event in another object ... keeping track of what it's
+  // listening to.
+  _.each(listenMethods, function(implementation, method) {
+    Events[method] = function(obj, name, callback) {
+      var listeningTo = this._listeningTo || (this._listeningTo = {});
+      var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
+      listeningTo[id] = obj;
+      if (!callback && typeof name === 'object') callback = this;
+      obj[implementation](name, callback, this);
+      return this;
+    };
+  });
+
+  // Aliases for backwards compatibility.
+  Events.bind   = Events.on;
+  Events.unbind = Events.off;
+
+  // Allow the `Backbone` object to serve as a global event bus, for folks who
+  // want global "pubsub" in a convenient place.
+  _.extend(Backbone, Events);
+
+  // Backbone.Model
+  // --------------
+
+  // Backbone **Models** are the basic data object in the framework --
+  // frequently representing a row in a table in a database on your server.
+  // A discrete chunk of data and a bunch of useful, related methods for
+  // performing computations and transformations on that data.
+
+  // Create a new model with the specified attributes. A client id (`cid`)
+  // is automatically generated and assigned for you.
+  var Model = Backbone.Model = function(attributes, options) {
+    var attrs = attributes || {};
+    options || (options = {});
+    //MODIFIED
+    //this.cid = _.uniqueId('c');
+    this.cid = _.uniqueId(this.cidPrefix || 'c');
+    this.attributes = {};
+    if (options.collection) this.collection = options.collection;
+    if (options.parse) attrs = this.parse(attrs, options) || {};
+    attrs = _.defaults({}, attrs, _.result(this, 'defaults'));
+    this.set(attrs, options);
+    this.changed = {};
+    this.initialize.apply(this, arguments);
+  };
+
+  // Attach all inheritable methods to the Model prototype.
+  _.extend(Model.prototype, Events, {
+
+    // A hash of attributes whose current and previous value differ.
+    changed: null,
+
+    // The value returned during the last failed validation.
+    validationError: null,
+
+    // The default name for the JSON `id` attribute is `"id"`. MongoDB and
+    // CouchDB users may want to set this to `"_id"`.
+    idAttribute: 'id',
+
+    // Initialize is an empty function by default. Override it with your own
+    // initialization logic.
+    initialize: function(){},
+
+    // Return a copy of the model's `attributes` object.
+    toJSON: function(options) {
+      return _.clone(this.attributes);
+    },
+
+    // Proxy `Backbone.sync` by default -- but override this if you need
+    // custom syncing semantics for *this* particular model.
+    sync: function() {
+      return Backbone.sync.apply(this, arguments);
+    },
+
+    // Get the value of an attribute.
+    get: function(attr) {
+      return this.attributes[attr];
+    },
+
+    // Get the HTML-escaped value of an attribute.
+    escape: function(attr) {
+      return _.escape(this.get(attr));
+    },
+
+    // Returns `true` if the attribute contains a value that is not null
+    // or undefined.
+    has: function(attr) {
+      return this.get(attr) != null;
+    },
+
+    // Set a hash of model attributes on the object, firing `"change"`. This is
+    // the core primitive operation of a model, updating the data and notifying
+    // anyone who needs to know about the change in state. The heart of the beast.
+    set: function(key, val, options) {
+      var attr, attrs, unset, changes, silent, changing, prev, current;
+      if (key == null) return this;
+
+      // Handle both `"key", value` and `{key: value}` -style arguments.
+      if (typeof key === 'object') {
+        attrs = key;
+        options = val;
+      } else {
+        (attrs = {})[key] = val;
+      }
+
+      options || (options = {});
+
+      // Run validation.
+      if (!this._validate(attrs, options)) return false;
+
+      // Extract attributes and options.
+      unset           = options.unset;
+      silent          = options.silent;
+      changes         = [];
+      changing        = this._changing;
+      this._changing  = true;
+
+      if (!changing) {
+        this._previousAttributes = _.clone(this.attributes);
+        this.changed = {};
+      }
+      current = this.attributes, prev = this._previousAttributes;
+
+      // Check for changes of `id`.
+      if (this.idAttribute in attrs) this.id = attrs[this.idAttribute];
+
+      // For each `set` attribute, update or delete the current value.
+      for (attr in attrs) {
+        val = attrs[attr];
+        if (!_.isEqual(current[attr], val)) changes.push(attr);
+        if (!_.isEqual(prev[attr], val)) {
+          this.changed[attr] = val;
+        } else {
+          delete this.changed[attr];
+        }
+        unset ? delete current[attr] : current[attr] = val;
+      }
+
+      // Trigger all relevant attribute changes.
+      if (!silent) {
+        if (changes.length) this._pending = options;
+        for (var i = 0, l = changes.length; i < l; i++) {
+          this.trigger('change:' + changes[i], this, current[changes[i]], options);
+        }
+      }
+
+      // You might be wondering why there's a `while` loop here. Changes can
+      // be recursively nested within `"change"` events.
+      if (changing) return this;
+      if (!silent) {
+        while (this._pending) {
+          options = this._pending;
+          this._pending = false;
+          this.trigger('change', this, options);
+        }
+      }
+      this._pending = false;
+      this._changing = false;
+      return this;
+    },
+
+    // Remove an attribute from the model, firing `"change"`. `unset` is a noop
+    // if the attribute doesn't exist.
+    unset: function(attr, options) {
+      return this.set(attr, void 0, _.extend({}, options, {unset: true}));
+    },
+
+    // Clear all attributes on the model, firing `"change"`.
+    clear: function(options) {
+      var attrs = {};
+      for (var key in this.attributes) attrs[key] = void 0;
+      return this.set(attrs, _.extend({}, options, {unset: true}));
+    },
+
+    // Determine if the model has changed since the last `"change"` event.
+    // If you specify an attribute name, determine if that attribute has changed.
+    hasChanged: function(attr) {
+      if (attr == null) return !_.isEmpty(this.changed);
+      return _.has(this.changed, attr);
+    },
+
+    // Return an object containing all the attributes that have changed, or
+    // false if there are no changed attributes. Useful for determining what
+    // parts of a view need to be updated and/or what attributes need to be
+    // persisted to the server. Unset attributes will be set to undefined.
+    // You can also pass an attributes object to diff against the model,
+    // determining if there *would be* a change.
+    changedAttributes: function(diff) {
+      if (!diff) return this.hasChanged() ? _.clone(this.changed) : false;
+      var val, changed = false;
+      var old = this._changing ? this._previousAttributes : this.attributes;
+      for (var attr in diff) {
+        if (_.isEqual(old[attr], (val = diff[attr]))) continue;
+        (changed || (changed = {}))[attr] = val;
+      }
+      return changed;
+    },
+
+    // Get the previous value of an attribute, recorded at the time the last
+    // `"change"` event was fired.
+    previous: function(attr) {
+      if (attr == null || !this._previousAttributes) return null;
+      return this._previousAttributes[attr];
+    },
+
+    // Get all of the attributes of the model at the time of the previous
+    // `"change"` event.
+    previousAttributes: function() {
+      return _.clone(this._previousAttributes);
+    },
+
+    // Fetch the model from the server. If the server's representation of the
+    // model differs from its current attributes, they will be overridden,
+    // triggering a `"change"` event.
+    fetch: function(options) {
+      options = options ? _.clone(options) : {};
+      if (options.parse === void 0) options.parse = true;
+      var model = this;
+      var success = options.success;
+      options.success = function(resp) {
+        if (!model.set(model.parse(resp, options), options)) return false;
+        if (success) success(model, resp, options);
+        model.trigger('sync', model, resp, options);
+      };
+      wrapError(this, options);
+      return this.sync('read', this, options);
+    },
+
+    // Set a hash of model attributes, and sync the model to the server.
+    // If the server returns an attributes hash that differs, the model's
+    // state will be `set` again.
+    save: function(key, val, options) {
+      var attrs, method, xhr, attributes = this.attributes;
+
+      // Handle both `"key", value` and `{key: value}` -style arguments.
+      if (key == null || typeof key === 'object') {
+        attrs = key;
+        options = val;
+      } else {
+        (attrs = {})[key] = val;
+      }
+
+      options = _.extend({validate: true}, options);
+
+      // If we're not waiting and attributes exist, save acts as
+      // `set(attr).save(null, opts)` with validation. Otherwise, check if
+      // the model will be valid when the attributes, if any, are set.
+      if (attrs && !options.wait) {
+        if (!this.set(attrs, options)) return false;
+      } else {
+        if (!this._validate(attrs, options)) return false;
+      }
+
+      // Set temporary attributes if `{wait: true}`.
+      if (attrs && options.wait) {
+        this.attributes = _.extend({}, attributes, attrs);
+      }
+
+      // After a successful server-side save, the client is (optionally)
+      // updated with the server-side state.
+      if (options.parse === void 0) options.parse = true;
+      var model = this;
+      var success = options.success;
+      options.success = function(resp) {
+        // Ensure attributes are restored during synchronous saves.
+        model.attributes = attributes;
+        var serverAttrs = model.parse(resp, options);
+        if (options.wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
+        if (_.isObject(serverAttrs) && !model.set(serverAttrs, options)) {
+          return false;
+        }
+        if (success) success(model, resp, options);
+        model.trigger('sync', model, resp, options);
+      };
+      wrapError(this, options);
+
+      method = this.isNew() ? 'create' : (options.patch ? 'patch' : 'update');
+      if (method === 'patch') options.attrs = attrs;
+      xhr = this.sync(method, this, options);
+
+      // Restore attributes.
+      if (attrs && options.wait) this.attributes = attributes;
+
+      return xhr;
+    },
+
+    // Destroy this model on the server if it was already persisted.
+    // Optimistically removes the model from its collection, if it has one.
+    // If `wait: true` is passed, waits for the server to respond before removal.
+    destroy: function(options) {
+      options = options ? _.clone(options) : {};
+      var model = this;
+      var success = options.success;
+
+      var destroy = function() {
+        model.trigger('destroy', model, model.collection, options);
+      };
+
+      options.success = function(resp) {
+        if (options.wait || model.isNew()) destroy();
+        if (success) success(model, resp, options);
+        if (!model.isNew()) model.trigger('sync', model, resp, options);
+      };
+
+      if (this.isNew()) {
+        options.success();
+        return false;
+      }
+      wrapError(this, options);
+
+      var xhr = this.sync('delete', this, options);
+      if (!options.wait) destroy();
+      return xhr;
+    },
+
+    // Default URL for the model's representation on the server -- if you're
+    // using Backbone's restful methods, override this to change the endpoint
+    // that will be called.
+    url: function() {
+      var base =
+        _.result(this, 'urlRoot') ||
+        _.result(this.collection, 'url') ||
+        urlError();
+      if (this.isNew()) return base;
+      return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(this.id);
+    },
+
+    // **parse** converts a response into the hash of attributes to be `set` on
+    // the model. The default implementation is just to pass the response along.
+    parse: function(resp, options) {
+      return resp;
+    },
+
+    // Create a new model with identical attributes to this one.
+    clone: function() {
+      return new this.constructor(this.attributes);
+    },
+
+    // A model is new if it has never been saved to the server, and lacks an id.
+    isNew: function() {
+      return !this.has(this.idAttribute);
+    },
+
+    // Check if the model is currently in a valid state.
+    isValid: function(options) {
+      return this._validate({}, _.extend(options || {}, { validate: true }));
+    },
+
+    // Run validation against the next complete set of model attributes,
+    // returning `true` if all is well. Otherwise, fire an `"invalid"` event.
+    _validate: function(attrs, options) {
+      if (!options.validate || !this.validate) return true;
+      attrs = _.extend({}, this.attributes, attrs);
+      var error = this.validationError = this.validate(attrs, options) || null;
+      if (!error) return true;
+      this.trigger('invalid', this, error, _.extend(options, {validationError: error}));
+      return false;
+    }
+
+  });
+
+  // Underscore methods that we want to implement on the Model.
+  var modelMethods = ['keys', 'values', 'pairs', 'invert', 'pick', 'omit'];
+
+  // Mix in each Underscore method as a proxy to `Model#attributes`.
+  _.each(modelMethods, function(method) {
+    Model.prototype[method] = function() {
+      var args = slice.call(arguments);
+      args.unshift(this.attributes);
+      return _[method].apply(_, args);
+    };
+  });
+
+  // Backbone.Collection
+  // -------------------
+
+  // If models tend to represent a single row of data, a Backbone Collection is
+  // more analagous to a table full of data ... or a small slice or page of that
+  // table, or a collection of rows that belong together for a particular reason
+  // -- all of the messages in this particular folder, all of the documents
+  // belonging to this particular author, and so on. Collections maintain
+  // indexes of their models, both in order, and for lookup by `id`.
+
+  // Create a new **Collection**, perhaps to contain a specific type of `model`.
+  // If a `comparator` is specified, the Collection will maintain
+  // its models in sort order, as they're added and removed.
+  var Collection = Backbone.Collection = function(models, options) {
+    options || (options = {});
+    if (options.model) this.model = options.model;
+    if (options.comparator !== void 0) this.comparator = options.comparator;
+    this._reset();
+    this.initialize.apply(this, arguments);
+    if (models) this.reset(models, _.extend({silent: true}, options));
+  };
+
+  // Default options for `Collection#set`.
+  var setOptions = {add: true, remove: true, merge: true};
+  var addOptions = {add: true, remove: false};
+
+  // Define the Collection's inheritable methods.
+  _.extend(Collection.prototype, Events, {
+
+    // The default model for a collection is just a **Backbone.Model**.
+    // This should be overridden in most cases.
+    model: Model,
+
+    // Initialize is an empty function by default. Override it with your own
+    // initialization logic.
+    initialize: function(){},
+
+    // The JSON representation of a Collection is an array of the
+    // models' attributes.
+    toJSON: function(options) {
+      return this.map(function(model){ return model.toJSON(options); });
+    },
+
+    // Proxy `Backbone.sync` by default.
+    sync: function() {
+      return Backbone.sync.apply(this, arguments);
+    },
+
+    // Add a model, or list of models to the set.
+    add: function(models, options) {
+      return this.set(models, _.extend({merge: false}, options, addOptions));
+    },
+
+    // Remove a model, or a list of models from the set.
+    remove: function(models, options) {
+      var singular = !_.isArray(models);
+      models = singular ? [models] : _.clone(models);
+      options || (options = {});
+      var i, l, index, model;
+      for (i = 0, l = models.length; i < l; i++) {
+        model = models[i] = this.get(models[i]);
+        if (!model) continue;
+        delete this._byId[model.id];
+        delete this._byId[model.cid];
+        index = this.indexOf(model);
+        this.models.splice(index, 1);
+        this.length--;
+        if (!options.silent) {
+          options.index = index;
+          model.trigger('remove', model, this, options);
+        }
+        this._removeReference(model, options);
+      }
+      return singular ? models[0] : models;
+    },
+
+    // Update a collection by `set`-ing a new list of models, adding new ones,
+    // removing models that are no longer present, and merging models that
+    // already exist in the collection, as necessary. Similar to **Model#set**,
+    // the core operation for updating the data contained by the collection.
+    set: function(models, options) {
+      options = _.defaults({}, options, setOptions);
+      if (options.parse) models = this.parse(models, options);
+      var singular = !_.isArray(models);
+      models = singular ? (models ? [models] : []) : _.clone(models);
+      var i, l, id, model, attrs, existing, sort;
+      var at = options.at;
+      var targetModel = this.model;
+      var sortable = this.comparator && (at == null) && options.sort !== false;
+      var sortAttr = _.isString(this.comparator) ? this.comparator : null;
+      var toAdd = [], toRemove = [], modelMap = {};
+      var add = options.add, merge = options.merge, remove = options.remove;
+      var order = !sortable && add && remove ? [] : false;
+
+      // Turn bare objects into model references, and prevent invalid models
+      // from being added.
+      for (i = 0, l = models.length; i < l; i++) {
+        attrs = models[i] || {};
+        if (attrs instanceof Model) {
+          id = model = attrs;
+        } else {
+          id = attrs[targetModel.prototype.idAttribute || 'id'];
+        }
+
+        // If a duplicate is found, prevent it from being added and
+        // optionally merge it into the existing model.
+        if (existing = this.get(id)) {
+          if (remove) modelMap[existing.cid] = true;
+          if (merge) {
+            attrs = attrs === model ? model.attributes : attrs;
+            if (options.parse) attrs = existing.parse(attrs, options);
+            existing.set(attrs, options);
+            if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
+          }
+          models[i] = existing;
+
+        // If this is a new, valid model, push it to the `toAdd` list.
+        } else if (add) {
+          model = models[i] = this._prepareModel(attrs, options);
+          if (!model) continue;
+          toAdd.push(model);
+          this._addReference(model, options);
+        }
+
+        // Do not add multiple models with the same `id`.
+        model = existing || model;
+        if (order && (model.isNew() || !modelMap[model.id])) order.push(model);
+        modelMap[model.id] = true;
+      }
+
+      // Remove nonexistent models if appropriate.
+      if (remove) {
+        for (i = 0, l = this.length; i < l; ++i) {
+          if (!modelMap[(model = this.models[i]).cid]) toRemove.push(model);
+        }
+        if (toRemove.length) this.remove(toRemove, options);
+      }
+
+      // See if sorting is needed, update `length` and splice in new models.
+      if (toAdd.length || (order && order.length)) {
+        if (sortable) sort = true;
+        this.length += toAdd.length;
+        if (at != null) {
+          for (i = 0, l = toAdd.length; i < l; i++) {
+            this.models.splice(at + i, 0, toAdd[i]);
+          }
+        } else {
+          if (order) this.models.length = 0;
+          var orderedModels = order || toAdd;
+          for (i = 0, l = orderedModels.length; i < l; i++) {
+            this.models.push(orderedModels[i]);
+          }
+        }
+      }
+
+      // Silently sort the collection if appropriate.
+      if (sort) this.sort({silent: true});
+
+      // Unless silenced, it's time to fire all appropriate add/sort events.
+      if (!options.silent) {
+        for (i = 0, l = toAdd.length; i < l; i++) {
+          (model = toAdd[i]).trigger('add', model, this, options);
+        }
+        if (sort || (order && order.length)) this.trigger('sort', this, options);
+      }
+
+      // Return the added (or merged) model (or models).
+      return singular ? models[0] : models;
+    },
+
+    // When you have more items than you want to add or remove individually,
+    // you can reset the entire set with a new list of models, without firing
+    // any granular `add` or `remove` events. Fires `reset` when finished.
+    // Useful for bulk operations and optimizations.
+    reset: function(models, options) {
+      options || (options = {});
+      for (var i = 0, l = this.models.length; i < l; i++) {
+        this._removeReference(this.models[i], options);
+      }
+      options.previousModels = this.models;
+      this._reset();
+      models = this.add(models, _.extend({silent: true}, options));
+      if (!options.silent) this.trigger('reset', this, options);
+      return models;
+    },
+
+    // Add a model to the end of the collection.
+    push: function(model, options) {
+      return this.add(model, _.extend({at: this.length}, options));
+    },
+
+    // Remove a model from the end of the collection.
+    pop: function(options) {
+      var model = this.at(this.length - 1);
+      this.remove(model, options);
+      return model;
+    },
+
+    // Add a model to the beginning of the collection.
+    unshift: function(model, options) {
+      return this.add(model, _.extend({at: 0}, options));
+    },
+
+    // Remove a model from the beginning of the collection.
+    shift: function(options) {
+      var model = this.at(0);
+      this.remove(model, options);
+      return model;
+    },
+
+    // Slice out a sub-array of models from the collection.
+    slice: function() {
+      return slice.apply(this.models, arguments);
+    },
+
+    // Get a model from the set by id.
+    get: function(obj) {
+      if (obj == null) return void 0;
+      return this._byId[obj] || this._byId[obj.id] || this._byId[obj.cid];
+    },
+
+    // Get the model at the given index.
+    at: function(index) {
+      return this.models[index];
+    },
+
+    // Return models with matching attributes. Useful for simple cases of
+    // `filter`.
+    where: function(attrs, first) {
+      if (_.isEmpty(attrs)) return first ? void 0 : [];
+      return this[first ? 'find' : 'filter'](function(model) {
+        for (var key in attrs) {
+          if (attrs[key] !== model.get(key)) return false;
+        }
+        return true;
+      });
+    },
+
+    // Return the first model with matching attributes. Useful for simple cases
+    // of `find`.
+    findWhere: function(attrs) {
+      return this.where(attrs, true);
+    },
+
+    // Force the collection to re-sort itself. You don't need to call this under
+    // normal circumstances, as the set will maintain sort order as each item
+    // is added.
+    sort: function(options) {
+      if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
+      options || (options = {});
+
+      // Run sort based on type of `comparator`.
+      if (_.isString(this.comparator) || this.comparator.length === 1) {
+        this.models = this.sortBy(this.comparator, this);
+      } else {
+        this.models.sort(_.bind(this.comparator, this));
+      }
+
+      if (!options.silent) this.trigger('sort', this, options);
+      return this;
+    },
+
+    // Pluck an attribute from each model in the collection.
+    pluck: function(attr) {
+      return _.invoke(this.models, 'get', attr);
+    },
+
+    // Fetch the default set of models for this collection, resetting the
+    // collection when they arrive. If `reset: true` is passed, the response
+    // data will be passed through the `reset` method instead of `set`.
+    fetch: function(options) {
+      options = options ? _.clone(options) : {};
+      if (options.parse === void 0) options.parse = true;
+      var success = options.success;
+      var collection = this;
+      options.success = function(resp) {
+        var method = options.reset ? 'reset' : 'set';
+        collection[method](resp, options);
+        if (success) success(collection, resp, options);
+        collection.trigger('sync', collection, resp, options);
+      };
+      wrapError(this, options);
+      return this.sync('read', this, options);
+    },
+
+    // Create a new instance of a model in this collection. Add the model to the
+    // collection immediately, unless `wait: true` is passed, in which case we
+    // wait for the server to agree.
+    create: function(model, options) {
+      options = options ? _.clone(options) : {};
+      if (!(model = this._prepareModel(model, options))) return false;
+      if (!options.wait) this.add(model, options);
+      var collection = this;
+      var success = options.success;
+      options.success = function(model, resp) {
+        if (options.wait) collection.add(model, options);
+        if (success) success(model, resp, options);
+      };
+      model.save(null, options);
+      return model;
+    },
+
+    // **parse** converts a response into a list of models to be added to the
+    // collection. The default implementation is just to pass it through.
+    parse: function(resp, options) {
+      return resp;
+    },
+
+    // Create a new collection with an identical list of models as this one.
+    clone: function() {
+      return new this.constructor(this.models);
+    },
+
+    // Private method to reset all internal state. Called when the collection
+    // is first initialized or reset.
+    _reset: function() {
+      this.length = 0;
+      this.models = [];
+      this._byId  = {};
+    },
+
+    // Prepare a hash of attributes (or other model) to be added to this
+    // collection.
+    _prepareModel: function(attrs, options) {
+      if (attrs instanceof Model) return attrs;
+      options = options ? _.clone(options) : {};
+      options.collection = this;
+      var model = new this.model(attrs, options);
+      if (!model.validationError) return model;
+      this.trigger('invalid', this, model.validationError, options);
+      return false;
+    },
+
+    // Internal method to create a model's ties to a collection.
+    _addReference: function(model, options) {
+      this._byId[model.cid] = model;
+      if (model.id != null) this._byId[model.id] = model;
+      if (!model.collection) model.collection = this;
+      model.on('all', this._onModelEvent, this);
+    },
+
+    // Internal method to sever a model's ties to a collection.
+    _removeReference: function(model, options) {
+      if (this === model.collection) delete model.collection;
+      model.off('all', this._onModelEvent, this);
+    },
+
+    // Internal method called every time a model in the set fires an event.
+    // Sets need to update their indexes when models change ids. All other
+    // events simply proxy through. "add" and "remove" events that originate
+    // in other collections are ignored.
+    _onModelEvent: function(event, model, collection, options) {
+      if ((event === 'add' || event === 'remove') && collection !== this) return;
+      if (event === 'destroy') this.remove(model, options);
+      if (model && event === 'change:' + model.idAttribute) {
+        delete this._byId[model.previous(model.idAttribute)];
+        if (model.id != null) this._byId[model.id] = model;
+      }
+      this.trigger.apply(this, arguments);
+    }
+
+  });
+
+  // Underscore methods that we want to implement on the Collection.
+  // 90% of the core usefulness of Backbone Collections is actually implemented
+  // right here:
+  var methods = ['forEach', 'each', 'map', 'collect', 'reduce', 'foldl',
+    'inject', 'reduceRight', 'foldr', 'find', 'detect', 'filter', 'select',
+    'reject', 'every', 'all', 'some', 'any', 'include', 'contains', 'invoke',
+    'max', 'min', 'toArray', 'size', 'first', 'head', 'take', 'initial', 'rest',
+    'tail', 'drop', 'last', 'without', 'difference', 'indexOf', 'shuffle',
+    'lastIndexOf', 'isEmpty', 'chain', 'sample'];
+
+  // Mix in each Underscore method as a proxy to `Collection#models`.
+  _.each(methods, function(method) {
+    Collection.prototype[method] = function() {
+      var args = slice.call(arguments);
+      args.unshift(this.models);
+      return _[method].apply(_, args);
+    };
+  });
+
+  // Underscore methods that take a property name as an argument.
+  var attributeMethods = ['groupBy', 'countBy', 'sortBy', 'indexBy'];
+
+  // Use attributes instead of properties.
+  _.each(attributeMethods, function(method) {
+    Collection.prototype[method] = function(value, context) {
+      var iterator = _.isFunction(value) ? value : function(model) {
+        return model.get(value);
+      };
+      return _[method](this.models, iterator, context);
+    };
+  });
+
+  // Backbone.View
+  // -------------
+
+  // Backbone Views are almost more convention than they are actual code. A View
+  // is simply a JavaScript object that represents a logical chunk of UI in the
+  // DOM. This might be a single item, an entire list, a sidebar or panel, or
+  // even the surrounding frame which wraps your whole app. Defining a chunk of
+  // UI as a **View** allows you to define your DOM events declaratively, without
+  // having to worry about render order ... and makes it easy for the view to
+  // react to specific changes in the state of your models.
+
+  // Creating a Backbone.View creates its initial element outside of the DOM,
+  // if an existing element is not provided...
+  var View = Backbone.View = function(options) {
+    this.cid = _.uniqueId('view');
+    options || (options = {});
+    _.extend(this, _.pick(options, viewOptions));
+    this._ensureElement();
+    this.initialize.apply(this, arguments);
+    this.delegateEvents();
+  };
+
+  // Cached regex to split keys for `delegate`.
+  var delegateEventSplitter = /^(\S+)\s*(.*)$/;
+
+  // List of view options to be merged as properties.
+  var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
+
+  // Set up all inheritable **Backbone.View** properties and methods.
+  _.extend(View.prototype, Events, {
+
+    // The default `tagName` of a View's element is `"div"`.
+    tagName: 'div',
+
+    // jQuery delegate for element lookup, scoped to DOM elements within the
+    // current view. This should be preferred to global lookups where possible.
+    $: function(selector) {
+      return this.$el.find(selector);
+    },
+
+    // Initialize is an empty function by default. Override it with your own
+    // initialization logic.
+    initialize: function(){},
+
+    // **render** is the core function that your view should override, in order
+    // to populate its element (`this.el`), with the appropriate HTML. The
+    // convention is for **render** to always return `this`.
+    render: function() {
+      return this;
+    },
+
+    // Remove this view by taking the element out of the DOM, and removing any
+    // applicable Backbone.Events listeners.
+    remove: function() {
+      this.$el.remove();
+      this.stopListening();
+      return this;
+    },
+
+    // Change the view's element (`this.el` property), including event
+    // re-delegation.
+    setElement: function(element, delegate) {
+      if (this.$el) this.undelegateEvents();
+      this.$el = element instanceof Backbone.$ ? element : Backbone.$(element);
+      this.el = this.$el[0];
+      if (delegate !== false) this.delegateEvents();
+      return this;
+    },
+
+    // Set callbacks, where `this.events` is a hash of
+    //
+    // *{"event selector": "callback"}*
+    //
+    //     {
+    //       'mousedown .title':  'edit',
+    //       'click .button':     'save',
+    //       'click .open':       function(e) { ... }
+    //     }
+    //
+    // pairs. Callbacks will be bound to the view, with `this` set properly.
+    // Uses event delegation for efficiency.
+    // Omitting the selector binds the event to `this.el`.
+    // This only works for delegate-able events: not `focus`, `blur`, and
+    // not `change`, `submit`, and `reset` in Internet Explorer.
+    delegateEvents: function(events) {
+      if (!(events || (events = _.result(this, 'events')))) return this;
+      this.undelegateEvents();
+      for (var key in events) {
+        var method = events[key];
+        if (!_.isFunction(method)) method = this[events[key]];
+        if (!method) continue;
+
+        var match = key.match(delegateEventSplitter);
+        var eventName = match[1], selector = match[2];
+        method = _.bind(method, this);
+        eventName += '.delegateEvents' + this.cid;
+        if (selector === '') {
+          this.$el.on(eventName, method);
+        } else {
+          this.$el.on(eventName, selector, method);
+        }
+      }
+      return this;
+    },
+
+    // Clears all callbacks previously bound to the view with `delegateEvents`.
+    // You usually don't need to use this, but may wish to if you have multiple
+    // Backbone views attached to the same DOM element.
+    undelegateEvents: function() {
+      this.$el.off('.delegateEvents' + this.cid);
+      return this;
+    },
+
+    // Ensure that the View has a DOM element to render into.
+    // If `this.el` is a string, pass it through `$()`, take the first
+    // matching element, and re-assign it to `el`. Otherwise, create
+    // an element from the `id`, `className` and `tagName` properties.
+    _ensureElement: function() {
+      if (!this.el) {
+        var attrs = _.extend({}, _.result(this, 'attributes'));
+        if (this.id) attrs.id = _.result(this, 'id');
+        if (this.className) attrs['class'] = _.result(this, 'className');
+        var $el = Backbone.$('<' + _.result(this, 'tagName') + '>').attr(attrs);
+        this.setElement($el, false);
+      } else {
+        this.setElement(_.result(this, 'el'), false);
+      }
+    }
+
+  });
+
+  // Backbone.sync
+  // -------------
+
+  // Override this function to change the manner in which Backbone persists
+  // models to the server. You will be passed the type of request, and the
+  // model in question. By default, makes a RESTful Ajax request
+  // to the model's `url()`. Some possible customizations could be:
+  //
+  // * Use `setTimeout` to batch rapid-fire updates into a single request.
+  // * Send up the models as XML instead of JSON.
+  // * Persist models via WebSockets instead of Ajax.
+  //
+  // Turn on `Backbone.emulateHTTP` in order to send `PUT` and `DELETE` requests
+  // as `POST`, with a `_method` parameter containing the true HTTP method,
+  // as well as all requests with the body as `application/x-www-form-urlencoded`
+  // instead of `application/json` with the model in a param named `model`.
+  // Useful when interfacing with server-side languages like **PHP** that make
+  // it difficult to read the body of `PUT` requests.
+  Backbone.sync = function(method, model, options) {
+    var type = methodMap[method];
+
+    // Default options, unless specified.
+    _.defaults(options || (options = {}), {
+      emulateHTTP: Backbone.emulateHTTP,
+      emulateJSON: Backbone.emulateJSON
+    });
+
+    // Default JSON-request options.
+    var params = {type: type, dataType: 'json'};
+
+    // Ensure that we have a URL.
+    if (!options.url) {
+      params.url = _.result(model, 'url') || urlError();
+    }
+
+    // Ensure that we have the appropriate request data.
+    if (options.data == null && model && (method === 'create' || method === 'update' || method === 'patch')) {
+      params.contentType = 'application/json';
+      params.data = JSON.stringify(options.attrs || model.toJSON(options));
+    }
+
+    // For older servers, emulate JSON by encoding the request into an HTML-form.
+    if (options.emulateJSON) {
+      params.contentType = 'application/x-www-form-urlencoded';
+      params.data = params.data ? {model: params.data} : {};
+    }
+
+    // For older servers, emulate HTTP by mimicking the HTTP method with `_method`
+    // And an `X-HTTP-Method-Override` header.
+    if (options.emulateHTTP && (type === 'PUT' || type === 'DELETE' || type === 'PATCH')) {
+      params.type = 'POST';
+      if (options.emulateJSON) params.data._method = type;
+      var beforeSend = options.beforeSend;
+      options.beforeSend = function(xhr) {
+        xhr.setRequestHeader('X-HTTP-Method-Override', type);
+        if (beforeSend) return beforeSend.apply(this, arguments);
+      };
+    }
+
+    // Don't process data on a non-GET request.
+    if (params.type !== 'GET' && !options.emulateJSON) {
+      params.processData = false;
+    }
+
+    // If we're sending a `PATCH` request, and we're in an old Internet Explorer
+    // that still has ActiveX enabled by default, override jQuery to use that
+    // for XHR instead. Remove this line when jQuery supports `PATCH` on IE8.
+    if (params.type === 'PATCH' && noXhrPatch) {
+      params.xhr = function() {
+        return new ActiveXObject("Microsoft.XMLHTTP");
+      };
+    }
+
+    // Make the request, allowing the user to override any Ajax options.
+    var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
+    model.trigger('request', model, xhr, options);
+    return xhr;
+  };
+
+  var noXhrPatch =
+    typeof window !== 'undefined' && !!window.ActiveXObject &&
+      !(window.XMLHttpRequest && (new XMLHttpRequest).dispatchEvent);
+
+  // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
+  var methodMap = {
+    'create': 'POST',
+    'update': 'PUT',
+    'patch':  'PATCH',
+    'delete': 'DELETE',
+    'read':   'GET'
+  };
+
+  // Set the default implementation of `Backbone.ajax` to proxy through to `$`.
+  // Override this if you'd like to use a different library.
+  Backbone.ajax = function() {
+    return Backbone.$.ajax.apply(Backbone.$, arguments);
+  };
+
+  // Backbone.Router
+  // ---------------
+
+  // Routers map faux-URLs to actions, and fire events when routes are
+  // matched. Creating a new one sets its `routes` hash, if not set statically.
+  var Router = Backbone.Router = function(options) {
+    options || (options = {});
+    if (options.routes) this.routes = options.routes;
+    this._bindRoutes();
+    this.initialize.apply(this, arguments);
+  };
+
+  // Cached regular expressions for matching named param parts and splatted
+  // parts of route strings.
+  var optionalParam = /\((.*?)\)/g;
+  var namedParam    = /(\(\?)?:\w+/g;
+  var splatParam    = /\*\w+/g;
+  var escapeRegExp  = /[\-{}\[\]+?.,\\\^$|#\s]/g;
+
+  // Set up all inheritable **Backbone.Router** properties and methods.
+  _.extend(Router.prototype, Events, {
+
+    // Initialize is an empty function by default. Override it with your own
+    // initialization logic.
+    initialize: function(){},
+
+    // Manually bind a single named route to a callback. For example:
+    //
+    //     this.route('search/:query/p:num', 'search', function(query, num) {
+    //       ...
+    //     });
+    //
+    route: function(route, name, callback) {
+      if (!_.isRegExp(route)) route = this._routeToRegExp(route);
+      if (_.isFunction(name)) {
+        callback = name;
+        name = '';
+      }
+      if (!callback) callback = this[name];
+      var router = this;
+      Backbone.history.route(route, function(fragment) {
+        var args = router._extractParameters(route, fragment);
+        router.execute(callback, args);
+        router.trigger.apply(router, ['route:' + name].concat(args));
+        router.trigger('route', name, args);
+        Backbone.history.trigger('route', router, name, args);
+      });
+      return this;
+    },
+
+    // Execute a route handler with the provided parameters.  This is an
+    // excellent place to do pre-route setup or post-route cleanup.
+    execute: function(callback, args) {
+      if (callback) callback.apply(this, args);
+    },
+
+    // Simple proxy to `Backbone.history` to save a fragment into the history.
+    navigate: function(fragment, options) {
+      Backbone.history.navigate(fragment, options);
+      return this;
+    },
+
+    // Bind all defined routes to `Backbone.history`. We have to reverse the
+    // order of the routes here to support behavior where the most general
+    // routes can be defined at the bottom of the route map.
+    _bindRoutes: function() {
+      if (!this.routes) return;
+      this.routes = _.result(this, 'routes');
+      var route, routes = _.keys(this.routes);
+      while ((route = routes.pop()) != null) {
+        this.route(route, this.routes[route]);
+      }
+    },
+
+    // Convert a route string into a regular expression, suitable for matching
+    // against the current location hash.
+    _routeToRegExp: function(route) {
+      route = route.replace(escapeRegExp, '\\$&')
+                   .replace(optionalParam, '(?:$1)?')
+                   .replace(namedParam, function(match, optional) {
+                     return optional ? match : '([^/?]+)';
+                   })
+                   .replace(splatParam, '([^?]*?)');
+      return new RegExp('^' + route + '(?:\\?([\\s\\S]*))?$');
+    },
+
+    // Given a route, and a URL fragment that it matches, return the array of
+    // extracted decoded parameters. Empty or unmatched parameters will be
+    // treated as `null` to normalize cross-browser behavior.
+    _extractParameters: function(route, fragment) {
+      var params = route.exec(fragment).slice(1);
+      return _.map(params, function(param, i) {
+        // Don't decode the search params.
+        if (i === params.length - 1) return param || null;
+        return param ? decodeURIComponent(param) : null;
+      });
+    }
+
+  });
+
+  // Backbone.History
+  // ----------------
+
+  // Handles cross-browser history management, based on either
+  // [pushState](http://diveintohtml5.info/history.html) and real URLs, or
+  // [onhashchange](https://developer.mozilla.org/en-US/docs/DOM/window.onhashchange)
+  // and URL fragments. If the browser supports neither (old IE, natch),
+  // falls back to polling.
+  var History = Backbone.History = function() {
+    this.handlers = [];
+    _.bindAll(this, 'checkUrl');
+
+    // Ensure that `History` can be used outside of the browser.
+    if (typeof window !== 'undefined') {
+      this.location = window.location;
+      this.history = window.history;
+    }
+  };
+
+  // Cached regex for stripping a leading hash/slash and trailing space.
+  var routeStripper = /^[#\/]|\s+$/g;
+
+  // Cached regex for stripping leading and trailing slashes.
+  var rootStripper = /^\/+|\/+$/g;
+
+  // Cached regex for detecting MSIE.
+  var isExplorer = /msie [\w.]+/;
+
+  // Cached regex for removing a trailing slash.
+  var trailingSlash = /\/$/;
+
+  // Cached regex for stripping urls of hash.
+  var pathStripper = /#.*$/;
+
+  // Has the history handling already been started?
+  History.started = false;
+
+  // Set up all inheritable **Backbone.History** properties and methods.
+  _.extend(History.prototype, Events, {
+
+    // The default interval to poll for hash changes, if necessary, is
+    // twenty times a second.
+    interval: 50,
+
+    // Are we at the app root?
+    atRoot: function() {
+      return this.location.pathname.replace(/[^\/]$/, '$&/') === this.root;
+    },
+
+    // Gets the true hash value. Cannot use location.hash directly due to bug
+    // in Firefox where location.hash will always be decoded.
+    getHash: function(window) {
+      var match = (window || this).location.href.match(/#(.*)$/);
+      return match ? match[1] : '';
+    },
+
+    // Get the cross-browser normalized URL fragment, either from the URL,
+    // the hash, or the override.
+    getFragment: function(fragment, forcePushState) {
+      if (fragment == null) {
+        if (this._hasPushState || !this._wantsHashChange || forcePushState) {
+          fragment = decodeURI(this.location.pathname + this.location.search);
+          var root = this.root.replace(trailingSlash, '');
+          if (!fragment.indexOf(root)) fragment = fragment.slice(root.length);
+        } else {
+          fragment = this.getHash();
+        }
+      }
+      return fragment.replace(routeStripper, '');
+    },
+
+    // Start the hash change handling, returning `true` if the current URL matches
+    // an existing route, and `false` otherwise.
+    start: function(options) {
+      if (History.started) throw new Error("Backbone.history has already been started");
+      History.started = true;
+
+      // Figure out the initial configuration. Do we need an iframe?
+      // Is pushState desired ... is it available?
+      this.options          = _.extend({root: '/'}, this.options, options);
+      this.root             = this.options.root;
+      this._wantsHashChange = this.options.hashChange !== false;
+      this._wantsPushState  = !!this.options.pushState;
+      this._hasPushState    = !!(this.options.pushState && this.history && this.history.pushState);
+      var fragment          = this.getFragment();
+      var docMode           = document.documentMode;
+      var oldIE             = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
+
+      // Normalize root to always include a leading and trailing slash.
+      this.root = ('/' + this.root + '/').replace(rootStripper, '/');
+
+      if (oldIE && this._wantsHashChange) {
+        var frame = Backbone.$('<iframe src="javascript:0" tabindex="-1">');
+        this.iframe = frame.hide().appendTo('body')[0].contentWindow;
+        this.navigate(fragment);
+      }
+
+      // Depending on whether we're using pushState or hashes, and whether
+      // 'onhashchange' is supported, determine how we check the URL state.
+      if (this._hasPushState) {
+        Backbone.$(window).on('popstate', this.checkUrl);
+      } else if (this._wantsHashChange && ('onhashchange' in window) && !oldIE) {
+        Backbone.$(window).on('hashchange', this.checkUrl);
+      } else if (this._wantsHashChange) {
+        this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
+      }
+
+      // Determine if we need to change the base url, for a pushState link
+      // opened by a non-pushState browser.
+      this.fragment = fragment;
+      var loc = this.location;
+
+      // Transition from hashChange to pushState or vice versa if both are
+      // requested.
+      if (this._wantsHashChange && this._wantsPushState) {
+
+        // If we've started off with a route from a `pushState`-enabled
+        // browser, but we're currently in a browser that doesn't support it...
+        if (!this._hasPushState && !this.atRoot()) {
+          this.fragment = this.getFragment(null, true);
+          this.location.replace(this.root + '#' + this.fragment);
+          // Return immediately as browser will do redirect to new url
+          return true;
+
+        // Or if we've started out with a hash-based route, but we're currently
+        // in a browser where it could be `pushState`-based instead...
+        } else if (this._hasPushState && this.atRoot() && loc.hash) {
+          this.fragment = this.getHash().replace(routeStripper, '');
+          this.history.replaceState({}, document.title, this.root + this.fragment);
+        }
+
+      }
+
+      if (!this.options.silent) return this.loadUrl();
+    },
+
+    // Disable Backbone.history, perhaps temporarily. Not useful in a real app,
+    // but possibly useful for unit testing Routers.
+    stop: function() {
+      Backbone.$(window).off('popstate', this.checkUrl).off('hashchange', this.checkUrl);
+      if (this._checkUrlInterval) clearInterval(this._checkUrlInterval);
+      History.started = false;
+    },
+
+    // Add a route to be tested when the fragment changes. Routes added later
+    // may override previous routes.
+    route: function(route, callback) {
+      this.handlers.unshift({route: route, callback: callback});
+    },
+
+    // Checks the current URL to see if it has changed, and if it has,
+    // calls `loadUrl`, normalizing across the hidden iframe.
+    checkUrl: function(e) {
+      var current = this.getFragment();
+      if (current === this.fragment && this.iframe) {
+        current = this.getFragment(this.getHash(this.iframe));
+      }
+      if (current === this.fragment) return false;
+      if (this.iframe) this.navigate(current);
+      this.loadUrl();
+    },
+
+    // Attempt to load the current URL fragment. If a route succeeds with a
+    // match, returns `true`. If no defined routes matches the fragment,
+    // returns `false`.
+    loadUrl: function(fragment) {
+      fragment = this.fragment = this.getFragment(fragment);
+      return _.any(this.handlers, function(handler) {
+        if (handler.route.test(fragment)) {
+          handler.callback(fragment);
+          return true;
+        }
+      });
+    },
+
+    // Save a fragment into the hash history, or replace the URL state if the
+    // 'replace' option is passed. You are responsible for properly URL-encoding
+    // the fragment in advance.
+    //
+    // The options object can contain `trigger: true` if you wish to have the
+    // route callback be fired (not usually desirable), or `replace: true`, if
+    // you wish to modify the current URL without adding an entry to the history.
+    navigate: function(fragment, options) {
+      if (!History.started) return false;
+      if (!options || options === true) options = {trigger: !!options};
+
+      var url = this.root + (fragment = this.getFragment(fragment || ''));
+
+      // Strip the hash for matching.
+      fragment = fragment.replace(pathStripper, '');
+
+      if (this.fragment === fragment) return;
+      this.fragment = fragment;
+
+      // Don't include a trailing slash on the root.
+      if (fragment === '' && url !== '/') url = url.slice(0, -1);
+
+      // If pushState is available, we use it to set the fragment as a real URL.
+      if (this._hasPushState) {
+        this.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, url);
+
+      // If hash changes haven't been explicitly disabled, update the hash
+      // fragment to store history.
+      } else if (this._wantsHashChange) {
+        this._updateHash(this.location, fragment, options.replace);
+        if (this.iframe && (fragment !== this.getFragment(this.getHash(this.iframe)))) {
+          // Opening and closing the iframe tricks IE7 and earlier to push a
+          // history entry on hash-tag change.  When replace is true, we don't
+          // want this.
+          if(!options.replace) this.iframe.document.open().close();
+          this._updateHash(this.iframe.location, fragment, options.replace);
+        }
+
+      // If you've told us that you explicitly don't want fallback hashchange-
+      // based history, then `navigate` becomes a page refresh.
+      } else {
+        return this.location.assign(url);
+      }
+      if (options.trigger) return this.loadUrl(fragment);
+    },
+
+    // Update the hash location, either replacing the current entry, or adding
+    // a new one to the browser history.
+    _updateHash: function(location, fragment, replace) {
+      if (replace) {
+        var href = location.href.replace(/(javascript:|#).*$/, '');
+        location.replace(href + '#' + fragment);
+      } else {
+        // Some browsers require that `hash` contains a leading #.
+        location.hash = '#' + fragment;
+      }
+    }
+
+  });
+
+  // Create the default Backbone.history.
+  Backbone.history = new History;
+
+  // Helpers
+  // -------
+
+  // Helper function to correctly set up the prototype chain, for subclasses.
+  // Similar to `goog.inherits`, but uses a hash of prototype properties and
+  // class properties to be extended.
+  var extend = function(protoProps, staticProps) {
+    var parent = this;
+    var child;
+
+    // The constructor function for the new subclass is either defined by you
+    // (the "constructor" property in your `extend` definition), or defaulted
+    // by us to simply call the parent's constructor.
+    if (protoProps && _.has(protoProps, 'constructor')) {
+      child = protoProps.constructor;
+    } else {
+      child = function(){ return parent.apply(this, arguments); };
+    }
+
+    // Add static properties to the constructor function, if supplied.
+    _.extend(child, parent, staticProps);
+
+    // Set the prototype chain to inherit from `parent`, without calling
+    // `parent`'s constructor function.
+    var Surrogate = function(){ this.constructor = child; };
+    Surrogate.prototype = parent.prototype;
+    child.prototype = new Surrogate;
+
+    // Add prototype properties (instance properties) to the subclass,
+    // if supplied.
+    if (protoProps) _.extend(child.prototype, protoProps);
+
+    // Set a convenience property in case the parent's prototype is needed
+    // later.
+    child.__super__ = parent.prototype;
+
+    return child;
+  };
+
+  // Set up inheritance for the model, collection, router, view and history.
+  Model.extend = Collection.extend = Router.extend = View.extend = History.extend = extend;
+
+  // Throw an error when a URL is needed, and none is supplied.
+  var urlError = function() {
+    throw new Error('A "url" property or function must be specified');
+  };
+
+  // Wrap an optional error callback with a fallback error event.
+  var wrapError = function(model, options) {
+    var error = options.error;
+    options.error = function(resp) {
+      if (error) error(model, resp, options);
+      model.trigger('error', model, resp, options);
+    };
+  };
+
+  return Backbone;
+
+}));