//     Backbone.js 0.9.1

//     (c) 2010-2012 Jeremy Ashkenas, DocumentCloud Inc.
//     Backbone may be freely distributed under the MIT license.
//     For all details and documentation:
//     http://backbonejs.org

(function(){

    // Initial Setup
    // -------------

    // Save a reference to the global object (`window` in the browser, `global`
    // on the server).
    var root = this;

    // 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 a local reference to slice/splice.
    var slice = Array.prototype.slice;
    var splice = Array.prototype.splice;

    // The top-level namespace. All public Backbone classes and modules will
    // be attached to this. Exported for both CommonJS and the browser.
    var Backbone;
    if (typeof exports !== 'undefined') {
	Backbone = exports;
    } else {
	Backbone = root.Backbone = {};
    }

    // Current version of the library. Keep in sync with `package.json`.
    Backbone.VERSION = '0.9.1';

    // Require Underscore, if we're on the server, and it's not already present.
    var _ = root._;
    if (!_ && (typeof require !== 'undefined')) _ = require('underscore');

    // For Backbone's purposes, jQuery, Zepto, or Ender owns the `$` variable.
    var $ = root.jQuery || root.Zepto || root.ender;

    // Set the JavaScript library that will be used for DOM manipulation and
    // Ajax calls (a.k.a. the `$` variable). By default Backbone will use: jQuery,
    // Zepto, or Ender; but the `setDomLibrary()` method lets you inject an
    // alternate JavaScript library (or a mock library for testing your views
    // outside of a browser).
    Backbone.setDomLibrary = function(lib) {
	$ = lib;
    };

    // 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 `"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 one or more space separated events, `events`, to a `callback`
	// function. Passing `"all"` will bind the callback to all events fired.
	on: function(events, callback, context) {
	    var calls, event, node, tail, list;
	    if (!callback) return this;
	    events = events.split(/\s+/);
	    calls = this._callbacks || (this._callbacks = {});
	    while (event = events.shift()) {
		// Create an immutable callback list, allowing traversal during
		// modification.  The tail is an empty object that will always be used
		// as the next node.
		list = calls[event];
		node = list ? list.tail : {};
		node.next = tail = {};
		node.context = context;
		node.callback = callback;
		calls[event] = {tail: tail, next: list ? list.next : node};
	    }
	    return this;
	},

	// 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 `events` is null, removes all bound callbacks for all events.
	off: function(events, callback, context) {
	    var event, calls, node, tail, cb, ctx;
	    if (!events) {
		delete this._callbacks;
	    } else if (calls = this._callbacks) {
		events = events.split(/\s+/);
		while (event = events.shift()) {
		    node = calls[event];
		    delete calls[event];
		    if (!callback || !node) continue;
		    // Create a new list, omitting the indicated callbacks.
		    tail = node.tail;
		    while ((node = node.next) !== tail) {
			cb = node.callback;
			ctx = node.context;
			if (cb !== callback || (context && ctx !== context)) {
			    this.on(event, cb, ctx);
			}
		    }
		}
	    }
	    return this;
	},

	// Trigger one more many events, firing all bound callbacks. Callbacks are
	// passed the same arguments as `trigger` is, apart from the event name.
	// Listening for `"all"` passes the true event name as the first argument.
	trigger: function(events) {
	    var event, node, calls, tail, args, all, rest;
	    if (!(calls = this._callbacks)) return this;
	    all = calls.all;
	    events = events.split(/\s+/);
	    rest = slice.call(arguments, 1);
	    while (event = events.shift()) {
		if (node = calls[event]) {
		    tail = node.tail;
		    while ((node = node.next) !== tail) {
			node.callback.apply(node.context || this, rest);
		    }
		}
		if (node = all) {
		    tail = node.tail;
		    args = [event].concat(rest);
		    while ((node = node.next) !== tail) {
			node.callback.apply(node.context || this, args);
		    }
		}
	    }
	    return this;
	}

    };

    // Aliases for backwards compatibility.
    Events.bind   = Events.on;
    Events.unbind = Events.off;

    // Backbone.Model
    // --------------

    // Create a new model, with defined attributes. A client id (`cid`)
    // is automatically generated and assigned for you.
    var Model = Backbone.Model = function(attributes, options) {
	var defaults;
	attributes || (attributes = {});
	if (options && options.parse) attributes = this.parse(attributes);
	if (defaults = getValue(this, 'defaults')) {
	    attributes = _.extend({}, defaults, attributes);
	}
	if (options && options.collection) this.collection = options.collection;
	this.attributes = {};
	this._escapedAttributes = {};
	this.cid = _.uniqueId('c');
	this.changed = {};
	this._silent = {};
	this._pending = {};
	this.set(attributes, {silent: true});
	// Reset change tracking.
	this.changed = {};
	this._silent = {};
	this._pending = {};
	this._previousAttributes = _.clone(this.attributes);
	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,

	// A hash of attributes that have silently changed since the last time
	// `change` was called.  Will become pending attributes on the next call.
	_silent: null,

	// A hash of attributes that have changed since the last `'change'` event
	// began.
	_pending: 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() {
	    return _.clone(this.attributes);
	},

	// Get the value of an attribute.
	get: function(attr) {
	    return this.attributes[attr];
	},

	// Get the HTML-escaped value of an attribute.
	escape: function(attr) {
	    var html;
	    if (html = this._escapedAttributes[attr]) return html;
	    var val = this.attributes[attr];
	    return this._escapedAttributes[attr] = _.escape(val == null ? '' : '' + val);
	},

	// Returns `true` if the attribute contains a value that is not null
	// or undefined.
	has: function(attr) {
	    return this.attributes[attr] != null;
	},

	// Set a hash of model attributes on the object, firing `"change"` unless
	// you choose to silence it.
	set: function(key, value, options) {
	    var attrs, attr, val;
	    if (_.isObject(key) || key == null) {
		attrs = key;
		options = value;
	    } else {
		attrs = {};
		attrs[key] = value;
	    }

	    // Extract attributes and options.
	    options || (options = {});
	    if (!attrs) return this;
	    if (attrs instanceof Model) attrs = attrs.attributes;
	    if (options.unset) for (attr in attrs) attrs[attr] = void 0;

	    // Run validation.
	    if (!this._validate(attrs, options)) return false;

	    // Check for changes of `id`.
	    if (this.idAttribute in attrs) this.id = attrs[this.idAttribute];

	    var changes = options.changes = {};
	    var now = this.attributes;
	    var escaped = this._escapedAttributes;
	    var prev = this._previousAttributes || {};

	    for (attr in attrs) {
		val = attrs[attr];
		// If the new and current value differ, record the change.
		if (!_.isEqual(now[attr], val) || (options.unset && _.has(now, attr))) {
		    delete escaped[attr];
		    (options.silent ? this._silent : changes)[attr] = true;
		}
		// Update the current value.
		options.unset ? delete now[attr] : now[attr] = val;
		// If the new and previous value differ, record the change.  If not,
		// then remove changes for this attribute.
		if (!_.isEqual(prev[attr], val) || (_.has(now, attr) != _.has(prev, attr))) {
		    this.changed[attr] = val;
		    if (!options.silent) this._pending[attr] = true;
		} else {
		    delete this.changed[attr];
		    delete this._pending[attr];
		}
	    }

	    // Fire the `"change"` events.
	    if (!options.silent) this.change(options);
	    return this;
	},

	// Remove an attribute from the model, firing `"change"` unless you choose
	// to silence it. `unset` is a noop if the attribute doesn't exist.
	unset: function(attr, options) {
	    (options || (options = {})).unset = true;
	    return this.set(attr, null, options);
	},

	// Clear all attributes on the model, firing `"change"` unless you choose
	// to silence it.
	clear: function(options) {
	    (options || (options = {})).unset = true;
	    return this.set(_.clone(this.attributes), options);
	},

	// Fetch the model from the server. If the server's representation of the
	// model differs from its current attributes, they will be overriden,
	// triggering a `"change"` event.
	fetch: function(options) {
	    options = options ? _.clone(options) : {};
	    var model = this;
	    var success = options.success;
	    options.success = function(resp, status, xhr) {
		if (!model.set(model.parse(resp, xhr), options)) return false;
		if (success) success(model, resp);
	    };
	    options.error = Backbone.wrapError(options.error, model, options);
	    return (this.sync || Backbone.sync).call(this, '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, value, options) {
	    var attrs, current;
	    if (_.isObject(key) || key == null) {
		attrs = key;
		options = value;
	    } else {
		attrs = {};
		attrs[key] = value;
	    }

	    options = options ? _.clone(options) : {};
	    if (options.wait) current = _.clone(this.attributes);
	    var silentOptions = _.extend({}, options, {silent: true});
	    if (attrs && !this.set(attrs, options.wait ? silentOptions : options)) {
		return false;
	    }
	    var model = this;
	    var success = options.success;
	    options.success = function(resp, status, xhr) {
		var serverAttrs = model.parse(resp, xhr);
		if (options.wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
		if (!model.set(serverAttrs, options)) return false;
		if (success) {
		    success(model, resp);
		} else {
		    model.trigger('sync', model, resp, options);
		}
	    };
	    options.error = Backbone.wrapError(options.error, model, options);
	    var method = this.isNew() ? 'create' : 'update';
	    var xhr = (this.sync || Backbone.sync).call(this, method, this, options);
	    if (options.wait) this.set(current, silentOptions);
	    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 triggerDestroy = function() {
		model.trigger('destroy', model, model.collection, options);
	    };

	    if (this.isNew()) return triggerDestroy();
	    options.success = function(resp) {
		if (options.wait) triggerDestroy();
		if (success) {
		    success(model, resp);
		} else {
		    model.trigger('sync', model, resp, options);
		}
	    };
	    options.error = Backbone.wrapError(options.error, model, options);
	    var xhr = (this.sync || Backbone.sync).call(this, 'delete', this, options);
	    if (!options.wait) triggerDestroy();
	    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 = getValue(this.collection, 'url') || getValue(this, 'urlRoot') || urlError();
	    if (this.isNew()) return base;
	    return base + (base.charAt(base.length - 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, xhr) {
	    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.id == null;
	},

	// Call this method to manually fire a `"change"` event for this model and
	// a `"change:attribute"` event for each changed attribute.
	// Calling this will cause all objects observing the model to update.
	change: function(options) {
	    options || (options = {});
	    var changing = this._changing;
	    this._changing = true;
	    // Silent changes become pending changes.
	    for (var attr in this._silent) this._pending[attr] = true;
	    // Silent changes are triggered.
	    var changes = _.extend({}, options.changes, this._silent);
	    this._silent = {};
	    for (var attr in changes) {
		this.trigger('change:' + attr, this, this.attributes[attr], options);
	    }
	    if (changing) return this;
	    // Continue firing `"change"` events while there are pending changes.
	    while (!_.isEmpty(this._pending)) {
		this._pending = {};
		this.trigger('change', this, options);
		// Pending and silent changes still remain.
		for (var attr in this.changed) {
		    if (this._pending[attr] || this._silent[attr]) continue;
		    delete this.changed[attr];
		}
		this._previousAttributes = _.clone(this.attributes);
	    }
	    this._changing = false;
	    return this;
	},

	// 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 (!arguments.length) 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, old = this._previousAttributes;
	    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 (!arguments.length || !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);
	},

	// Check if the model is currently in a valid state. It's only possible to
	// get into an *invalid* state if you're using silent changes.
	isValid: function() {
	    return !this.validate(this.attributes);
	},

	// Run validation against the next complete set of model attributes,
	// returning `true` if all is well. If a specific `error` callback has
	// been passed, call that instead of firing the general `"error"` event.
	_validate: function(attrs, options) {
	    if (options.silent || !this.validate) return true;
	    attrs = _.extend({}, this.attributes, attrs);
	    var error = this.validate(attrs, options);
	    if (!error) return true;
	    if (options && options.error) {
		options.error(this, error, options);
	    } else {
		this.trigger('error', this, error, options);
	    }
	    return false;
	}

    });

    // Backbone.Collection
    // -------------------

    // Provides a standard collection class for our sets of models, ordered
    // or unordered. 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.comparator) this.comparator = options.comparator;
	this._reset();
	this.initialize.apply(this, arguments);
	if (models) this.reset(models, {silent: true, parse: options.parse});
    };

    // 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() {
	    return this.map(function(model){ return model.toJSON(); });
	},

	// Add a model, or list of models to the set. Pass **silent** to avoid
	// firing the `add` event for every new model.
	add: function(models, options) {
	    var i, index, length, model, cid, id, cids = {}, ids = {}, dups = [];
	    options || (options = {});
	    models = _.isArray(models) ? models.slice() : [models];

	    // Begin by turning bare objects into model references, and preventing
	    // invalid models or duplicate models from being added.
	    for (i = 0, length = models.length; i < length; i++) {
		if (!(model = models[i] = this._prepareModel(models[i], options))) {
		    throw new Error("Can't add an invalid model to a collection");
		}
		cid = model.cid;
		id = model.id;
		if (cids[cid] || this._byCid[cid] || ((id != null) && (ids[id] || this._byId[id]))) {
		    dups.push(i);
		    continue;
		}
		cids[cid] = ids[id] = model;
	    }

	    // Remove duplicates.
	    i = dups.length;
	    while (i--) {
		models.splice(dups[i], 1);
	    }

	    // Listen to added models' events, and index models for lookup by
	    // `id` and by `cid`.
	    for (i = 0, length = models.length; i < length; i++) {
		(model = models[i]).on('all', this._onModelEvent, this);
		this._byCid[model.cid] = model;
		if (model.id != null) this._byId[model.id] = model;
	    }

	    // Insert models into the collection, re-sorting if needed, and triggering
	    // `add` events unless silenced.
	    this.length += length;
	    index = options.at != null ? options.at : this.models.length;
	    splice.apply(this.models, [index, 0].concat(models));
	    if (this.comparator) this.sort({silent: true});
	    if (options.silent) return this;
	    for (i = 0, length = this.models.length; i < length; i++) {
		if (!cids[(model = this.models[i]).cid]) continue;
		options.index = i;
		model.trigger('add', model, this, options);
	    }
	    return this;
	},

	// Remove a model, or a list of models from the set. Pass silent to avoid
	// firing the `remove` event for every model removed.
	remove: function(models, options) {
	    var i, l, index, model;
	    options || (options = {});
	    models = _.isArray(models) ? models.slice() : [models];
	    for (i = 0, l = models.length; i < l; i++) {
		model = this.getByCid(models[i]) || this.get(models[i]);
		if (!model) continue;
		delete this._byId[model.id];
		delete this._byCid[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);
	    }
	    return this;
	},

	// Add a model to the end of the collection.
	push: function(model, options) {
	    model = this._prepareModel(model, options);
	    this.add(model, options);
	    return model;
	},

	// 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) {
	    model = this._prepareModel(model, options);
	    this.add(model, _.extend({at: 0}, options));
	    return model;
	},

	// Remove a model from the beginning of the collection.
	shift: function(options) {
	    var model = this.at(0);
	    this.remove(model, options);
	    return model;
	},

	// Get a model from the set by id.
	get: function(id) {
	    if (id == null) return void 0;
	    return this._byId[id.id != null ? id.id : id];
	},

	// Get a model from the set by client id.
	getByCid: function(cid) {
	    return cid && this._byCid[cid.cid || cid];
	},

	// Get the model at the given index.
	at: function(index) {
	    return this.models[index];
	},

	// 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) {
	    options || (options = {});
	    if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
	    var boundComparator = _.bind(this.comparator, this);
	    if (this.comparator.length == 1) {
		this.models = this.sortBy(boundComparator);
	    } else {
		this.models.sort(boundComparator);
	    }
	    if (!options.silent) this.trigger('reset', this, options);
	    return this;
	},

	// Pluck an attribute from each model in the collection.
	pluck: function(attr) {
	    return _.map(this.models, function(model){ return model.get(attr); });
	},

	// 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 `add` or `remove` events. Fires `reset` when finished.
	reset: function(models, options) {
	    models  || (models = []);
	    options || (options = {});
	    for (var i = 0, l = this.models.length; i < l; i++) {
		this._removeReference(this.models[i]);
	    }
	    this._reset();
	    this.add(models, {silent: true, parse: options.parse});
	    if (!options.silent) this.trigger('reset', this, options);
	    return this;
	},

	// Fetch the default set of models for this collection, resetting the
	// collection when they arrive. If `add: true` is passed, appends the
	// models to the collection instead of resetting.
	fetch: function(options) {
	    options = options ? _.clone(options) : {};
	    if (options.parse === undefined) options.parse = true;
	    var collection = this;
	    var success = options.success;
	    options.success = function(resp, status, xhr) {
		collection[options.add ? 'add' : 'reset'](collection.parse(resp, xhr), options);
		if (success) success(collection, resp);
	    };
	    options.error = Backbone.wrapError(options.error, collection, options);
	    return (this.sync || Backbone.sync).call(this, '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) {
	    var coll = this;
	    options = options ? _.clone(options) : {};
	    model = this._prepareModel(model, options);
	    if (!model) return false;
	    if (!options.wait) coll.add(model, options);
	    var success = options.success;
	    options.success = function(nextModel, resp, xhr) {
		if (options.wait) coll.add(nextModel, options);
		if (success) {
		    success(nextModel, resp);
		} else {
		    nextModel.trigger('sync', 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, xhr) {
	    return resp;
	},

	// Proxy to _'s chain. Can't be proxied the same way the rest of the
	// underscore methods are proxied because it relies on the underscore
	// constructor.
	chain: function () {
	    return _(this.models).chain();
	},

	// Reset all internal state. Called when the collection is reset.
	_reset: function(options) {
	    this.length = 0;
	    this.models = [];
	    this._byId  = {};
	    this._byCid = {};
	},

	// Prepare a model or hash of attributes to be added to this collection.
	_prepareModel: function(model, options) {
	    options || (options = {});
	    if (!(model instanceof Model)) {
		var attrs = model;
		options.collection = this;
		model = new this.model(attrs, options);
		if (!model._validate(model.attributes, options)) model = false;
	    } else if (!model.collection) {
		model.collection = this;
	    }
	    return model;
	},

	// Internal method to remove a model's ties to a collection.
	_removeReference: function(model) {
	    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)];
		this._byId[model.id] = model;
	    }
	    this.trigger.apply(this, arguments);
	}

    });

    // Underscore methods that we want to implement on the Collection.
    var methods = ['forEach', 'each', 'map', 'reduce', 'reduceRight', 'find',
		   'detect', 'filter', 'select', 'reject', 'every', 'all', 'some', 'any',
		   'include', 'contains', 'invoke', 'max', 'min', 'sortBy', 'sortedIndex',
		   'toArray', 'size', 'first', 'initial', 'rest', 'last', 'without', 'indexOf',
		   'shuffle', 'lastIndexOf', 'isEmpty', 'groupBy'];

    // Mix in each Underscore method as a proxy to `Collection#models`.
    _.each(methods, function(method) {
	Collection.prototype[method] = function() {
	    return _[method].apply(_, [this.models].concat(_.toArray(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 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) {
				  Backbone.history || (Backbone.history = new History);
				  if (!_.isRegExp(route)) route = this._routeToRegExp(route);
				  if (!callback) callback = this[name];
				  Backbone.history.route(route, _.bind(function(fragment) {
				      var args = this._extractParameters(route, fragment);
				      callback && callback.apply(this, args);
				      this.trigger.apply(this, ['route:' + name].concat(args));
				      Backbone.history.trigger('route', this, name, args);
				  }, this));
				  return this;
			      },

			      // Simple proxy to `Backbone.history` to save a fragment into the history.
			      navigate: function(fragment, options) {
				  Backbone.history.navigate(fragment, options);
			      },

			      // 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;
				  var routes = [];
				  for (var route in this.routes) {
				      routes.unshift([route, this.routes[route]]);
				  }
				  for (var i = 0, l = routes.length; i < l; i++) {
				      this.route(routes[i][0], routes[i][1], this[routes[i][1]]);
				  }
			      },

			      // Convert a route string into a regular expression, suitable for matching
			      // against the current location hash.
			      _routeToRegExp: function(route) {
				  route = route.replace(escapeRegExp, '\\$&')
				      .replace(namedParam, '([^\/]+)')
				      .replace(splatParam, '(.*?)');
				  return new RegExp('^' + route + '$');
			      },

			      // Given a route, and a URL fragment that it matches, return the array of
			      // extracted parameters.
			      _extractParameters: function(route, fragment) {
				  return route.exec(fragment).slice(1);
			      }

			  });

			  // Backbone.History
			  // ----------------

			  // Handles cross-browser history management, based on URL fragments. If the
			  // browser does not support `onhashchange`, falls back to polling.
			  var History = Backbone.History = function() {
			      this.handlers = [];
			      _.bindAll(this, 'checkUrl');
			  };

			  // Cached regex for cleaning leading hashes and slashes .
			  var routeStripper = /^[#\/]/;

			  // Cached regex for detecting MSIE.
			  var isExplorer = /msie [\w.]+/;

			  // 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,

			      // Gets the true hash value. Cannot use location.hash directly due to bug
			      // in Firefox where location.hash will always be decoded.
			      getHash: function(windowOverride) {
				  var loc = windowOverride ? windowOverride.location : window.location;
				  var match = loc.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 || forcePushState) {
					  fragment = window.location.pathname;
					  var search = window.location.search;
					  if (search) fragment += search;
				      } else {
					  fragment = this.getHash();
				      }
				  }
				  if (!fragment.indexOf(this.options.root)) fragment = fragment.substr(this.options.root.length);
				  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._wantsHashChange = this.options.hashChange !== false;
				  this._wantsPushState  = !!this.options.pushState;
				  this._hasPushState    = !!(this.options.pushState && window.history && window.history.pushState);
				  var fragment          = this.getFragment();
				  var docMode           = document.documentMode;
				  var oldIE             = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));

				  if (oldIE) {
				      this.iframe = $('<iframe src="javascript:0" tabindex="-1" />').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) {
				      $(window).bind('popstate', this.checkUrl);
				  } else if (this._wantsHashChange && ('onhashchange' in window) && !oldIE) {
				      $(window).bind('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 = window.location;
				  var atRoot  = loc.pathname == this.options.root;

				  // 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._wantsHashChange && this._wantsPushState && !this._hasPushState && !atRoot) {
				      this.fragment = this.getFragment(null, true);
				      window.location.replace(this.options.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._wantsPushState && this._hasPushState && atRoot && loc.hash) {
				      this.fragment = this.getHash().replace(routeStripper, '');
				      window.history.replaceState({}, document.title, loc.protocol + '//' + loc.host + this.options.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() {
				  $(window).unbind('popstate', this.checkUrl).unbind('hashchange', this.checkUrl);
				  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() || this.loadUrl(this.getHash());
			      },

			      // 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(fragmentOverride) {
				  var fragment = this.fragment = this.getFragment(fragmentOverride);
				  var matched = _.any(this.handlers, function(handler) {
				      if (handler.route.test(fragment)) {
					  handler.callback(fragment);
					  return true;
				      }
				  });
				  return matched;
			      },

			      // 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 frag = (fragment || '').replace(routeStripper, '');
				  if (this.fragment == frag) return;

				  // If pushState is available, we use it to set the fragment as a real URL.
				  if (this._hasPushState) {
				      if (frag.indexOf(this.options.root) != 0) frag = this.options.root + frag;
				      this.fragment = frag;
				      window.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, frag);

				      // If hash changes haven't been explicitly disabled, update the hash
				      // fragment to store history.
				  } else if (this._wantsHashChange) {
				      this.fragment = frag;
				      this._updateHash(window.location, frag, options.replace);
				      if (this.iframe && (frag != 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, frag, options.replace);
				      }

				      // If you've told us that you explicitly don't want fallback hashchange-
				      // based history, then `navigate` becomes a page refresh.
				  } else {
				      window.location.assign(this.options.root + fragment);
				  }
				  if (options.trigger) 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) {
				      location.replace(location.toString().replace(/(javascript:|#).*$/, '') + '#' + fragment);
				  } else {
				      location.hash = fragment;
				  }
			      }
			  });

			  // Backbone.View
			  // -------------

			  // 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');
			      this._configure(options || {});
			      this._ensureElement();
			      this.initialize.apply(this, arguments);
			      this.delegateEvents();
			  };

			  // Cached regex to split keys for `delegate`.
			  var eventSplitter = /^(\S+)\s*(.*)$/;

			  // List of view options to be merged as properties.
			  var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName'];

			  // 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 prefered 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 from the DOM. Note that the view isn't present in the
			      // DOM by default, so calling this method may be a no-op.
			      remove: function() {
				  this.$el.remove();
				  return this;
			      },

			      // For small amounts of DOM Elements, where a full-blown template isn't
			      // needed, use **make** to manufacture elements, one at a time.
			      //
			      //     var el = this.make('li', {'class': 'row'}, this.model.escape('title'));
			      //
			      make: function(tagName, attributes, content) {
				  var el = document.createElement(tagName);
				  if (attributes) $(el).attr(attributes);
				  if (content) $(el).html(content);
				  return el;
			      },

			      // 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 $) ? element : $(element);
				  this.el = this.$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 = getValue(this, 'events')))) return;
				  this.undelegateEvents();
				  for (var key in events) {
				      var method = events[key];
				      if (!_.isFunction(method)) method = this[events[key]];
				      if (!method) throw new Error('Method "' + events[key] + '" does not exist');
				      var match = key.match(eventSplitter);
				      var eventName = match[1], selector = match[2];
				      method = _.bind(method, this);
				      eventName += '.delegateEvents' + this.cid;
				      if (selector === '') {
					  this.$el.bind(eventName, method);
				      } else {
					  this.$el.delegate(selector, eventName, method);
				      }
				  }
			      },

			      // 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.unbind('.delegateEvents' + this.cid);
			      },

			      // Performs the initial configuration of a View with a set of options.
			      // Keys with special meaning *(model, collection, id, className)*, are
			      // attached directly to the view.
			      _configure: function(options) {
				  if (this.options) options = _.extend({}, this.options, options);
				  for (var i = 0, l = viewOptions.length; i < l; i++) {
				      var attr = viewOptions[i];
				      if (options[attr]) this[attr] = options[attr];
				  }
				  this.options = options;
			      },

			      // 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 = getValue(this, 'attributes') || {};
				      if (this.id) attrs.id = this.id;
				      if (this.className) attrs['class'] = this.className;
				      this.setElement(this.make(this.tagName, attrs), false);
				  } else {
				      this.setElement(this.el, false);
				  }
			      }

			  });

			  // The self-propagating extend function that Backbone classes use.
			  var extend = function (protoProps, classProps) {
			      var child = inherits(this, protoProps, classProps);
			      child.extend = this.extend;
			      return child;
			  };

			  // Set up inheritance for the model, collection, and view.
			  Model.extend = Collection.extend = Router.extend = View.extend = extend;

			  // Backbone.sync
			  // -------------

			  // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
			  var methodMap = {
			      'create': 'POST',
			      'update': 'PUT',
			      'delete': 'DELETE',
			      'read':   'GET'
			  };

			  // 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.
			      options || (options = {});

			      // Default JSON-request options.
			      var params = {type: type, dataType: 'json'};

			      // Ensure that we have a URL.
			      if (!options.url) {
				  params.url = getValue(model, 'url') || urlError();
			      }

			      // Ensure that we have the appropriate request data.
			      if (!options.data && model && (method == 'create' || method == 'update')) {
				  params.contentType = 'application/json';
				  params.data = JSON.stringify(model.toJSON());
			      }

			      // For older servers, emulate JSON by encoding the request into an HTML-form.
			      if (Backbone.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 (Backbone.emulateHTTP) {
				  if (type === 'PUT' || type === 'DELETE') {
				      if (Backbone.emulateJSON) params.data._method = type;
				      params.type = 'POST';
				      params.beforeSend = function(xhr) {
					  xhr.setRequestHeader('X-HTTP-Method-Override', type);
				      };
				  }
			      }

			      // Don't process data on a non-GET request.
			      if (params.type !== 'GET' && !Backbone.emulateJSON) {
				  params.processData = false;
			      }

			      // Make the request, allowing the user to override any Ajax options.
			      return $.ajax(_.extend(params, options));
			  };

			  // Wrap an optional error callback with a fallback error event.
			  Backbone.wrapError = function(onError, originalModel, options) {
			      return function(model, resp) {
				  resp = model === originalModel ? resp : model;
				  if (onError) {
				      onError(originalModel, resp, options);
				  } else {
				      originalModel.trigger('error', originalModel, resp, options);
				  }
			      };
			  };

			  // Helpers
			  // -------

			  // Shared empty constructor function to aid in prototype-chain creation.
			  var ctor = function(){};

			  // 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 inherits = function(parent, protoProps, staticProps) {
			      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 && protoProps.hasOwnProperty('constructor')) {
				  child = protoProps.constructor;
			      } else {
				  child = function(){ parent.apply(this, arguments); };
			      }

			      // Inherit class (static) properties from parent.
			      _.extend(child, parent);

			      // Set the prototype chain to inherit from `parent`, without calling
			      // `parent`'s constructor function.
			      ctor.prototype = parent.prototype;
			      child.prototype = new ctor();

			      // Add prototype properties (instance properties) to the subclass,
			      // if supplied.
			      if (protoProps) _.extend(child.prototype, protoProps);

			      // Add static properties to the constructor function, if supplied.
			      if (staticProps) _.extend(child, staticProps);

			      // Correctly set child's `prototype.constructor`.
			      child.prototype.constructor = child;

			      // Set a convenience property in case the parent's prototype is needed later.
			      child.__super__ = parent.prototype;

			      return child;
			  };

			  // Helper function to get a value from a Backbone object as a property
			  // or as a function.
			  var getValue = function(object, prop) {
			      if (!(object && object[prop])) return null;
			      return _.isFunction(object[prop]) ? object[prop]() : object[prop];
			  };

			  // 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');
			  };
			  
			 }).call(this);
