text: window.wp = window.wp || {};
  
  (function($){
  	var Attachment, Attachments, Query, compare, l10n, media;
  
  	/**
  	 * wp.media( attributes )
  	 *
  	 * Handles the default media experience. Automatically creates
  	 * and opens a media frame, and returns the result.
  	 * Does nothing if the controllers do not exist.
  	 *
  	 * @param  {object} attributes The properties passed to the main media controller.
  	 * @return {object}            A media workflow.
  	 */
  	media = wp.media = function( attributes ) {
  		var MediaFrame = media.view.MediaFrame,
  			frame;
  
  		if ( ! MediaFrame )
  			return;
  
  		attributes = _.defaults( attributes || {}, {
  			frame: 'select'
  		});
  
  		if ( 'select' === attributes.frame && MediaFrame.Select )
  			frame = new MediaFrame.Select( attributes );
  		else if ( 'post' === attributes.frame && MediaFrame.Post )
  			frame = new MediaFrame.Post( attributes );
  
  		delete attributes.frame;
  
  		return frame;
  	};
  
  	_.extend( media, { model: {}, view: {}, controller: {}, frames: {} });
  
  	// Link any localized strings.
  	l10n = media.model.l10n = typeof _wpMediaModelsL10n === 'undefined' ? {} : _wpMediaModelsL10n;
  
  	// Link any settings.
  	media.model.settings = l10n.settings || {};
  	delete l10n.settings;
  
  	/**
  	 * ========================================================================
  	 * UTILITIES
  	 * ========================================================================
  	 */
  
  	/**
  	 * A basic comparator.
  	 *
  	 * @param  {mixed}  a  The primary parameter to compare.
  	 * @param  {mixed}  b  The primary parameter to compare.
  	 * @param  {string} ac The fallback parameter to compare, a's cid.
  	 * @param  {string} bc The fallback parameter to compare, b's cid.
  	 * @return {number}    -1: a should come before b.
  	 *                      0: a and b are of the same rank.
  	 *                      1: b should come before a.
  	 */
  	compare = function( a, b, ac, bc ) {
  		if ( _.isEqual( a, b ) )
  			return ac === bc ? 0 : (ac > bc ? -1 : 1);
  		else
  			return a > b ? -1 : 1;
  	};
  
  	_.extend( media, {
  		/**
  		 * media.template( id )
  		 *
  		 * Fetches a template by id.
  		 * See wp.template() in `wp-includes/js/wp-util.js`.
  		 */
  		template: wp.template,
  
  		/**
  		 * media.post( [action], [data] )
  		 *
  		 * Sends a POST request to WordPress.
  		 * See wp.ajax.post() in `wp-includes/js/wp-util.js`.
  		 */
  		post: wp.ajax.post,
  
  		/**
  		 * media.ajax( [action], [options] )
  		 *
  		 * Sends an XHR request to WordPress.
  		 * See wp.ajax.send() in `wp-includes/js/wp-util.js`.
  		 */
  		ajax: wp.ajax.send,
  
  		// Scales a set of dimensions to fit within bounding dimensions.
  		fit: function( dimensions ) {
  			var width     = dimensions.width,
  				height    = dimensions.height,
  				maxWidth  = dimensions.maxWidth,
  				maxHeight = dimensions.maxHeight,
  				constraint;
  
  			// Compare ratios between the two values to determine which
  			// max to constrain by. If a max value doesn't exist, then the
  			// opposite side is the constraint.
  			if ( ! _.isUndefined( maxWidth ) && ! _.isUndefined( maxHeight ) ) {
  				constraint = ( width / height > maxWidth / maxHeight ) ? 'width' : 'height';
  			} else if ( _.isUndefined( maxHeight ) ) {
  				constraint = 'width';
  			} else if (  _.isUndefined( maxWidth ) && height > maxHeight ) {
  				constraint = 'height';
  			}
  
  			// If the value of the constrained side is larger than the max,
  			// then scale the values. Otherwise return the originals; they fit.
  			if ( 'width' === constraint && width > maxWidth ) {
  				return {
  					width : maxWidth,
  					height: Math.round( maxWidth * height / width )
  				};
  			} else if ( 'height' === constraint && height > maxHeight ) {
  				return {
  					width : Math.round( maxHeight * width / height ),
  					height: maxHeight
  				};
  			} else {
  				return {
  					width : width,
  					height: height
  				};
  			}
  		},
  
  		// Truncates a string by injecting an ellipsis into the middle.
  		// Useful for filenames.
  		truncate: function( string, length, replacement ) {
  			length = length || 30;
  			replacement = replacement || '&hellip;';
  
  			if ( string.length <= length )
  				return string;
  
  			return string.substr( 0, length / 2 ) + replacement + string.substr( -1 * length / 2 );
  		}
  	});
  
  
  	/**
  	 * ========================================================================
  	 * MODELS
  	 * ========================================================================
  	 */
  
  	 /**
  	  * wp.media.attachment
  	  */
  	 media.attachment = function( id ) {
  		return Attachment.get( id );
  	 };
  
  	/**
  	 * wp.media.model.Attachment
  	 */
  	Attachment = media.model.Attachment = Backbone.Model.extend({
  		sync: function( method, model, options ) {
  			// If the attachment does not yet have an `id`, return an instantly
  			// rejected promise. Otherwise, all of our requests will fail.
  			if ( _.isUndefined( this.id ) )
  				return $.Deferred().rejectWith( this ).promise();
  
  			// Overload the `read` request so Attachment.fetch() functions correctly.
  			if ( 'read' === method ) {
  				options = options || {};
  				options.context = this;
  				options.data = _.extend( options.data || {}, {
  					action: 'get-attachment',
  					id: this.id
  				});
  				return media.ajax( options );
  
  			// Overload the `update` request so properties can be saved.
  			} else if ( 'update' === method ) {
  				// If we do not have the necessary nonce, fail immeditately.
  				if ( ! this.get('nonces') || ! this.get('nonces').update )
  					return $.Deferred().rejectWith( this ).promise();
  
  				options = options || {};
  				options.context = this;
  
  				// Set the action and ID.
  				options.data = _.extend( options.data || {}, {
  					action:  'save-attachment',
  					id:      this.id,
  					nonce:   this.get('nonces').update,
  					post_id: media.model.settings.post.id
  				});
  
  				// Record the values of the changed attributes.
  				if ( model.hasChanged() ) {
  					options.data.changes = {};
  
  					_.each( model.changed, function( value, key ) {
  						options.data.changes[ key ] = this.get( key );
  					}, this );
  				}
  
  				return media.ajax( options );
  
  			// Overload the `delete` request so attachments can be removed.
  			// This will permanently delete an attachment.
  			} else if ( 'delete' === method ) {
  				options = options || {};
  
  				if ( ! options.wait )
  					this.destroyed = true;
  
  				options.context = this;
  				options.data = _.extend( options.data || {}, {
  					action:   'delete-post',
  					id:       this.id,
  					_wpnonce: this.get('nonces')['delete']
  				});
  
  				return media.ajax( options ).done( function() {
  					this.destroyed = true;
  				}).fail( function() {
  					this.destroyed = false;
  				});
  
  			// Otherwise, fall back to `Backbone.sync()`.
  			} else {
  				return Backbone.Model.prototype.sync.apply( this, arguments );
  			}
  		},
  
  		parse: function( resp, xhr ) {
  			if ( ! resp )
  				return resp;
  
  			// Convert date strings into Date objects.
  			resp.date = new Date( resp.date );
  			resp.modified = new Date( resp.modified );
  			return resp;
  		},
  
  		saveCompat: function( data, options ) {
  			var model = this;
  
  			// If we do not have the necessary nonce, fail immeditately.
  			if ( ! this.get('nonces') || ! this.get('nonces').update )
  				return $.Deferred().rejectWith( this ).promise();
  
  			return media.post( 'save-attachment-compat', _.defaults({
  				id:      this.id,
  				nonce:   this.get('nonces').update,
  				post_id: media.model.settings.post.id
  			}, data ) ).done( function( resp, status, xhr ) {
  				model.set( model.parse( resp, xhr ), options );
  			});
  		}
  	}, {
  		create: function( attrs ) {
  			return Attachments.all.push( attrs );
  		},
  
  		get: _.memoize( function( id, attachment ) {
  			return Attachments.all.push( attachment || { id: id } );
  		})
  	});
  
  	/**
  	 * wp.media.model.Attachments
  	 */
  	Attachments = media.model.Attachments = Backbone.Collection.extend({
  		model: Attachment,
  
  		initialize: function( models, options ) {
  			options = options || {};
  
  			this.props   = new Backbone.Model();
  			this.filters = options.filters || {};
  
  			// Bind default `change` events to the `props` model.
  			this.props.on( 'change', this._changeFilteredProps, this );
  
  			this.props.on( 'change:order',   this._changeOrder,   this );
  			this.props.on( 'change:orderby', this._changeOrderby, this );
  			this.props.on( 'change:query',   this._changeQuery,   this );
  
  			// Set the `props` model and fill the default property values.
  			this.props.set( _.defaults( options.props || {} ) );
  
  			// Observe another `Attachments` collection if one is provided.
  			if ( options.observe )
  				this.observe( options.observe );
  		},
  
  		// Automatically sort the collection when the order changes.
  		_changeOrder: function( model, order ) {
  			if ( this.comparator )
  				this.sort();
  		},
  
  		// Set the default comparator only when the `orderby` property is set.
  		_changeOrderby: function( model, orderby ) {
  			// If a different comparator is defined, bail.
  			if ( this.comparator && this.comparator !== Attachments.comparator )
  				return;
  
  			if ( orderby && 'post__in' !== orderby )
  				this.comparator = Attachments.comparator;
  			else
  				delete this.comparator;
  		},
  
  		// If the `query` property is set to true, query the server using
  		// the `props` values, and sync the results to this collection.
  		_changeQuery: function( model, query ) {
  			if ( query ) {
  				this.props.on( 'change', this._requery, this );
  				this._requery();
  			} else {
  				this.props.off( 'change', this._requery, this );
  			}
  		},
  
  		_changeFilteredProps: function( model, options ) {
  			// If this is a query, updating the collection will be handled by
  			// `this._requery()`.
  			if ( this.props.get('query') )
  				return;
  
  			var changed = _.chain( model.changed ).map( function( t, prop ) {
  				var filter = Attachments.filters[ prop ],
  					term = model.get( prop );
  
  				if ( ! filter )
  					return;
  
  				if ( term && ! this.filters[ prop ] )
  					this.filters[ prop ] = filter;
  				else if ( ! term && this.filters[ prop ] === filter )
  					delete this.filters[ prop ];
  				else
  					return;
  
  				// Record the change.
  				return true;
  			}, this ).any().value();
  
  			if ( ! changed )
  				return;
  
  			// If no `Attachments` model is provided to source the searches
  			// from, then automatically generate a source from the existing
  			// models.
  			if ( ! this._source )
  				this._source = new Attachments( this.models );
  
  			this.reset( this._source.filter( this.validator, this ) );
  		},
  
  		validateDestroyed: false,
  
  		validator: function( attachment ) {
  			if ( ! this.validateDestroyed && attachment.destroyed )
  				return false;
  			return _.all( this.filters, function( filter, key ) {
  				return !! filter.call( this, attachment );
  			}, this );
  		},
  
  		validate: function( attachment, options ) {
  			var valid = this.validator( attachment ),
  				hasAttachment = !! this.get( attachment.cid );
  
  			if ( ! valid && hasAttachment )
  				this.remove( attachment, options );
  			else if ( valid && ! hasAttachment )
  				this.add( attachment, options );
  
  			return this;
  		},
  
  		validateAll: function( attachments, options ) {
  			options = options || {};
  
  			_.each( attachments.models, function( attachment ) {
  				this.validate( attachment, { silent: true });
  			}, this );
  
  			if ( ! options.silent )
  				this.trigger( 'reset', this, options );
  
  			return this;
  		},
  
  		observe: function( attachments ) {
  			this.observers = this.observers || [];
  			this.observers.push( attachments );
  
  			attachments.on( 'add change remove', this._validateHandler, this );
  			attachments.on( 'reset', this._validateAllHandler, this );
  			this.validateAll( attachments );
  			return this;
  		},
  
  		unobserve: function( attachments ) {
  			if ( attachments ) {
  				attachments.off( null, null, this );
  				this.observers = _.without( this.observers, attachments );
  
  			} else {
  				_.each( this.observers, function( attachments ) {
  					attachments.off( null, null, this );
  				}, this );
  				delete this.observers;
  			}
  
  			return this;
  		},
  
  		_validateHandler: function( attachment, attachments, options ) {
  			// If we're not mirroring this `attachments` collection,
  			// only retain the `silent` option.
  			options = attachments === this.mirroring ? options : {
  				silent: options && options.silent
  			};
  
  			return this.validate( attachment, options );
  		},
  
  		_validateAllHandler: function( attachments, options ) {
  			return this.validateAll( attachments, options );
  		},
  
  		mirror: function( attachments ) {
  			if ( this.mirroring && this.mirroring === attachments )
  				return this;
  
  			this.unmirror();
  			this.mirroring = attachments;
  
  			// Clear the collection silently. A `reset` event will be fired
  			// when `observe()` calls `validateAll()`.
  			this.reset( [], { silent: true } );
  			this.observe( attachments );
  
  			return this;
  		},
  
  		unmirror: function() {
  			if ( ! this.mirroring )
  				return;
  
  			this.unobserve( this.mirroring );
  			delete this.mirroring;
  		},
  
  		more: function( options ) {
  			var deferred = $.Deferred(),
  				mirroring = this.mirroring,
  				attachments = this;
  
  			if ( ! mirroring || ! mirroring.more )
  				return deferred.resolveWith( this ).promise();
  
  			// If we're mirroring another collection, forward `more` to
  			// the mirrored collection. Account for a race condition by
  			// checking if we're still mirroring that collection when
  			// the request resolves.
  			mirroring.more( options ).done( function() {
  				if ( this === attachments.mirroring )
  					deferred.resolveWith( this );
  			});
  
  			return deferred.promise();
  		},
  
  		hasMore: function() {
  			return this.mirroring ? this.mirroring.hasMore() : false;
  		},
  
  		parse: function( resp, xhr ) {
  			if ( ! _.isArray( resp ) )
  				resp = [resp];
  
  			return _.map( resp, function( attrs ) {
  				var id, attachment, newAttributes;
  
  				if ( attrs instanceof Backbone.Model ) {
  					id = attrs.get( 'id' );
  					attrs = attrs.attributes;
  				} else {
  					id = attrs.id;
  				}
  
  				attachment = Attachment.get( id );
  				newAttributes = attachment.parse( attrs, xhr );
  
  				if ( ! _.isEqual( attachment.attributes, newAttributes ) )
  					attachment.set( newAttributes );
  
  				return attachment;
  			});
  		},
  
  		_requery: function() {
  			if ( this.props.get('query') )
  				this.mirror( Query.get( this.props.toJSON() ) );
  		},
  
  		// If this collection is sorted by `menuOrder`, recalculates and saves
  		// the menu order to the database.
  		saveMenuOrder: function() {
  			if ( 'menuOrder' !== this.props.get('orderby') )
  				return;
  
  			// Removes any uploading attachments, updates each attachment's
  			// menu order, and returns an object with an { id: menuOrder }
  			// mapping to pass to the request.
  			var attachments = this.chain().filter( function( attachment ) {
  				return ! _.isUndefined( attachment.id );
  			}).map( function( attachment, index ) {
  				// Indices start at 1.
  				index = index + 1;
  				attachment.set( 'menuOrder', index );
  				return [ attachment.id, index ];
  			}).object().value();
  
  			if ( _.isEmpty( attachments ) )
  				return;
  
  			return media.post( 'save-attachment-order', {
  				nonce:       media.model.settings.post.nonce,
  				post_id:     media.model.settings.post.id,
  				attachments: attachments
  			});
  		}
  	}, {
  		comparator: function( a, b, options ) {
  			var key   = this.props.get('orderby'),
  				order = this.props.get('order') || 'DESC',
  				ac    = a.cid,
  				bc    = b.cid;
  
  			a = a.get( key );
  			b = b.get( key );
  
  			if ( 'date' === key || 'modified' === key ) {
  				a = a || new Date();
  				b = b || new Date();
  			}
  
  			// If `options.ties` is set, don't enforce the `cid` tiebreaker.
  			if ( options && options.ties )
  				ac = bc = null;
  
  			return ( 'DESC' === order ) ? compare( a, b, ac, bc ) : compare( b, a, bc, ac );
  		},
  
  		filters: {
  			// Note that this client-side searching is *not* equivalent
  			// to our server-side searching.
  			search: function( attachment ) {
  				if ( ! this.props.get('search') )
  					return true;
  
  				return _.any(['title','filename','description','caption','name'], function( key ) {
  					var value = attachment.get( key );
  					return value && -1 !== value.search( this.props.get('search') );
  				}, this );
  			},
  
  			type: function( attachment ) {
  				var type = this.props.get('type');
  				return ! type || -1 !== type.indexOf( attachment.get('type') );
  			},
  
  			uploadedTo: function( attachment ) {
  				var uploadedTo = this.props.get('uploadedTo');
  				if ( _.isUndefined( uploadedTo ) )
  					return true;
  
  				return uploadedTo === attachment.get('uploadedTo');
  			}
  		}
  	});
  
  	Attachments.all = new Attachments();
  
  	/**
  	 * wp.media.query
  	 */
  	media.query = function( props ) {
  		return new Attachments( null, {
  			props: _.extend( _.defaults( props || {}, { orderby: 'date' } ), { query: true } )
  		});
  	};
  
  	/**
  	 * wp.media.model.Query
  	 *
  	 * A set of attachments that corresponds to a set of consecutively paged
  	 * queries on the server.
  	 *
  	 * Note: Do NOT change this.args after the query has been initialized.
  	 *       Things will break.
  	 */
  	Query = media.model.Query = Attachments.extend({
  		initialize: function( models, options ) {
  			var allowed;
  
  			options = options || {};
  			Attachments.prototype.initialize.apply( this, arguments );
  
  			this.args     = options.args;
  			this._hasMore = true;
  			this.created  = new Date();
  
  			this.filters.order = function( attachment ) {
  				var orderby = this.props.get('orderby'),
  					order = this.props.get('order');
  
  				if ( ! this.comparator )
  					return true;
  
  				// We want any items that can be placed before the last
  				// item in the set. If we add any items after the last
  				// item, then we can't guarantee the set is complete.
  				if ( this.length ) {
  					return 1 !== this.comparator( attachment, this.last(), { ties: true });
  
  				// Handle the case where there are no items yet and
  				// we're sorting for recent items. In that case, we want
  				// changes that occurred after we created the query.
  				} else if ( 'DESC' === order && ( 'date' === orderby || 'modified' === orderby ) ) {
  					return attachment.get( orderby ) >= this.created;
  
  				// If we're sorting by menu order and we have no items,
  				// accept any items that have the default menu order (0).
  				} else if ( 'ASC' === order && 'menuOrder' === orderby ) {
  					return attachment.get( orderby ) === 0;
  				}
  
  				// Otherwise, we don't want any items yet.
  				return false;
  			};
  
  			// Observe the central `wp.Uploader.queue` collection to watch for
  			// new matches for the query.
  			//
  			// Only observe when a limited number of query args are set. There
  			// are no filters for other properties, so observing will result in
  			// false positives in those queries.
  			allowed = [ 's', 'order', 'orderby', 'posts_per_page', 'post_mime_type', 'post_parent' ];
  			if ( wp.Uploader && _( this.args ).chain().keys().difference( allowed ).isEmpty().value() )
  				this.observe( wp.Uploader.queue );
  		},
  
  		hasMore: function() {
  			return this._hasMore;
  		},
  
  		more: function( options ) {
  			var query = this;
  
  			if ( this._more && 'pending' === this._more.state() )
  				return this._more;
  
  			if ( ! this.hasMore() )
  				return $.Deferred().resolveWith( this ).promise();
  
  			options = options || {};
  			options.remove = false;
  
  			return this._more = this.fetch( options ).done( function( resp ) {
  				if ( _.isEmpty( resp ) || -1 === this.args.posts_per_page || resp.length < this.args.posts_per_page )
  					query._hasMore = false;
  			});
  		},
  
  		sync: function( method, model, options ) {
  			var fallback;
  
  			// Overload the read method so Attachment.fetch() functions correctly.
  			if ( 'read' === method ) {
  				options = options || {};
  				options.context = this;
  				options.data = _.extend( options.data || {}, {
  					action:  'query-attachments',
  					post_id: media.model.settings.post.id
  				});
  
  				// Clone the args so manipulation is non-destructive.
  				args = _.clone( this.args );
  
  				// Determine which page to query.
  				if ( -1 !== args.posts_per_page )
  					args.paged = Math.floor( this.length / args.posts_per_page ) + 1;
  
  				options.data.query = args;
  				return media.ajax( options );
  
  			// Otherwise, fall back to Backbone.sync()
  			} else {
  				fallback = Attachments.prototype.sync ? Attachments.prototype : Backbone;
  				return fallback.sync.apply( this, arguments );
  			}
  		}
  	}, {
  		defaultProps: {
  			orderby: 'date',
  			order:   'DESC'
  		},
  
  		defaultArgs: {
  			posts_per_page: 40
  		},
  
  		orderby: {
  			allowed:  [ 'name', 'author', 'date', 'title', 'modified', 'uploadedTo', 'id', 'post__in', 'menuOrder' ],
  			valuemap: {
  				'id':         'ID',
  				'uploadedTo': 'parent',
  				'menuOrder':  'menu_order ID'
  			}
  		},
  
  		propmap: {
  			'search':    's',
  			'type':      'post_mime_type',
  			'perPage':   'posts_per_page',
  			'menuOrder': 'menu_order',
  			'uploadedTo': 'post_parent'
  		},
  
  		// Caches query objects so queries can be easily reused.
  		get: (function(){
  			var queries = [];
  
  			return function( props, options ) {
  				var args     = {},
  					orderby  = Query.orderby,
  					defaults = Query.defaultProps,
  					query;
  
  				// Remove the `query` property. This isn't linked to a query,
  				// this *is* the query.
  				delete props.query;
  
  				// Fill default args.
  				_.defaults( props, defaults );
  
  				// Normalize the order.
  				props.order = props.order.toUpperCase();
  				if ( 'DESC' !== props.order && 'ASC' !== props.order )
  					props.order = defaults.order.toUpperCase();
  
  				// Ensure we have a valid orderby value.
  				if ( ! _.contains( orderby.allowed, props.orderby ) )
  					props.orderby = defaults.orderby;
  
  				// Generate the query `args` object.
  				// Correct any differing property names.
  				_.each( props, function( value, prop ) {
  					if ( _.isNull( value ) )
  						return;
  
  					args[ Query.propmap[ prop ] || prop ] = value;
  				});
  
  				// Fill any other default query args.
  				_.defaults( args, Query.defaultArgs );
  
  				// `props.orderby` does not always map directly to `args.orderby`.
  				// Substitute exceptions specified in orderby.keymap.
  				args.orderby = orderby.valuemap[ props.orderby ] || props.orderby;
  
  				// Search the query cache for matches.
  				query = _.find( queries, function( query ) {
  					return _.isEqual( query.args, args );
  				});
  
  				// Otherwise, create a new query and add it to the cache.
  				if ( ! query ) {
  					query = new Query( [], _.extend( options || {}, {
  						props: props,
  						args:  args
  					} ) );
  					queries.push( query );
  				}
  
  				return query;
  			};
  		}())
  	});
  
  	/**
  	 * wp.media.model.Selection
  	 *
  	 * Used to manage a selection of attachments in the views.
  	 */
  	media.model.Selection = Attachments.extend({
  		initialize: function( models, options ) {
  			Attachments.prototype.initialize.apply( this, arguments );
  			this.multiple = options && options.multiple;
  
  			// Refresh the `single` model whenever the selection changes.
  			// Binds `single` instead of using the context argument to ensure
  			// it receives no parameters.
  			this.on( 'add remove reset', _.bind( this.single, this, false ) );
  		},
  
  		// Override the selection's add method.
  		// If the workflow does not support multiple
  		// selected attachments, reset the selection.
  		add: function( models, options ) {
  			if ( ! this.multiple )
  				this.remove( this.models );
  
  			return Attachments.prototype.add.call( this, models, options );
  		},
  
  		single: function( model ) {
  			var previous = this._single;
  
  			// If a `model` is provided, use it as the single model.
  			if ( model )
  				this._single = model;
  
  			// If the single model isn't in the selection, remove it.
  			if ( this._single && ! this.get( this._single.cid ) )
  				delete this._single;
  
  			this._single = this._single || this.last();
  
  			// If single has changed, fire an event.
  			if ( this._single !== previous ) {
  				if ( previous ) {
  					previous.trigger( 'selection:unsingle', previous, this );
  
  					// If the model was already removed, trigger the collection
  					// event manually.
  					if ( ! this.get( previous.cid ) )
  						this.trigger( 'selection:unsingle', previous, this );
  				}
  				if ( this._single )
  					this._single.trigger( 'selection:single', this._single, this );
  			}
  
  			// Return the single model, or the last model as a fallback.
  			return this._single;
  		}
  	});
  
  	// Clean up. Prevents mobile browsers caching
  	$(window).on('unload', function(){
  		window.wp = null;
  	});
  
  }(jQuery));