CaffGeek/MBACNationals

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Web.Admin/2014/wordpress/wp-includes/js/media-models.js

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/* global _wpMediaModelsL10n:false */
window.wp = window.wp || {};

(function($){
    var Attachment, Attachments, Query, PostImage, 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 {wp.media.view.MediaFrame} 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 );
        } else if ( 'image' === attributes.frame && MediaFrame.ImageDetails ) {
            frame = new MediaFrame.ImageDetails( attributes );
        } else if ( 'audio' === attributes.frame && MediaFrame.AudioDetails ) {
            frame = new MediaFrame.AudioDetails( attributes );
        } else if ( 'video' === attributes.frame && MediaFrame.VideoDetails ) {
            frame = new MediaFrame.VideoDetails( attributes );
        }

        delete attributes.frame;

        media.frame = 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`.
         *
         * @borrows wp.template as template
         */
        template: wp.template,

        /**
         * media.post( [action], [data] )
         *
         * Sends a POST request to WordPress.
         * See wp.ajax.post() in `wp-includes/js/wp-util.js`.
         *
         * @borrows wp.ajax.post as post
         */
        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`.
         *
         * @borrows wp.ajax.send as ajax
         */
        ajax: wp.ajax.send,

        /**
         * Scales a set of dimensions to fit within bounding dimensions.
         *
         * @param {Object} dimensions
         * @returns {Object}
         */
        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.
         *
         * @param {String} string
         * @param {Number} [length=30]
         * @param {String} [replacement=…]
         * @returns {String} The string, unless length is greater than string.length.
         */
        truncate: function( string, length, replacement ) {
            length = length || 30;
            replacement = replacement || '…';

            if ( string.length <= length ) {
                return string;
            }

            return string.substr( 0, length / 2 ) + replacement + string.substr( -1 * length / 2 );
        }
    });

    /**
     * ========================================================================
     * MODELS
     * ========================================================================
     */
    /**
     * wp.media.attachment
     *
     * @static
     * @param {String} id A string used to identify a model.
     * @returns {wp.media.model.Attachment}
     */
    media.attachment = function( id ) {
        return Attachment.get( id );
    };

    /**
     * wp.media.model.Attachment
     *
     * @constructor
     * @augments Backbone.Model
     */
    Attachment = media.model.Attachment = Backbone.Model.extend({
        /**
         * Triggered when attachment details change
         * Overrides Backbone.Model.sync
         *
         * @param {string} method
         * @param {wp.media.model.Attachment} model
         * @param {Object} [options={}]
         *
         * @returns {Promise}
         */
        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 {
                /**
                 * Call `sync` directly on Backbone.Model
                 */
                return Backbone.Model.prototype.sync.apply( this, arguments );
            }
        },
        /**
         * Convert date strings into Date objects.
         *
         * @param {Object} resp The raw response object, typically returned by fetch()
         * @returns {Object} The modified response object, which is the attributes hash
         *    to be set on the model.
         */
        parse: function( resp ) {
            if ( ! resp ) {
                return resp;
            }

            resp.date = new Date( resp.date );
            resp.modified = new Date( resp.modified );
            return resp;
        },
        /**
         * @param {Object} data The properties to be saved.
         * @param {Object} options Sync options. e.g. patch, wait, success, error.
         *
         * @this Backbone.Model
         *
         * @returns {Promise}
         */
        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 );
            });
        }
    }, {
        /**
         * Add a model to the end of the static 'all' collection and return it.
         *
         * @static
         * @param {Object} attrs
         * @returns {wp.media.model.Attachment}
         */
        create: function( attrs ) {
            return Attachments.all.push( attrs );
        },
        /**
         * Retrieve a model, or add it to the end of the static 'all' collection before returning it.
         *
         * @static
         * @param {string} id A string used to identify a model.
         * @param {Backbone.Model|undefined} attachment
         * @returns {wp.media.model.Attachment}
         */
        get: _.memoize( function( id, attachment ) {
            return Attachments.all.push( attachment || { id: id } );
        })
    });

    /**
     * wp.media.model.PostImage
     *
     * @constructor
     * @augments Backbone.Model
     **/
    PostImage = media.model.PostImage = Backbone.Model.extend({

        initialize: function( attributes ) {
            this.attachment = false;

            if ( attributes.attachment_id ) {
                this.attachment = Attachment.get( attributes.attachment_id );
                if ( this.attachment.get( 'url' ) ) {
                    this.dfd = $.Deferred();
                    this.dfd.resolve();
                } else {
                    this.dfd = this.attachment.fetch();
                }
                this.bindAttachmentListeners();
            }

            // keep url in sync with changes to the type of link
            this.on( 'change:link', this.updateLinkUrl, this );
            this.on( 'change:size', this.updateSize, this );

            this.setLinkTypeFromUrl();
            this.setAspectRatio();

            this.set( 'originalUrl', attributes.url );
        },

        bindAttachmentListeners: function() {
            this.listenTo( this.attachment, 'sync', this.setLinkTypeFromUrl );
            this.listenTo( this.attachment, 'sync', this.setAspectRatio );
            this.listenTo( this.attachment, 'change', this.updateSize );
        },

        changeAttachment: function( attachment, props ) {
            this.stopListening( this.attachment );
            this.attachment = attachment;
            this.bindAttachmentListeners();

            this.set( 'attachment_id', this.attachment.get( 'id' ) );
            this.set( 'caption', this.attachment.get( 'caption' ) );
            this.set( 'alt', this.attachment.get( 'alt' ) );
            this.set( 'size', props.get( 'size' ) );
            this.set( 'align', props.get( 'align' ) );
            this.set( 'link', props.get( 'link' ) );
            this.updateLinkUrl();
            this.updateSize();
        },

        setLinkTypeFromUrl: function() {
            var linkUrl = this.get( 'linkUrl' ),
                type;

            if ( ! linkUrl ) {
                this.set( 'link', 'none' );
                return;
            }

            // default to custom if there is a linkUrl
            type = 'custom';

            if ( this.attachment ) {
                if ( this.attachment.get( 'url' ) === linkUrl ) {
                    type = 'file';
                } else if ( this.attachment.get( 'link' ) === linkUrl ) {
                    type = 'post';
                }
            } else {
                if ( this.get( 'url' ) === linkUrl ) {
                    type = 'file';
                }
            }

            this.set( 'link', type );
        },

        updateLinkUrl: function() {
            var link = this.get( 'link' ),
                url;

            switch( link ) {
                case 'file':
                    if ( this.attachment ) {
                        url = this.attachment.get( 'url' );
                    } else {
                        url = this.get( 'url' );
                    }
                    this.set( 'linkUrl', url );
                    break;
                case 'post':
                    this.set( 'linkUrl', this.attachment.get( 'link' ) );
                    break;
                case 'none':
                    this.set( 'linkUrl', '' );
                    break;
            }
        },

        updateSize: function() {
            var size;

            if ( ! this.attachment ) {
                return;
            }

            if ( this.get( 'size' ) === 'custom' ) {
                this.set( 'width', this.get( 'customWidth' ) );
                this.set( 'height', this.get( 'customHeight' ) );
                this.set( 'url', this.get( 'originalUrl' ) );
                return;
            }

            size = this.attachment.get( 'sizes' )[ this.get( 'size' ) ];

            if ( ! size ) {
                return;
            }

            this.set( 'url', size.url );
            this.set( 'width', size.width );
            this.set( 'height', size.height );
        },

        setAspectRatio: function() {
            var full;

            if ( this.attachment && this.attachment.get( 'sizes' ) ) {
                full = this.attachment.get( 'sizes' ).full;

                if ( full ) {
                    this.set( 'aspectRatio', full.width / full.height );
                    return;
                }
            }

            this.set( 'aspectRatio', this.get( 'customWidth' ) / this.get( 'customHeight' ) );
        }
    });

    /**
     * wp.media.model.Attachments
     *
     * @constructor
     * @augments Backbone.Collection
     */
    Attachments = media.model.Attachments = Backbone.Collection.extend({
        /**
         * @type {wp.media.model.Attachment}
         */
        model: Attachment,
        /**
         * @param {Array} [models=[]] Array of models used to populate the collection.
         * @param {Object} [options={}]
         */
        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.
         *
         * @access private
         */
        _changeOrder: function() {
            if ( this.comparator ) {
                this.sort();
            }
        },
        /**
         * Set the default comparator only when the `orderby` property is set.
         *
         * @access private
         *
         * @param {Backbone.Model} model
         * @param {string} orderby
         */
        _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.
         *
         * @access private
         *
         * @param {Backbone.Model} model
         * @param {Boolean} query
         */
        _changeQuery: function( model, query ) {
            if ( query ) {
                this.props.on( 'change', this._requery, this );
                this._requery();
            } else {
                this.props.off( 'change', this._requery, this );
            }
        },
        /**
         * @access private
         *
         * @param {Backbone.Model} model
         */
        _changeFilteredProps: function( model ) {
            // 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,
        /**
         * @param {wp.media.model.Attachment} attachment
         * @returns {Boolean}
         */
        validator: function( attachment ) {
            if ( ! this.validateDestroyed && attachment.destroyed ) {
                return false;
            }
            return _.all( this.filters, function( filter ) {
                return !! filter.call( this, attachment );
            }, this );
        },
        /**
         * @param {wp.media.model.Attachment} attachment
         * @param {Object} options
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        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;
        },

        /**
         * @param {wp.media.model.Attachments} attachments
         * @param {object} [options={}]
         *
         * @fires wp.media.model.Attachments#reset
         *
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        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;
        },
        /**
         * @param {wp.media.model.Attachments} attachments
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        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;
        },
        /**
         * @param {wp.media.model.Attachments} attachments
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        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;
        },
        /**
         * @access private
         *
         * @param {wp.media.model.Attachments} attachment
         * @param {wp.media.model.Attachments} attachments
         * @param {Object} options
         *
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        _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 );
        },
        /**
         * @access private
         *
         * @param {wp.media.model.Attachments} attachments
         * @param {Object} options
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        _validateAllHandler: function( attachments, options ) {
            return this.validateAll( attachments, options );
        },
        /**
         * @param {wp.media.model.Attachments} attachments
         * @returns {wp.media.model.Attachments} Returns itself to allow chaining
         */
        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;
        },
        /**
         * @param {Object} options
         * @returns {Promise}
         */
        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();
        },
        /**
         * @returns {Boolean}
         */
        hasMore: function() {
            return this.mirroring ? this.mirroring.hasMore() : false;
        },
        /**
         * Overrides Backbone.Collection.parse
         *
         * @param {Object|Array} resp The raw response Object/Array.
         * @param {Object} xhr
         * @returns {Array} The array of model attributes to be added to the collection
         */
        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;
            });
        },
        /**
         * @access private
         */
        _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.
         *
         * @returns {undefined|Promise}
         */
        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
            });
        }
    }, {
        /**
         * @static
         * Overrides Backbone.Collection.comparator
         *
         * @param {Backbone.Model} a
         * @param {Backbone.Model} b
         * @param {Object} options
         * @returns {Number} -1 if the first model should come before the second,
         *    0 if they are of the same rank and
         *    1 if the first model should come after.
         */
        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 );
        },
        /**
         * @namespace
         */
        filters: {
            /**
             * @static
             * Note that this client-side searching is *not* equivalent
             * to our server-side searching.
             *
             * @param {wp.media.model.Attachment} attachment
             *
             * @this wp.media.model.Attachments
             *
             * @returns {Boolean}
             */
            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 );
            },
            /**
             * @static
             * @param {wp.media.model.Attachment} attachment
             *
             * @this wp.media.model.Attachments
             *
             * @returns {Boolean}
             */
            type: function( attachment ) {
                var type = this.props.get('type');
                return ! type || -1 !== type.indexOf( attachment.get('type') );
            },
            /**
             * @static
             * @param {wp.media.model.Attachment} attachment
             *
             * @this wp.media.model.Attachments
             *
             * @returns {Boolean}
             */
            uploadedTo: function( attachment ) {
                var uploadedTo = this.props.get('uploadedTo');
                if ( _.isUndefined( uploadedTo ) ) {
                    return true;
                }

                return uploadedTo === attachment.get('uploadedTo');
            }
        }
    });

    /**
     * @static
     * @member {wp.media.model.Attachments}
     */
    Attachments.all = new Attachments();

    /**
     * wp.media.query
     *
     * @static
     * @returns {wp.media.model.Attachments}
     */
    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.
     *
     * @constructor
     * @augments wp.media.model.Attachments
     * @augments Backbone.Collection
     */
    Query = media.model.Query = Attachments.extend({
        /**
         * @global wp.Uploader
         *
         * @param {Array} [models=[]] Array of models used to populate the collection.
         * @param {Object} [options={}]
         */
        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 );
            }
        },
        /**
         * @returns {Boolean}
         */
        hasMore: function() {
            return this._hasMore;
        },
        /**
         * @param {Object} [options={}]
         * @returns {Promise}
         */
        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;
                }
            });
        },
        /**
         * Overrides Backbone.Collection.sync
         * Overrides wp.media.model.Attachments.sync
         *
         * @param {String} method
         * @param {Backbone.Model} model
         * @param {Object} [options={}]
         * @returns {Promise}
         */
        sync: function( method, model, options ) {
            var args, 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 {
                /**
                 * Call wp.media.model.Attachments.sync or Backbone.sync
                 */
                fallback = Attachments.prototype.sync ? Attachments.prototype : Backbone;
                return fallback.sync.apply( this, arguments );
            }
        }
    }, {
        /**
         * @readonly
         */
        defaultProps: {
            orderby: 'date',
            order:   'DESC'
        },
        /**
         * @readonly
         */
        defaultArgs: {
            posts_per_page: 40
        },
        /**
         * @readonly
         */
        orderby: {
            allowed:  [ 'name', 'author', 'date', 'title', 'modified', 'uploadedTo', 'id', 'post__in', 'menuOrder' ],
            valuemap: {
                'id':         'ID',
                'uploadedTo': 'parent',
                'menuOrder':  'menu_order ID'
            }
        },
        /**
         * @readonly
         */
        propmap: {
            'search':    's',
            'type':      'post_mime_type',
            'perPage':   'posts_per_page',
            'menuOrder': 'menu_order',
            'uploadedTo': 'post_parent'
        },
        /**
         * @static
         * @method
         *
         * @returns {wp.media.model.Query} A new query.
         */
        // Caches query objects so queries can be easily reused.
        get: (function(){
            /**
             * @static
             * @type Array
             */
            var queries = [];

            /**
             * @param {Object} props
             * @param {Object} options
             * @returns {Query}
             */
            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.
     *
     * @constructor
     * @augments wp.media.model.Attachments
     * @augments Backbone.Collection
     */
    media.model.Selection = Attachments.extend({
        /**
         * Refresh the `single` model whenever the selection changes.
         * Binds `single` instead of using the context argument to ensure
         * it receives no parameters.
         *
         * @param {Array} [models=[]] Array of models used to populate the collection.
         * @param {Object} [options={}]
         */
        initialize: function( models, options ) {
            /**
             * call 'initialize' directly on the parent class
             */
            Attachments.prototype.initialize.apply( this, arguments );
            this.multiple = options && options.multiple;

            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.
         *
         * Overrides Backbone.Collection.add
         * Overrides wp.media.model.Attachments.add
         *
         * @param {Array} models
         * @param {Object} options
         * @returns {wp.media.model.Attachment[]}
         */
        add: function( models, options ) {
            if ( ! this.multiple ) {
                this.remove( this.models );
            }
            /**
             * call 'add' directly on the parent class
             */
            return Attachments.prototype.add.call( this, models, options );
        },

        /**
         * Triggered when toggling (clicking on) an attachment in the modal
         *
         * @param {undefined|boolean|wp.media.model.Attachment} model
         *
         * @fires wp.media.model.Selection#selection:single
         * @fires wp.media.model.Selection#selection:unsingle
         *
         * @returns {Backbone.Model}
         */
        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));