API Docs for: 3.8.0
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File: uploader/js/uploader-flash.js

/**
* This module provides a UI for file selection and multiple file upload capability using
* Flash as a transport engine.
* The supported features include: automatic upload queue management, upload progress
* tracking, file filtering, server response retrieval and error reporting.
*
* @module uploader-flash
*/

// Shorthands for external modules
var substitute            = Y.Lang.sub,
    UploaderQueue         = Y.Uploader.Queue;


/**
* This module provides a UI for file selection and multiple file upload capability
* using Flash as a transport engine.
* @class UploaderFlash
* @extends Widget
* @param {Object} config Configuration object.
* @constructor
*/

function UploaderFlash() {
    UploaderFlash.superclass.constructor.apply ( this, arguments );
}



Y.UploaderFlash = Y.extend(UploaderFlash, Y.Widget, {

    /**
    * Stored value of the current button state (based on
    * mouse events dispatched by the Flash player)
    * @property _buttonState
    * @type {String}
    * @protected
    */
    _buttonState: "up",

    /**
    * Stored value of the current button focus state (based
    * on keyboard and mouse events).
    * @property _buttonFocus
    * @type {Boolean}
    * @protected
    */
    _buttonFocus: false,

    /**
    * Stored value of the unique id for the container that holds the
    * Flash uploader.
    *
    * @property _swfContainerId
    * @type {String}
    * @protected
    */
    _swfContainerId: null,

    /**
    * Stored reference to the instance of SWF used to host the
    * Flash uploader.
    *
    * @property _swfReference
    * @type {SWF}
    * @protected
    */
    _swfReference: null,

    /**
    * Stored reference to the instance of Uploader.Queue used to manage
    * the upload process. This is a read-only property that only exists
    * during an active upload process. Only one queue can be active at
    * a time; if an upload start is attempted while a queue is active,
    * it will be ignored.
    *
    * @property queue
    * @type {Y.Uploader.Queue}
    */
    queue: null,

    /**
    * Stored event bindings for keyboard navigation to and from the uploader.
    *
    * @property _tabElementBindings
    * @type {Object}
    * @protected
    */
    _tabElementBindings: null,


    /**
    * Construction logic executed during UploaderFlash instantiation.
    *
    * @method initializer
    * @protected
    */
    initializer : function () {

        // Assign protected variable values
        this._swfContainerId = Y.guid("uploader");
        this._swfReference = null;
        this.queue = null;
        this._buttonState = "up";
        this._buttonFocus = null;
        this._tabElementBindings = null;
        this._fileList = [];

        // Publish available events

        /**
        * Signals that files have been selected.
        *
        * @event fileselect
        * @param event {Event} The event object for the `fileselect` with the
        *                      following payload:
        *  <dl>
        *      <dt>fileList</dt>
        *          <dd>An `Array` of files selected by the user, encapsulated
        *              in Y.FileFlash objects.</dd>
        *  </dl>
        */
        this.publish("fileselect");

        /**
        * Signals that an upload of multiple files has been started.
        *
        * @event uploadstart
        * @param event {Event} The event object for the `uploadstart`.
        */
        this.publish("uploadstart");

        /**
        * Signals that an upload of a specific file has started.
        *
        * @event fileuploadstart
        * @param event {Event} The event object for the `fileuploadstart` with the
        *                      following payload:
        *  <dl>
        *      <dt>file</dt>
        *          <dd>A reference to the Y.File that dispatched the event.</dd>
        *      <dt>originEvent</dt>
        *          <dd>The original event dispatched by Y.File.</dd>
        *  </dl>
        */
        this.publish("fileuploadstart");

        /**
        * Reports on upload progress of a specific file.
        *
        * @event uploadprogress
        * @param event {Event} The event object for the `uploadprogress` with the
        *                      following payload:
        *  <dl>
        *      <dt>bytesLoaded</dt>
        *          <dd>The number of bytes of the file that has been uploaded</dd>
        *      <dt>bytesTotal</dt>
        *          <dd>The total number of bytes in the file</dd>
        *      <dt>percentLoaded</dt>
        *          <dd>The fraction of the file that has been uploaded, out of 100</dd>
        *      <dt>originEvent</dt>
        *          <dd>The original event dispatched by the SWF uploader</dd>
        *  </dl>
        */
        this.publish("uploadprogress");

        /**
        * Reports on the total upload progress of the file list.
        *
        * @event totaluploadprogress
        * @param event {Event} The event object for the `totaluploadprogress` with the
        *                      following payload:
        *  <dl>
        *      <dt>bytesLoaded</dt>
        *          <dd>The number of bytes of the file list that has been uploaded</dd>
        *      <dt>bytesTotal</dt>
        *          <dd>The total number of bytes in the file list</dd>
        *      <dt>percentLoaded</dt>
        *          <dd>The fraction of the file list that has been uploaded, out of 100</dd>
        *  </dl>
        */
        this.publish("totaluploadprogress");

        /**
        * Signals that a single file upload has been completed.
        *
        * @event uploadcomplete
        * @param event {Event} The event object for the `uploadcomplete` with the
        *                      following payload:
        *  <dl>
        *      <dt>file</dt>
        *          <dd>The pointer to the instance of `Y.File` whose upload has been completed.</dd>
        *      <dt>originEvent</dt>
        *          <dd>The original event fired by the SWF Uploader</dd>
        *      <dt>data</dt>
        *          <dd>Data returned by the server.</dd>
        *  </dl>
        */
        this.publish("uploadcomplete");

        /**
        * Signals that the upload process of the entire file list has been completed.
        *
        * @event alluploadscomplete
        * @param event {Event} The event object for the `alluploadscomplete`.
        */
        this.publish("alluploadscomplete");

        /**
        * Signals that a error has occurred in a specific file's upload process.
        *
        * @event uploaderror
        * @param event {Event} The event object for the `uploaderror` with the
        *                      following payload:
        *  <dl>
        *      <dt>originEvent</dt>
        *          <dd>The original error event fired by the SWF Uploader. </dd>
        *      <dt>file</dt>
        *          <dd>The pointer at the instance of Y.FileFlash that returned the error.</dd>
        *      <dt>source</dt>
        *          <dd>The source of the upload error, either "io" or "http"</dd>
        *      <dt>message</dt>
        *          <dd>The message that accompanied the error. Corresponds to the text of
        *              the error in cases where source is "io", and to the HTTP status for
                                     cases where source is "http".</dd>
        *  </dl>
        */
        this.publish("uploaderror");

        /**
        * Signals that a mouse has begun hovering over the `Select Files` button.
        *
        * @event mouseenter
        * @param event {Event} The event object for the `mouseenter` event.
        */
        this.publish("mouseenter");

        /**
        * Signals that a mouse has stopped hovering over the `Select Files` button.
        *
        * @event mouseleave
        * @param event {Event} The event object for the `mouseleave` event.
        */
        this.publish("mouseleave");

        /**
        * Signals that a mouse button has been pressed over the `Select Files` button.
        *
        * @event mousedown
        * @param event {Event} The event object for the `mousedown` event.
        */
        this.publish("mousedown");

        /**
        * Signals that a mouse button has been released over the `Select Files` button.
        *
        * @event mouseup
        * @param event {Event} The event object for the `mouseup` event.
        */
        this.publish("mouseup");

        /**
        * Signals that a mouse has been clicked over the `Select Files` button.
        *
        * @event click
        * @param event {Event} The event object for the `click` event.
        */
        this.publish("click");
    },

    /**
    * Creates the DOM structure for the UploaderFlash.
    * UploaderFlash's DOM structure consists of two layers: the base "Select Files"
    * button that can be replaced by the developer's widget of choice; and a transparent
    * Flash overlay positoned above the button that captures all input events.
    * The `position` style attribute of the `boundingBox` of the `Uploader` widget
    * is forced to be `relative`, in order to accommodate the Flash player overlay
    * (which is `position`ed `absolute`ly).
    *
    * @method renderUI
    * @protected
    */
    renderUI : function () {
        var boundingBox = this.get("boundingBox"),
            contentBox = this.get('contentBox'),
            selFilesButton = this.get("selectFilesButton"),
            flashContainer = Y.one("#" + this._swfContainerId),
            params = {
                version: "10.0.45",
                fixedAttributes: {
                    wmode: "transparent",
                    allowScriptAccess:"always",
                    allowNetworking:"all",
                    scale: "noscale"
                }
            };

        boundingBox.setStyle("position", "relative");
        selFilesButton.setStyles({width: "100%", height: "100%"});
        contentBox.append(selFilesButton);
        contentBox.append(Y.Node.create(substitute(UploaderFlash.FLASH_CONTAINER, {
            swfContainerId: this._swfContainerId
        })));

        this._swfReference = new Y.SWF(flashContainer, this.get("swfURL"), params);
    },

    /**
    * Binds handlers to the UploaderFlash UI events and propagates attribute
    * values to the Flash player.
    * The propagation of initial values is set to occur once the Flash player
    * instance is ready (as indicated by the `swfReady` event.)
    *
    * @method bindUI
    * @protected
    */
    bindUI : function () {

        this._swfReference.on("swfReady", function () {
            this._setMultipleFiles();
            this._setFileFilters();
            this._triggerEnabled();
            this._attachTabElements();
            this.after("multipleFilesChange", this._setMultipleFiles, this);
            this.after("fileFiltersChange", this._setFileFilters, this);
            this.after("enabledChange", this._triggerEnabled, this);
            this.after("tabElementsChange", this._attachTabElements);
        }, this);

        this._swfReference.on("fileselect", this._updateFileList, this);



        // this._swfReference.on("trace", function (ev) {console.log(ev.message);});

        this._swfReference.on("mouseenter", function () {
            this.fire("mouseenter");
            this._setButtonClass("hover", true);
            if (this._buttonState === "down") {
                this._setButtonClass("active", true);
            }
        }, this);

        this._swfReference.on("mouseleave", function () {
            this.fire("mouseleave");
            this._setButtonClass("hover", false);
            this._setButtonClass("active", false);
        }, this);

        this._swfReference.on("mousedown", function () {
            this.fire("mousedown");
            this._buttonState = "down";
            this._setButtonClass("active", true);
        }, this);

        this._swfReference.on("mouseup", function () {
            this.fire("mouseup");
            this._buttonState = "up";
            this._setButtonClass("active", false);
        }, this);

        this._swfReference.on("click", function () {
            this.fire("click");
            this._buttonFocus = true;
            this._setButtonClass("focus", true);
            Y.one("body").focus();
            this._swfReference._swf.focus();
        }, this);
    },

    /**
    * Attaches keyboard bindings to enabling tabbing to and from the instance of the Flash
    * player in the Uploader widget. If the previous and next elements are specified, the
    * keyboard bindings enable the user to tab from the `tabElements["from"]` node to the
    * Flash-powered "Select Files" button, and to the `tabElements["to"]` node.
    *
    * @method _attachTabElements
    * @protected
    * @param ev {Event} Optional event payload if called as a `tabElementsChange` handler.
    */
    _attachTabElements : function () {
        if (this.get("tabElements") !== null && this.get("tabElements").from !== null && this.get("tabElements").to !== null) {

            if (this._tabElementBindings !== null) {
                this._tabElementBindings.from.detach();
                this._tabElementBindings.to.detach();
                this._tabElementBindings.tabback.detach();
                this._tabElementBindings.tabforward.detach();
                this._tabElementBindings.focus.detach();
                this._tabElementBindings.blur.detach();
            }
            else {
                this._tabElementBindings = {};
            }

            var fromElement = Y.one(this.get("tabElements").from),
                toElement = Y.one(this.get("tabElements").to);


            this._tabElementBindings.from = fromElement.on("keydown", function (ev) {
                if (ev.keyCode === 9 && !ev.shiftKey) {
                    ev.preventDefault();
                    this._swfReference._swf.setAttribute("tabindex", 0);
                    this._swfReference._swf.setAttribute("role", "button");
                    this._swfReference._swf.setAttribute("aria-label", this.get("selectButtonLabel"));
                    this._swfReference._swf.focus();
                }
            }, this);

            this._tabElementBindings.to = toElement.on("keydown", function (ev) {
                if (ev.keyCode === 9 && ev.shiftKey) {
                    ev.preventDefault();
                    this._swfReference._swf.setAttribute("tabindex", 0);
                    this._swfReference._swf.setAttribute("role", "button");
                    this._swfReference._swf.setAttribute("aria-label", this.get("selectButtonLabel"));
                    this._swfReference._swf.focus();
                }
            }, this);

            this._tabElementBindings.tabback = this._swfReference.on("tabback", function () {
                this._swfReference._swf.blur();
                setTimeout(function () {
                    fromElement.focus();
                }, 30);
            }, this);

            this._tabElementBindings.tabforward = this._swfReference.on("tabforward", function () {
                this._swfReference._swf.blur();
                setTimeout(function () {
                    toElement.focus();
                }, 30);
            }, this);

            this._tabElementBindings.focus = this._swfReference._swf.on("focus", function () {
                this._buttonFocus = true;
                this._setButtonClass("focus", true);
            }, this);

            this._tabElementBindings.blur = this._swfReference._swf.on("blur", function () {
                this._buttonFocus = false;
                this._setButtonClass("focus", false);
            }, this);
        }
        else if (this._tabElementBindings !== null) {
            this._tabElementBindings.from.detach();
            this._tabElementBindings.to.detach();
            this._tabElementBindings.tabback.detach();
            this._tabElementBindings.tabforward.detach();
            this._tabElementBindings.focus.detach();
            this._tabElementBindings.blur.detach();
        }
    },


    /**
    * Adds or removes a specified state CSS class to the underlying uploader button.
    *
    * @method _setButtonClass
    * @protected
    * @param state {String} The name of the state enumerated in `buttonClassNames` attribute
    * from which to derive the needed class name.
    * @param add {Boolean} A Boolean indicating whether to add or remove the class.
    */
    _setButtonClass : function (state, add) {
        if (add) {
            this.get("selectFilesButton").addClass(this.get("buttonClassNames")[state]);
        }
        else {
            this.get("selectFilesButton").removeClass(this.get("buttonClassNames")[state]);
        }
    },


    /**
    * Syncs the state of the `fileFilters` attribute between the instance of UploaderFlash
    * and the Flash player.
    *
    * @method _setFileFilters
    * @private
    */
    _setFileFilters : function () {
        if (this._swfReference && this.get("fileFilters").length > 0) {
            this._swfReference.callSWF("setFileFilters", [this.get("fileFilters")]);
        }
    },



    /**
    * Syncs the state of the `multipleFiles` attribute between this class
    * and the Flash uploader.
    *
    * @method _setMultipleFiles
    * @private
    */
    _setMultipleFiles : function () {
        if (this._swfReference) {
            this._swfReference.callSWF("setAllowMultipleFiles", [this.get("multipleFiles")]);
        }
    },

    /**
    * Syncs the state of the `enabled` attribute between this class
    * and the Flash uploader.
    *
    * @method _triggerEnabled
    * @private
    */
    _triggerEnabled : function () {
        if (this.get("enabled")) {
            this._swfReference.callSWF("enable");
            this._swfReference._swf.setAttribute("aria-disabled", "false");
            this._setButtonClass("disabled", false);
        }
        else {
            this._swfReference.callSWF("disable");
            this._swfReference._swf.setAttribute("aria-disabled", "true");
            this._setButtonClass("disabled", true);
        }
    },

    /**
    * Getter for the `fileList` attribute
    *
    * @method _getFileList
    * @private
    */
    _getFileList : function () {
        return this._fileList.concat();
    },

    /**
    * Setter for the `fileList` attribute
    *
    * @method _setFileList
    * @private
    */
    _setFileList : function (val) {
        this._fileList = val.concat();
        return this._fileList.concat();
    },

    /**
    * Adjusts the content of the `fileList` based on the results of file selection
    * and the `appendNewFiles` attribute. If the `appendNewFiles` attribute is true,
    * then selected files are appended to the existing list; otherwise, the list is
    * cleared and populated with the newly selected files.
    *
    * @method _updateFileList
    * @param ev {Event} The file selection event received from the uploader.
    * @private
    */
    _updateFileList : function (ev) {

        Y.one("body").focus();
        this._swfReference._swf.focus();


        var newfiles = ev.fileList,
            fileConfObjects = [],
            parsedFiles = [],
            swfRef = this._swfReference,
            filterFunc = this.get("fileFilterFunction"),
            oldfiles;

        Y.each(newfiles, function (value) {
            var newFileConf = {};
            newFileConf.id = value.fileId;
            newFileConf.name = value.fileReference.name;
            newFileConf.size = value.fileReference.size;
            newFileConf.type = value.fileReference.type;
            newFileConf.dateCreated = value.fileReference.creationDate;
            newFileConf.dateModified = value.fileReference.modificationDate;
            newFileConf.uploader = swfRef;

            fileConfObjects.push(newFileConf);
        });

         if (filterFunc) {
            Y.each(fileConfObjects, function (value) {
                var newfile = new Y.FileFlash(value);
                if (filterFunc(newfile)) {
                    parsedFiles.push(newfile);
                }
            });
         }
         else {
            Y.each(fileConfObjects, function (value) {
                parsedFiles.push(new Y.FileFlash(value));
            });
         }

        if (parsedFiles.length > 0) {
            oldfiles = this.get("fileList");

            this.set("fileList",
                             this.get("appendNewFiles") ? oldfiles.concat(parsedFiles) : parsedFiles );

            this.fire("fileselect", { fileList: parsedFiles });
        }

    },



    /**
    * Handles and retransmits events fired by `Y.FileFlash` and `Y.Uploader.Queue`.
    *
    * @method _uploadEventHandler
    * @param event The event dispatched during the upload process.
    * @private
    */
    _uploadEventHandler : function (event) {

        switch (event.type) {
            case "file:uploadstart":
                 this.fire("fileuploadstart", event);
                break;
            case "file:uploadprogress":
                 this.fire("uploadprogress", event);
                break;
            case "uploaderqueue:totaluploadprogress":
                 this.fire("totaluploadprogress", event);
                break;
            case "file:uploadcomplete":
                 this.fire("uploadcomplete", event);
                break;
            case "uploaderqueue:alluploadscomplete":
                 this.queue = null;
                 this.fire("alluploadscomplete", event);
                break;
            case "file:uploaderror": //overflow intentional
            case "uploaderqueue:uploaderror":
                 this.fire("uploaderror", event);
                break;
            case "file:uploadcancel": // overflow intentional
            case "uploaderqueue:uploadcancel":
                 this.fire("uploadcancel", event);
            break;
        }

    },



    /**
    * Starts the upload of a specific file.
    *
    * @method upload
    * @param file {Y.FileFlash} Reference to the instance of the file to be uploaded.
    * @param url {String} The URL to upload the file to.
    * @param [postVars] {Object} A set of key-value pairs to send as variables along with the file upload HTTP request.
    *                          If not specified, the values from the attribute `postVarsPerFile` are used instead.
    */
    upload : function (file, url, postvars) {

        var uploadURL = url || this.get("uploadURL"),
            postVars = postvars || this.get("postVarsPerFile"),
            fileId = file.get("id");

            postVars = postVars.hasOwnProperty(fileId) ? postVars[fileId] : postVars;

        if (file instanceof Y.FileFlash) {

            file.on("uploadstart", this._uploadEventHandler, this);
            file.on("uploadprogress", this._uploadEventHandler, this);
            file.on("uploadcomplete", this._uploadEventHandler, this);
            file.on("uploaderror", this._uploadEventHandler, this);
            file.on("uploadcancel", this._uploadEventHandler, this);

            file.startUpload(uploadURL, postVars, this.get("fileFieldName"));
        }
    },

    /**
    * Starts the upload of all files on the file list, using an automated queue.
    *
    * @method uploadAll
    * @param url {String} The URL to upload the files to.
    * @param [postVars] {Object} A set of key-value pairs to send as variables along with the file upload HTTP request.
    *                          If not specified, the values from the attribute `postVarsPerFile` are used instead.
    */
    uploadAll : function (url, postvars) {
        this.uploadThese(this.get("fileList"), url, postvars);
    },

    /**
    * Starts the upload of the files specified in the first argument, using an automated queue.
    *
    * @method uploadThese
    * @param files {Array} The list of files to upload.
    * @param url {String} The URL to upload the files to.
    * @param [postVars] {Object} A set of key-value pairs to send as variables along with the file upload HTTP request.
    *                          If not specified, the values from the attribute `postVarsPerFile` are used instead.
    */
    uploadThese : function (files, url, postvars) {
        if (!this.queue) {
            var uploadURL = url || this.get("uploadURL"),
                postVars = postvars || this.get("postVarsPerFile");

            this.queue = new UploaderQueue({
                simUploads: this.get("simLimit"),
                errorAction: this.get("errorAction"),
                fileFieldName: this.get("fileFieldName"),
                fileList: files,
                uploadURL: uploadURL,
                perFileParameters: postVars,
                retryCount: this.get("retryCount")
            });

            this.queue.on("uploadstart", this._uploadEventHandler, this);
            this.queue.on("uploadprogress", this._uploadEventHandler, this);
            this.queue.on("totaluploadprogress", this._uploadEventHandler, this);
            this.queue.on("uploadcomplete", this._uploadEventHandler, this);
            this.queue.on("alluploadscomplete", this._uploadEventHandler, this);
            this.queue.on("alluploadscancelled", function () {this.queue = null;}, this);
            this.queue.on("uploaderror", this._uploadEventHandler, this);
            this.queue.startUpload();

            this.fire("uploadstart");
        }
    }
},

{
    /**
    * The template for the Flash player container. Since the Flash player container needs
    * to completely overlay the &lquot;Select Files&rqot; control, it's positioned absolutely,
    * with width and height set to 100% of the parent.
    *
    * @property FLASH_CONTAINER
    * @type {HTML}
    * @static
    * @default '<div id="{swfContainerId}" style="position:absolute; top:0px; left: 0px; margin: 0; padding: 0;
    *           border: 0; width:100%; height:100%"></div>'
    */
    FLASH_CONTAINER: '<div id="{swfContainerId}" style="position:absolute; top:0px; left: 0px; margin: 0; ' +
                     'padding: 0; border: 0; width:100%; height:100%"></div>',

    /**
    * The template for the "Select Files" button.
    *
    * @property SELECT_FILES_BUTTON
    * @type {HTML}
    * @static
    * @default "<button type='button' class='yui3-button' tabindex='-1'>{selectButtonLabel}</button>"
    */
    SELECT_FILES_BUTTON: "<button type='button' class='yui3-button' tabindex='-1'>{selectButtonLabel}</button>",

    /**
    * The static property reflecting the type of uploader that `Y.Uploader`
    * aliases. The UploaderFlash value is `"flash"`.
    *
    * @property TYPE
    * @type {String}
    * @static
    */
    TYPE: "flash",

    /**
    * The identity of the widget.
    *
    * @property NAME
    * @type String
    * @default 'uploader'
    * @readOnly
    * @protected
    * @static
    */
    NAME: "uploader",

    /**
    * Static property used to define the default attribute configuration of
    * the Widget.
    *
    * @property ATTRS
    * @type {Object}
    * @protected
    * @static
    */
    ATTRS: {

        /**
        * A Boolean indicating whether newly selected files should be appended
        * to the existing file list, or whether they should replace it.
        *
        * @attribute appendNewFiles
        * @type {Boolean}
        * @default true
        */
        appendNewFiles : {
            value: true
        },

        /**
        * The names of CSS classes that correspond to different button states
        * of the "Select Files" control. These classes are assigned to the
        * "Select Files" control based on the mouse states reported by the
        * Flash player. The keys for the class names are:
        * <ul>
        *   <li> <strong>`hover`</strong>: the class corresponding to mouse hovering over
        *      the "Select Files" button.</li>
        *   <li> <strong>`active`</strong>: the class corresponding to mouse down state of
        *      the "Select Files" button.</li>
        *   <li> <strong>`disabled`</strong>: the class corresponding to the disabled state
        *      of the "Select Files" button.</li>
        *   <li> <strong>`focus`</strong>: the class corresponding to the focused state of
        *      the "Select Files" button.</li>
        * </ul>
        * @attribute buttonClassNames
        * @type {Object}
        * @default { hover: "yui3-button-hover",
        *            active: "yui3-button-active",
        *            disabled: "yui3-button-disabled",
        *            focus: "yui3-button-selected"
        *          }
        */
        buttonClassNames: {
            value: {
                "hover": "yui3-button-hover",
                "active": "yui3-button-active",
                "disabled": "yui3-button-disabled",
                "focus": "yui3-button-selected"
            }
        },

        /**
        * A Boolean indicating whether the uploader is enabled or disabled for user input.
        *
        * @attribute enabled
        * @type {Boolean}
        * @default true
        */
        enabled : {
            value: true
        },

        /**
        * The action  performed when an upload error occurs for a specific file being uploaded.
        * The possible values are:
        * <ul>
        *   <li> <strong>`UploaderQueue.CONTINUE`</strong>: the error is ignored and the upload process is continued.</li>
        *   <li> <strong>`UploaderQueue.STOP`</strong>: the upload process is stopped as soon as any other parallel file
        *     uploads are finished.</li>
        *   <li> <strong>`UploaderQueue.RESTART_ASAP`</strong>: the file is added back to the front of the queue.</li>
        *   <li> <strong>`UploaderQueue.RESTART_AFTER`</strong>: the file is added to the back of the queue.</li>
        * </ul>
        * @attribute errorAction
        * @type {String}
        * @default UploaderQueue.CONTINUE
        */
        errorAction: {
            value: "continue",
            validator: function (val) {
                return (
                    val === UploaderQueue.CONTINUE ||
                    val === UploaderQueue.STOP ||
                    val === UploaderQueue.RESTART_ASAP ||
                    val === UploaderQueue.RESTART_AFTER
                );
            }
        },

        /**
        * An array indicating what fileFilters should be applied to the file
        * selection dialog. Each element in the array should be an object with
        * the following key-value pairs:
        * {
        *   description : String
         extensions: String of the form &lquot;*.ext1;*.ext2;*.ext3;...&rquot;
        * }
        * @attribute fileFilters
        * @type {Array}
        * @default []
        */
        fileFilters: {
            value: []
        },

        /**
        * A filtering function that is applied to every file selected by the user.
        * The function receives the `Y.File` object and must return a Boolean value.
        * If a `false` value is returned, the file in question is not added to the
        * list of files to be uploaded.
        * Use this function to put limits on file sizes or check the file names for
        * correct extension, but make sure that a server-side check is also performed,
        * since any client-side restrictions are only advisory and can be circumvented.
        *
        * @attribute fileFilterFunction
        * @type {Function}
        * @default null
        */
        fileFilterFunction: {
            value: null
        },

        /**
        * A String specifying what should be the POST field name for the file
        * content in the upload request.
        *
        * @attribute fileFieldName
        * @type {String}
        * @default Filedata
        */
        fileFieldName: {
            value: "Filedata"
        },

        /**
        * The array of files to be uploaded. All elements in the array
        * must be instances of `Y.FileFlash` and be instantiated with a `fileId`
        * retrieved from an instance of the uploader.
        *
        * @attribute fileList
        * @type {Array}
        * @default []
        */
        fileList: {
            value: [],
            getter: "_getFileList",
            setter: "_setFileList"
        },

        /**
        * A Boolean indicating whether multiple file selection is enabled.
        *
        * @attribute multipleFiles
        * @type {Boolean}
        * @default false
        */
        multipleFiles: {
            value: false
        },

        /**
        * An object, keyed by `fileId`, containing sets of key-value pairs
        * that should be passed as POST variables along with each corresponding
        * file. This attribute is only used if no POST variables are specifed
        * in the upload method call.
        *
        * @attribute postVarsPerFile
        * @type {Object}
        * @default {}
        */
        postVarsPerFile: {
            value: {}
        },

        /**
        * The label for the "Select Files" widget. This is the value that replaces the
        * `{selectButtonLabel}` token in the `SELECT_FILES_BUTTON` template.
        *
        * @attribute selectButtonLabel
        * @type {String}
        * @default "Select Files"
        */
        selectButtonLabel: {
            value: "Select Files"
        },

        /**
        * The widget that serves as the "Select Files" control for the file uploader
        *
        *
        * @attribute selectFilesButton
        * @type {Node | Widget}
        * @default A standard HTML button with YUI CSS Button skin.
        */
        selectFilesButton : {
            valueFn: function () {
                return Y.Node.create(substitute(Y.UploaderFlash.SELECT_FILES_BUTTON, {selectButtonLabel: this.get("selectButtonLabel")}));
             }
        },

        /**
        * The number of files that can be uploaded
        * simultaneously if the automatic queue management
        * is used. This value can be in the range between 2
        * and 5.
        *
        * @attribute simLimit
        * @type {Number}
        * @default 2
        */
        simLimit: {
            value: 2,
            validator: function (val) {
                    return (val >= 2 && val <= 5);
            }
        },

        /**
        * The URL to the SWF file of the flash uploader. A copy local to
        * the server that hosts the page on which the uploader appears is
        * recommended.
        *
        * @attribute swfURL
        * @type {String}
        * @default "CDN Prefix + uploader/assets/flashuploader.swf" with a
        * random GET parameter for IE (to prevent buggy behavior when the SWF
        * is cached).
        */
        swfURL: {
            valueFn: function () {
                var prefix = Y.Env.cdn + "uploader/assets/flashuploader.swf";

                if (Y.UA.ie > 0) {
                    return (prefix + "?t=" + Y.guid("uploader"));
                }

                return prefix;
            }
        },

        /**
        * The id's or `Node` references of the DOM elements that precede
        * and follow the `Select Files` button in the tab order. Specifying
        * these allows keyboard navigation to and from the Flash player
        * layer of the uploader.
        * The two keys corresponding to the DOM elements are:
        <ul>
        *   <li> `from`: the id or the `Node` reference corresponding to the
        *     DOM element that precedes the `Select Files` button in the tab order.</li>
        *   <li> `to`: the id or the `Node` reference corresponding to the
        *     DOM element that follows the `Select Files` button in the tab order.</li>
        * </ul>
        * @attribute tabElements
        * @type {Object}
        * @default null
        */
        tabElements: {
            value: null
        },

        /**
        * The URL to which file upload requested are POSTed. Only used if a different url is not passed to the upload method call.
        *
        * @attribute uploadURL
        * @type {String}
        * @default ""
        */
        uploadURL: {
            value: ""
        },

        /**
        * The number of times to try re-uploading a file that failed to upload before
        * cancelling its upload.
        *
        * @attribute retryCount
        * @type {Number}
        * @default 3
        */
        retryCount: {
            value: 3
        }
    }
});

Y.UploaderFlash.Queue = UploaderQueue;