phaser/src/loader/Loader.js

/* jshint wsh:true */
/**
* @author       Richard Davey <rich@photonstorm.com>
* @copyright    2014 Photon Storm Ltd.
* @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/

/**
* The Loader handles loading all external content such as Images, Sounds, Texture Atlases and data files.
*
* The loader uses a combination of tag loading (eg. Image elements) and XHR and provides progress and completion callbacks.
*
* Parallel loading is supported but must be enabled explicitly with {@link Phaser.Loader#enableParallel enableParallel}.
* Load-before behavior of parallel resources is controlled by synchronization points as discussed in {@link Phaser.Loader#withSyncPoint withSyncPoint}.
*
* Texture Atlases can be created with tools such as [Texture Packer](https://www.codeandweb.com/texturepacker/phaser) and
* [Shoebox](http://renderhjs.net/shoebox/)
*
* @class Phaser.Loader
* @param {Phaser.Game} game - A reference to the currently running game.
*/
Phaser.Loader = function (game) {

    /**
    * Local reference to game.
    * @property {Phaser.Game} game
    * @protected
    */
    this.game = game;

    /**
    * True if the Loader is in the process of loading the queue.
    * @property {boolean} isLoading
    * @default
    */
    this.isLoading = false;

    /**
    * True if all assets in the queue have finished loading.
    * @property {boolean} hasLoaded
    * @default
    */
    this.hasLoaded = false;

    /**
    * You can optionally link a progress sprite with {@link Phaser.Loader#setPreloadSprite setPreloadSprite}.
    *
    * This property is an object containing: sprite, rect, direction, width and height
    *
    * @property {?object} preloadSprite
    * @protected
    */
    this.preloadSprite = null;

    /**
    * The crossOrigin value applied to loaded images. Very often this needs to be set to 'anonymous'.
    * @property {boolean|string} crossOrigin
    * @default
    */
    this.crossOrigin = false;

    /**
    * If you want to append a URL before the path of any asset you can set this here.
    * Useful if allowing the asset base url to be configured outside of the game code.
    * The string _must_ end an "/".
    *
    * @property {string} baseURL
    */
    this.baseURL = '';

    /**
    * This event is dispatched when the loading process starts: before the first file has been requested,
    * but after all the initial packs have been loaded.
    *
    * @property {Phaser.Signal} onLoadStart
    */
    this.onLoadStart = new Phaser.Signal();

    /**
    * This event is dispatched when the final file in the load queue has either loaded or failed.
    *
    * @property {Phaser.Signal} onLoadComplete
    */
    this.onLoadComplete = new Phaser.Signal();

    /**
    * This event is dispatched when an asset pack has either loaded or failed to load.
    *
    * This is called when the asset pack manifest file has loaded and successfully added its contents to the loader queue.
    *
    * Params: `(pack key, success?, total packs loaded, total packs)`
    *
    * @property {Phaser.Signal} onPackComplete
    */
    this.onPackComplete = new Phaser.Signal();

    /**
    * This event is dispatched immediately before a file starts loading.
    * It's possible the file may fail (eg. download error, invalid format) after this event is sent.
    *
    * Params: `(progress, file key, file url)`
    *
    * @property {Phaser.Signal} onFileStart
    */
    this.onFileStart = new Phaser.Signal();

    /**
    * This event is dispatched when a file has either loaded or failed to load.
    *
    * Params: `(progress, file key, success?, total loaded files, total files)`
    * 
    * @property {Phaser.Signal} onFileComplete
    */
    this.onFileComplete = new Phaser.Signal();
   
    /**
    * This event is dispatched when a file (or pack) errors as a result of the load request.
    *
    * For files it will be triggered before `onFileComplete`. For packs it will be triggered before `onPackComplete`.
    *
    * Params: `(file key, file)`
    *
    * @property {Phaser.Signal} onFileError
    */
    this.onFileError = new Phaser.Signal();

    /**
    * If true and if the browser supports XDomainRequest, it will be used in preference for XHR.
    *
    * This is only relevant for IE 9 and should _only_ be enabled for IE 9 clients when required by the server/CDN.
    *
    * @property {boolean} useXDomainRequest
    * @deprecated This is only relevant for IE 9.
    */
    this.useXDomainRequest = false;

    /**
    * @private
    * @property {boolean} _warnedAboutXDomainRequest - Control number of warnings for using XDR outside of IE 9.
    */
    this._warnedAboutXDomainRequest = false;

    /**
    * If true then parallel downloading will be enabled.
    * @property {integer} enableParallel
    */
    this.enableParallel = false;

    /**
    * The number of concurrent assets to try and fetch at once.
    * Most browsers limit 6 requests per domain.
    *
    * @property {integer} maxParallelDownloads
    * @protected
    */
    this.maxParallelDownloads = 6;

    /**
    * A counter: if more than zero, files will be automatically added as a synchronization point.
    * @property {integer} _withSyncPointDepth;
    */
    this._withSyncPointDepth = 0;

    /**
    * Contains all the information for asset files (including packs) to load.
    *
    * File/assets are only removed from the list after all loading completes.
    *
    * @property {file[]} _fileList
    * @private
    */
    this._fileList = [];

    /**
    * Inflight files (or packs) that are being fetched/processed.
    *
    * This means that if there are any files in the flight queue there should still be processing
    * going on; it should only be empty before or after loading.
    *
    * The files in the queue may have additional properties added to them,
    * including `requestObject` which is normally the associated XHR.
    *
    * @property {file[]} _flightQueue
    * @private
    */
    this._flightQueue = [];

    /**
    * The offset into the fileList past all the complete (loaded or error) entries.
    *
    * @property {integer} _processingHead
    * @private
    */
    this._processingHead = 0;

    /**
    * True when the first file (not pack) has loading started.
    * This used to to control dispatching `onLoadStart` which happens after any initial packs are loaded.
    *
    * @property {boolean} _initialPacksLoaded
    * @private
    */
    this._fileLoadStarted = false;

    /**
    * Total packs seen - adjusted when a pack is added.
    * @property {integer} _totalPackCount
    * @private
    */
    this._totalPackCount = 0;

    /**
    * Total files seen - adjusted when a file is added.
    * @property {integer} _totalFileCount
    * @private
    */
    this._totalFileCount = 0;
    
    /**
    * Total packs loaded - adjusted just prior to `onPackComplete`.
    * @property {integer} _loadedPackCount
    * @private
    */
    this._loadedPackCount = 0;

    /**
    * Total files loaded - adjusted just prior to `onFileComplete`.
    * @property {integer} _loadedFileCount
    * @private
    */
    this._loadedFileCount = 0;

};

/**
* @constant
* @type {number}
*/
Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY = 0;

/**
* @constant
* @type {number}
*/
Phaser.Loader.TEXTURE_ATLAS_JSON_HASH = 1;

/**
* @constant
* @type {number}
*/
Phaser.Loader.TEXTURE_ATLAS_XML_STARLING = 2;

/**
* @constant
* @type {number}
*/
Phaser.Loader.PHYSICS_LIME_CORONA_JSON = 3;

/**
* @constant
* @type {number}
*/
Phaser.Loader.PHYSICS_PHASER_JSON = 4;

Phaser.Loader.prototype = {

    /**
    * Set a Sprite to be a "preload" sprite by passing it to this method.
    *
    * A "preload" sprite will have its width or height crop adjusted based on the percentage of the loader in real-time.
    * This allows you to easily make loading bars for games.
    *
    * The sprite will automatically be made visible when calling this.
    *
    * @method Phaser.Loader#setPreloadSprite
    * @param {Phaser.Sprite|Phaser.Image} sprite - The sprite or image that will be cropped during the load.
    * @param {number} [direction=0] - A value of zero means the sprite will be cropped horizontally, a value of 1 means its will be cropped vertically.
    */
    setPreloadSprite: function (sprite, direction) {

        direction = direction || 0;

        this.preloadSprite = { sprite: sprite, direction: direction, width: sprite.width, height: sprite.height, rect: null };

        if (direction === 0)
        {
            //  Horizontal rect
            this.preloadSprite.rect = new Phaser.Rectangle(0, 0, 1, sprite.height);
        }
        else
        {
            //  Vertical rect
            this.preloadSprite.rect = new Phaser.Rectangle(0, 0, sprite.width, 1);
        }

        sprite.crop(this.preloadSprite.rect);

        sprite.visible = true;

    },

    /**
    * Called automatically by ScaleManager when the game resizes in RESIZE scalemode.
    *
    * This can be used to adjust the preloading sprite size, eg.
    *
    * @method Phaser.Loader#resize
    * @protected
    */
    resize: function () {

        if (this.preloadSprite && this.preloadSprite.height !== this.preloadSprite.sprite.height)
        {
            this.preloadSprite.rect.height = this.preloadSprite.sprite.height;
        }

    },

    /**
    * Check whether a file/asset with a specific key is queued to be loaded.
    *
    * To access a loaded asset use Phaser.Cache, eg. {@link Phaser.Cache#checkImageKey}
    *
    * @method Phaser.Loader#checkKeyExists
    * @param {string} type - The type asset you want to check.
    * @param {string} key - Key of the asset you want to check.
    * @return {boolean} Return true if exists, otherwise return false.
    */
    checkKeyExists: function (type, key) {

        return this.getAssetIndex(type, key) > -1;

    },

    /**
    * Get the queue-index of the file/asset with a specific key.
    *
    * Only assets in the download file queue will be found.
    *
    * @method Phaser.Loader#getAssetIndex
    * @param {string} type - The type asset you want to check.
    * @param {string} key - Key of the asset you want to check.
    * @return {number} The index of this key in the filelist, or -1 if not found.
    *     The index may change and should only be used immediately following this call
    */
    getAssetIndex: function (type, key) {

        var bestFound = -1;

        for (var i = 0; i < this._fileList.length; i++)
        {
            var file = this._fileList[i];
            if (file.type === type && file.key === key)
            {
                bestFound = i;
                // An already loaded/loading file may be superceded.
                if (!file.loaded && !file.loading)
                {
                    break;
                }
            }
        }

        return bestFound;

    },

    /**
    * Find a file/asset with a specific key.
    *
    * Only assets in the download file queue will be found.
    *
    * @method Phaser.Loader#getAsset
    * @param {string} type - The type asset you want to check.
    * @param {string} key - Key of the asset you want to check.
    * @return {any} Returns an object if found that has 2 properties: `index` and `file`; otherwise a non-true value is returned.
    *     The index may change and should only be used immediately following this call.
    */
    getAsset: function (type, key) {

        var fileIndex = this.getAssetIndex(type, key);

        if (fileIndex > -1)
        {
            return { index: fileIndex, file: this._fileList[fileIndex] };
        }

        return false;

    },

    /**
    * Reset the loader and clear any queued assets.
    *
    * This will abort any loading and clear any queued assets.
    *
    * @method Phaser.Loader#reset
    * @protected
    * @param {boolean} [hard=false] - If true then the preload sprite and other artifacts may also be cleared.
    */
    reset: function (hard) {

        if (hard)
        {
            this.preloadSprite = null;
        }

        this.isLoading = false;

        this._processingHead = 0;
        this._fileList.length = 0;
        this._flightQueue.length = 0;

        this._fileLoadStarted = false;
        this._totalFileCount = 0;
        this._totalPackCount = 0;
        this._loadedPackCount = 0;
        this._loadedFileCount = 0;

    },

    /**
    * Internal function that adds a new entry to the file list. Do not call directly.
    *
    * @method Phaser.Loader#addToFileList
    * @protected
    * @param {string} type - The type of resource to add to the list (image, audio, xml, etc).
    * @param {string} key - The unique Cache ID key of this resource.
    * @param {string} url - The URL the asset will be loaded from.
    * @param {object} [properties=(none)] - Any additional properties needed to load the file. These are added directly to the added file object and overwrite any defaults.
    * @param {boolean} [overwrite=false] - If true then this will overwrite a file asset of the same type/key. Otherwise it will will only add a new asset. If overwrite is true, and the asset is already being loaded (or has been loaded), then it is appended instead.
    */
    addToFileList: function (type, key, url, properties, overwrite) {

        var file = {
            type: type,
            key: key,
            url: url,
            syncPoint: this._withSyncPointDepth > 0,
            data: null,
            loading: false,
            loaded: false,
            error: false
        };

        if (properties)
        {
            for (var prop in properties)
            {
                file[prop] = properties[prop];
            }
        }

        var fileIndex = this.getAssetIndex(type, key);
        
        if (overwrite && fileIndex > -1)
        {
            var currentFile = this._fileList[fileIndex];
            if (!currentFile.loading && !currentFile.loaded)
            {
                this._fileList[fileIndex] = file;
            }
            else
            {
                this._fileList.push(file);
                this._totalFileCount++;
            }
        }
        else if (fileIndex === -1)
        {
            this._fileList.push(file);
            this._totalFileCount++;
        }

    },

    /**
    * Internal function that replaces an existing entry in the file list with a new one. Do not call directly.
    *
    * @method Phaser.Loader#replaceInFileList
    * @protected
    * @param {string} type - The type of resource to add to the list (image, audio, xml, etc).
    * @param {string} key - The unique Cache ID key of this resource.
    * @param {string} url - The URL the asset will be loaded from.
    * @param {object} properties - Any additional properties needed to load the file.
    */
    replaceInFileList: function (type, key, url, properties) {

        return this.addToFileList(type, key, url, properties, true);

    },

    /**
    * Add a JSON resource pack ('packfile') to the Loader.
    *
    * Packs are always put before the first non-pack file that is not loaded/loading.
    * This means that all packs added before any loading has started are added to the front
    * of the file/asset list, in order added.
    *
    * @method Phaser.Loader#pack
    * @param {string} key - Unique asset key of this resource pack.
    * @param {string} [url] - URL of the Asset Pack JSON file. If you wish to pass a json object instead set this to null and pass the object as the data parameter.
    * @param {object} [data] - The Asset Pack JSON data. Use this to pass in a json data object rather than loading it from a URL. TODO
    * @param {object} [callbackContext=(loader)] - Some Loader operations, like Binary and Script require a context for their callbacks. Pass the context here.
    * @return {Phaser.Loader} This Loader instance.
    */
    pack: function (key, url, data, callbackContext) {

        if (typeof url === 'undefined') { url = null; }
        if (typeof data === 'undefined') { data = null; }
        if (typeof callbackContext === 'undefined') { callbackContext = null; }

        if (!url && !data)
        {
            console.warn('Phaser.Loader.pack - Both url and data are null. One must be set.');

            return this;
        }

        var pack = {
            type: 'packfile',
            key: key,
            url: url,
            syncPoint: true,
            data: null,
            loading: false,
            loaded: false,
            error: false,
            callbackContext: callbackContext
        };

        //  A data object has been given
        if (data)
        {
            if (typeof data === 'string')
            {
                data = JSON.parse(data);
            }
            
            pack.data = data || {};
        }
        
        // Add before first non-pack/no-loaded ~ last pack from start prior to loading
        // (Read one past for splice-to-end)
        for (var i = 0; i < this._fileList.length + 1; i++)
        {
            var file = this._fileList[i];
            if (!file || (!file.loaded && !file.loading && file.type !== 'packfile'))
            {
                this._fileList.splice(i, 1, pack);
                this._totalPackCount++;
                break;
            }
        }

        return this;

    },

    /**
    * Add an 'image' to the Loader.
    *
    * @method Phaser.Loader#image
    * @param {string} key - Unique asset key of this image file.
    * @param {string} url - URL of image file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    image: function (key, url, overwrite) {

        if (typeof overwrite === 'undefined') { overwrite = false; }

        this.addToFileList('image', key, url, undefined, overwrite);

        return this;

    },

    /**
    * Add a 'text' file to the Loader.
    *
    * @method Phaser.Loader#text
    * @param {string} key - Unique asset key of the text file.
    * @param {string} url - URL of the text file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    text: function (key, url, overwrite) {

        if (typeof overwrite === 'undefined') { overwrite = false; }

        this.addToFileList('text', key, url, undefined, overwrite);

        return this;

    },

    /**
    * Add a 'json' file to the Loader.
    *
    * @method Phaser.Loader#json
    * @param {string} key - Unique asset key of the json file.
    * @param {string} url - URL of the json file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    json: function (key, url, overwrite) {

        if (typeof overwrite === 'undefined') { overwrite = false; }

        this.addToFileList('json', key, url, undefined, overwrite);

        return this;

    },

    /**
    * Add an XML ('xml') file to the Loader.
    *
    * @method Phaser.Loader#xml
    * @param {string} key - Unique asset key of the xml file.
    * @param {string} url - URL of the xml file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    xml: function (key, url, overwrite) {

        if (typeof overwrite === 'undefined') { overwrite = false; }

        this.addToFileList('xml', key, url, undefined, overwrite);

        return this;

    },

    /**
    * Add a JavaScript ('script') file to the Loader.
    *
    * The loaded JavaScript is automatically turned into a script tag and executed, so be careful what you load!
    *
    * A callback, which will be invoked as the script tag has been created, can also be specified.
    * The callback must return relevant `data`.
    *
    * @method Phaser.Loader#script
    * @param {string} key - Unique asset key of the script file.
    * @param {string} url - URL of the JavaScript file.
    * @param {function} [callback=(none)] - Optional callback that will be called after the script tag has loaded, so you can perform additional processing.
    * @param {object} [callbackContext=(loader)] - The context under which the callback will be applied. If not specified it will use the callback itself as the context.
    * @return {Phaser.Loader} This Loader instance.
    */
    script: function (key, url, callback, callbackContext) {

        if (typeof callback === 'undefined') { callback = false; }
        // Why is the default callback context the ..callback?
        if (callback !== false && typeof callbackContext === 'undefined') { callbackContext = callback; }

        this.addToFileList('script', key, url, { syncPoint: true, callback: callback, callbackContext: callbackContext });

        return this;

    },

    /**
    * Add a 'binary' file to the Loader.
    *
    * It will be loaded via xhr with a responseType of "arraybuffer". You can specify an optional callback to process the file after load.
    * When the callback is called it will be passed 2 parameters: the key of the file and the file data.
    *
    * WARNING: If a callback is specified the data will be set to whatever it returns. Always return the data object, even if you didn't modify it.
    *
    * @method Phaser.Loader#binary
    * @param {string} key - Unique asset key of the binary file.
    * @param {string} url - URL of the binary file.
    * @param {function} [callback=(none)] - Optional callback that will be passed the file after loading, so you can perform additional processing on it.
    * @param {object} [callbackContext] - The context under which the callback will be applied. If not specified it will use the callback itself as the context.
    * @return {Phaser.Loader} This Loader instance.
    */
    binary: function (key, url, callback, callbackContext) {

        if (typeof callback === 'undefined') { callback = false; }
        // Why is the default callback context the ..callback?
        if (callback !== false && typeof callbackContext === 'undefined') { callbackContext = callback; }

        this.addToFileList('binary', key, url, { callback: callback, callbackContext: callbackContext });

        return this;

    },

    /**
    * Add a new sprite sheet ('spritesheet') to the loader.
    *
    * @method Phaser.Loader#spritesheet
    * @param {string} key - Unique asset key of the sheet file.
    * @param {string} url - URL of the sheet file.
    * @param {number} frameWidth - Width of each single frame.
    * @param {number} frameHeight - Height of each single frame.
    * @param {number} [frameMax=-1] - How many frames in this sprite sheet. If not specified it will divide the whole image into frames.
    * @param {number} [margin=0] - If the frames have been drawn with a margin, specify the amount here.
    * @param {number} [spacing=0] - If the frames have been drawn with spacing between them, specify the amount here.
    * @return {Phaser.Loader} This Loader instance.
    */
    spritesheet: function (key, url, frameWidth, frameHeight, frameMax, margin, spacing) {

        if (typeof frameMax === 'undefined') { frameMax = -1; }
        if (typeof margin === 'undefined') { margin = 0; }
        if (typeof spacing === 'undefined') { spacing = 0; }

        this.addToFileList('spritesheet', key, url, { frameWidth: frameWidth, frameHeight: frameHeight, frameMax: frameMax, margin: margin, spacing: spacing });

        return this;

    },

    /**
    * Add a new 'audio' file to the loader.
    *
    * @method Phaser.Loader#audio
    * @param {string} key - Unique asset key of the audio file.
    * @param {string[]|string} urls - An array containing the URLs of the audio files, i.e.: [ 'jump.mp3', 'jump.ogg', 'jump.m4a' ] or a single string containing just one URL.
    *     BLOB urls are supported, but Phaser will not validate the audio file's type in this case; the program must first ensure the BLOB url is playable.
    * @param {boolean} autoDecode - When using Web Audio the audio files can either be decoded at load time or run-time. They can't be played until they are decoded, but this let's you control when that happens. Decoding is a non-blocking async process.
    * @return {Phaser.Loader} This Loader instance.
    */
    audio: function (key, urls, autoDecode) {

        if (typeof autoDecode === 'undefined') { autoDecode = true; }

        this.addToFileList('audio', key, urls, { buffer: null, autoDecode: autoDecode });

        return this;

    },

    /**
    * Add a new audiosprite file to the loader.
    *
    * Audio Sprites are a combination of audio files and a JSON configuration.
    * The JSON follows the format of that created by https://github.com/tonistiigi/audiosprite
    *
    * @method Phaser.Loader#audiosprite
    * @param {string} key - Unique asset key of the audio file.
    * @param {Array|string} urls - An array containing the URLs of the audio files, i.e.: [ 'audiosprite.mp3', 'audiosprite.ogg', 'audiosprite.m4a' ] or a single string containing just one URL.
    * @param {string} atlasURL - The URL of the audiosprite configuration json.
    * @return {Phaser.Loader} This Loader instance.
    */
    audiosprite: function(key, urls, atlasURL) {

        this.audio(key, urls);

        this.json(key + '-audioatlas', atlasURL);

        return this;

    },

    /**
    * Add a new 'tilemap' loading request. If data is supplied the object is loaded immediately.
    *
    * @method Phaser.Loader#tilemap
    * @param {string} key - Unique asset key of the tilemap data.
    * @param {string} [url] - The url of the map data file (csv/json)
    * @param {object} [data] - An optional JSON data object. If given then the url is ignored and this JSON object is used for map data instead.
    * @param {number} [format=Phaser.Tilemap.CSV] - The format of the map data. Either Phaser.Tilemap.CSV or Phaser.Tilemap.TILED_JSON.
    * @return {Phaser.Loader} This Loader instance.
    */
    tilemap: function (key, url, data, format) {

        if (typeof url === 'undefined') { url = null; }
        if (typeof data === 'undefined') { data = null; }
        if (typeof format === 'undefined') { format = Phaser.Tilemap.CSV; }

        if (!url && !data)
        {
            console.warn('Phaser.Loader.tilemap - Both url and data are null. One must be set.');

            return this;
        }

        //  A map data object has been given
        if (data)
        {
            switch (format)
            {
                //  A csv string or object has been given
                case Phaser.Tilemap.CSV:
                    break;

                //  An xml string or object has been given
                case Phaser.Tilemap.TILED_JSON:

                    if (typeof data === 'string')
                    {
                        data = JSON.parse(data);
                    }
                    break;
            }

            this.game.cache.addTilemap(key, null, data, format);
        }
        else
        {
            this.addToFileList('tilemap', key, url, { format: format });
        }

        return this;

    },

    /**
    * Add a new 'physics' data object loading request. If data is supplied the object is loaded immediately.
    *
    * The data must be in Lime + Corona JSON format. Physics Editor by code'n'web exports in this format natively.
    *
    * @method Phaser.Loader#physics
    * @param {string} key - Unique asset key of the physics json data.
    * @param {string} [url] - The url of the map data file (csv/json)
    * @param {object} [data] - An optional JSON data object. If given then the url is ignored and this JSON object is used for physics data instead.
    * @param {string} [format=Phaser.Physics.LIME_CORONA_JSON] - The format of the physics data.
    * @return {Phaser.Loader} This Loader instance.
    */
    physics: function (key, url, data, format) {

        if (typeof url === 'undefined') { url = null; }
        if (typeof data === 'undefined') { data = null; }
        if (typeof format === 'undefined') { format = Phaser.Physics.LIME_CORONA_JSON; }

        if (!url && !data)
        {
            console.warn('Phaser.Loader.physics - Both url and data are null. One must be set.');

            return this;
        }

        //  A map data object has been given
        if (data)
        {
            if (typeof data === 'string')
            {
                data = JSON.parse(data);
            }

            this.game.cache.addPhysicsData(key, null, data, format);
        }
        else
        {
            this.addToFileList('physics', key, url, { format: format });
        }

        return this;

    },

    /**
    * Add a new bitmap font ('bitmapfont') loading request.
    *
    * @method Phaser.Loader#bitmapFont
    * @param {string} key - Unique asset key of the bitmap font.
    * @param {string} textureURL - The url of the font image file.
    * @param {string} [xmlURL] - The url of the font data file (xml/fnt)
    * @param {object} [xmlData] - An optional XML data object.
    * @param {number} [xSpacing=0] - If you'd like to add additional horizontal spacing between the characters then set the pixel value here.
    * @param {number} [ySpacing=0] - If you'd like to add additional vertical spacing between the lines then set the pixel value here.
    * @return {Phaser.Loader} This Loader instance.
    */
    bitmapFont: function (key, textureURL, xmlURL, xmlData, xSpacing, ySpacing) {

        if (typeof xmlURL === 'undefined') { xmlURL = null; }
        if (typeof xmlData === 'undefined') { xmlData = null; }
        if (typeof xSpacing === 'undefined') { xSpacing = 0; }
        if (typeof ySpacing === 'undefined') { ySpacing = 0; }

        //  A URL to a json/xml file has been given
        if (xmlURL)
        {
            this.addToFileList('bitmapfont', key, textureURL, { xmlURL: xmlURL, xSpacing: xSpacing, ySpacing: ySpacing });
        }
        else
        {
            //  An xml string or object has been given
            if (typeof xmlData === 'string')
            {
                var xml = this.parseXml(xmlData);

                if (!xml)
                {
                    throw new Error("Phaser.Loader. Invalid Bitmap Font XML given");
                }

                this.addToFileList('bitmapfont', key, textureURL, { xmlURL: null, xmlData: xml, xSpacing: xSpacing, ySpacing: ySpacing });
            }
        }

        return this;

    },

    /**
    * Add a new texture atlas ('textureatlas') to the loader. This atlas uses the JSON Array data format.
    *
    * Texture Atlases can be created with tools such as [Texture Packer](https://www.codeandweb.com/texturepacker/phaser) and
    * [Shoebox](http://renderhjs.net/shoebox/)
    *
    * @method Phaser.Loader#atlasJSONArray
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlasJSONArray: function (key, textureURL, atlasURL, atlasData) {

        return this.atlas(key, textureURL, atlasURL, atlasData, Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY);

    },

    /**
    * Add a new texture atlas ('textureatlas') to the loader. This atlas uses the JSON Hash data format.
    *
    * Texture Atlases can be created with tools such as [Texture Packer](https://www.codeandweb.com/texturepacker/phaser) and
    * [Shoebox](http://renderhjs.net/shoebox/)
    *
    * @method Phaser.Loader#atlasJSONHash
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlasJSONHash: function (key, textureURL, atlasURL, atlasData) {

        return this.atlas(key, textureURL, atlasURL, atlasData, Phaser.Loader.TEXTURE_ATLAS_JSON_HASH);

    },

    /**
    * Add a new texture atlas ('textureatlas') to the loader. This atlas uses the Starling XML data format.
    *
    * @method Phaser.Loader#atlasXML
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlasXML: function (key, textureURL, atlasURL, atlasData) {

        return this.atlas(key, textureURL, atlasURL, atlasData, Phaser.Loader.TEXTURE_ATLAS_XML_STARLING);

    },

    /**
    * Add a new texture atlas ('textureatlas') to the loader.
    *
    * Texture Atlases can be created with tools such as [Texture Packer](https://www.codeandweb.com/texturepacker/phaser) and
    * [Shoebox](http://renderhjs.net/shoebox/)
    *
    * @method Phaser.Loader#atlas
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @param {number} [format] - A value describing the format of the data, the default is Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlas: function (key, textureURL, atlasURL, atlasData, format) {

        if (typeof atlasURL === 'undefined') { atlasURL = null; }
        if (typeof atlasData === 'undefined') { atlasData = null; }
        if (typeof format === 'undefined') { format = Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY; }

        //  A URL to a json/xml file has been given
        if (atlasURL)
        {
            this.addToFileList('textureatlas', key, textureURL, { atlasURL: atlasURL, format: format });
        }
        else
        {
            switch (format)
            {
                //  A json string or object has been given
                case Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY:

                    if (typeof atlasData === 'string')
                    {
                        atlasData = JSON.parse(atlasData);
                    }
                    break;

                //  An xml string or object has been given
                case Phaser.Loader.TEXTURE_ATLAS_XML_STARLING:

                    if (typeof atlasData === 'string')
                    {
                        var xml = this.parseXml(atlasData);

                        if (!xml)
                        {
                            throw new Error("Phaser.Loader. Invalid Texture Atlas XML given");
                        }

                        atlasData = xml;
                    }
                    break;
            }

            this.addToFileList('textureatlas', key, textureURL, { atlasURL: null, atlasData: atlasData, format: format });

        }

        return this;

    },

    /**
    * Add a synchronization point to the assets/files added within the supplied callback.
    *
    * A synchronization point denotes that an asset _must_ be completely loaded before
    * subsequent assets can be loaded. An asset marked as a sync-point does not need to wait
    * for previous assets to load (unless they are sync-points). Resources, such as packs, may still
    * be downloaded around sync-points, as long as they do not finalize loading.
    *
    * @method Phader.Loader#withSyncPoints
    * @param {function} callback - The callback is invoked and is supplied with a single argument: the loader.
    * @param {object} [callbackContext=(loader)] - Context for the callback.
    * @return {Phaser.Loader} This Loader instance.
    */
    withSyncPoint: function (callback, callbackContext) {

        this._withSyncPointDepth++;
        try {
            callback.call(callbackContext || this, this);
        } finally {
            this._withSyncPointDepth--;
        }

        return this;
    },

    /**
    * Add a synchronization point to a specific file/asset in the load queue.
    *
    * This has no effect on already loaded assets.    
    *
    * @method Phader.Loader#withSyncPoints
    * @param {function} callback - The callback is invoked and is supplied with a single argument: the loader.
    * @param {object} [callbackContext=(loader)] - Context for the callback.
    * @return {Phaser.Loader} This Loader instance.
    * @see {@link Phaser.Loader#withSyncPoint withSyncPoint}
    */
    addSyncPoint: function (type, key) {

        var asset = this.getAsset(type, key);
        if (asset)
        {
            asset.file.syncPoint = true;
        }

        return this;
    },

    /**
    * Remove a file/asset from the loading queue.
    *
    * A file that is loaded or has started loading cannot be removed.
    *
    * @method Phaser.Loader#removeFile
    * @protected
    * @param {string} type - The type of resource to add to the list (image, audio, xml, etc).
    * @param {string} key - Key of the file you want to remove.
    */
    removeFile: function (type, key) {

        var asset = this.getAsset(type, key);

        if (asset)
        {
            if (!asset.loaded && !asset.loading) {
                this._fileList.splice(asset.index, 1);
            }
        }

    },

    /**
    * Remove all file loading requests - this is _insufficient_ to stop current loading. Use `reset` instead.
    *
    * @method Phaser.Loader#removeAll
    * @protected
    */
    removeAll: function () {

        this._fileList.length = 0;
        this._flightQueue.length = 0;

    },

    /**
    * Start loading the assets. Normally you don't need to call this yourself as the StateManager will do so.
    *
    * @method Phaser.Loader#start
    */
    start: function () {

        if (this.isLoading)
        {
            return;
        }

        this.hasLoaded = false;
        this.isLoading = true;

        this.updateProgress();

        this.processLoadQueue();

    },

    /**
    * Process the next item(s) in the file/asset queue.
    *
    * Process the queue and start loading enough items to fill up the inflight queue.
    *
    * If a sync-file is encountered then subsequent asset processing is delayed until it completes.
    * The exception to this rule is that packfiles can be downloaded (but not processed) even if
    * there appear other sync files (ie. packs) - this enables multiple packfiles to be fetched in parallel.
    * such as during the start phaser.
    *
    * @method Phaser.Loader#processLoadQueue
    * @private
    */
    processLoadQueue: function () {

        if (!this.isLoading)
        {
            console.warn('Phaser.Loader - active loading cancelled/reset');
            this.finishedLoading(true);
            return;
        }

        // Empty the flight queue as applicable
        for (var i = 0; i < this._flightQueue.length; i++)
        {
            var file = this._flightQueue[i];
            
            if (file.loaded || file.error)
            {
                this._flightQueue.splice(i, 1);
                i--;

                file.loading = false;
                file.requestUrl = null;
                file.requestObject = null;

                if (file.error)
                {
                    this.onFileError.dispatch(file.key, file);
                }

                if (file.type !== 'packfile')
                {
                    this._loadedFileCount++;
                    this.onFileComplete.dispatch(this.progress, file.key, !file.error, this._loadedFileCount, this._totalFileCount);
                }
                else if (file.type === 'packfile' && file.error)
                {
                    // Non-error pack files are handled when processing the file queue
                    this._loadedPackCount++;
                    this.onPackComplete.dispatch(file.key, !file.error, this._loadedPackCount, this._totalPackCount);
                }

            }
        }

        // When true further non-pack file downloads are suppressed
        var syncblock = false;

        var inflightLimit = Phaser.Math.clamp(
            this.maxParallelDownloads, 1, this.enableParallel ? 12 : 1);

        for (var i = this._processingHead; i < this._fileList.length; i++)
        {
            var file = this._fileList[i];

            // Pack is fetched (ie. has data) and is currently at the start of the process queue.
            if (file.type === 'packfile' && !file.error && file.data && i === this._processingHead)
            {
                // Pack may have been supplied with initial data
                this.loaded = true;

                // Processing the pack / adds more files
                this.processPack(file);

                this._loadedPackCount++;
                this.onPackComplete.dispatch(file.key, !file.error, this._loadedPackCount, this._totalPackCount);
            }

            if (file.loaded || file.error)
            {
                // Item at the start of file list finished, can skip it in future
                if (i === this._processingHead)
                {
                    this._processingHead = i + 1;
                }
            }
            else if (!file.loading && this._flightQueue.length < inflightLimit)
            {
                // -> not loaded/failed, not loading
                if (file.type === 'packfile' && !file.data)
                {
                    // Fetches the pack data: the pack is processed above as it reaches queue-start.
                    // (Packs do not trigger onLoadStart or onFileStart.)
                    this._flightQueue.push(file);
                    file.loading = true;

                    this.loadFile(file);
                }
                else if (!syncblock)
                {
                    if (!this._fileLoadStarted)
                    {
                        this._fileLoadStarted = true;
                        this.onLoadStart.dispatch();
                    }

                    this._flightQueue.push(file);
                    file.loading = true;
                    this.onFileStart.dispatch(this.progress, file.key, file.url);
                    
                    this.loadFile(file);
                }
            }

            if (!file.loaded && file.syncPoint)
            {
                syncblock = true;
            }

            // Stop looking if queue full - or if syncblocked and there are no more packs.
            // (As only packs can be loaded around a syncblock)
            if (this._flightQueue.length >= inflightLimit ||
                (syncblock && this._loadedPackCount === this._totalPackCount))
            {
                break;
            }
        }

        this.updateProgress();

        // True when all items in the queue have been advanced over
        // (There should be no inflight items as they are complete - loaded/error.)
        if (this._processingHead >= this._fileList.length)
        {
            this.finishedLoading();
        }
        else if (!this._flightQueue.length)
        {
            // Flight queue is empty but file list is not done being processed.
            // This indicates a critical internal error with no known recovery.
            console.warn("Phaser.Loader - aborting: processing queue empty, loading may have stalled");
            var _this = this;
            setTimeout(function () {
                _this.finishedLoading(true);
            }, 2000);
        }

    },

    /**
    * The loading is all finished.
    *
    * @method Phaser.Loader#finishedLoading
    * @private
    * @param {boolean} [abnormal=true] - True if the loading finished abnormally.
    */
    finishedLoading: function (abnormal) {

        if (this.hasLoaded)
        {
            return;
        }

        this.hasLoaded = true;
        this.isLoading = false;

        // If there were no files make sure to trigger the event anyway, for consistency
        if (!abnormal && !this._fileLoadStarted)
        {
            this._fileLoadStarted = true;
            this.onLoadStart.dispatch();
        }

        this.onLoadComplete.dispatch();

        this.reset();

    },

    /**
    * Informs the loader that the given file resource has been fetched and processed;
    * or such a request has failed.
    *
    * @method Phaser.Loader#asyncComplete
    * @private
    * @param {object} file
    * @param {string} [error=''] - The error message, if any. No message implies no error.
    */
    asyncComplete: function (file, errorMessage) {

        if (typeof errorMessage === 'undefined') { errorMessage = ''; }

        file.loaded = true;
        file.error = !!errorMessage;
        if (errorMessage)
        {
            file.errorMessage = errorMessage;

            console.warn('Phaser.Loader - ' + file.type + '[' + file.key + ']' + ': ' + errorMessage);
        }

        this.processLoadQueue();

    },

    /**
    * Process pack data. This will usually modify the file list.
    *
    * @method Phaser.Loader#processPack
    * @private
    * @param {object} pack
    */
    processPack: function (pack) {

        var packData = pack.data[pack.key];

        if (!packData)
        {
            console.warn('Phaser.Loader - ' + pack.key + ': pack has data, but not for pack key');
            return;
        }

        for (var i = 0; i < packData.length; i++)
        {
            var file = packData[i];

            switch (file.type)
            {
                case "image":
                    this.image(file.key, file.url, file.overwrite);
                    break;

                case "text":
                    this.text(file.key, file.url, file.overwrite);
                    break;

                case "json":
                    this.json(file.key, file.url, file.overwrite);
                    break;

                case "xml":
                    this.xml(file.key, file.url, file.overwrite);
                    break;

                case "script":
                    this.script(file.key, file.url, file.callback, pack.callbackContext || this);
                    break;

                case "binary":
                    this.binary(file.key, file.url, file.callback, pack.callbackContext || this);
                    break;

                case "spritesheet":
                    this.spritesheet(file.key, file.url, file.frameWidth, file.frameHeight, file.frameMax, file.margin, file.spacing);
                    break;

                case "audio":
                    this.audio(file.key, file.urls, file.autoDecode);
                    break;

                case "tilemap":
                    this.tilemap(file.key, file.url, file.data, Phaser.Tilemap[file.format]);
                    break;

                case "physics":
                    this.physics(file.key, file.url, file.data, Phaser.Loader[file.format]);
                    break;

                case "bitmapFont":
                    this.bitmapFont(file.key, file.textureURL, file.xmlURL, file.xmlData, file.xSpacing, file.ySpacing);
                    break;

                case "atlasJSONArray":
                    this.atlasJSONArray(file.key, file.textureURL, file.atlasURL, file.atlasData);
                    break;

                case "atlasJSONHash":
                    this.atlasJSONHash(file.key, file.textureURL, file.atlasURL, file.atlasData);
                    break;

                case "atlasXML":
                    this.atlasXML(file.key, file.textureURL, file.atlasURL, file.atlasData);
                    break;

                case "atlas":
                    this.atlas(file.key, file.textureURL, file.atlasURL, file.atlasData, Phaser.Loader[file.format]);
                    break;
            }
        }

    },

    /**
    * Transforms the asset URL. The default implementation prepends the baseURL.
    *
    * @method Phaser.Loader#transformUrl
    * @protected
    */
    transformUrl: function (url /*, file */) {
        return this.baseURL + url;
    },

    /**
    * Start fetching a resource.
    *
    * All code paths, async or otherwise, from this function must return to `asyncComplete`.
    *
    * @method Phaser.Loader#loadFile
    * @private
    * @param {object} file
    */
    loadFile: function (file) {

        //  Image or Data?
        switch (file.type)
        {
            case 'packfile':
                this.xhrLoad(file, this.transformUrl(file.url, file), 'text', this.fileComplete);
                break;

            case 'image':
            case 'spritesheet':
            case 'textureatlas':
            case 'bitmapfont':
                this.loadImageTag(file);
                break;

            case 'audio':
                file.url = this.getAudioURL(file.url);

                if (file.url)
                {
                    //  WebAudio or Audio Tag?
                    if (this.game.sound.usingWebAudio)
                    {
                        this.xhrLoad(file, this.transformUrl(file.url, file), 'arraybuffer', this.fileComplete);
                    }
                    else if (this.game.sound.usingAudioTag)
                    {
                        this.loadAudioTag(file);
                    }
                }
                else
                {
                    this.fileError(file, null, 'no supported audio URL specified');
                }
                break;

            case 'json':

                this.xhrLoad(file, this.transformUrl(file.url, file), 'text', this.jsonLoadComplete);
                break;

            case 'xml':

                this.xhrLoad(file, this.transformUrl(file.url, file), 'text', this.xmlLoadComplete);
                break;

            case 'tilemap':

                if (file.format === Phaser.Tilemap.TILED_JSON)
                {
                    this.xhrLoad(file, this.transformUrl(file.url, file), 'text', this.jsonLoadComplete);
                }
                else if (file.format === Phaser.Tilemap.CSV)
                {
                    this.xhrLoad(file, this.transformUrl(file.url, file), 'text', this.csvLoadComplete);
                }
                else
                {
                    this.asyncComplete(file, "invalid Tilemap format: " + file.format);
                }
                break;

            case 'text':
            case 'script':
            case 'physics':
                this.xhrLoad(file, this.transformUrl(file.url, file), 'text', this.fileComplete);
                break;

            case 'binary':
                this.xhrLoad(file, this.transformUrl(file.url, file), 'arraybuffer', this.fileComplete);
                break;
        }

    },

    /**
    * Continue async loading through an Image tag.
    * @private
    */
    loadImageTag: function (file) {

        var _this = this;

        file.data = new Image();
        file.data.name = file.key;

        if (this.crossOrigin)
        {
            file.data.crossOrigin = this.crossOrigin;
        }
        
        file.data.onload = function () {
            if (file.data.onload)
            {
                file.data.onload = null;
                file.data.onerror = null;
                _this.fileComplete(file);
            }
        };
        file.data.onerror = function () {
            if (file.data.onload)
            {
                file.data.onload = null;
                file.data.onerror = null;
                _this.fileError(file);
            }
        };

        file.data.src = this.transformUrl(file.url, file);
        
        // Image is immediately-available/cached
        if (file.data.complete && file.data.width && file.data.height)
        {
            file.data.onload = null;
            file.data.onerror = null;
            this.fileComplete(file);
        }

    },

    /**
    * Continue async loading through an Audio tag.
    * @private
    */
    loadAudioTag: function (file) {

        var _this = this;

        if (this.game.sound.touchLocked)
        {
            //  If audio is locked we can't do this yet, so need to queue this load request. Bum.
            file.data = new Audio();
            file.data.name = file.key;
            file.data.preload = 'auto';
            file.data.src = this.transformUrl(file.url, file);

            this.fileComplete(file);
        }
        else
        {
            file.data = new Audio();
            file.data.name = file.key;
            
            var playThroughEvent = function () {
                file.data.removeEventListener('canplaythrough', playThroughEvent, false);
                file.data.onerror = null;
                // Why does this cycle through games?
                Phaser.GAMES[_this.game.id].load.fileComplete(file);
            };
            file.data.onerror = function () {
                file.data.removeEventListener('canplaythrough', playThroughEvent, false);
                file.data.onerror = null;
                _this.fileError(file);
            };

            file.data.preload = 'auto';
            file.data.src = this.transformUrl(file.url, file);
            file.data.addEventListener('canplaythrough', playThroughEvent, false);
            file.data.load();
        }

    },

    /**
    * Starts the xhr loader.
    *
    * This is designed specifically to use with asset file processing.
    *
    * @method Phaser.Loader#xhrLoad
    * @private
    * @param {object} file - The file/pack to load.
    * @param {string} url - The URL of the file.
    * @param {string} type - The xhr responseType.
    * @param {function} onload - The function to call on success. Invoked in `this` context and supplied with `(file, xhr)` arguments.
    * @param {function} [onerror=fileError]  The function to call on error. Invoked in `this` context and supplied with `(file, xhr)` arguments.
    */
    xhrLoad: function (file, url, type, onload, onerror) {

        if (this.useXDomainRequest && window.XDomainRequest)
        {
            this.xhrLoadWithXDR(file, url, type, onload, onerror);
            return;
        }

        var xhr = new XMLHttpRequest();
        xhr.open("GET", url, true);
        xhr.responseType = type;

        onerror = onerror || this.fileError;

        var _this = this;

        xhr.onload = function () {
            try {
                return onload.call(_this, file, xhr);
            } catch (e) {
                _this.asyncComplete(file, e.message || 'Exception');
            }
        };

        xhr.onerror = function () {
            try {
                return onerror.call(_this, file, xhr);
            } catch (e) {
                _this.asyncComplete(file, e.message || 'Exception');
            }
        };

        file.requestObject = xhr;
        file.requestUrl = url;

        xhr.send();

    },

    /**
    * Starts the xhr loader - using XDomainRequest.
    * This should _only_ be used with IE 9. Phaser does not support IE 8 and XDR is deprecated in IE 10.
    * 
    * This is designed specifically to use with asset file processing.
    *
    * @method Phaser.Loader#xhrLoad
    * @private
    * @param {object} file - The file/pack to load.
    * @param {string} url - The URL of the file.
    * @param {string} type - The xhr responseType.
    * @param {function} onload - The function to call on success. Invoked in `this` context and supplied with `(file, xhr)` arguments.
    * @param {function} [onerror=fileError]  The function to call on error. Invoked in `this` context and supplied with `(file, xhr)` arguments.
    * @deprecated This is only relevant for IE 9.
    */
    xhrLoadWithXDR: function (file, url, type, onload, onerror) {

        // Special IE9 magic .. only
        if (!this._warnedAboutXDomainRequest &&
            (!this.game.device.ie || this.game.device.ieVersion >= 10))
        {
            this._warnedAboutXDomainRequest = true;
            console.warn("Phaser.Loader - using XDomainRequest outside of IE 9");
        }

        // Ref: http://blogs.msdn.com/b/ieinternals/archive/2010/05/13/xdomainrequest-restrictions-limitations-and-workarounds.aspx
        var xhr = new window.XDomainRequest();
        xhr.open('GET', url, true);
        xhr.responseType = type;

        // XDomainRequest has a few quirks. Occasionally it will abort requests
        // A way to avoid this is to make sure ALL callbacks are set even if not used
        // More info here: http://stackoverflow.com/questions/15786966/xdomainrequest-aborts-post-on-ie-9
        xhr.timeout = 3000;

        onerror = onerror || this.fileError;

        var _this = this;

        xhr.onerror = function () {
            try {
                return onerror.call(_this, file, xhr);
            } catch (e) {
                _this.asyncComplete(file, e.message || 'Exception');
            }
        };

        xhr.ontimeout = function () {
            try {
                return onerror.call(_this, file, xhr);
            } catch (e) {
                _this.asyncComplete(file, e.message || 'Exception');
            }
        };

        xhr.onprogress = function() {};

        xhr.onload = function () {
            try {
                return onload.call(_this, file, xhr);
            } catch (e) {
                _this.asyncComplete(file, e.message || 'Exception');
            }
        };

        file.requestObject = xhr;
        file.requestUrl = url;

        //  Note: The xdr.send() call is wrapped in a timeout to prevent an issue with the interface where some requests are lost
        //  if multiple XDomainRequests are being sent at the same time.
        setTimeout(function () {
            xhr.send();
        }, 0);

    },

    /**
    * Give a bunch of URLs, return the first URL that has an extension this device thinks it can play.
    *
    * It is assumed that the device can play "blob:" or "data:" URIs - There is no mime-type checking on data URIs.
    *
    * @method Phaser.Loader#getAudioURL
    * @private
    * @param {string[]|string} urls - Either an array of audio file URLs or a string containing a single URL path.
    * @return {string} The URL to try and fetch; or null.
    */
    getAudioURL: function (urls) {

        if (typeof urls === 'string') { urls = [urls]; }

        for (var i = 0; i < urls.length; i++)
        {
            var url = urls[i];

            // It is assumed that a direct-data URI can be played.
            if (url.indexOf("blob:") === 0 || url.indexOf("data:") === 0)
            {
                return url;
            }

            var extension = url.toLowerCase();
            extension = extension.substr((Math.max(0, extension.lastIndexOf(".")) || Infinity) + 1);

            if (extension.indexOf("?") >= 0)
            {
                extension = extension.substr(0, extension.indexOf("?"));
            }

            if (this.game.device.canPlayAudio(extension))
            {
                return urls[i];
            }
        }

        return null;

    },

    /**
    * Error occured when loading a file.
    *
    * @method Phaser.Loader#fileError
    * @private
    * @param {object} file
    * @param {?XMLHttpRequest} xhr - XHR request, unspecified if loaded via other means (eg. tags)
    * @param {string} reason
    */
    fileError: function (file, xhr, reason) {

        var url = file.requestUrl || this.transformUrl(file.url, file);
        var message = 'error loading asset from URL ' + url;

        if (!reason && xhr)
        {
            reason = xhr.status;
        }

        if (reason)
        {
            message = message + ' (' + reason + ')';
        }

        this.asyncComplete(file, message);

    },

    /**
    * Called when a file/resources had been downloaded and needs to be processed further.
    *
    * @method Phaser.Loader#fileComplete
    * @private
    * @param {object} file - File loaded
    * @param {?XMLHttpRequest} xhr - XHR request, unspecified if loaded via other means (eg. tags)
    */
    fileComplete: function (file, xhr) {

        var loadNext = true;

        switch (file.type)
        {
            case 'packfile':
                
                // Pack data must never be false-ish after it is fetched without error
                var data = JSON.parse(xhr.responseText);
                file.data = data || {};
                break;

            case 'image':

                this.game.cache.addImage(file.key, file.url, file.data);
                break;

            case 'spritesheet':

                this.game.cache.addSpriteSheet(file.key, file.url, file.data, file.frameWidth, file.frameHeight, file.frameMax, file.margin, file.spacing);
                break;

            case 'textureatlas':

                if (file.atlasURL == null)
                {
                    this.game.cache.addTextureAtlas(file.key, file.url, file.data, file.atlasData, file.format);
                }
                else
                {
                    //  Load the JSON or XML before carrying on with the next file
                    loadNext = false;

                    if (file.format == Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY || file.format == Phaser.Loader.TEXTURE_ATLAS_JSON_HASH)
                    {
                        this.xhrLoad(file, this.transformUrl(file.atlasURL, file), 'text', this.jsonLoadComplete);
                    }
                    else if (file.format == Phaser.Loader.TEXTURE_ATLAS_XML_STARLING)
                    {
                        this.xhrLoad(file, this.transformUrl(file.atlasURL, file), 'text', this.xmlLoadComplete);
                    }
                    else
                    {
                        throw new Error("Phaser.Loader. Invalid Texture Atlas format: " + file.format);
                    }
                }
                break;

            case 'bitmapfont':

                if (!file.xmlURL)
                {
                    this.game.cache.addBitmapFont(file.key, file.url, file.data, file.xmlData, file.xSpacing, file.ySpacing);
                }
                else
                {
                    //  Load the XML before carrying on with the next file
                    loadNext = false;
                    this.xhrLoad(file, this.transformUrl(file.xmlURL, file), 'text', this.xmlLoadComplete);
                }
                break;

            case 'audio':

                if (this.game.sound.usingWebAudio)
                {
                    file.data = xhr.response;

                    this.game.cache.addSound(file.key, file.url, file.data, true, false);

                    if (file.autoDecode)
                    {
                        var that = this;
                        var key = file.key;

                        this.game.cache.updateSound(key, 'isDecoding', true);

                        this.game.sound.context.decodeAudioData(file.data, function (buffer) {
                            if (buffer)
                            {
                                that.game.cache.decodedSound(key, buffer);
                                that.game.sound.onSoundDecode.dispatch(key, that.game.cache.getSound(key));
                            }
                        });
                    }
                }
                else
                {
                    this.game.cache.addSound(file.key, file.url, file.data, false, true);
                }
                break;

            case 'text':
                file.data = xhr.responseText;
                this.game.cache.addText(file.key, file.url, file.data);
                break;

            case 'physics':
                var data = JSON.parse(this.responseText);
                this.game.cache.addPhysicsData(file.key, file.url, data, file.format);
                break;

            case 'script':
                file.data = document.createElement('script');
                file.data.language = 'javascript';
                file.data.type = 'text/javascript';
                file.data.defer = false;
                file.data.text = xhr.responseText;
                document.head.appendChild(file.data);
                if (file.callback)
                {
                    file.data = file.callback.call(file.callbackContext, file.key, xhr.responseText);
                }
                break;

            case 'binary':
                if (file.callback)
                {
                    file.data = file.callback.call(file.callbackContext, file.key, this.response);
                }
                else
                {
                    file.data = xhr.response;
                }

                this.game.cache.addBinary(file.key, file.data);

                break;
        }

        if (loadNext)
        {
            this.asyncComplete(file);
        }

    },

    /**
    * Successfully loaded a JSON file - only used for certain types.
    *
    * @method Phaser.Loader#jsonLoadComplete
    * @private
    * @param {object} file - File associated with this request
    * @param {XMLHttpRequest} xhr
    */
    jsonLoadComplete: function (file, xhr) {

        var data = JSON.parse(xhr.responseText);

        if (file.type === 'tilemap')
        {
            this.game.cache.addTilemap(file.key, file.url, data, file.format);
        }
        else if (file.type === 'json')
        {
            this.game.cache.addJSON(file.key, file.url, data);
        }
        else
        {
            this.game.cache.addTextureAtlas(file.key, file.url, file.data, data, file.format);
        }

        this.asyncComplete(file);

    },

    /**
    * Successfully loaded a CSV file - only used for certain types.
    *
    * @method Phaser.Loader#csvLoadComplete
    * @private
    * @param {object} file - File associated with this request
    * @param {XMLHttpRequest} xhr
    */
    csvLoadComplete: function (file, xhr) {

        var data = xhr.responseText;

        this.game.cache.addTilemap(file.key, file.url, data, file.format);

        this.asyncComplete(file);

    },

    /**
    * Successfully loaded an XML file - only used for certain types.
    *
    * @method Phaser.Loader#xmlLoadComplete
    * @private
    * @param {object} file - File associated with this request
    * @param {XMLHttpRequest} xhr
    */
    xmlLoadComplete: function (file, xhr) {

        // Always try parsing the content as XML, regardless of actually response type
        var data = xhr.responseText;
        var xml = this.parseXml(data);

        if (!xml)
        {
            var responseType = xhr.responseType || xhr.contentType; // contentType for MS-XDomainRequest
            console.warn('Phaser.Loader - ' + file.key + ': invalid XML (' + responseType + ')');
            this.asyncComplete(file, "invalid XML");
            return;
        }

        if (file.type === 'bitmapfont')
        {
            this.game.cache.addBitmapFont(file.key, file.url, file.data, xml, file.xSpacing, file.ySpacing);
        }
        else if (file.type === 'textureatlas')
        {
            this.game.cache.addTextureAtlas(file.key, file.url, file.data, xml, file.format);
        }
        else if (file.type === 'xml')
        {
            this.game.cache.addXML(file.key, file.url, xml);
        }

        this.asyncComplete(file);

    },

    /**
    * Parses string data as XML.
    *
    * @method parseXml
    * @private
    * @param {string} data - The XML text to parse
    * @return {?XMLDocument} Returns the xml document, or null if such could not parsed to a valid document.
    */
    parseXml: function (data) {

        var xml;
        try
        {
            if (window['DOMParser'])
            {
                var domparser = new DOMParser();
                xml = domparser.parseFromString(data, "text/xml");
            }
            else
            {
                xml = new ActiveXObject("Microsoft.XMLDOM");
                // Why is this 'false'?
                xml.async = 'false';
                xml.loadXML(data);
            }
        }
        catch (e)
        {
            xml = null;
        }

        if (!xml || !xml.documentElement || xml.getElementsByTagName("parsererror").length)
        {
            return null;
        }
        else
        {
            return xml;
        }

    },

    /**
    * Update the loading sprite progress.
    *
    * @method Phaser.Loader#nextFile
    * @private
    * @param {object} previousFile
    * @param {boolean} success - Whether the previous asset loaded successfully or not.
    */
    updateProgress: function () {

        if (this.preloadSprite)
        {
            if (this.preloadSprite.direction === 0)
            {
                this.preloadSprite.rect.width = Math.floor((this.preloadSprite.width / 100) * this.progress);
            }
            else
            {
                this.preloadSprite.rect.height = Math.floor((this.preloadSprite.height / 100) * this.progress);
            }

            this.preloadSprite.sprite.updateCrop();
        }

    },

    /**
    * Returns the number of files that have already been loaded, even if they errored.
    *
    * @method Phaser.Loader#totalLoadedFiles
    * @protected
    * @return {number} The number of files that have already been loaded (even if they errored)
    */
    totalLoadedFiles: function () {

        return this._loadedFileCount;

    },

    /**
    * Returns the number of files still waiting to be processed in the load queue. This value decreases as each file in the queue is loaded.
    *
    * @method Phaser.Loader#totalQueuedFiles
    * @protected
    * @return {number} The number of files that still remain in the load queue.
    */
    totalQueuedFiles: function () {

        return this._totalFileCount - this._loadedFileCount;

    },

    /**
    * Returns the number of asset packs that have already been loaded, even if they errored.
    *
    * @method Phaser.Loader#totalLoadedPacks
    * @protected
    * @return {number} The number of asset packs that have already been loaded (even if they errored)
    */
    totalLoadedPacks: function () {

        return this._totalPackCount;

    },

    /**
    * Returns the number of asset packs still waiting to be processed in the load queue. This value decreases as each pack in the queue is loaded.
    *
    * @method Phaser.Loader#totalQueuedPacks
    * @protected
    * @return {number} The number of asset packs that still remain in the load queue.
    */
    totalQueuedPacks: function () {

        return this._totalPackCount - this._loadedPackCount;

    }

};

/**
* The non-rounded load progress value (from 0.0 to 100.0).
*
* A general indicator of the progress.
* It is possible for the progress to decrease, after `onLoadStart`, if more files are dynamically added.
*
* @memberof Phaser.Loader#progressFloat
* @property {number}
*/
Object.defineProperty(Phaser.Loader.prototype, "progressFloat", {

    get: function () {
        var progress = (this._loadedFileCount / this._totalFileCount) * 100;
        return Phaser.Math.clamp(progress || 0, 0, 100);
    }

});

/**
* The rounded load progress percentage value (from 0 to 100). See {@link Phaser.Loader#progressFloat}.
*
* @name Phaser.Loader#progress
* @property {integer}
*/
Object.defineProperty(Phaser.Loader.prototype, "progress", {

    get: function () {
        return Math.round(this.progressFloat);
    }

});

Phaser.Loader.prototype.constructor = Phaser.Loader;