Proyectos de Subversion Moodle

/**

The YUI module contains the components required for building the YUI seed file.

This includes the script loading mechanism, a simple queue, and the core

utilities for the library.

@module yui

@main yui

@submodule yui-base

**/

/*jshint eqeqeq: false*/

if (typeof YUI != 'undefined') {

    YUI._YUI = YUI;

}

/**

The YUI global namespace object. This is the constructor for all YUI instances.

This is a self-instantiable factory function, meaning you don't need to precede

it with the `new` operator. You can invoke it directly like this:

    YUI().use('*', function (Y) {

        // Y is a new YUI instance.

    });

But it also works like this:

    var Y = YUI();

The `YUI` constructor accepts an optional config object, like this:

    YUI({

        debug: true,

        combine: false

    }).use('node', function (Y) {

        // Y.Node is ready to use.

    });

See the API docs for the <a href="config.html">Config</a> class for the complete

list of supported configuration properties accepted by the YUI constuctor.

If a global `YUI` object is already defined, the existing YUI object will not be

overwritten, to ensure that defined namespaces are preserved.

Each YUI instance has full custom event support, but only if the event system is

available.

@class YUI

@uses EventTarget

@constructor

@global

@param {Object} [config]* Zero or more optional configuration objects. Config

    values are stored in the `Y.config` property. See the

    <a href="config.html">Config</a> docs for the list of supported properties.

**/

    /*global YUI*/

    /*global YUI_config*/

    var YUI = function() {

        var i = 0,

            Y = this,

            args = arguments,

            l = args.length,

            instanceOf = function(o, type) {

                return (o && o.hasOwnProperty && (o instanceof type));

            },

            gconf = (typeof YUI_config !== 'undefined') && YUI_config;

        if (!(instanceOf(Y, YUI))) {

            Y = new YUI();

        } else {

            // set up the core environment

            Y._init();

            /**

            Master configuration that might span multiple contexts in a non-

            browser environment. It is applied first to all instances in all

            contexts.

            @example

                YUI.GlobalConfig = {

                    filter: 'debug'

                };

                YUI().use('node', function (Y) {

                    // debug files used here

                });

                YUI({

                    filter: 'min'

                }).use('node', function (Y) {

                    // min files used here

                });

            @property {Object} GlobalConfig

            @global

            @static

            **/

            if (YUI.GlobalConfig) {

                Y.applyConfig(YUI.GlobalConfig);

            }

            /**

            Page-level config applied to all YUI instances created on the

            current page. This is applied after `YUI.GlobalConfig` and before

            any instance-level configuration.

            @example

                // Single global var to include before YUI seed file

                YUI_config = {

                    filter: 'debug'

                };

                YUI().use('node', function (Y) {

                    // debug files used here

                });

                YUI({

                    filter: 'min'

                }).use('node', function (Y) {

                    // min files used here

                });

            @property {Object} YUI_config

            @global

            **/

            if (gconf) {

                Y.applyConfig(gconf);

            }

            // bind the specified additional modules for this instance

            if (!l) {

                Y._afterConfig();

                Y._setup();

            }

        }

        if (l) {

            // Each instance can accept one or more configuration objects.

            // These are applied after YUI.GlobalConfig and YUI_Config,

            // overriding values set in those config files if there is a

            // matching property.

            for (; i < l; i++) {

                Y.applyConfig(args[i]);

            }

            Y._afterConfig();

            Y._setup();

        }

        Y.instanceOf = instanceOf;

        return Y;

    };

(function() {

    var proto, prop,

        VERSION = '3.18.1',

        PERIOD = '.',

        BASE = 'http://yui.yahooapis.com/',

        /*

            These CSS class names can't be generated by

            getClassName since it is not available at the

            time they are being used.

        */

        DOC_LABEL = 'yui3-js-enabled',

        CSS_STAMP_EL = 'yui3-css-stamp',

        NOOP = function() {},

        SLICE = Array.prototype.slice,

        APPLY_TO_AUTH = { 'io.xdrReady': 1,   // the functions applyTo

                          'io.xdrResponse': 1,   // can call. this should

                          'SWF.eventHandler': 1 }, // be done at build time

        hasWin = (typeof window != 'undefined'),

        win = (hasWin) ? window : null,

        doc = (hasWin) ? win.document : null,

        docEl = doc && doc.documentElement,

        docClass = docEl && docEl.className,

        instances = {},

        time = new Date().getTime(),

        add = function(el, type, fn, capture) {

            if (el && el.addEventListener) {

                el.addEventListener(type, fn, capture);

            } else if (el && el.attachEvent) {

                el.attachEvent('on' + type, fn);

            }

        },

        remove = function(el, type, fn, capture) {

            if (el && el.removeEventListener) {

                // this can throw an uncaught exception in FF

                try {

                    el.removeEventListener(type, fn, capture);

                } catch (ex) {}

            } else if (el && el.detachEvent) {

                el.detachEvent('on' + type, fn);

            }

        },

        handleReady = function() {

            YUI.Env.DOMReady = true;

            if (hasWin) {

                remove(doc, 'DOMContentLoaded', handleReady);

            }

        },

        handleLoad = function() {

            YUI.Env.windowLoaded = true;

            YUI.Env.DOMReady = true;

            if (hasWin) {

                remove(window, 'load', handleLoad);

            }

        },

        getLoader = function(Y, o) {

            var loader = Y.Env._loader,

                lCore = [ 'loader-base' ],

                G_ENV = YUI.Env,

                mods = G_ENV.mods;

            if (loader) {

                //loader._config(Y.config);

                loader.ignoreRegistered = false;

                loader.onEnd = null;

                loader.data = null;

                loader.required = [];

                loader.loadType = null;

            } else {

                loader = new Y.Loader(Y.config);

                Y.Env._loader = loader;

            }

            if (mods && mods.loader) {

                lCore = [].concat(lCore, YUI.Env.loaderExtras);

            }

            YUI.Env.core = Y.Array.dedupe([].concat(YUI.Env.core, lCore));

            return loader;

        },

        clobber = function(r, s) {

            for (var i in s) {

                if (s.hasOwnProperty(i)) {

                    r[i] = s[i];

                }

            }

        },

        ALREADY_DONE = { success: true };

//  Stamp the documentElement (HTML) with a class of "yui-loaded" to

//  enable styles that need to key off of JS being enabled.

if (docEl && docClass.indexOf(DOC_LABEL) == -1) {

    if (docClass) {

        docClass += ' ';

    }

    docClass += DOC_LABEL;

    docEl.className = docClass;

}

if (VERSION.indexOf('@') > -1) {

    VERSION = '3.5.0'; // dev time hack for cdn test

}

proto = {

    /**

    Applies a new configuration object to the config of this YUI instance. This

    will merge new group/module definitions, and will also update the loader

    cache if necessary. Updating `Y.config` directly will not update the cache.

    @method applyConfig

    @param {Object} o the configuration object.

    @since 3.2.0

    **/

    applyConfig: function(o) {

        o = o || NOOP;

        var attr,

            name,

            // detail,

            config = this.config,

            mods = config.modules,

            groups = config.groups,

            aliases = config.aliases,

            loader = this.Env._loader;

        for (name in o) {

            if (o.hasOwnProperty(name)) {

                attr = o[name];

                if (mods && name == 'modules') {

                    clobber(mods, attr);

                } else if (aliases && name == 'aliases') {

                    clobber(aliases, attr);

                } else if (groups && name == 'groups') {

                    clobber(groups, attr);

                } else if (name == 'win') {

                    config[name] = (attr && attr.contentWindow) || attr;

                    config.doc = config[name] ? config[name].document : null;

                } else if (name == '_yuid') {

                    // preserve the guid

                } else {

                    config[name] = attr;

                }

            }

        }

        if (loader) {

            loader._config(o);

        }

    },

    /**

    Old way to apply a config to this instance (calls `applyConfig` under the

    hood).

    @private

    @method _config

    @param {Object} o The config to apply

    **/

    _config: function(o) {

        this.applyConfig(o);

    },

    /**

    Initializes this YUI instance.

    @private

    @method _init

    **/

    _init: function() {

        var filter, el,

            Y = this,

            G_ENV = YUI.Env,

            Env = Y.Env,

            prop;

        /**

        The version number of this YUI instance.

        This value is typically updated by a script when a YUI release is built,

        so it may not reflect the correct version number when YUI is run from

        the development source tree.

        @property {String} version

        **/

        Y.version = VERSION;

        if (!Env) {

            Y.Env = {

                core: ['get', 'features', 'intl-base', 'yui-log', 'yui-later'],

                loaderExtras: ['loader-rollup', 'loader-yui3'],

                mods: {}, // flat module map

                versions: {}, // version module map

                base: BASE,

                cdn: BASE + VERSION + '/',

                // bootstrapped: false,

                _idx: 0,

                _used: {},

                _attached: {},

                _exported: {},

                _missed: [],

                _yidx: 0,

                _uidx: 0,

                _guidp: 'y',

                _loaded: {},

                // serviced: {},

                // Regex in English:

                // I'll start at the \b(yui).

                // 1. Look in the test string for "yui" or

                //    "yui-base" or "yui-davglass" or "yui-foobar" that comes after a word break.  That is, it

                //    can't match "foyui" or "i_heart_yui". This can be anywhere in the string.

                // 2. After #1 must come a forward slash followed by the string matched in #1, so

                //    "yui-base/yui-base" or "yui-pants/yui-pants".

                // 3. The second occurence of the #1 token can optionally be followed by "-debug" or "-min",

                //    so "yui/yui-min", "yui/yui-debug", "yui-base/yui-base-debug". NOT "yui/yui-tshirt".

                // 4. This is followed by ".js", so "yui/yui.js".

                // 0. Going back to the beginning, now. If all that stuff in 1-4 comes after a "?" in the string,

                //    then capture the junk between the LAST "&" and the string in 1-4.  So

                //    "blah?foo/yui/yui.js" will capture "foo/" and "blah?some/thing.js&3.3.0/build/yui-davglass/yui-davglass.js"

                //    will capture "3.3.0/build/"

                //

                // Regex Exploded:

                // (?:\?             Find a ?

                //   (?:[^&]*&)      followed by 0..n characters followed by an &

                //   *               in fact, find as many sets of characters followed by a & as you can

                //   ([^&]*)         capture the stuff after the last & in \1

                // )?                but it's ok if all this ?junk&more_junk stuff isn't even there

                // \b(               after a word break find either the string

                //    yui(?:-\w+)?   "yui" optionally followed by a -, then more characters

                // )                 and store the yui-* string in \2

                // \/\2              then comes a / followed by the yui-* string in \2

                // (?:-(min|debug))? optionally followed by "-min" or "-debug"

                // .js               and ending in ".js"

                _BASE_RE: /(?:\?(?:[^&]*&)*([^&]*))?\b(yui(?:-\w+)?)\/\2(?:-(min|debug))?\.js/,

                parseBasePath: function(src, pattern) {

                    var match = src.match(pattern),

                        path, filter;

                    if (match) {

                        path = RegExp.leftContext || src.slice(0, src.indexOf(match[0]));

                        // this is to set up the path to the loader.  The file

                        // filter for loader should match the yui include.

                        filter = match[3];

                        // extract correct path for mixed combo urls

                        // http://yuilibrary.com/projects/yui3/ticket/2528423

                        if (match[1]) {

                            path += '?' + match[1];

                        }

                        path = {

                            filter: filter,

                            path: path

                        };

                    }

                    return path;

                },

                getBase: G_ENV && G_ENV.getBase ||

                        function(pattern) {

                            var nodes = (doc && doc.getElementsByTagName('script')) || [],

                                path = Env.cdn, parsed,

                                i, len, src;

                            for (i = 0, len = nodes.length; i < len; ++i) {

                                src = nodes[i].src;

                                if (src) {

                                    parsed = Y.Env.parseBasePath(src, pattern);

                                    if (parsed) {

                                        filter = parsed.filter;

                                        path = parsed.path;

                                        break;

                                    }

                                }

                            }

                            // use CDN default

                            return path;

                        }

            };

            Env = Y.Env;

            Env._loaded[VERSION] = {};

            if (G_ENV && Y !== YUI) {

                Env._yidx = ++G_ENV._yidx;

                Env._guidp = ('yui_' + VERSION + '_' +

                             Env._yidx + '_' + time).replace(/[^a-z0-9_]+/g, '_');

            } else if (YUI._YUI) {

                G_ENV = YUI._YUI.Env;

                Env._yidx += G_ENV._yidx;

                Env._uidx += G_ENV._uidx;

                for (prop in G_ENV) {

                    if (!(prop in Env)) {

                        Env[prop] = G_ENV[prop];

                    }

                }

                delete YUI._YUI;

            }

            Y.id = Y.stamp(Y);

            instances[Y.id] = Y;

        }

        Y.constructor = YUI;

        // configuration defaults

        Y.config = Y.config || {

            bootstrap: true,

            cacheUse: true,

            debug: true,

            doc: doc,

            fetchCSS: true,

            throwFail: true,

            useBrowserConsole: true,

            useNativeES5: true,

            win: win

        };

        //Register the CSS stamp element

        if (doc && !doc.getElementById(CSS_STAMP_EL)) {

            el = doc.createElement('div');

            el.innerHTML = '<div id="' + CSS_STAMP_EL + '" style="position: absolute !important; visibility: hidden !important"></div>';

            YUI.Env.cssStampEl = el.firstChild;

            if (doc.body) {

                doc.body.appendChild(YUI.Env.cssStampEl);

            } else {

                docEl.insertBefore(YUI.Env.cssStampEl, docEl.firstChild);

            }

        } else if (doc && doc.getElementById(CSS_STAMP_EL) && !YUI.Env.cssStampEl) {

            YUI.Env.cssStampEl = doc.getElementById(CSS_STAMP_EL);

        }

        Y.config.lang = Y.config.lang || 'en-US';

        Y.config.base = YUI.config.base ||

                (YUI.config.defaultBase && YUI.config.root && YUI.config.defaultBase + YUI.config.root) ||

                Y.Env.getBase(Y.Env._BASE_RE);

        if (!filter || (!('mindebug').indexOf(filter))) {

            filter = 'min';

        }

        filter = (filter) ? '-' + filter : filter;

        Y.config.loaderPath = YUI.config.loaderPath || 'loader/loader' + filter + '.js';

    },

    /**

    This method is called after all other configuration has been applied to

    the YUI instance.

    @method _afterConfig

    @private

    **/

    _afterConfig: function () {

        var Y = this;

        // We need to set up Y.config.global after the rest of the configuration

        // so that setting it in user configuration prevents the library from

        // using eval(). This is critical for Content Security Policy enabled

        // sites and other environments like Chrome extensions

        if (!Y.config.hasOwnProperty('global')) {

            Y.config.global = Function('return this')();

        }

    },

    /**

    Finishes the instance setup. Attaches whatever YUI modules were defined

    at the time that this instance was created.

    @method _setup

    @private

    **/

    _setup: function() {

        var i, Y = this,

            core = [],

            mods = YUI.Env.mods,

            extendedCore = Y.config.extendedCore || [],

            extras = Y.config.core || [].concat(YUI.Env.core).concat(extendedCore); //Clone it..

        for (i = 0; i < extras.length; i++) {

            if (mods[extras[i]]) {

                core.push(extras[i]);

            }

        }

        Y._attach(['yui-base']);

        Y._attach(core);

        if (Y.Loader) {

            getLoader(Y);

        }

        // Y.log(Y.id + ' initialized', 'info', 'yui');

    },

    /**

    Executes the named method on the specified YUI instance if that method is

    whitelisted.

    @method applyTo

    @param {String} id YUI instance id.

    @param {String} method Name of the method to execute. For example:

        'Object.keys'.

    @param {Array} args Arguments to apply to the method.

    @return {Mixed} Return value from the applied method, or `null` if the

        specified instance was not found or the method was not whitelisted.

    **/

    applyTo: function(id, method, args) {

        if (!(method in APPLY_TO_AUTH)) {

            this.log(method + ': applyTo not allowed', 'warn', 'yui');

            return null;

        }

        var instance = instances[id], nest, m, i;

        if (instance) {

            nest = method.split('.');

            m = instance;

            for (i = 0; i < nest.length; i = i + 1) {

                m = m[nest[i]];

                if (!m) {

                    this.log('applyTo not found: ' + method, 'warn', 'yui');

                }

            }

            return m && m.apply(instance, args);

        }

        return null;

    },

/**

Registers a YUI module and makes it available for use in a `YUI().use()` call or

as a dependency for other modules.

The easiest way to create a first-class YUI module is to use

<a href="http://yui.github.com/shifter/">Shifter</a>, the YUI component build

tool.

Shifter will automatically wrap your module code in a `YUI.add()` call along

with any configuration info required for the module.

@example

    YUI.add('davglass', function (Y) {

        Y.davglass = function () {

            Y.log('Dav was here!');

        };

    }, '3.4.0', {

        requires: ['harley-davidson', 'mt-dew']

    });

@method add

@param {String} name Module name.

@param {Function} fn Function containing module code. This function will be

    executed whenever the module is attached to a specific YUI instance.

    @param {YUI} fn.Y The YUI instance to which this module is attached.

    @param {String} fn.name Name of the module

@param {String} version Module version number. This is currently used only for

    informational purposes, and is not used internally by YUI.

@param {Object} [details] Module config.

    @param {Array} [details.requires] Array of other module names that must be

        attached before this module can be attached.

    @param {Array} [details.optional] Array of optional module names that should

        be attached before this module is attached if they've already been

        loaded. If the `loadOptional` YUI option is `true`, optional modules

        that have not yet been loaded will be loaded just as if they were hard

        requirements.

    @param {Array} [details.use] Array of module names that are included within

        or otherwise provided by this module, and which should be attached

        automatically when this module is attached. This makes it possible to

        create "virtual rollup" modules that simply attach a collection of other

        modules or submodules.

@return {YUI} This YUI instance.

**/

    add: function(name, fn, version, details) {

        details = details || {};

        var env = YUI.Env,

            mod = {

                name: name,

                fn: fn,

                version: version,

                details: details

            },

            //Instance hash so we don't apply it to the same instance twice

            applied = {},

            loader, inst, modInfo,

            i, versions = env.versions;

        env.mods[name] = mod;

        versions[version] = versions[version] || {};

        versions[version][name] = mod;

        for (i in instances) {

            if (instances.hasOwnProperty(i)) {

                inst = instances[i];

                if (!applied[inst.id]) {

                    applied[inst.id] = true;

                    loader = inst.Env._loader;

                    if (loader) {

                        modInfo = loader.getModuleInfo(name);

                        if (!modInfo || modInfo.temp) {

                            loader.addModule(details, name);

                        }

                    }

                }

            }

        }

        return this;

    },

    /**

    Executes the callback function associated with each required module,

    attaching the module to this YUI instance.

    @method _attach

    @param {Array} r The array of modules to attach

    @param {Boolean} [moot=false] If `true`, don't throw a warning if the module

        is not attached.

    @private

    **/

    _attach: function(r, moot) {

        var i, name, mod, details, req, use, after,

            mods = YUI.Env.mods,

            aliases = YUI.Env.aliases,

            Y = this, j,

            cache = YUI.Env._renderedMods,

            loader = Y.Env._loader,

            done = Y.Env._attached,

            exported = Y.Env._exported,

            len = r.length, loader, def, go,

            c = [],

            modArgs, esCompat, reqlen, modInfo,

            condition,

            __exports__, __imports__;

        //Check for conditional modules (in a second+ instance) and add their requirements

        //TODO I hate this entire method, it needs to be fixed ASAP (3.5.0) ^davglass

        for (i = 0; i < len; i++) {

            name = r[i];

            mod = mods[name];

            c.push(name);

            if (loader && loader.conditions[name]) {

                for (j in loader.conditions[name]) {

                    if (loader.conditions[name].hasOwnProperty(j)) {

                        def = loader.conditions[name][j];

                        go = def && ((def.ua && Y.UA[def.ua]) || (def.test && def.test(Y)));

                        if (go) {

                            c.push(def.name);

                        }

                    }

                }

            }

        }

        r = c;

        len = r.length;

        for (i = 0; i < len; i++) {

            if (!done[r[i]]) {

                name = r[i];

                mod = mods[name];

                if (aliases && aliases[name] && !mod) {

                    Y._attach(aliases[name]);

                    continue;

                }

                if (!mod) {

                    modInfo = loader && loader.getModuleInfo(name);

                    if (modInfo) {

                        mod = modInfo;

                        moot = true;

                    }

                    // Y.log('no js def for: ' + name, 'info', 'yui');

                    //if (!loader || !loader.moduleInfo[name]) {

                    //if ((!loader || !loader.moduleInfo[name]) && !moot) {

                    if (!moot && name) {

                        if ((name.indexOf('skin-') === -1) && (name.indexOf('css') === -1)) {

                            Y.Env._missed.push(name);

                            Y.Env._missed = Y.Array.dedupe(Y.Env._missed);

                            Y.message('NOT loaded: ' + name, 'warn', 'yui');

                        }

                    }

                } else {

                    done[name] = true;

                    //Don't like this, but in case a mod was asked for once, then we fetch it

                    //We need to remove it from the missed list ^davglass

                    for (j = 0; j < Y.Env._missed.length; j++) {

                        if (Y.Env._missed[j] === name) {

                            Y.message('Found: ' + name + ' (was reported as missing earlier)', 'warn', 'yui');

                            Y.Env._missed.splice(j, 1);

                        }

                    }

                    // Optional dependencies normally work by modifying the

                    // dependency list of a module. If the dependency's test

                    // passes it is added to the list. If not, it's not loaded.

                    // This following check ensures that optional dependencies

                    // are not attached when they were already loaded into the

                    // page (when bundling for example)

                    if (loader && !loader._canBeAttached(name)) {

                        Y.log('Failed to attach module ' + name, 'warn', 'yui');

                        return true;

                    }

                    /*

                        If it's a temp module, we need to redo it's requirements if it's already loaded

                        since it may have been loaded by another instance and it's dependencies might

                        have been redefined inside the fetched file.

                    */

                    if (loader && cache && cache[name] && cache[name].temp) {

                        loader.getRequires(cache[name]);

                        req = [];

                        modInfo = loader.getModuleInfo(name);

                        for (j in modInfo.expanded_map) {

                            if (modInfo.expanded_map.hasOwnProperty(j)) {

                                req.push(j);

                            }

                        }

                        Y._attach(req);

                    }

                    details = mod.details;

                    req = details.requires;

                    esCompat = details.es;

                    use = details.use;

                    after = details.after;

                    //Force Intl load if there is a language (Loader logic) @todo fix this shit

                    if (details.lang) {

                        req = req || [];

                        req.unshift('intl');

                    }

                    if (req) {

                        reqlen = req.length;

                        for (j = 0; j < reqlen; j++) {

                            if (!done[req[j]]) {

                                if (!Y._attach(req)) {

                                    return false;

                                }

                                break;

                            }

                        }

                    }

                    if (after) {

                        for (j = 0; j < after.length; j++) {

                            if (!done[after[j]]) {

                                if (!Y._attach(after, true)) {

                                    return false;

                                }

                                break;

                            }

                        }

                    }

                    if (mod.fn) {

                        modArgs = [Y, name];

                        if (esCompat) {

                            __imports__ = {};

                            __exports__ = {};

                            // passing `exports` and `imports` onto the module function

                            modArgs.push(__imports__, __exports__);

                            if (req) {

                                reqlen = req.length;

                                for (j = 0; j < reqlen; j++) {

                                    __imports__[req[j]] = exported.hasOwnProperty(req[j]) ? exported[req[j]] : Y;

                                }

                            }

                        }

                        if (Y.config.throwFail) {

                            __exports__ = mod.fn.apply(esCompat ? undefined : mod, modArgs);

                        } else {

                            try {

                                __exports__ = mod.fn.apply(esCompat ? undefined : mod, modArgs);

                            } catch (e) {

                                Y.error('Attach error: ' + name, e, name);

                                return false;

                            }

                        }

                        if (esCompat) {

                            // store the `exports` in case others `es` modules requires it

                            exported[name] = __exports__;

                            // If an ES module is conditionally loaded and set

                            // to be used "instead" another module, replace the

                            // trigger module's content with the conditionally

                            // loaded one so the values returned by require()

                            // still makes sense

                            condition = mod.details.condition;

                            if (condition && condition.when === 'instead') {

                                exported[condition.trigger] = __exports__;

                            }

                        }

                    }

                    if (use) {

                        for (j = 0; j < use.length; j++) {

                            if (!done[use[j]]) {

                                if (!Y._attach(use)) {

                                    return false;

                                }

                                break;

                            }

                        }

                    }

                }

            }

        }

        return true;

    },

    /**

    Delays the `use` callback until another event has taken place such as

    `window.onload`, `domready`, `contentready`, or `available`.

    @private

    @method _delayCallback

    @param {Function} cb The original `use` callback.

    @param {String|Object} until Either an event name ('load', 'domready', etc.)

        or an object containing event/args keys for contentready/available.

    @return {Function}

    **/

    _delayCallback: function(cb, until) {

        var Y = this,

            mod = ['event-base'];

        until = (Y.Lang.isObject(until) ? until : { event: until });

        if (until.event === 'load') {

            mod.push('event-synthetic');

        }

        Y.log('Delaying use callback until: ' + until.event, 'info', 'yui');

        return function() {

            Y.log('Use callback fired, waiting on delay', 'info', 'yui');

            var args = arguments;

            Y._use(mod, function() {

                Y.log('Delayed use wrapper callback after dependencies', 'info', 'yui');

                Y.on(until.event, function() {

                    args[1].delayUntil = until.event;

                    Y.log('Delayed use callback done after ' + until.event, 'info', 'yui');

                    cb.apply(Y, args);

                }, until.args);

            });

        };

    },

    /**

    Attaches one or more modules to this YUI instance. When this is executed,

    the requirements of the desired modules are analyzed, and one of several

    things can happen:

      * All required modules have already been loaded, and just need to be

        attached to this YUI instance. In this case, the `use()` callback will

        be executed synchronously after the modules are attached.

      * One or more modules have not yet been loaded, or the Get utility is not

        available, or the `bootstrap` config option is `false`. In this case,

        a warning is issued indicating that modules are missing, but all

        available modules will still be attached and the `use()` callback will

        be executed synchronously.

      * One or more modules are missing and the Loader is not available but the

        Get utility is, and `bootstrap` is not `false`. In this case, the Get

        utility will be used to load the Loader, and we will then proceed to

        the following state:

      * One or more modules are missing and the Loader is available. In this

        case, the Loader will be used to resolve the dependency tree for the

        missing modules and load them and their dependencies. When the Loader is

        finished loading modules, the `use()` callback will be executed

        asynchronously.

    @example

        // Loads and attaches dd and its dependencies.

        YUI().use('dd', function (Y) {

            // ...

        });

        // Loads and attaches dd and node as well as all of their dependencies.

        YUI().use(['dd', 'node'], function (Y) {

            // ...

        });

        // Attaches all modules that have already been loaded.

        YUI().use('*', function (Y) {

            // ...

        });

        // Attaches a gallery module.

        YUI().use('gallery-yql', function (Y) {

            // ...

        });

        // Attaches a YUI 2in3 module.

        YUI().use('yui2-datatable', function (Y) {

            // ...

        });

    @method use

    @param {String|Array} modules* One or more module names to attach.

    @param {Function} [callback] Callback function to be executed once all

        specified modules and their dependencies have been attached.

    @param {YUI} callback.Y The YUI instance created for this sandbox.

    @param {Object} callback.status Object containing `success`, `msg` and

        `data` properties.

    @chainable

    **/

    use: function() {

        var args = SLICE.call(arguments, 0),

            callback = args[args.length - 1],

            Y = this,

            i = 0,

            name,

            Env = Y.Env,

            provisioned = true;

        // The last argument supplied to use can be a load complete callback

        if (Y.Lang.isFunction(callback)) {

            args.pop();

            if (Y.config.delayUntil) {

                callback = Y._delayCallback(callback, Y.config.delayUntil);

            }

        } else {

            callback = null;

        }

        if (Y.Lang.isArray(args[0])) {

            args = args[0];