File: intl/js/Intl.js

            var _mods = {},
            
                ROOT_LANG = "yuiRootLang",
                ACTIVE_LANG = "yuiActiveLang",
                NONE = [];
            
            /**
             * Provides utilities to support the management of localized resources (strings and formatting patterns).
             *
             * @module intl
             */
            
            /**
             * The Intl utility provides a central location for managing sets of localized resources (strings and formatting patterns).
             *
             * @class Intl
             * @uses EventTarget
             * @static
             */
            Y.mix(Y.namespace("Intl"), {
            
                /**
                 * Private method to retrieve the language hash for a given module.
                 *
                 * @method _mod
                 * @private
                 *
                 * @param {String} module The name of the module
                 * @return {Object} The hash of localized resources for the module, keyed by BCP language tag
                 */
                _mod : function(module) {
                    if (!_mods[module]) {
                        _mods[module] = {};
                    }
                    return _mods[module];
                },
            
                /**
                 * Sets the active language for the given module.
                 *
                 * Returns false on failure, which would happen if the language had not been registered through the <a href="#method_add">add()</a> method.
                 *
                 * @method setLang
                 *
                 * @param {String} module The module name.
                 * @param {String} lang The BCP 47 language tag.
                 * @return boolean true if successful, false if not.
                 */
                setLang : function(module, lang) {
                    var langs = this._mod(module),
                        currLang = langs[ACTIVE_LANG],
                        exists = !!langs[lang];
            
                    if (exists && lang !== currLang) {
                        langs[ACTIVE_LANG] = lang;
                        this.fire("intl:langChange", {module: module, prevVal: currLang, newVal: (lang === ROOT_LANG) ? "" : lang});
                    }
            
                    return exists;
                },
            
                /**
                 * Get the currently active language for the given module.
                 *
                 * @method getLang
                 *
                 * @param {String} module The module name.
                 * @return {String} The BCP 47 language tag.
                 */
                getLang : function(module) {
                    var lang = this._mod(module)[ACTIVE_LANG];
                    return (lang === ROOT_LANG) ? "" : lang;
                },
            
                /**
                 * Register a hash of localized resources for the given module and language
                 *
                 * @method add
                 *
                 * @param {String} module The module name.
                 * @param {String} lang The BCP 47 language tag.
                 * @param {Object} strings The hash of localized values, keyed by the string name.
                 */
                add : function(module, lang, strings) {
                    lang = lang || ROOT_LANG;
                    this._mod(module)[lang] = strings;
                    this.setLang(module, lang);
                },
            
                /**
                 * Gets the module's localized resources for the currently active language (as provided by the <a href="#method_getLang">getLang</a> method).
                 * <p>
                 * Optionally, the localized resources for alternate languages which have been added to Intl (see the <a href="#method_add">add</a> method) can
                 * be retrieved by providing the BCP 47 language tag as the lang parameter.
                 * </p>
                 * @method get
                 *
                 * @param {String} module The module name.
                 * @param {String} key Optional. A single resource key. If not provided, returns a copy (shallow clone) of all resources.
                 * @param {String} lang Optional. The BCP 47 language tag. If not provided, the module's currently active language is used.
                 * @return String | Object A copy of the module's localized resources, or a single value if key is provided.
                 */
                get : function(module, key, lang) {
                    var mod = this._mod(module),
                        strs;
            
                    lang = lang || mod[ACTIVE_LANG];
                    strs = mod[lang] || {};
            
                    return (key) ? strs[key] : Y.merge(strs);
                },
            
                /**
                 * Gets the list of languages for which localized resources are available for a given module, based on the module
                 * meta-data (part of loader). If loader is not on the page, returns an empty array.
                 *
                 * @method getAvailableLangs
                 * @param {String} module The name of the module
                 * @return {Array} The array of languages available.
                 */
                getAvailableLangs : function(module) {
                    var loader = Y.Env._loader,
                        mod = loader && loader.moduleInfo[module],
                        langs = mod && mod.lang;
                    return (langs) ? langs.concat() : NONE;
            
                }
            });
            
            Y.augment(Y.Intl, Y.EventTarget);
            
            /**
             * Notification event to indicate when the lang for a module has changed. There is no default behavior associated with this event,
             * so the on and after moments are equivalent.
             *
             * @event intl:langChange
             * @param {EventFacade} e The event facade
             * <p>The event facade contains:</p>
             * <dl>
             *     <dt>module</dt><dd>The name of the module for which the language changed</dd>
             *     <dt>newVal</dt><dd>The new language tag</dd>
             *     <dt>prevVal</dt><dd>The current language tag</dd>
             * </dl>
             */
            Y.Intl.publish("intl:langChange", {emitFacade:true});