/**
 * @author Jacky Nguyen <jacky@sencha.com>
 * @docauthor Jacky Nguyen <jacky@sencha.com>
 * @class Ext.ClassManager
 *
 * Ext.ClassManager manages all classes and handles mapping from string class name to
 * actual class objects throughout the whole framework. It is not generally accessed directly, rather through
 * these convenient shorthands:
 *
 * - {@link Ext#define Ext.define}
 * - {@link Ext#create Ext.create}
 * - {@link Ext#widget Ext.widget}
 * - {@link Ext#getClass Ext.getClass}
 * - {@link Ext#getClassName Ext.getClassName}
 *
 * # Basic syntax:
 *
 *     Ext.define(className, properties);
 *
 * in which `properties` is an object represent a collection of properties that apply to the class. See
 * {@link Ext.ClassManager#create} for more detailed instructions.
 *
 *     Ext.define('Person', {
 *          name: 'Unknown',
 *
 *          constructor: function(name) {
 *              if (name) {
 *                  this.name = name;
 *              }
 *
 *              return this;
 *          },
 *
 *          eat: function(foodType) {
 *              alert("I'm eating: " + foodType);
 *
 *              return this;
 *          }
 *     });
 *
 *     var aaron = new Person("Aaron");
 *     aaron.eat("Sandwich"); // alert("I'm eating: Sandwich");
 *
 * Ext.Class has a powerful set of extensible {@link Ext.Class#registerPreprocessor pre-processors} which takes care of
 * everything related to class creation, including but not limited to inheritance, mixins, configuration, statics, etc.
 *
 * # Inheritance:
 *
 *     Ext.define('Developer', {
 *          extend: 'Person',
 *
 *          constructor: function(name, isGeek) {
 *              this.isGeek = isGeek;
 *
 *              // Apply a method from the parent class' prototype
 *              this.callParent([name]);
 *
 *              return this;
 *
 *          },
 *
 *          code: function(language) {
 *              alert("I'm coding in: " + language);
 *
 *              this.eat("Bugs");
 *
 *              return this;
 *          }
 *     });
 *
 *     var jacky = new Developer("Jacky", true);
 *     jacky.code("JavaScript"); // alert("I'm coding in: JavaScript");
 *                               // alert("I'm eating: Bugs");
 *
 * See {@link Ext.Base#callParent} for more details on calling superclass' methods
 *
 * # Mixins:
 *
 *     Ext.define('CanPlayGuitar', {
 *          playGuitar: function() {
 *             alert("F#...G...D...A");
 *          }
 *     });
 *
 *     Ext.define('CanComposeSongs', {
 *          composeSongs: function() { ... }
 *     });
 *
 *     Ext.define('CanSing', {
 *          sing: function() {
 *              alert("I'm on the highway to hell...")
 *          }
 *     });
 *
 *     Ext.define('Musician', {
 *          extend: 'Person',
 *
 *          mixins: {
 *              canPlayGuitar: 'CanPlayGuitar',
 *              canComposeSongs: 'CanComposeSongs',
 *              canSing: 'CanSing'
 *          }
 *     })
 *
 *     Ext.define('CoolPerson', {
 *          extend: 'Person',
 *
 *          mixins: {
 *              canPlayGuitar: 'CanPlayGuitar',
 *              canSing: 'CanSing'
 *          },
 *
 *          sing: function() {
 *              alert("Ahem....");
 *
 *              this.mixins.canSing.sing.call(this);
 *
 *              alert("[Playing guitar at the same time...]");
 *
 *              this.playGuitar();
 *          }
 *     });
 *
 *     var me = new CoolPerson("Jacky");
 *
 *     me.sing(); // alert("Ahem...");
 *                // alert("I'm on the highway to hell...");
 *                // alert("[Playing guitar at the same time...]");
 *                // alert("F#...G...D...A");
 *
 * # Config:
 *
 *     Ext.define('SmartPhone', {
 *          config: {
 *              hasTouchScreen: false,
 *              operatingSystem: 'Other',
 *              price: 500
 *          },
 *
 *          isExpensive: false,
 *
 *          constructor: function(config) {
 *              this.initConfig(config);
 *
 *              return this;
 *          },
 *
 *          applyPrice: function(price) {
 *              this.isExpensive = (price > 500);
 *
 *              return price;
 *          },
 *
 *          applyOperatingSystem: function(operatingSystem) {
 *              if (!(/^(iOS|Android|BlackBerry)$/i).test(operatingSystem)) {
 *                  return 'Other';
 *              }
 *
 *              return operatingSystem;
 *          }
 *     });
 *
 *     var iPhone = new SmartPhone({
 *          hasTouchScreen: true,
 *          operatingSystem: 'iOS'
 *     });
 *
 *     iPhone.getPrice(); // 500;
 *     iPhone.getOperatingSystem(); // 'iOS'
 *     iPhone.getHasTouchScreen(); // true;
 *     iPhone.hasTouchScreen(); // true
 *
 *     iPhone.isExpensive; // false;
 *     iPhone.setPrice(600);
 *     iPhone.getPrice(); // 600
 *     iPhone.isExpensive; // true;
 *
 *     iPhone.setOperatingSystem('AlienOS');
 *     iPhone.getOperatingSystem(); // 'Other'
 *
 * # Statics:
 *
 *     Ext.define('Computer', {
 *          statics: {
 *              factory: function(brand) {
 *                 // 'this' in static methods refer to the class itself
 *                  return new this(brand);
 *              }
 *          },
 *
 *          constructor: function() { ... }
 *     });
 *
 *     var dellComputer = Computer.factory('Dell');
 *
 * Also see {@link Ext.Base#statics} and {@link Ext.Base#self} for more details on accessing
 * static properties within class methods
 *
 * @singleton
 */
(function(Class, alias) {

    var slice = Array.prototype.slice;

    var Manager = Ext.ClassManager = {

        /**
         * @property {Object} classes
         * All classes which were defined through the ClassManager. Keys are the
         * name of the classes and the values are references to the classes.
         * @private
         */
        classes: {},

        /**
         * @private
         */
        existCache: {},

        /**
         * @private
         */
        namespaceRewrites: [{
            from: 'Ext.',
            to: Ext
        }],

        /**
         * @private
         */
        maps: {
            alternateToName: {},
            aliasToName: {},
            nameToAliases: {}
        },

        /** @private */
        enableNamespaceParseCache: true,

        /** @private */
        namespaceParseCache: {},

        /** @private */
        instantiators: [],

        //<debug>
        /** @private */
        instantiationCounts: {},
        //</debug>

        /**
         * Checks if a class has already been created.
         *
         * @param {String} className
         * @return {Boolean} exist
         */
        isCreated: function(className) {
            var i, ln, part, root, parts;

            //<debug error>
            if (typeof className !== 'string' || className.length < 1) {
                Ext.Error.raise({
                    sourceClass: "Ext.ClassManager",
                    sourceMethod: "exist",
                    msg: "Invalid classname, must be a string and must not be empty"
                });
            }
            //</debug>

            if (this.classes.hasOwnProperty(className) || this.existCache.hasOwnProperty(className)) {
                return true;
            }

            root = Ext.global;
            parts = this.parseNamespace(className);

            for (i = 0, ln = parts.length; i < ln; i++) {
                part = parts[i];

                if (typeof part !== 'string') {
                    root = part;
                } else {
                    if (!root || !root[part]) {
                        return false;
                    }

                    root = root[part];
                }
            }

            Ext.Loader.historyPush(className);

            this.existCache[className] = true;

            return true;
        },

        /**
         * Supports namespace rewriting
         * @private
         */
        parseNamespace: function(namespace) {
            //<debug error>
            if (typeof namespace !== 'string') {
                Ext.Error.raise({
                    sourceClass: "Ext.ClassManager",
                    sourceMethod: "parseNamespace",
                    msg: "Invalid namespace, must be a string"
                });
            }
            //</debug>

            var cache = this.namespaceParseCache;

            if (this.enableNamespaceParseCache) {
                if (cache.hasOwnProperty(namespace)) {
                    return cache[namespace];
                }
            }

            var parts = [],
                rewrites = this.namespaceRewrites,
                rewrite, from, to, i, ln, root = Ext.global;

            for (i = 0, ln = rewrites.length; i < ln; i++) {
                rewrite = rewrites[i];
                from = rewrite.from;
                to = rewrite.to;

                if (namespace === from || namespace.substring(0, from.length) === from) {
                    namespace = namespace.substring(from.length);

                    if (typeof to !== 'string') {
                        root = to;
                    } else {
                        parts = parts.concat(to.split('.'));
                    }

                    break;
                }
            }

            parts.push(root);

            parts = parts.concat(namespace.split('.'));

            if (this.enableNamespaceParseCache) {
                cache[namespace] = parts;
            }

            return parts;
        },

        /**
         * Creates a namespace and assign the `value` to the created object
         *
         *     Ext.ClassManager.setNamespace('MyCompany.pkg.Example', someObject);
         *
         *     alert(MyCompany.pkg.Example === someObject); // alerts true
         *
         * @param {String} name
         * @param {Object} value
         */
        setNamespace: function(name, value) {
            var root = Ext.global,
                parts = this.parseNamespace(name),
                ln = parts.length - 1,
                leaf = parts[ln],
                i, part;

            for (i = 0; i < ln; i++) {
                part = parts[i];

                if (typeof part !== 'string') {
                    root = part;
                } else {
                    if (!root[part]) {
                        root[part] = {};
                    }

                    root = root[part];
                }
            }

            root[leaf] = value;

            return root[leaf];
        },

        /**
         * The new Ext.ns, supports namespace rewriting
         * @private
         */
        createNamespaces: function() {
            var root = Ext.global,
                parts, part, i, j, ln, subLn;

            for (i = 0, ln = arguments.length; i < ln; i++) {
                parts = this.parseNamespace(arguments[i]);

                for (j = 0, subLn = parts.length; j < subLn; j++) {
                    part = parts[j];

                    if (typeof part !== 'string') {
                        root = part;
                    } else {
                        if (!root[part]) {
                            root[part] = {};
                        }

                        root = root[part];
                    }
                }
            }

            return root;
        },

        /**
         * Sets a name reference to a class.
         *
         * @param {String} name
         * @param {Object} value
         * @return {Ext.ClassManager} this
         */
        set: function(name, value) {
            var targetName = this.getName(value);

            this.classes[name] = this.setNamespace(name, value);

            if (targetName && targetName !== name) {
                this.maps.alternateToName[name] = targetName;
            }

            return this;
        },

        /**
         * Retrieve a class by its name.
         *
         * @param {String} name
         * @return {Ext.Class} class
         */
        get: function(name) {
            if (this.classes.hasOwnProperty(name)) {
                return this.classes[name];
            }

            var root = Ext.global,
                parts = this.parseNamespace(name),
                part, i, ln;

            for (i = 0, ln = parts.length; i < ln; i++) {
                part = parts[i];

                if (typeof part !== 'string') {
                    root = part;
                } else {
                    if (!root || !root[part]) {
                        return null;
                    }

                    root = root[part];
                }
            }

            return root;
        },

        /**
         * Register the alias for a class.
         *
         * @param {Ext.Class/String} cls a reference to a class or a className
         * @param {String} alias Alias to use when referring to this class
         */
        setAlias: function(cls, alias) {
            var aliasToNameMap = this.maps.aliasToName,
                nameToAliasesMap = this.maps.nameToAliases,
                className;

            if (typeof cls === 'string') {
                className = cls;
            } else {
                className = this.getName(cls);
            }

            if (alias && aliasToNameMap[alias] !== className) {
                //<debug info>
                if (aliasToNameMap.hasOwnProperty(alias) && Ext.isDefined(Ext.global.console)) {
                    Ext.global.console.log("[Ext.ClassManager] Overriding existing alias: '" + alias + "' " +
                        "of: '" + aliasToNameMap[alias] + "' with: '" + className + "'. Be sure it's intentional.");
                }
                //</debug>

                aliasToNameMap[alias] = className;
            }

            if (!nameToAliasesMap[className]) {
                nameToAliasesMap[className] = [];
            }

            if (alias) {
                Ext.Array.include(nameToAliasesMap[className], alias);
            }

            return this;
        },

        /**
         * Get a reference to the class by its alias.
         *
         * @param {String} alias
         * @return {Ext.Class} class
         */
        getByAlias: function(alias) {
            return this.get(this.getNameByAlias(alias));
        },

        /**
         * Get the name of a class by its alias.
         *
         * @param {String} alias
         * @return {String} className
         */
        getNameByAlias: function(alias) {
            return this.maps.aliasToName[alias] || '';
        },

        /**
         * Get the name of a class by its alternate name.
         *
         * @param {String} alternate
         * @return {String} className
         */
        getNameByAlternate: function(alternate) {
            return this.maps.alternateToName[alternate] || '';
        },

        /**
         * Get the aliases of a class by the class name
         *
         * @param {String} name
         * @return {String[]} aliases
         */
        getAliasesByName: function(name) {
            return this.maps.nameToAliases[name] || [];
        },

        /**
         * Get the name of the class by its reference or its instance.
         *
         *     Ext.ClassManager.getName(Ext.Action); // returns "Ext.Action"
         *
         * {@link Ext#getClassName Ext.getClassName} is alias for {@link Ext.ClassManager#getName Ext.ClassManager.getName}.
         *
         * @param {Ext.Class/Object} object
         * @return {String} className
         */
        getName: function(object) {
            return object && object.$className || '';
        },

        /**
         * Get the class of the provided object; returns null if it's not an instance
         * of any class created with Ext.define.
         *
         *     var component = new Ext.Component();
         *
         *     Ext.ClassManager.getClass(component); // returns Ext.Component
         *
         * {@link Ext#getClass Ext.getClass} is alias for {@link Ext.ClassManager#getClass Ext.ClassManager.getClass}.
         *
         * @param {Object} object
         * @return {Ext.Class} class
         */
        getClass: function(object) {
            return object && object.self || null;
        },

        /**
         * Defines a class.
         *
         * {@link Ext#define Ext.define} and {@link Ext.ClassManager#create Ext.ClassManager.create} are almost aliases
         * of each other, with the only exception that Ext.define allows definition of {@link Ext.Class#override overrides}.
         * To avoid trouble, always use Ext.define.
         *
         *     Ext.define('My.awesome.Class', {
         *         someProperty: 'something',
         *         someMethod: function() { ... }
         *         ...
         *
         *     }, function() {
         *         alert('Created!');
         *         alert(this === My.awesome.Class); // alerts true
         *
         *         var myInstance = new this();
         *     });
         *
         * @param {String} className The class name to create in string dot-namespaced format, for example:
         * `My.very.awesome.Class`, `FeedViewer.plugin.CoolPager`. It is highly recommended to follow this simple convention:
         *
         * - The root and the class name are 'CamelCased'
         * - Everything else is lower-cased
         *
         * @param {Object} data The key-value pairs of properties to apply to this class. Property names can be of any valid
         * strings, except those in the reserved list below:
         *
         * - {@link Ext.Base#self self}
         * - {@link Ext.Class#alias alias}
         * - {@link Ext.Class#alternateClassName alternateClassName}
         * - {@link Ext.Class#config config}
         * - {@link Ext.Class#extend extend}
         * - {@link Ext.Class#inheritableStatics inheritableStatics}
         * - {@link Ext.Class#mixins mixins}
         * - {@link Ext.Class#override override} (only when using {@link Ext#define Ext.define})
         * - {@link Ext.Class#requires requires}
         * - {@link Ext.Class#singleton singleton}
         * - {@link Ext.Class#statics statics}
         * - {@link Ext.Class#uses uses}
         *
         * @param {Function} [createdFn] callback to execute after the class is created, the execution scope of which
         * (`this`) will be the newly created class itself.
         *
         * @return {Ext.Base}
         */
        create: function(className, data, createdFn) {
            var manager = this;

            //<debug error>
            if (typeof className !== 'string') {
                Ext.Error.raise({
                    sourceClass: "Ext",
                    sourceMethod: "define",
                    msg: "Invalid class name '" + className + "' specified, must be a non-empty string"
                });
            }
            //</debug>

            data.$className = className;

            return new Class(data, function() {
                var postprocessorStack = data.postprocessors || manager.defaultPostprocessors,
                    registeredPostprocessors = manager.postprocessors,
                    index = 0,
                    postprocessors = [],
                    postprocessor, process, i, ln;

                delete data.postprocessors;

                for (i = 0, ln = postprocessorStack.length; i < ln; i++) {
                    postprocessor = postprocessorStack[i];

                    if (typeof postprocessor === 'string') {
                        postprocessor = registeredPostprocessors[postprocessor];

                        if (!postprocessor.always) {
                            if (data[postprocessor.name] !== undefined) {
                                postprocessors.push(postprocessor.fn);
                            }
                        }
                        else {
                            postprocessors.push(postprocessor.fn);
                        }
                    }
                    else {
                        postprocessors.push(postprocessor);
                    }
                }

                process = function(clsName, cls, clsData) {
                    postprocessor = postprocessors[index++];

                    if (!postprocessor) {
                        manager.set(className, cls);

                        Ext.Loader.historyPush(className);

                        if (createdFn) {
                            createdFn.call(cls, cls);
                        }

                        return;
                    }

                    if (postprocessor.call(this, clsName, cls, clsData, process) !== false) {
                        process.apply(this, arguments);
                    }
                };

                process.call(manager, className, this, data);
            });
        },

        /**
         * Instantiate a class by its alias.
         *
         * If {@link Ext.Loader} is {@link Ext.Loader#setConfig enabled} and the class has not been defined yet, it will
         * attempt to load the class via synchronous loading.
         *
         *     var window = Ext.ClassManager.instantiateByAlias('widget.window', { width: 600, height: 800, ... });
         *
         * {@link Ext#createByAlias Ext.createByAlias} is alias for {@link Ext.ClassManager#instantiateByAlias Ext.ClassManager.instantiateByAlias}.
         *
         * @param {String} alias
         * @param {Object...} args Additional arguments after the alias will be passed to the
         * class constructor.
         * @return {Object} instance
         */
        instantiateByAlias: function() {
            var alias = arguments[0],
                args = slice.call(arguments),
                className = this.getNameByAlias(alias);

            if (!className) {
                className = this.maps.aliasToName[alias];

                //<debug error>
                if (!className) {
                    Ext.Error.raise({
                        sourceClass: "Ext",
                        sourceMethod: "createByAlias",
                        msg: "Cannot create an instance of unrecognized alias: " + alias
                    });
                }
                //</debug>

                //<debug warn>
                if (Ext.global.console) {
                    Ext.global.console.warn("[Ext.Loader] Synchronously loading '" + className + "'; consider adding " +
                         "Ext.require('" + alias + "') above Ext.onReady");
                }
                //</debug>

                Ext.syncRequire(className);
            }

            args[0] = className;

            return this.instantiate.apply(this, args);
        },

        /**
         * Instantiate a class by either full name, alias or alternate name.
         *
         * If {@link Ext.Loader} is {@link Ext.Loader#setConfig enabled} and the class has not been defined yet, it will
         * attempt to load the class via synchronous loading.
         *
         * For example, all these three lines return the same result:
         *
         *     // alias
         *     var window = Ext.ClassManager.instantiate('widget.window', { width: 600, height: 800, ... });
         *
         *     // alternate name
         *     var window = Ext.ClassManager.instantiate('Ext.Window', { width: 600, height: 800, ... });
         *
         *     // full class name
         *     var window = Ext.ClassManager.instantiate('Ext.window.Window', { width: 600, height: 800, ... });
         *
         * {@link Ext#create Ext.create} is alias for {@link Ext.ClassManager#instantiate Ext.ClassManager.instantiate}.
         *
         * @param {String} name
         * @param {Object...} args Additional arguments after the name will be passed to the class' constructor.
         * @return {Object} instance
         */
        instantiate: function() {
            var name = arguments[0],
                args = slice.call(arguments, 1),
                alias = name,
                possibleName, cls;

            if (typeof name !== 'function') {
                //<debug error>
                if ((typeof name !== 'string' || name.length < 1)) {
                    Ext.Error.raise({
                        sourceClass: "Ext",
                        sourceMethod: "create",
                        msg: "Invalid class name or alias '" + name + "' specified, must be a non-empty string"
                    });
                }
                //</debug>

                cls = this.get(name);
            }
            else {
                cls = name;
            }

            // No record of this class name, it's possibly an alias, so look it up
            if (!cls) {
                possibleName = this.getNameByAlias(name);

                if (possibleName) {
                    name = possibleName;

                    cls = this.get(name);
                }
            }

            // Still no record of this class name, it's possibly an alternate name, so look it up
            if (!cls) {
                possibleName = this.getNameByAlternate(name);

                if (possibleName) {
                    name = possibleName;

                    cls = this.get(name);
                }
            }

            // Still not existing at this point, try to load it via synchronous mode as the last resort
            if (!cls) {
                //<debug warn>
                if (Ext.global.console) {
                    Ext.global.console.warn("[Ext.Loader] Synchronously loading '" + name + "'; consider adding " +
                         "Ext.require('" + ((possibleName) ? alias : name) + "') above Ext.onReady");
                }
                //</debug>

                Ext.syncRequire(name);

                cls = this.get(name);
            }

            //<debug error>
            if (!cls) {
                Ext.Error.raise({
                    sourceClass: "Ext",
                    sourceMethod: "create",
                    msg: "Cannot create an instance of unrecognized class name / alias: " + alias
                });
            }

            if (typeof cls !== 'function') {
                Ext.Error.raise({
                    sourceClass: "Ext",
                    sourceMethod: "create",
                    msg: "'" + name + "' is a singleton and cannot be instantiated"
                });
            }
            //</debug>

            //<debug>
            if (!this.instantiationCounts[name]) {
                this.instantiationCounts[name] = 0;
            }

            this.instantiationCounts[name]++;
            //</debug>

            return this.getInstantiator(args.length)(cls, args);
        },

        /**
         * @private
         * @param name
         * @param args
         */
        dynInstantiate: function(name, args) {
            args = Ext.Array.from(args, true);
            args.unshift(name);

            return this.instantiate.apply(this, args);
        },

        /**
         * @private
         * @param length
         */
        getInstantiator: function(length) {
            if (!this.instantiators[length]) {
                var i = length,
                    args = [];

                for (i = 0; i < length; i++) {
                    args.push('a['+i+']');
                }

                this.instantiators[length] = new Function('c', 'a', 'return new c('+args.join(',')+')');
            }

            return this.instantiators[length];
        },

        /**
         * @private
         */
        postprocessors: {},

        /**
         * @private
         */
        defaultPostprocessors: [],

        /**
         * Register a post-processor function.
         *
         * @param {String} name
         * @param {Function} postprocessor
         */
        registerPostprocessor: function(name, fn, always) {
            this.postprocessors[name] = {
                name: name,
                always: always ||  false,
                fn: fn
            };

            return this;
        },

        /**
         * Set the default post processors array stack which are applied to every class.
         *
         * @param {String/String[]} The name of a registered post processor or an array of registered names.
         * @return {Ext.ClassManager} this
         */
        setDefaultPostprocessors: function(postprocessors) {
            this.defaultPostprocessors = Ext.Array.from(postprocessors);

            return this;
        },

        /**
         * Insert this post-processor at a specific position in the stack, optionally relative to
         * any existing post-processor
         *
         * @param {String} name The post-processor name. Note that it needs to be registered with
         * {@link Ext.ClassManager#registerPostprocessor} before this
         * @param {String} offset The insertion position. Four possible values are:
         * 'first', 'last', or: 'before', 'after' (relative to the name provided in the third argument)
         * @param {String} relativeName
         * @return {Ext.ClassManager} this
         */
        setDefaultPostprocessorPosition: function(name, offset, relativeName) {
            var defaultPostprocessors = this.defaultPostprocessors,
                index;

            if (typeof offset === 'string') {
                if (offset === 'first') {
                    defaultPostprocessors.unshift(name);

                    return this;
                }
                else if (offset === 'last') {
                    defaultPostprocessors.push(name);

                    return this;
                }

                offset = (offset === 'after') ? 1 : -1;
            }

            index = Ext.Array.indexOf(defaultPostprocessors, relativeName);

            if (index !== -1) {
                Ext.Array.splice(defaultPostprocessors, Math.max(0, index + offset), 0, name);
            }

            return this;
        },

        /**
         * Converts a string expression to an array of matching class names. An expression can either refers to class aliases
         * or class names. Expressions support wildcards:
         *
         *     // returns ['Ext.window.Window']
         *     var window = Ext.ClassManager.getNamesByExpression('widget.window');
         *
         *     // returns ['widget.panel', 'widget.window', ...]
         *     var allWidgets = Ext.ClassManager.getNamesByExpression('widget.*');
         *
         *     // returns ['Ext.data.Store', 'Ext.data.ArrayProxy', ...]
         *     var allData = Ext.ClassManager.getNamesByExpression('Ext.data.*');
         *
         * @param {String} expression
         * @return {String[]} classNames
         */
        getNamesByExpression: function(expression) {
            var nameToAliasesMap = this.maps.nameToAliases,
                names = [],
                name, alias, aliases, possibleName, regex, i, ln;

            //<debug error>
            if (typeof expression !== 'string' || expression.length < 1) {
                Ext.Error.raise({
                    sourceClass: "Ext.ClassManager",
                    sourceMethod: "getNamesByExpression",
                    msg: "Expression " + expression + " is invalid, must be a non-empty string"
                });
            }
            //</debug>

            if (expression.indexOf('*') !== -1) {
                expression = expression.replace(/\*/g, '(.*?)');
                regex = new RegExp('^' + expression + '$');

                for (name in nameToAliasesMap) {
                    if (nameToAliasesMap.hasOwnProperty(name)) {
                        aliases = nameToAliasesMap[name];

                        if (name.search(regex) !== -1) {
                            names.push(name);
                        }
                        else {
                            for (i = 0, ln = aliases.length; i < ln; i++) {
                                alias = aliases[i];

                                if (alias.search(regex) !== -1) {
                                    names.push(name);
                                    break;
                                }
                            }
                        }
                    }
                }

            } else {
                possibleName = this.getNameByAlias(expression);

                if (possibleName) {
                    names.push(possibleName);
                } else {
                    possibleName = this.getNameByAlternate(expression);

                    if (possibleName) {
                        names.push(possibleName);
                    } else {
                        names.push(expression);
                    }
                }
            }

            return names;
        }
    };

    var defaultPostprocessors = Manager.defaultPostprocessors;
    //<feature classSystem.alias>

    /**
     * @cfg {String[]} alias
     * @member Ext.Class
     * List of short aliases for class names.  Most useful for defining xtypes for widgets:
     *
     *     Ext.define('MyApp.CoolPanel', {
     *         extend: 'Ext.panel.Panel',
     *         alias: ['widget.coolpanel'],
     *         title: 'Yeah!'
     *     });
     *
     *     // Using Ext.create
     *     Ext.widget('widget.coolpanel');
     *     // Using the shorthand for widgets and in xtypes
     *     Ext.widget('panel', {
     *         items: [
     *             {xtype: 'coolpanel', html: 'Foo'},
     *             {xtype: 'coolpanel', html: 'Bar'}
     *         ]
     *     });
     */
    Manager.registerPostprocessor('alias', function(name, cls, data) {
        var aliases = data.alias,
            i, ln;

        delete data.alias;

        for (i = 0, ln = aliases.length; i < ln; i++) {
            alias = aliases[i];

            this.setAlias(cls, alias);
        }
    });

    /**
     * @cfg {Boolean} singleton
     * @member Ext.Class
     * When set to true, the class will be instantiated as singleton.  For example:
     *
     *     Ext.define('Logger', {
     *         singleton: true,
     *         log: function(msg) {
     *             console.log(msg);
     *         }
     *     });
     *
     *     Logger.log('Hello');
     */
    Manager.registerPostprocessor('singleton', function(name, cls, data, fn) {
        fn.call(this, name, new cls(), data);
        return false;
    });

    /**
     * @cfg {String/String[]} alternateClassName
     * @member Ext.Class
     * Defines alternate names for this class.  For example:
     *
     *     Ext.define('Developer', {
     *         alternateClassName: ['Coder', 'Hacker'],
     *         code: function(msg) {
     *             alert('Typing... ' + msg);
     *         }
     *     });
     *
     *     var joe = Ext.create('Developer');
     *     joe.code('stackoverflow');
     *
     *     var rms = Ext.create('Hacker');
     *     rms.code('hack hack');
     */
    Manager.registerPostprocessor('alternateClassName', function(name, cls, data) {
        var alternates = data.alternateClassName,
            i, ln, alternate;

        if (!(alternates instanceof Array)) {
            alternates = [alternates];
        }

        for (i = 0, ln = alternates.length; i < ln; i++) {
            alternate = alternates[i];

            //<debug error>
            if (typeof alternate !== 'string') {
                Ext.Error.raise({
                    sourceClass: "Ext",
                    sourceMethod: "define",
                    msg: "Invalid alternate of: '" + alternate + "' for class: '" + name + "'; must be a valid string"
                });
            }
            //</debug>

            this.set(alternate, cls);
        }
    });

    Manager.setDefaultPostprocessors(['alias', 'singleton', 'alternateClassName']);

    Ext.apply(Ext, {
        /**
         * @method
         * @member Ext
         * @alias Ext.ClassManager#instantiate
         */
        create: alias(Manager, 'instantiate'),

        /**
         * @private
         * API to be stablized
         *
         * @param {Object} item
         * @param {String} namespace
         */
        factory: function(item, namespace) {
            if (item instanceof Array) {
                var i, ln;

                for (i = 0, ln = item.length; i < ln; i++) {
                    item[i] = Ext.factory(item[i], namespace);
                }

                return item;
            }

            var isString = (typeof item === 'string');

            if (isString || (item instanceof Object && item.constructor === Object)) {
                var name, config = {};

                if (isString) {
                    name = item;
                }
                else {
                    name = item.className;
                    config = item;
                    delete config.className;
                }

                if (namespace !== undefined && name.indexOf(namespace) === -1) {
                    name = namespace + '.' + Ext.String.capitalize(name);
                }

                return Ext.create(name, config);
            }

            if (typeof item === 'function') {
                return Ext.create(item);
            }

            return item;
        },

        /**
         * Convenient shorthand to create a widget by its xtype, also see {@link Ext.ClassManager#instantiateByAlias}
         *
         *     var button = Ext.widget('button'); // Equivalent to Ext.create('widget.button')
         *     var panel = Ext.widget('panel'); // Equivalent to Ext.create('widget.panel')
         *
         * @method
         * @member Ext
         * @param {String} name  xtype of the widget to create.
         * @param {Object...} args  arguments for the widget constructor.
         * @return {Object} widget instance
         */
        widget: function(name) {
            var args = slice.call(arguments);
            args[0] = 'widget.' + name;

            return Manager.instantiateByAlias.apply(Manager, args);
        },

        /**
         * @method
         * @member Ext
         * @alias Ext.ClassManager#instantiateByAlias
         */
        createByAlias: alias(Manager, 'instantiateByAlias'),

        /**
         * @cfg {String} override
         * @member Ext.Class
         * 
         * Defines an override applied to a class. Note that **overrides can only be created using
         * {@link Ext#define}.** {@link Ext.ClassManager#create} only creates classes.
         * 
         * To define an override, include the override property. The content of an override is
         * aggregated with the specified class in order to extend or modify that class. This can be
         * as simple as setting default property values or it can extend and/or replace methods.
         * This can also extend the statics of the class.
         *
         * One use for an override is to break a large class into manageable pieces.
         *
         *      // File: /src/app/Panel.js
         *
         *      Ext.define('My.app.Panel', {
         *          extend: 'Ext.panel.Panel',
         *          requires: [
         *              'My.app.PanelPart2',
         *              'My.app.PanelPart3'
         *          ]
         *
         *          constructor: function (config) {
         *              this.callSuper(arguments); // calls Ext.panel.Panel's constructor
         *              //...
         *          },
         *
         *          statics: {
         *              method: function () {
         *                  return 'abc';
         *              }
         *          }
         *      });
         *
         *      // File: /src/app/PanelPart2.js
         *      Ext.define('My.app.PanelPart2', {
         *          override: 'My.app.Panel',
         *
         *          constructor: function (config) {
         *              this.callSuper(arguments); // calls My.app.Panel's constructor
         *              //...
         *          }
         *      });
         *
         * Another use of overrides is to provide optional parts of classes that can be
         * independently required. In this case, the class may even be unaware of the
         * override altogether.
         *
         *      Ext.define('My.ux.CoolTip', {
         *          override: 'Ext.tip.ToolTip',
         *
         *          constructor: function (config) {
         *              this.callSuper(arguments); // calls Ext.tip.ToolTip's constructor
         *              //...
         *          }
         *      });
         *
         * The above override can now be required as normal.
         *
         *      Ext.define('My.app.App', {
         *          requires: [
         *              'My.ux.CoolTip'
         *          ]
         *      });
         *
         * Overrides can also contain statics:
         *
         *      Ext.define('My.app.BarMod', {
         *          override: 'Ext.foo.Bar',
         *
         *          statics: {
         *              method: function (x) {
         *                  return this.callSuper([x * 2]); // call Ext.foo.Bar.method
         *              }
         *          }
         *      });
         *
         * IMPORTANT: An override is only included in a build if the class it overrides is
         * required. Otherwise, the override, like the target class, is not included.
         */
        
        /**
         * @method
         *
         * @member Ext
         * @alias Ext.ClassManager#create
         */
        define: function (className, data, createdFn) {
            if (!data.override) {
                return Manager.create.apply(Manager, arguments);
            }

            var requires = data.requires,
                uses = data.uses,
                overrideName = className;

            className = data.override;

            // hoist any 'requires' or 'uses' from the body onto the faux class:
            data = Ext.apply({}, data);
            delete data.requires;
            delete data.uses;
            delete data.override;

            // make sure className is in the requires list:
            if (typeof requires == 'string') {
                requires = [ className, requires ];
            } else if (requires) {
                requires = requires.slice(0);
                requires.unshift(className);
            } else {
                requires = [ className ];
            }

// TODO - we need to rework this to allow the override to not require the target class
//  and rather 'wait' for it in such a way that if the target class is not in the build,
//  neither are any of its overrides.
//
//  Also, this should process the overrides for a class ASAP (ideally before any derived
//  classes) if the target class 'requires' the overrides. Without some special handling, the
//  overrides so required will be processed before the class and have to be bufferred even
//  in a build.
//
// TODO - we should probably support the "config" processor on an override (to config new
//  functionaliy like Aria) and maybe inheritableStatics (although static is now supported
//  by callSuper). If inheritableStatics causes those statics to be included on derived class
//  constructors, that probably means "no" to this since an override can come after other
//  classes extend the target.
            return Manager.create(overrideName, {
                    requires: requires,
                    uses: uses,
                    isPartial: true,
                    constructor: function () {
                        //<debug error>
                        throw new Error("Cannot create override '" + overrideName + "'");
                        //</debug>
                    }
                }, function () {
                    var cls = Manager.get(className);
                    if (cls.override) { // if (normal class)
                        cls.override(data);
                    } else { // else (singleton)
                        cls.self.override(data);
                    }

                    if (createdFn) {
                        // called once the override is applied and with the context of the
                        // overridden class (the override itself is a meaningless, name-only
                        // thing).
                        createdFn.call(cls);
                    }
                });
        },

        /**
         * @method
         * @member Ext
         * @alias Ext.ClassManager#getName
         */
        getClassName: alias(Manager, 'getName'),

        /**
         * Returns the displayName property or className or object.
         * When all else fails, returns "Anonymous".
         * @param {Object} object
         * @return {String}
         */
        getDisplayName: function(object) {
            if (object.displayName) {
                return object.displayName;
            }

            if (object.$name && object.$class) {
                return Ext.getClassName(object.$class) + '#' + object.$name;
            }

            if (object.$className) {
                return object.$className;
            }

            return 'Anonymous';
        },

        /**
         * @method
         * @member Ext
         * @alias Ext.ClassManager#getClass
         */
        getClass: alias(Manager, 'getClass'),

        /**
         * Creates namespaces to be used for scoping variables and classes so that they are not global.
         * Specifying the last node of a namespace implicitly creates all other nodes. Usage:
         *
         *     Ext.namespace('Company', 'Company.data');
         *
         *     // equivalent and preferable to the above syntax
         *     Ext.namespace('Company.data');
         *
         *     Company.Widget = function() { ... };
         *
         *     Company.data.CustomStore = function(config) { ... };
         *
         * @method
         * @member Ext
         * @param {String} namespace1
         * @param {String} namespace2
         * @param {String} etc
         * @return {Object} The namespace object. (If multiple arguments are passed, this will be the last namespace created)
         */
        namespace: alias(Manager, 'createNamespaces')
    });

    /**
     * Old name for {@link Ext#widget}.
     * @deprecated 4.0.0 Use {@link Ext#widget} instead.
     * @method
     * @member Ext
     * @alias Ext#widget
     */
    Ext.createWidget = Ext.widget;

    /**
     * Convenient alias for {@link Ext#namespace Ext.namespace}
     * @method
     * @member Ext
     * @alias Ext#namespace
     */
    Ext.ns = Ext.namespace;

    Class.registerPreprocessor('className', function(cls, data) {
        if (data.$className) {
            cls.$className = data.$className;
            //<debug>
            cls.displayName = cls.$className;
            //</debug>
        }
    }, true);

    Class.setDefaultPreprocessorPosition('className', 'first');

    Class.registerPreprocessor('xtype', function(cls, data) {
        var xtypes = Ext.Array.from(data.xtype),
            widgetPrefix = 'widget.',
            aliases = Ext.Array.from(data.alias),
            i, ln, xtype;

        data.xtype = xtypes[0];
        data.xtypes = xtypes;

        aliases = data.alias = Ext.Array.from(data.alias);

        for (i = 0,ln = xtypes.length; i < ln; i++) {
            xtype = xtypes[i];

            //<debug error>
            if (typeof xtype != 'string' || xtype.length < 1) {
                throw new Error("[Ext.define] Invalid xtype of: '" + xtype + "' for class: '" + name + "'; must be a valid non-empty string");
            }
            //</debug>

            aliases.push(widgetPrefix + xtype);
        }

        data.alias = aliases;
    });

    Class.setDefaultPreprocessorPosition('xtype', 'last');

    Class.registerPreprocessor('alias', function(cls, data) {
        var aliases = Ext.Array.from(data.alias),
            xtypes = Ext.Array.from(data.xtypes),
            widgetPrefix = 'widget.',
            widgetPrefixLength = widgetPrefix.length,
            i, ln, alias, xtype;

        for (i = 0, ln = aliases.length; i < ln; i++) {
            alias = aliases[i];

            //<debug error>
            if (typeof alias != 'string') {
                throw new Error("[Ext.define] Invalid alias of: '" + alias + "' for class: '" + name + "'; must be a valid string");
            }
            //</debug>

            if (alias.substring(0, widgetPrefixLength) === widgetPrefix) {
                xtype = alias.substring(widgetPrefixLength);
                Ext.Array.include(xtypes, xtype);

                if (!cls.xtype) {
                    cls.xtype = data.xtype = xtype;
                }
            }
        }

        data.alias = aliases;
        data.xtypes = xtypes;
    });

    Class.setDefaultPreprocessorPosition('alias', 'last');

})(Ext.Class, Ext.Function.alias);