Version 3.18.1
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File: base/js/BaseCore.js

                /**
                 * The base module provides the Base class, which objects requiring attribute and custom event support can extend.
                 * The module also provides two ways to reuse code - It augments Base with the Plugin.Host interface which provides
                 * plugin support and also provides the BaseCore.build method which provides a way to build custom classes using extensions.
                 *
                 * @module base
                 */
            
                /**
                 * <p>The base-core module provides the BaseCore class, the lightest version of Base,
                 * which provides Base's basic lifecycle management and ATTRS construction support,
                 * but doesn't fire init/destroy or attribute change events.</p>
                 *
                 * <p>It mixes in AttributeCore, which is the lightest version of Attribute</p>
                 *
                 * @module base
                 * @submodule base-core
                 */
                var O = Y.Object,
                    L = Y.Lang,
                    DOT = ".",
                    INITIALIZED = "initialized",
                    DESTROYED = "destroyed",
                    INITIALIZER = "initializer",
                    VALUE = "value",
                    OBJECT_CONSTRUCTOR = Object.prototype.constructor,
                    DEEP = "deep",
                    SHALLOW = "shallow",
                    DESTRUCTOR = "destructor",
            
                    AttributeCore = Y.AttributeCore,
            
                    _wlmix = function(r, s, wlhash) {
                        var p;
                        for (p in s) {
                            if(wlhash[p]) {
                                r[p] = s[p];
                            }
                        }
                        return r;
                    };
            
                /**
                 * The BaseCore class, is the lightest version of Base, and provides Base's
                 * basic lifecycle management and ATTRS construction support, but doesn't
                 * fire init/destroy or attribute change events.
                 *
                 * BaseCore also handles the chaining of initializer and destructor methods across
                 * the hierarchy as part of object construction and destruction. Additionally, attributes
                 * configured through the static <a href="#property_BaseCore.ATTRS">ATTRS</a>
                 * property for each class in the hierarchy will be initialized by BaseCore.
                 *
                 * Classes which require attribute support, but don't intend to use/expose attribute
                 * change events can extend BaseCore instead of Base for optimal kweight and
                 * runtime performance.
                 *
                 * **3.11.0 BACK COMPAT NOTE FOR COMPONENT DEVELOPERS**
                 *
                 * Prior to version 3.11.0, ATTRS would get added a class at a time. That is:
                 *
                 * <pre>
                 *    for each (class in the hierarchy) {
                 *       Call the class Extension constructors.
                 *
                 *       Add the class ATTRS.
                 *
                 *       Call the class initializer
                 *       Call the class Extension initializers.
                 *    }
                 * </pre>
                 *
                 * As of 3.11.0, ATTRS from all classes in the hierarchy are added in one `addAttrs` call
                 * before **any** initializers are called. That is, the flow becomes:
                 *
                 * <pre>
                 *    for each (class in the hierarchy) {
                 *       Call the class Extension constructors.
                 *    }
                 *
                 *    Add ATTRS for all classes
                 *
                 *    for each (class in the hierarchy) {
                 *       Call the class initializer.
                 *       Call the class Extension initializers.
                 *    }
                 * </pre>
                 *
                 * Adding all ATTRS at once fixes subtle edge-case issues with subclass ATTRS overriding
                 * superclass `setter`, `getter` or `valueFn` definitions and being unable to get/set attributes
                 * defined by the subclass. It also leaves us with a cleaner order of operation flow moving
                 * forward.
                 *
                 * However, it may require component developers to upgrade their components, for the following
                 * scenarios:
                 *
                 * 1. It impacts components which may have `setter`, `getter` or `valueFn` code which
                 * expects a superclass' initializer to have run.
                 *
                 * This is expected to be rare, but to support it, Base now supports a `_preAddAttrs()`, method
                 * hook (same signature as `addAttrs`). Components can implement this method on their prototype
                 * for edge cases which do require finer control over the order in which attributes are added
                 * (see widget-htmlparser for example).
                 *
                 * 2. Extension developers may need to move code from Extension constructors to `initializer`s
                 *
                 * Older extensions, which were written before `initializer` support was added, had a lot of
                 * initialization code in their constructors. For example, code which acccessed superclass
                 * attributes. With the new flow this code would not be able to see attributes. The recommendation
                 * is to move this initialization code to an `initializer` on the Extension, which was the
                 * recommendation for anything created after `initializer` support for Extensions was added.
                 *
                 * @class BaseCore
                 * @constructor
                 * @uses AttributeCore
                 * @param {Object} cfg Object with configuration property name/value pairs.
                 * The object can be used to provide initial values for the objects published
                 * attributes.
                 */
                function BaseCore(cfg) {
                    if (!this._BaseInvoked) {
                        this._BaseInvoked = true;
            
                        Y.log('constructor called', 'life', 'base');
                        this._initBase(cfg);
                    }
                    else { Y.log('Based constructor called more than once. Ignoring duplicate calls', 'life', 'base'); }
                }
            
                /**
                 * The list of properties which can be configured for each attribute
                 * (e.g. setter, getter, writeOnce, readOnly etc.)
                 *
                 * @property _ATTR_CFG
                 * @type Array
                 * @static
                 * @private
                 */
                BaseCore._ATTR_CFG = AttributeCore._ATTR_CFG.concat("cloneDefaultValue");
            
                /**
                 * The array of non-attribute configuration properties supported by this class.
                 *
                 * For example `BaseCore` defines a "plugins" configuration property which
                 * should not be set up as an attribute. This property is primarily required so
                 * that when <a href="#property__allowAdHocAttrs">`_allowAdHocAttrs`</a> is enabled by a class,
                 * non-attribute configuration properties don't get added as ad-hoc attributes.
                 *
                 * @property _NON_ATTRS_CFG
                 * @type Array
                 * @static
                 * @private
                 */
                BaseCore._NON_ATTRS_CFG = ["plugins"];
            
                /**
                 * This property controls whether or not instances of this class should
                 * allow users to add ad-hoc attributes through the constructor configuration
                 * hash.
                 *
                 * AdHoc attributes are attributes which are not defined by the class, and are
                 * not handled by the MyClass._NON_ATTRS_CFG
                 *
                 * @property _allowAdHocAttrs
                 * @type boolean
                 * @default undefined (false)
                 * @protected
                 */
            
                /**
                 * The string to be used to identify instances of this class.
                 *
                 * Classes extending BaseCore, should define their own
                 * static NAME property, which should be camelCase by
                 * convention (e.g. MyClass.NAME = "myClass";).
                 *
                 * @property NAME
                 * @type String
                 * @static
                 */
                BaseCore.NAME = "baseCore";
            
                /**
                 * The default set of attributes which will be available for instances of this class, and
                 * their configuration. In addition to the configuration properties listed by
                 * AttributeCore's <a href="AttributeCore.html#method_addAttr">addAttr</a> method,
                 * the attribute can also be configured with a "cloneDefaultValue" property, which
                 * defines how the statically defined value field should be protected
                 * ("shallow", "deep" and false are supported values).
                 *
                 * By default if the value is an object literal or an array it will be "shallow"
                 * cloned, to protect the default value.
                 *
                 * @property ATTRS
                 * @type Object
                 * @static
                 */
                BaseCore.ATTRS = {
                    /**
                     * Flag indicating whether or not this object
                     * has been through the init lifecycle phase.
                     *
                     * @attribute initialized
                     * @readonly
                     * @default false
                     * @type boolean
                     */
                    initialized: {
                        readOnly:true,
                        value:false
                    },
            
                    /**
                     * Flag indicating whether or not this object
                     * has been through the destroy lifecycle phase.
                     *
                     * @attribute destroyed
                     * @readonly
                     * @default false
                     * @type boolean
                     */
                    destroyed: {
                        readOnly:true,
                        value:false
                    }
                };
            
                /**
                Provides a way to safely modify a `Y.BaseCore` subclass' static `ATTRS`
                after the class has been defined or created.
            
                BaseCore-based classes cache information about the class hierarchy in order
                to efficiently create instances. This cache includes includes the aggregated
                `ATTRS` configs. If the static `ATTRS` configs need to be modified after the
                class has been defined or create, then use this method which will make sure
                to clear any cached data before making any modifications.
            
                @method modifyAttrs
                @param {Function} [ctor] The constructor function whose `ATTRS` should be
                    modified. If a `ctor` function is not specified, then `this` is assumed
                    to be the constructor which hosts the `ATTRS`.
                @param {Object} configs The collection of `ATTRS` configs to mix with the
                    existing attribute configurations.
                @static
                @since 3.10.0
                **/
                BaseCore.modifyAttrs = function (ctor, configs) {
                    // When called without a constructor, assume `this` is the constructor.
                    if (typeof ctor !== 'function') {
                        configs = ctor;
                        ctor    = this;
                    }
            
                    var attrs, attr, name;
            
                    // Eagerly create the `ATTRS` object if it doesn't already exist.
                    attrs = ctor.ATTRS || (ctor.ATTRS = {});
            
                    if (configs) {
                        // Clear cache because it has ATTRS aggregation data which is about
                        // to be modified.
                        ctor._CACHED_CLASS_DATA = null;
            
                        for (name in configs) {
                            if (configs.hasOwnProperty(name)) {
                                attr = attrs[name] || (attrs[name] = {});
                                Y.mix(attr, configs[name], true);
                            }
                        }
                    }
                };
            
                BaseCore.prototype = {
            
                    /**
                     * Internal construction logic for BaseCore.
                     *
                     * @method _initBase
                     * @param {Object} config The constructor configuration object
                     * @private
                     */
                    _initBase : function(config) {
                        Y.log('init called', 'life', 'base');
            
                        Y.stamp(this);
            
                        this._initAttribute(config);
            
                        // If Plugin.Host has been augmented [ through base-pluginhost ], setup it's
                        // initial state, but don't initialize Plugins yet. That's done after initialization.
                        var PluginHost = Y.Plugin && Y.Plugin.Host;
                        if (this._initPlugins && PluginHost) {
                            PluginHost.call(this);
                        }
            
                        if (this._lazyAddAttrs !== false) { this._lazyAddAttrs = true; }
            
                        /**
                         * The string used to identify the class of this object.
                         *
                         * @deprecated Use this.constructor.NAME
                         * @property name
                         * @type String
                         */
                        this.name = this.constructor.NAME;
            
                        this.init.apply(this, arguments);
                    },
            
                    /**
                     * Initializes AttributeCore
                     *
                     * @method _initAttribute
                     * @private
                     */
                    _initAttribute: function() {
                        AttributeCore.call(this);
                    },
            
                    /**
                     * Init lifecycle method, invoked during construction. Sets up attributes
                     * and invokes initializers for the class hierarchy.
                     *
                     * @method init
                     * @chainable
                     * @param {Object} cfg Object with configuration property name/value pairs
                     * @return {BaseCore} A reference to this object
                     */
                    init: function(cfg) {
                        Y.log('init called', 'life', 'base');
            
                        this._baseInit(cfg);
            
                        return this;
                    },
            
                    /**
                     * Internal initialization implementation for BaseCore
                     *
                     * @method _baseInit
                     * @private
                     */
                    _baseInit: function(cfg) {
                        this._initHierarchy(cfg);
            
                        if (this._initPlugins) {
                            // Need to initPlugins manually, to handle constructor parsing, static Plug parsing
                            this._initPlugins(cfg);
                        }
                        this._set(INITIALIZED, true);
                    },
            
                    /**
                     * Destroy lifecycle method. Invokes destructors for the class hierarchy.
                     *
                     * @method destroy
                     * @return {BaseCore} A reference to this object
                     * @chainable
                     */
                    destroy: function() {
                        this._baseDestroy();
                        return this;
                    },
            
                    /**
                     * Internal destroy implementation for BaseCore
                     *
                     * @method _baseDestroy
                     * @private
                     */
                    _baseDestroy : function() {
                        if (this._destroyPlugins) {
                            this._destroyPlugins();
                        }
                        this._destroyHierarchy();
                        this._set(DESTROYED, true);
                    },
            
                    /**
                     * Returns the class hierarchy for this object, with BaseCore being the last class in the array.
                     *
                     * @method _getClasses
                     * @protected
                     * @return {Function[]} An array of classes (constructor functions), making up the class hierarchy for this object.
                     * This value is cached the first time the method, or _getAttrCfgs, is invoked. Subsequent invocations return the
                     * cached value.
                     */
                    _getClasses : function() {
                        if (!this._classes) {
                            this._initHierarchyData();
                        }
                        return this._classes;
                    },
            
                    /**
                     * Returns an aggregated set of attribute configurations, by traversing
                     * the class hierarchy.
                     *
                     * @method _getAttrCfgs
                     * @protected
                     * @return {Object} The hash of attribute configurations, aggregated across classes in the hierarchy
                     * This value is cached the first time the method, or _getClasses, is invoked. Subsequent invocations return
                     * the cached value.
                     */
                    _getAttrCfgs : function() {
                        if (!this._attrs) {
                            this._initHierarchyData();
                        }
                        return this._attrs;
                    },
            
                    /**
                     * A helper method used to isolate the attrs config for this instance to pass to `addAttrs`,
                     * from the static cached ATTRS for the class.
                     *
                     * @method _getInstanceAttrCfgs
                     * @private
                     *
                     * @param {Object} allCfgs The set of all attribute configurations for this instance.
                     * Attributes will be removed from this set, if they belong to the filtered class, so
                     * that by the time all classes are processed, allCfgs will be empty.
                     *
                     * @return {Object} The set of attributes to be added for this instance, suitable
                     * for passing through to `addAttrs`.
                     */
                    _getInstanceAttrCfgs : function(allCfgs) {
            
                        var cfgs = {},
                            cfg,
                            val,
                            subAttr,
                            subAttrs,
                            subAttrPath,
                            attr,
                            attrCfg,
                            allSubAttrs = allCfgs._subAttrs,
                            attrCfgProperties = this._attrCfgHash();
            
                        for (attr in allCfgs) {
            
                            if (allCfgs.hasOwnProperty(attr) && attr !== "_subAttrs") {
            
                                attrCfg = allCfgs[attr];
            
                                // Need to isolate from allCfgs, because we're going to set values etc.
                                cfg = cfgs[attr] = _wlmix({}, attrCfg, attrCfgProperties);
            
                                val = cfg.value;
            
                                if (val && (typeof val === "object")) {
                                    this._cloneDefaultValue(attr, cfg);
                                }
            
                                if (allSubAttrs && allSubAttrs.hasOwnProperty(attr)) {
                                    subAttrs = allCfgs._subAttrs[attr];
            
                                    for (subAttrPath in subAttrs) {
                                        subAttr = subAttrs[subAttrPath];
            
                                        if (subAttr.path) {
                                            O.setValue(cfg.value, subAttr.path, subAttr.value);
                                        }
                                    }
                                }
                            }
                        }
            
                        return cfgs;
                    },
            
                    /**
                     * @method _filterAdHocAttrs
                     * @private
                     *
                     * @param {Object} allAttrs The set of all attribute configurations for this instance.
                     * Attributes will be removed from this set, if they belong to the filtered class, so
                     * that by the time all classes are processed, allCfgs will be empty.
                     * @param {Object} userVals The config object passed in by the user, from which adhoc attrs are to be filtered.
                     * @return {Object} The set of adhoc attributes passed in, in the form
                     * of an object with attribute name/configuration pairs.
                     */
                    _filterAdHocAttrs : function(allAttrs, userVals) {
                        var adHocs,
                            nonAttrs = this._nonAttrs,
                            attr;
            
                        if (userVals) {
                            adHocs = {};
                            for (attr in userVals) {
                                if (!allAttrs[attr] && !nonAttrs[attr] && userVals.hasOwnProperty(attr)) {
                                    adHocs[attr] = {
                                        value:userVals[attr]
                                    };
                                }
                            }
                        }
            
                        return adHocs;
                    },
            
                    /**
                     * A helper method used by _getClasses and _getAttrCfgs, which determines both
                     * the array of classes and aggregate set of attribute configurations
                     * across the class hierarchy for the instance.
                     *
                     * @method _initHierarchyData
                     * @private
                     */
                    _initHierarchyData : function() {
            
                        var ctor = this.constructor,
                            cachedClassData = ctor._CACHED_CLASS_DATA,
                            c,
                            i,
                            l,
                            attrCfg,
                            attrCfgHash,
                            needsAttrCfgHash = !ctor._ATTR_CFG_HASH,
                            nonAttrsCfg,
                            nonAttrs = {},
                            classes = [],
                            attrs = [];
            
                        // Start with `this` instance's constructor.
                        c = ctor;
            
                        if (!cachedClassData) {
            
                            while (c) {
                                // Add to classes
                                classes[classes.length] = c;
            
                                // Add to attributes
                                if (c.ATTRS) {
                                    attrs[attrs.length] = c.ATTRS;
                                }
            
                                // Aggregate ATTR cfg whitelist.
                                if (needsAttrCfgHash) {
                                    attrCfg     = c._ATTR_CFG;
                                    attrCfgHash = attrCfgHash || {};
            
                                    if (attrCfg) {
                                        for (i = 0, l = attrCfg.length; i < l; i += 1) {
                                            attrCfgHash[attrCfg[i]] = true;
                                        }
                                    }
                                }
            
                                // Commenting out the if. We always aggregate, since we don't
                                // know if we'll be needing this on the instance or not.
                                // if (this._allowAdHocAttrs) {
                                    nonAttrsCfg = c._NON_ATTRS_CFG;
                                    if (nonAttrsCfg) {
                                        for (i = 0, l = nonAttrsCfg.length; i < l; i++) {
                                            nonAttrs[nonAttrsCfg[i]] = true;
                                        }
                                    }
                                //}
            
                                c = c.superclass ? c.superclass.constructor : null;
                            }
            
                            // Cache computed `_ATTR_CFG_HASH` on the constructor.
                            if (needsAttrCfgHash) {
                                ctor._ATTR_CFG_HASH = attrCfgHash;
                            }
            
                            cachedClassData = ctor._CACHED_CLASS_DATA = {
                                classes : classes,
                                nonAttrs : nonAttrs,
                                attrs : this._aggregateAttrs(attrs)
                            };
            
                        }
            
                        this._classes = cachedClassData.classes;
                        this._attrs = cachedClassData.attrs;
                        this._nonAttrs = cachedClassData.nonAttrs;
                    },
            
                    /**
                     * Utility method to define the attribute hash used to filter/whitelist property mixes for
                     * this class for iteration performance reasons.
                     *
                     * @method _attrCfgHash
                     * @private
                     */
                    _attrCfgHash: function() {
                        return this.constructor._ATTR_CFG_HASH;
                    },
            
                    /**
                     * This method assumes that the value has already been checked to be an object.
                     * Since it's on a critical path, we don't want to re-do the check.
                     *
                     * @method _cloneDefaultValue
                     * @param {Object} cfg
                     * @private
                     */
                    _cloneDefaultValue : function(attr, cfg) {
            
                        var val = cfg.value,
                            clone = cfg.cloneDefaultValue;
            
                        if (clone === DEEP || clone === true) {
                            Y.log('Cloning default value for attribute:' + attr, 'info', 'base');
                            cfg.value = Y.clone(val);
                        } else if (clone === SHALLOW) {
                            Y.log('Merging default value for attribute:' + attr, 'info', 'base');
                            cfg.value = Y.merge(val);
                        } else if ((clone === undefined && (OBJECT_CONSTRUCTOR === val.constructor || L.isArray(val)))) {
                            cfg.value = Y.clone(val);
                        }
                        // else if (clone === false), don't clone the static default value.
                        // It's intended to be used by reference.
                    },
            
                    /**
                     * A helper method, used by _initHierarchyData to aggregate
                     * attribute configuration across the instances class hierarchy.
                     *
                     * The method will protect the attribute configuration value to protect the statically defined
                     * default value in ATTRS if required (if the value is an object literal, array or the
                     * attribute configuration has cloneDefaultValue set to shallow or deep).
                     *
                     * @method _aggregateAttrs
                     * @private
                     * @param {Array} allAttrs An array of ATTRS definitions across classes in the hierarchy
                     * (subclass first, Base last)
                     * @return {Object} The aggregate set of ATTRS definitions for the instance
                     */
                    _aggregateAttrs : function(allAttrs) {
            
                        var attr,
                            attrs,
                            subAttrsHash,
                            cfg,
                            path,
                            i,
                            cfgPropsHash = this._attrCfgHash(),
                            aggAttr,
                            aggAttrs = {};
            
                        if (allAttrs) {
                            for (i = allAttrs.length-1; i >= 0; --i) {
            
                                attrs = allAttrs[i];
            
                                for (attr in attrs) {
                                    if (attrs.hasOwnProperty(attr)) {
            
                                        // PERF TODO: Do we need to merge here, since we're merging later in getInstanceAttrCfgs
                                        // Should we move this down to only merge if we hit the path or valueFn ifs below?
                                        cfg = _wlmix({}, attrs[attr], cfgPropsHash);
            
                                        path = null;
                                        if (attr.indexOf(DOT) !== -1) {
                                            path = attr.split(DOT);
                                            attr = path.shift();
                                        }
            
                                        aggAttr = aggAttrs[attr];
            
                                        if (path && aggAttr && aggAttr.value) {
            
                                            subAttrsHash = aggAttrs._subAttrs;
            
                                            if (!subAttrsHash) {
                                                subAttrsHash = aggAttrs._subAttrs = {};
                                            }
            
                                            if (!subAttrsHash[attr]) {
                                                subAttrsHash[attr] = {};
                                            }
            
                                            subAttrsHash[attr][path.join(DOT)] = {
                                                value: cfg.value,
                                                path : path
                                            };
            
                                        } else if (!path) {
            
                                            if (!aggAttr) {
                                                aggAttrs[attr] = cfg;
                                            } else {
                                                if (aggAttr.valueFn && VALUE in cfg) {
                                                    aggAttr.valueFn = null;
                                                }
            
                                                // Mix into existing config.
                                                _wlmix(aggAttr, cfg, cfgPropsHash);
                                            }
                                        }
                                    }
                                }
                            }
                        }
            
                        return aggAttrs;
                    },
            
                    /**
                     * Initializes the class hierarchy for the instance, which includes
                     * initializing attributes for each class defined in the class's
                     * static <a href="#property_BaseCore.ATTRS">ATTRS</a> property and
                     * invoking the initializer method on the prototype of each class in the hierarchy.
                     *
                     * @method _initHierarchy
                     * @param {Object} userVals Object with configuration property name/value pairs
                     * @private
                     */
                    _initHierarchy : function(userVals) {
            
                        var lazy = this._lazyAddAttrs,
                            constr,
                            constrProto,
                            i,
                            l,
                            ci,
                            ei,
                            el,
                            ext,
                            extProto,
                            exts,
                            instanceAttrs,
                            initializers = [],
                            classes = this._getClasses(),
                            attrCfgs = this._getAttrCfgs(),
                            cl = classes.length - 1;
            
                        // Constructors
                        for (ci = cl; ci >= 0; ci--) {
            
                            constr = classes[ci];
                            constrProto = constr.prototype;
                            exts = constr._yuibuild && constr._yuibuild.exts;
            
                            // Using INITIALIZER in hasOwnProperty check, for performance reasons (helps IE6 avoid GC thresholds when
                            // referencing string literals). Not using it in apply, again, for performance "." is faster.
            
                            if (constrProto.hasOwnProperty(INITIALIZER)) {
                                // Store initializer while we're here and looping
                                initializers[initializers.length] = constrProto.initializer;
                            }
            
                            if (exts) {
                                for (ei = 0, el = exts.length; ei < el; ei++) {
            
                                    ext = exts[ei];
            
                                    // Ext Constructor
                                    ext.apply(this, arguments);
            
                                    extProto = ext.prototype;
                                    if (extProto.hasOwnProperty(INITIALIZER)) {
                                        // Store initializer while we're here and looping
                                        initializers[initializers.length] = extProto.initializer;
                                    }
                                }
                            }
                        }
            
                        // ATTRS
                        instanceAttrs = this._getInstanceAttrCfgs(attrCfgs);
            
                        if (this._preAddAttrs) {
                            this._preAddAttrs(instanceAttrs, userVals, lazy);
                        }
            
                        if (this._allowAdHocAttrs) {
                            this.addAttrs(this._filterAdHocAttrs(attrCfgs, userVals), userVals, lazy);
                        }
            
                        this.addAttrs(instanceAttrs, userVals, lazy);
            
                        // Initializers
                        for (i = 0, l = initializers.length; i < l; i++) {
                            initializers[i].apply(this, arguments);
                        }
                    },
            
                    /**
                     * Destroys the class hierarchy for this instance by invoking
                     * the destructor method on the prototype of each class in the hierarchy.
                     *
                     * @method _destroyHierarchy
                     * @private
                     */
                    _destroyHierarchy : function() {
                        var constr,
                            constrProto,
                            ci, cl, ei, el, exts, extProto,
                            classes = this._getClasses();
            
                        for (ci = 0, cl = classes.length; ci < cl; ci++) {
                            constr = classes[ci];
                            constrProto = constr.prototype;
                            exts = constr._yuibuild && constr._yuibuild.exts;
            
                            if (exts) {
                                for (ei = 0, el = exts.length; ei < el; ei++) {
                                    extProto = exts[ei].prototype;
                                    if (extProto.hasOwnProperty(DESTRUCTOR)) {
                                        extProto.destructor.apply(this, arguments);
                                    }
                                }
                            }
            
                            if (constrProto.hasOwnProperty(DESTRUCTOR)) {
                                constrProto.destructor.apply(this, arguments);
                            }
                        }
                    },
            
                    /**
                     * Default toString implementation. Provides the constructor NAME
                     * and the instance guid, if set.
                     *
                     * @method toString
                     * @return {String} String representation for this object
                     */
                    toString: function() {
                        return this.name + "[" + Y.stamp(this, true) + "]";
                    }
                };
            
                // Straightup augment, no wrapper functions
                Y.mix(BaseCore, AttributeCore, false, null, 1);
            
                // Fix constructor
                BaseCore.prototype.constructor = BaseCore;
            
                Y.BaseCore = BaseCore;