#

API Docs for: 3.10.3
Show: Inherited Protected Private Deprecated

# 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.
         *
         * @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 when processing ATTRS across the class hierarchy during
             * initialization. Returns a disposable object with the attributes defined for
             * the provided class, extracted from the set of all attributes passed in.
             *
             * @method _filterAttrCfgs
             * @private
             *
             * @param {Function} clazz The class for which the desired attributes are required.
             * @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 belonging to the class passed in, in the form
             * of an object with attribute name/configuration pairs.
             */
            _filterAttrCfgs : function(clazz, allCfgs) {

                var cfgs = null,
                    cfg,
                    val,
                    subAttr,
                    subAttrs,
                    subAttrPath,
                    attr,
                    attrCfg,
                    filtered = this._filteredAttrs,
                    attrs = clazz.ATTRS;

                if (attrs) {
                    for (attr in attrs) {
                        attrCfg = allCfgs[attr];

                        // Using hasOwnProperty, since it's faster (for the 80% case where filtered doesn't have attr) for the majority
                        // of browsers, FF being the major outlier. http://jsperf.com/in-vs-hasownproperty/6. May revisit.
                        if (attrCfg && !filtered.hasOwnProperty(attr)) {

                            if (!cfgs) {
                                cfgs = {};
                            }

                            // PERF TODO:
                            // Revisit once all unit tests pass for further optimizations. See if we really need to isolate this.
                            cfg = cfgs[attr] = _wlmix({}, attrCfg, this._attrCfgHash());

                            filtered[attr] = true;

                            val = cfg.value;

                            if (val && (typeof val === "object")) {
                                this._cloneDefaultValue(attr, cfg);
                            }

                            if (allCfgs._subAttrs && allCfgs._subAttrs.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 filterAttrCfg
                                // 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,
                    ci,
                    ei,
                    el,
                    extProto,
                    exts,
                    classes = this._getClasses(),
                    attrCfgs = this._getAttrCfgs(),
                    cl = classes.length - 1;

                this._filteredAttrs = {};

                for (ci = cl; ci >= 0; ci--) {

                    constr = classes[ci];
                    constrProto = constr.prototype;
                    exts = constr._yuibuild && constr._yuibuild.exts;

                    if (exts) {
                        for (ei = 0, el = exts.length; ei < el; ei++) {
                            exts[ei].apply(this, arguments);
                        }
                    }

                    this.addAttrs(this._filterAttrCfgs(constr, attrCfgs), userVals, lazy);

                    if (this._allowAdHocAttrs && ci === cl) {
                        this.addAttrs(this._filterAdHocAttrs(attrCfgs, userVals), userVals, lazy);
                    }

                    // 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)) {
                        constrProto.initializer.apply(this, arguments);
                    }

                    if (exts) {
                        for (ei = 0; ei < el; ei++) {
                            extProto = exts[ei].prototype;
                            if (extProto.hasOwnProperty(INITIALIZER)) {
                                extProto.initializer.apply(this, arguments);
                            }
                        }
                    }
                }

                this._filteredAttrs = null;
            },

            /**
             * 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;