/**
+ * The attribute module provides an augmentable Attribute implementation, which
+ * adds configurable attributes and attribute change events to the class being
+ * augmented. It also provides a State class, which is used internally by Attribute,
+ * but can also be used independently to provide a name/property/value data structure to
+ * store state.
+ *
+ * @module attribute
+ */
+
+ var O = Y.Object,
+ EventTarget = Y.EventTarget,
+
+ DOT = ".",
+ CHANGE = "Change",
+
+ // Externally configurable props
+ GETTER = "getter",
+ SETTER = "setter",
+ READ_ONLY = "readOnly",
+ WRITE_ONCE = "writeOnce",
+ VALIDATOR = "validator",
+ VALUE = "value",
+ VALUE_FN = "valueFn",
+ BROADCAST = "broadcast",
+ LAZY_ADD = "lazyAdd",
+
+ // Used for internal state management
+ ADDED = "added",
+ INITIALIZING = "initializing",
+ INIT_VALUE = "initValue",
+ PUBLISHED = "published",
+ DEF_VALUE = "defaultValue",
+ LAZY = "lazy",
+ IS_LAZY_ADD = "isLazyAdd",
+
+ INVALID_VALUE,
+ MODIFIABLE = {};
+
+ // Properties which can be changed after the attribute has been added.
+ MODIFIABLE[READ_ONLY] = 1;
+ MODIFIABLE[WRITE_ONCE] = 1;
+ MODIFIABLE[GETTER] = 1;
+ MODIFIABLE[BROADCAST] = 1;
+
+ /**
+ * <p>
+ * Attribute provides configurable attribute support along with attribute change events. It is designed to be
+ * augmented onto a host class, and provides the host with the ability to configure attributes to store and retrieve state,
+ * along with attribute change events.
+ * </p>
+ * <p>For example, attributes added to the host can be configured:</p>
+ * <ul>
+ * <li>As read only.</li>
+ * <li>As write once.</li>
+ * <li>With a setter function, which can be used to manipulate
+ * values passed to Attribute's <a href="#method_set">set</a> method, before they are stored.</li>
+ * <li>With a getter function, which can be used to manipulate stored values,
+ * before they are returned by Attribute's <a href="#method_get">get</a> method.</li>
+ * <li>With a validator function, to validate values before they are stored.</li>
+ * </ul>
+ *
+ * <p>See the <a href="#method_addAttr">addAttr</a> method, for the complete set of configuration
+ * options available for attributes</p>.
+ *
+ * <p><strong>NOTE:</strong> Most implementations will be better off extending the <a href="Base.html">Base</a> class,
+ * instead of augmenting Attribute directly. Base augments Attribute and will handle the initial configuration
+ * of attributes for derived classes, accounting for values passed into the constructor.</p>
+ *
+ * @class Attribute
+ * @uses EventTarget
+ */
+ function Attribute() {
+ Y.log('Attribute constructor called', 'info', 'attribute');
+
+ // Perf tweak - avoid creating event literals if not required.
+ this._ATTR_E_FACADE = {};
+
+ EventTarget.call(this, {emitFacade:true});
+ this._conf = new Y.State();
+ }
+
+ /**
+ * <p>The value to return from an attribute setter in order to prevent the set from going through.</p>
+ *
+ * <p>You can return this value from your setter if you wish to combine validator and setter
+ * functionality into a single setter function, which either returns the massaged value to be stored or
+ * Attribute.INVALID_VALUE to prevent invalid values from being stored.</p>
+ *
+ * @property Attribute.INVALID_VALUE
+ * @type Object
+ * @static
+ * @final
+ */
+ Attribute.INVALID_VALUE = {};
+ INVALID_VALUE = Attribute.INVALID_VALUE;
+
+ /**
+ * The list of properties which can be configured for
+ * each attribute (e.g. setter, getter, writeOnce etc.).
+ *
+ * This property is used internally as a whitelist for faster
+ * Y.mix operations.
+ *
+ * @property Attribute._ATTR_CFG
+ * @type Array
+ * @static
+ * @protected
+ */
+ Attribute._ATTR_CFG = [SETTER, GETTER, VALIDATOR, VALUE, VALUE_FN, WRITE_ONCE, READ_ONLY, LAZY_ADD, BROADCAST];
+
+ Attribute.prototype = {
+ /**
+ * <p>
+ * Adds an attribute with the provided configuration to the host object.
+ * </p>
+ * <p>
+ * The config argument object supports the following properties:
+ * </p>
+ *
+ * <dl>
+ * <dt>value <Any></dt>
+ * <dd>The initial value to set on the attribute</dd>
+ *
+ * <dt>valueFn <Function></dt>
+ * <dd>A function, which will return the initial value to set on the attribute. This is useful
+ * for cases where the attribute configuration is defined statically, but needs to
+ * reference the host instance ("this") to obtain an initial value.
+ * If defined, this precedence over the value property.</dd>
+ *
+ * <dt>readOnly <boolean></dt>
+ * <dd>Whether or not the attribute is read only. Attributes having readOnly set to true
+ * cannot be modified by invoking the set method.</dd>
+ *
+ * <dt>writeOnce <boolean></dt>
+ * <dd>Whether or not the attribute is "write once". Attributes having writeOnce set to true,
+ * can only have their values set once, be it through the default configuration,
+ * constructor configuration arguments, or by invoking set.</dd>
+ *
+ * <dt>setter <Function></dt>
+ * <dd>The setter function used to massage or normalize the value passed to the set method for the attribute.
+ * The value returned by the setter will be the final stored value. Returning
+ * <a href="#property_Attribute.INVALID_VALUE">Attribute.INVALID_VALUE</a>, from the setter will prevent
+ * the value from being stored.</dd>
+ *
+ * <dt>getter <Function></dt>
+ * <dd>The getter function used to massage or normalize the value returned by the get method for the attribute.
+ * The value returned by the getter function is the value which will be returned to the user when they
+ * invoke get.</dd>
+ *
+ * <dt>validator <Function></dt>
+ * <dd>The validator function invoked prior to setting the stored value. Returning
+ * false from the validator function will prevent the value from being stored.</dd>
+ *
+ * <dt>broadcast <int></dt>
+ * <dd>If and how attribute change events for this attribute should be broadcast. See CustomEvent's <a href="CustomEvent.html#property_broadcast">broadcast</a> property for
+ * valid values. By default attribute change events are not broadcast.</dd>
+ *
+ * <dt>lazyAdd <boolean></dt>
+ * <dd>Whether or not to delay initialization of the attribute until the first call to get/set it.
+ * This flag can be used to over-ride lazy initialization on a per attribute basis, when adding multiple attributes through
+ * the <a href="#method_addAttrs">addAttrs</a> method.</dd>
+ *
+ * </dl>
+ *
+ * <p>The setter, getter and validator are invoked with the value and name passed in as the first and second arguments, and with
+ * the context ("this") set to the host object.</p>
+ *
+ * @method addAttr
+ *
+ * @param {String} name The name of the attribute.
+ * @param {Object} config An object with attribute configuration property/value pairs, specifying the configuration for the attribute.
+ *
+ * <p>
+ * <strong>NOTE:</strong> The configuration object is modified when adding an attribute, so if you need
+ * to protect the original values, you will need to merge the object.
+ * </p>
+ *
+ * @param {boolean} lazy (optional) Whether or not to add this attribute lazily (on the first call to get/set).
+ *
+ * @return {Object} A reference to the host object.
+ *
+ * @chainable
+ */
+ addAttr: function(name, config, lazy) {
+
+ Y.log('Adding attribute: ' + name, 'info', 'attribute');
+ var conf = this._conf;
+
+ lazy = (LAZY_ADD in config) ? config[LAZY_ADD] : lazy;
+
+ if (lazy && !this.attrAdded(name)) {
+ Y.log('Lazy Add: ' + name, 'info', 'attribute');
+
+ conf.add(name, LAZY, config || {});
+ conf.add(name, ADDED, true);
+ } else {
+
+ if (this.attrAdded(name) && !conf.get(name, IS_LAZY_ADD)) { Y.log('Attribute: ' + name + ' already exists. Cannot add it again without removing it first', 'warn', 'attribute'); }
+
+ if (!this.attrAdded(name) || conf.get(name, IS_LAZY_ADD)) {
+ Y.log('Non-Lazy Add: ' + name, 'info', 'attribute');
+
+ config = config || {};
+
+ var value, hasValue = (VALUE in config);
+ if (config.readOnly && !hasValue) { Y.log('readOnly attribute: ' + name + ', added without an initial value. Value will be set on initial call to set', 'warn', 'attribute');}
+
+ if(hasValue) {
+ // We'll go through set, don't want to set value in _conf directory
+ value = config.value;
+ delete config.value;
+ }
+
+ config.added = true;
+ config.initializing = true;
+
+ conf.addAll(name, config);
+
+ if (hasValue) {
+ // Go through set, so that raw values get normalized/validated
+ this.set(name, value);
+ }
+
+ conf.remove(name, INITIALIZING);
+ }
+ }
+
+ return this;
+ },
+
+ /**
+ * Checks if the given attribute has been added to the host
+ *
+ * @method attrAdded
+ * @param {String} name The name of the attribute to check.
+ * @return {boolean} true if an attribute with the given name has been added, false if it hasn't. This method will return true for lazily added attributes.
+ */
+ attrAdded: function(name) {
+ return !!this._conf.get(name, ADDED);
+ },
+
+ /**
+ * Updates the configuration of an attribute which has already been added.
+ * <p>
+ * The properties which can be modified through this interface are limited
+ * to the following subset of attributes, which can be safely modified
+ * after a value has already been set on the attribute: readOnly, writeOnce,
+ * broadcast and getter.
+ * </p>
+ * @method modifyAttr
+ * @param {String} name The name of the attribute whose configuration is to be updated.
+ * @param {Object} config An object with configuration property/value pairs, specifying the configuration properties to modify.
+ */
+ modifyAttr: function(name, config) {
+ if (this.attrAdded(name)) {
+
+ if (this._isLazyAttr(name)) {
+ this._addLazyAttr(name);
+ }
+
+ var prop, conf = this._conf;
+ for (prop in config) {
+ if (MODIFIABLE[prop] && config.hasOwnProperty(prop)) {
+ conf.add(name, prop, config[prop]);
+
+ // If we reconfigured broadcast, need to republish
+ if (prop === BROADCAST) {
+ conf.remove(name, PUBLISHED);
+ }
+ }
+ }
+ }
+
+ if (!this.attrAdded(name)) {Y.log('Attribute modifyAttr:' + name + ' has not been added. Use addAttr to add the attribute', 'warn', 'attribute');}
+ },
+
+ /**
+ * Removes an attribute from the host object
+ *
+ * @method removeAttr
+ * @param {String} name The name of the attribute to be removed.
+ */
+ removeAttr: function(name) {
+ this._conf.removeAll(name);
+ },
+
+ /**
+ * Returns the current value of the attribute. If the attribute
+ * has been configured with a 'getter' function, this method will delegate
+ * to the 'getter' to obtain the value of the attribute.
+ *
+ * @method get
+ *
+ * @param {String} name The name of the attribute. If the value of the attribute is an Object,
+ * dot notation can be used to obtain the value of a property of the object (e.g. <code>get("x.y.z")</code>)
+ *
+ * @return {Any} The value of the attribute
+ */
+ get : function(name) {
+
+ var fullName = name,
+ conf = this._conf,
+ path,
+ getter,
+ val;
+
+ if (name.indexOf(DOT) !== -1) {
+ path = name.split(DOT);
+ name = path.shift();
+ }
+
+ // On Demand - Should be rare - handles out of order valueFn references
+ if (this._tCfgs && this._tCfgs[name]) {
+ var cfg = {};
+ cfg[name] = this._tCfgs[name];
+ delete this._tCfgs[name];
+ this._addAttrs(cfg, this._tVals);
+ }
+
+ // Lazy Init
+ if (this._isLazyAttr(name)) {
+ this._addLazyAttr(name);
+ }
+
+ val = conf.get(name, VALUE);
+ getter = conf.get(name, GETTER);
+
+ val = (getter) ? getter.call(this, val, fullName) : val;
+ val = (path) ? O.getValue(val, path) : val;
+
+ return val;
+ },
+
+ /**
+ * Checks whether or not the attribute is one which has been
+ * added lazily and still requires initialization.
+ *
+ * @method _isLazyAttr
+ * @private
+ * @param {String} name The name of the attribute
+ * @return {boolean} true if it's a lazily added attribute, false otherwise.
+ */
+ _isLazyAttr: function(name) {
+ return this._conf.get(name, LAZY);
+ },
+
+ /**
+ * Finishes initializing an attribute which has been lazily added.
+ *
+ * @method _addLazyAttr
+ * @private
+ * @param {Object} name The name of the attribute
+ */
+ _addLazyAttr: function(name) {
+ var conf = this._conf;
+ var lazyCfg = conf.get(name, LAZY);
+ conf.add(name, IS_LAZY_ADD, true);
+ conf.remove(name, LAZY);
+ this.addAttr(name, lazyCfg);
+ },
+
+ /**
+ * Sets the value of an attribute.
+ *
+ * @method set
+ * @chainable
+ *
+ * @param {String} name The name of the attribute. If the
+ * current value of the attribute is an Object, dot notation can be used
+ * to set the value of a property within the object (e.g. <code>set("x.y.z", 5)</code>).
+ *
+ * @param {Any} value The value to set the attribute to.
+ *
+ * @param {Object} opts (Optional) Optional event data to be mixed into
+ * the event facade passed to subscribers of the attribute's change event. This
+ * can be used as a flexible way to identify the source of a call to set, allowing
+ * the developer to distinguish between set called internally by the host, vs.
+ * set called externally by the application developer.
+ *
+ * @return {Object} A reference to the host object.
+ */
+ set : function(name, val, opts) {
+ return this._setAttr(name, val, opts);
+ },
+
+ /**
+ * Resets the attribute (or all attributes) to its initial value, as long as
+ * the attribute is not readOnly, or writeOnce.
+ *
+ * @method reset
+ * @param {String} name Optional. The name of the attribute to reset. If omitted, all attributes are reset.
+ * @return {Object} A reference to the host object.
+ * @chainable
+ */
+ reset : function(name) {
+ if (name) {
+ if (this._isLazyAttr(name)) {
+ this._addLazyAttr(name);
+ }
+ this.set(name, this._conf.get(name, INIT_VALUE));
+ } else {
+ var added = this._conf.data.added;
+ Y.each(added, function(v, n) {
+ this.reset(n);
+ }, this);
+ }
+ return this;
+ },
+
+ /**
+ * Allows setting of readOnly/writeOnce attributes. See <a href="#method_set">set</a> for argument details.
+ *
+ * @method _set
+ * @protected
+ * @chainable
+ *
+ * @param {String} name The name of the attribute.
+ * @param {Any} val The value to set the attribute to.
+ * @param {Object} opts (Optional) Optional event data to be mixed into
+ * the event facade passed to subscribers of the attribute's change event.
+ * @return {Object} A reference to the host object.
+ */
+ _set : function(name, val, opts) {
+ return this._setAttr(name, val, opts, true);
+ },
+
+ /**
+ * Provides the common implementation for the public set and protected _set methods.
+ *
+ * See <a href="#method_set">set</a> for argument details.
+ *
+ * @method _setAttr
+ * @protected
+ * @chainable
+ *
+ * @param {String} name The name of the attribute.
+ * @param {Any} value The value to set the attribute to.
+ * @param {Object} opts (Optional) Optional event data to be mixed into
+ * the event facade passed to subscribers of the attribute's change event.
+ * @param {boolean} force If true, allows the caller to set values for
+ * readOnly or writeOnce attributes which have already been set.
+ *
+ * @return {Object} A reference to the host object.
+ */
+ _setAttr : function(name, val, opts, force) {
+ var allowSet = true,
+ conf = this._conf,
+ data = conf.data,
+ initialSet,
+ strPath,
+ path,
+ currVal;
+
+ if (name.indexOf(DOT) !== -1) {
+ strPath = name;
+ path = name.split(DOT);
+ name = path.shift();
+ }
+
+ if (this._isLazyAttr(name)) {
+ this._addLazyAttr(name);
+ }
+
+ initialSet = (!data.value || !(name in data.value));
+
+ if (!this.attrAdded(name)) {
+ Y.log('Set attribute:' + name + ', aborted; Attribute is not configured', 'warn', 'attribute');
+ } else {
+
+ if (!initialSet && !force) {
+
+ if (conf.get(name, WRITE_ONCE)) {
+ Y.log('Set attribute:' + name + ', aborted; Attribute is writeOnce', 'warn', 'attribute');
+ allowSet = false;
+ }
+
+ if (conf.get(name, READ_ONLY)) {
+ Y.log('Set attribute:' + name + ', aborted; Attribute is readOnly', 'warn', 'attribute');
+ allowSet = false;
+ }
+ }
+
+ if (allowSet) {
+ currVal = this.get(name);
+
+ if (path) {
+ val = O.setValue(Y.clone(currVal), path, val);
+
+ if (val === undefined) {
+ Y.log('Set attribute path:' + strPath + ', aborted; Path is invalid', 'warn', 'attribute');
+ allowSet = false;
+ }
+ }
+
+ if (allowSet) {
+ if (conf.get(name, INITIALIZING)) {
+ this._setAttrVal(name, strPath, currVal, val);
+ } else {
+ this._fireAttrChange(name, strPath, currVal, val, opts);
+ }
+ }
+ }
+ }
+
+ return this;
+ },
+
+ /**
+ * Utility method to help setup the event payload and fire the attribute change event.
+ *
+ * @method _fireAttrChange
+ * @private
+ * @param {String} attrName The name of the attribute
+ * @param {String} subAttrName The full path of the property being changed,
+ * if this is a sub-attribute value being change. Otherwise null.
+ * @param {Any} currVal The current value of the attribute
+ * @param {Any} newVal The new value of the attribute
+ * @param {Object} opts Any additional event data to mix into the attribute change event's event facade.
+ */
+ _fireAttrChange : function(attrName, subAttrName, currVal, newVal, opts) {
+ var eventName = attrName + CHANGE,
+ conf = this._conf,
+ facade;
+
+ if (!conf.get(attrName, PUBLISHED)) {
+ this.publish(eventName, {
+ queuable:false,
+ defaultFn:this._defAttrChangeFn,
+ silent:true,
+ broadcast : conf.get(attrName, BROADCAST)
+ });
+ conf.add(attrName, PUBLISHED, true);
+ }
+
+ facade = (opts) ? Y.merge(opts) : this._ATTR_E_FACADE;
+
+ facade.type = eventName;
+ facade.attrName = attrName;
+ facade.subAttrName = subAttrName;
+ facade.prevVal = currVal;
+ facade.newVal = newVal;
+
+ this.fire(facade);
+ },
+
+ /**
+ * Default function for attribute change events.
+ *
+ * @private
+ * @method _defAttrChangeFn
+ * @param {EventFacade} e The event object for attribute change events.
+ */
+ _defAttrChangeFn : function(e) {
+ if (!this._setAttrVal(e.attrName, e.subAttrName, e.prevVal, e.newVal)) {
+ Y.log('State not updated and stopImmediatePropagation called for attribute: ' + e.attrName + ' , value:' + e.newVal, 'warn', 'attribute');
+ // Prevent "after" listeners from being invoked since nothing changed.
+ e.stopImmediatePropagation();
+ } else {
+ e.newVal = this._conf.get(e.attrName, VALUE);
+ }
+ },
+
+ /**
+ * Updates the stored value of the attribute in the privately held State object,
+ * if validation and setter passes.
+ *
+ * @method _setAttrVal
+ * @private
+ * @param {String} attrName The attribute name.
+ * @param {String} subAttrName The sub-attribute name, if setting a sub-attribute property ("x.y.z").
+ * @param {Any} prevVal The currently stored value of the attribute.
+ * @param {Any} newVal The value which is going to be stored.
+ *
+ * @return {booolean} true if the new attribute value was stored, false if not.
+ */
+ _setAttrVal : function(attrName, subAttrName, prevVal, newVal) {
+
+ var allowSet = true,
+ conf = this._conf,
+
+ validator = conf.get(attrName, VALIDATOR),
+ setter = conf.get(attrName, SETTER),
+ initializing = conf.get(attrName, INITIALIZING),
+
+ name = subAttrName || attrName,
+ retVal;
+
+ if (validator) {
+ var valid = validator.call(this, newVal, name);
+
+ if (!valid && initializing) {
+ newVal = conf.get(attrName, DEF_VALUE);
+ valid = true; // Assume it's valid, for perf.
+ }
+ }
+
+ if (!validator || valid) {
+ if (setter) {
+ retVal = setter.call(this, newVal, name);
+
+ if (retVal === INVALID_VALUE) {
+ Y.log('Attribute: ' + attrName + ', setter returned Attribute.INVALID_VALUE for value:' + newVal, 'warn', 'attribute');
+ allowSet = false;
+ } else if (retVal !== undefined){
+ Y.log('Attribute: ' + attrName + ', raw value: ' + newVal + ' modified by setter to:' + retVal, 'info', 'attribute');
+ newVal = retVal;
+ }
+ }
+
+ if (allowSet) {
+ if(!subAttrName && newVal === prevVal) {
+ Y.log('Attribute: ' + attrName + ', value unchanged:' + newVal, 'warn', 'attribute');
+ allowSet = false;
+ } else {
+ // Store value
+ if (conf.get(attrName, INIT_VALUE) === undefined) {
+ conf.add(attrName, INIT_VALUE, newVal);
+ }
+ conf.add(attrName, VALUE, newVal);
+ }
+ }
+
+ } else {
+ Y.log('Attribute:' + attrName + ', Validation failed for value:' + newVal, 'warn', 'attribute');
+ allowSet = false;
+ }
+
+ return allowSet;
+ },
+
+ /**
+ * Sets multiple attribute values.
+ *
+ * @method setAttrs
+ * @param {Object} attrs An object with attributes name/value pairs.
+ * @return {Object} A reference to the host object.
+ * @chainable
+ */
+ setAttrs : function(attrs) {
+ for (var attr in attrs) {
+ if ( attrs.hasOwnProperty(attr) ) {
+ this.set(attr, attrs[attr]);
+ }
+ }
+ return this;
+ },
+
+ /**
+ * Gets multiple attribute values.
+ *
+ * @method getAttrs
+ * @param {Array | boolean} attrs Optional. An array of attribute names. If omitted, all attribute values are
+ * returned. If set to true, all attributes modified from their initial values are returned.
+ * @return {Object} An object with attribute name/value pairs.
+ */
+ getAttrs : function(attrs) {
+ var o = {}, i, l, attr, val,
+ modifiedOnly = (attrs === true);
+
+ attrs = (attrs && !modifiedOnly) ? attrs : O.keys(this._conf.data.added);
+
+ for (i = 0, l = attrs.length; i < l; i++) {
+ // Go through get, to honor cloning/normalization
+ attr = attrs[i];
+ val = this.get(attr);
+
+ if (!modifiedOnly || this._conf.get(attr, VALUE) != this._conf.get(attr, INIT_VALUE)) {
+ o[attr] = this.get(attr);
+ }
+ }
+
+ return o;
+ },
+
+ /**
+ * Configures a group of attributes, and sets initial values.
+ *
+ * <p>
+ * <strong>NOTE:</strong> This method does not isolate the configuration object by merging/cloning.
+ * The caller is responsible for merging/cloning the configuration object if required.
+ * </p>
+ *
+ * @method addAttrs
+ * @chainable
+ *
+ * @param {Object} cfgs An object with attribute name/configuration pairs.
+ * @param {Object} values An object with attribute name/value pairs, defining the initial values to apply.
+ * Values defined in the cfgs argument will be over-written by values in this argument unless defined as read only.
+ * @param {boolean} lazy Whether or not to delay the intialization of these attributes until the first call to get/set.
+ * Individual attributes can over-ride this behavior by defining a lazyAdd configuration property in their configuration.
+ * See <a href="#method_addAttr">addAttr</a>.
+ *
+ * @return {Object} A reference to the host object.
+ */
+ addAttrs : function(cfgs, values, lazy) {
+ if (cfgs) {
+ this._tCfgs = cfgs;
+ this._tVals = this._splitAttrVals(values);
+
+ this._addAttrs(cfgs, this._tVals, lazy);
+
+ this._tCfgs = this._tVals = null;
+ }
+
+ return this;
+ },
+
+ /**
+ * Implementation behind the public addAttrs method.
+ *
+ * This method is invoked directly by get if it encounters a scenario
+ * in which an attribute's valueFn attempts to obtain the
+ * value an attribute in the same group of attributes, which has not yet
+ * been added (on demand initialization).
+ *
+ * @method _addAttrs
+ * @private
+ * @param {Object} cfgs An object with attribute name/configuration pairs.
+ * @param {Object} values An object with attribute name/value pairs, defining the initial values to apply.
+ * Values defined in the cfgs argument will be over-written by values in this argument unless defined as read only.
+ * @param {boolean} lazy Whether or not to delay the intialization of these attributes until the first call to get/set.
+ * Individual attributes can over-ride this behavior by defining a lazyAdd configuration property in their configuration.
+ * See <a href="#method_addAttr">addAttr</a>.
+ */
+ _addAttrs : function(cfgs, values, lazy) {
+ var attr,
+ attrCfg,
+ value;
+
+ for (attr in cfgs) {
+ if (cfgs.hasOwnProperty(attr)) {
+
+ // Not Merging. Caller is responsible for isolating configs
+ attrCfg = cfgs[attr];
+ attrCfg.defaultValue = attrCfg.value;
+
+ // Handle simple, complex and user values, accounting for read-only
+ value = this._getAttrInitVal(attr, attrCfg, this._tVals);
+
+ if (value !== undefined) {
+ attrCfg.value = value;
+ }
+
+ if (this._tCfgs[attr]) {
+ delete this._tCfgs[attr];
+ }
+
+ this.addAttr(attr, attrCfg, lazy);
+ }
+ }
+ },
+
+ /**
+ * Utility method to split out simple attribute name/value pairs ("x")
+ * from complex attribute name/value pairs ("x.y.z"), so that complex
+ * attributes can be keyed by the top level attribute name.
+ *
+ * @method _splitAttrVals
+ * @param {Object} valueHash An object with attribute name/value pairs
+ *
+ * @return {Object} An object literal with 2 properties - "simple" and "complex",
+ * containing simple and complex attribute values respectively keyed
+ * by the top level attribute name, or null, if valueHash is falsey.
+ *
+ * @private
+ */
+ _splitAttrVals : function(valueHash) {
+ var vals = {},
+ subvals = {},
+ path,
+ attr,
+ v, k;
+
+ if (valueHash) {
+ for (k in valueHash) {
+ if (valueHash.hasOwnProperty(k)) {
+ if (k.indexOf(DOT) !== -1) {
+ path = k.split(DOT);
+ attr = path.shift();
+ v = subvals[attr] = subvals[attr] || [];
+ v[v.length] = {
+ path : path,
+ value: valueHash[k]
+ };
+ } else {
+ vals[k] = valueHash[k];
+ }
+ }
+ }
+ return { simple:vals, complex:subvals };
+ } else {
+ return null;
+ }
+ },
+
+ /**
+ * Returns the initial value of the given attribute from
+ * either the default configuration provided, or the
+ * over-ridden value if it exists in the set of initValues
+ * provided and the attribute is not read-only.
+ *
+ * @param {String} attr The name of the attribute
+ * @param {Object} cfg The attribute configuration object
+ * @param {Object} initValues The object with simple and complex attribute name/value pairs returned from _splitAttrVals
+ *
+ * @return {Any} The initial value of the attribute.
+ *
+ * @method _getAttrInitVal
+ * @private
+ */
+ _getAttrInitVal : function(attr, cfg, initValues) {
+
+ var val = (cfg.valueFn) ? cfg.valueFn.call(this) : cfg.value,
+ simple,
+ complex,
+ i,
+ l,
+ path,
+ subval,
+ subvals;
+
+ if (!cfg.readOnly && initValues) {
+
+ Y.log('Checking initValues in _getAttrIniVal: ' + attr, 'info', 'attribute');
+
+ // Simple Attributes
+ simple = initValues.simple;
+ if (simple && simple.hasOwnProperty(attr)) {
+ val = simple[attr];
+ }
+
+ // Complex Attributes (complex values applied, after simple, incase both are set)
+ complex = initValues.complex;
+ if (complex && complex.hasOwnProperty(attr)) {
+ subvals = complex[attr];
+ for (i = 0, l = subvals.length; i < l; ++i) {
+ path = subvals[i].path;
+ subval = subvals[i].value;
+ O.setValue(val, path, subval);
+ }
+ }
+ }
+
+ Y.log('initValue for ' + attr + ':' + val, 'info', 'attribute');
+
+ return val;
+ }
+ };
+
+ // Basic prototype augment - no lazy constructor invocation.
+ Y.mix(Attribute, EventTarget, false, null, 1);
+
+ Y.Attribute = Attribute;
+