text: /*
  Copyright (c) 2010, Yahoo! Inc. All rights reserved.
  Code licensed under the BSD License:
  http://developer.yahoo.com/yui/license.html
  version: 3.4.0
  build: nightly
  */
  YUI.add('attribute-base', function(Y) {
  
      /**
       * The State class maintains state for a collection of named items, with 
       * a varying number of properties defined.
       *
       * It avoids the need to create a separate class for the item, and separate instances 
       * of these classes for each item, by storing the state in a 2 level hash table, 
       * improving performance when the number of items is likely to be large.
       *
       * @constructor
       * @class State
       */
      Y.State = function() { 
          /**
           * Hash of attributes
           * @property data
           */
          this.data = {};
      };
  
      Y.State.prototype = {
  
          /**
           * Adds a property to an item.
           *
           * @method add
           * @param name {String} The name of the item.
           * @param key {String} The name of the property.
           * @param val {Any} The value of the property.
           */
          add : function(name, key, val) {
              var d = this.data;
              d[key] = d[key] || {};
              d[key][name] = val;
          },
  
          /**
           * Adds multiple properties to an item.
           *
           * @method addAll
           * @param name {String} The name of the item.
           * @param o {Object} A hash of property/value pairs.
           */
          addAll: function(name, o) {
              var key;
              for (key in o) {
                  if (o.hasOwnProperty(key)) {
                      this.add(name, key, o[key]);
                  }
              }
          },
  
          /**
           * Removes a property from an item.
           *
           * @method remove
           * @param name {String} The name of the item.
           * @param key {String} The property to remove.
           */
          remove: function(name, key) {
              var d = this.data;
              if (d[key] && (name in d[key])) {
                  delete d[key][name];
              }
          },
  
          /**
           * Removes multiple properties from an item, or remove the item completely.
           *
           * @method removeAll
           * @param name {String} The name of the item.
           * @param o {Object|Array} Collection of properties to delete. If not provided, the entire item is removed.
           */
          removeAll: function(name, o) {
              var d = this.data;
  
              Y.each(o || d, function(v, k) {
                  if(Y.Lang.isString(k)) {
                      this.remove(name, k);
                  } else {
                      this.remove(name, v);
                  }
              }, this);
          },
  
          /**
           * For a given item, returns the value of the property requested, or undefined if not found.
           *
           * @method get
           * @param name {String} The name of the item
           * @param key {String} Optional. The property value to retrieve.
           * @return {Any} The value of the supplied property.
           */
          get: function(name, key) {
              var d = this.data;
              return (d[key] && name in d[key]) ?  d[key][name] : undefined;
          },
  
          /**
           * For the given item, returns a disposable object with all of the
           * item's property/value pairs.
           *
           * @method getAll
           * @param name {String} The name of the item
           * @return {Object} An object with property/value pairs for the item.
           */
          getAll : function(name) {
              var d = this.data, o;
  
              Y.each(d, function(v, k) {
                  if (name in d[k]) {
                      o = o || {};
                      o[k] = v[name];
                  }
              }, this);
  
              return o;
          }
      };
      /**
       * 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
       */
  
      /**
       * The attribute-base submodule provides core attribute handling support, with everything
       * aside from complex attribute handling in the provider's constructor.
       *
       * @module attribute
       * @submodule attribute-base
       */
      var O = Y.Object,
          Lang = Y.Lang,
          EventTarget = Y.EventTarget,
  
          DOT = ".",
          CHANGE = "Change",
  
          // Externally configurable props
          GETTER = "getter",
          SETTER = "setter",
          READ_ONLY = "readOnly",
          WRITE_ONCE = "writeOnce",
          INIT_ONLY = "initOnly",
          VALIDATOR = "validator",
          VALUE = "value",
          VALUE_FN = "valueFn",
          BROADCAST = "broadcast",
          LAZY_ADD = "lazyAdd",
          BYPASS_PROXY = "_bypassProxy",
  
          // 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 on to 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
       * @param attrs {Object} The attributes to add during construction (passed through to <a href="#method_addAttrs">addAttrs</a>). These can also be defined on the constructor being augmented with Attribute by defining the ATTRS property on the constructor.
       * @param values {Object} The initial attribute values to apply (passed through to <a href="#method_addAttrs">addAttrs</a>). These are not merged/cloned. The caller is responsible for isolating user provided values if required.
       * @param lazy {boolean} Whether or not to add attributes lazily (passed through to <a href="#method_addAttrs">addAttrs</a>).
       * @uses EventTarget
       */
      function Attribute(attrs, values, lazy) {
  
          var host = this; // help compression
  
          // Perf tweak - avoid creating event literals if not required.
          host._ATTR_E_FACADE = {};
  
          EventTarget.call(host, {emitFacade:true});
  
          // _conf maintained for backwards compat
          host._conf = host._state = new Y.State();
  
          host._stateProxy = host._stateProxy || null;
          host._requireAddAttr = host._requireAddAttr || false;
  
          this._initAttrs(attrs, values, lazy);
      }
  
      /**
       * <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 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 _ATTR_CFG
       * @type Array
       * @static
       * @protected
       */
      Attribute._ATTR_CFG = [SETTER, GETTER, VALIDATOR, VALUE, VALUE_FN, WRITE_ONCE, READ_ONLY, LAZY_ADD, BROADCAST, BYPASS_PROXY];
  
      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 &#60;Any&#62;</dt>
           *    <dd>The initial value to set on the attribute</dd>
           *
           *    <dt>valueFn &#60;Function | String&#62;</dt>
           *    <dd>
           *    <p>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 both the value and valueFn properties are defined, 
           *    the value returned by the valueFn has precedence over the value property, unless it returns undefined, in which 
           *    case the value property is used.</p>
           *
           *    <p>valueFn can also be set to a string, representing the name of the instance method to be used to retrieve the value.</p>
           *    </dd>
           *
           *    <dt>readOnly &#60;boolean&#62;</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 &#60;boolean&#62; or &#60;string&#62;</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.
           *        <p>The writeOnce attribute can also be set to the string "initOnly", in which case the attribute can only be set during initialization
           *        (when used with Base, this means it can only be set during construction)</p>
           *    </dd>
           *
           *    <dt>setter &#60;Function | String&#62;</dt>
           *    <dd>
           *    <p>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.
           *    </p>
           *    
           *    <p>setter can also be set to a string, representing the name of the instance method to be used as the setter function.</p>
           *    </dd>
           *      
           *    <dt>getter &#60;Function | String&#62;</dt>
           *    <dd>
           *    <p>
           *    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.
           *    </p>
           *
           *    <p>getter can also be set to a string, representing the name of the instance method to be used as the getter function.</p>
           *    </dd>
           *
           *    <dt>validator &#60;Function | String&#62;</dt>
           *    <dd>
           *    <p>
           *    The validator function invoked prior to setting the stored value. Returning
           *    false from the validator function will prevent the value from being stored.
           *    </p>
           *    
           *    <p>validator can also be set to a string, representing the name of the instance method to be used as the validator function.</p>
           *    </dd>
           *    
           *    <dt>broadcast &#60;int&#62;</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 &#60;boolean&#62;</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>
           *
           * <p>Configuration properties outside of the list mentioned above are considered private properties used internally by attribute, and are not intended for public use.</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 host = this, // help compression
                  state = host._state,
                  value,
                  hasValue;
  
              lazy = (LAZY_ADD in config) ? config[LAZY_ADD] : lazy;
  
              if (lazy && !host.attrAdded(name)) {
                  state.add(name, LAZY, config || {});
                  state.add(name, ADDED, true);
              } else {
  
                  if (host.attrAdded(name) && !state.get(name, IS_LAZY_ADD)) { Y.log('Attribute: ' + name + ' already exists. Cannot add it again without removing it first', 'warn', 'attribute'); }
  
                  if (!host.attrAdded(name) || state.get(name, IS_LAZY_ADD)) {
  
                      config = config || {};
  
                      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 config directly
                          value = config.value;
                          delete config.value;
                      }
  
                      config.added = true;
                      config.initializing = true;
  
                      state.addAll(name, config);
  
                      if (hasValue) {
                          // Go through set, so that raw values get normalized/validated
                          host.set(name, value);
                      }
  
                      state.remove(name, INITIALIZING);
                  }
              }
  
              return host;
          },
  
          /**
           * 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._state.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) {
              var host = this, // help compression
                  prop, state;
  
              if (host.attrAdded(name)) {
  
                  if (host._isLazyAttr(name)) {
                      host._addLazyAttr(name);
                  }
  
                  state = host._state;
                  for (prop in config) {
                      if (MODIFIABLE[prop] && config.hasOwnProperty(prop)) {
                          state.add(name, prop, config[prop]);
  
                          // If we reconfigured broadcast, need to republish
                          if (prop === BROADCAST) {
                              state.remove(name, PUBLISHED);
                          }
                      }
                  }
              }
  
              if (!host.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._state.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) {
              return this._getAttr(name);
          },
  
          /**
           * 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._state.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 state = this._state,
                  lazyCfg = state.get(name, LAZY);
  
              state.add(name, IS_LAZY_ADD, true);
              state.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) {
              var host = this,  // help compression
                  added;
  
              if (name) {
                  if (host._isLazyAttr(name)) {
                      host._addLazyAttr(name);
                  }
                  host.set(name, host._state.get(name, INIT_VALUE));
              } else {
                  added = host._state.data.added;
                  Y.each(added, function(v, n) {
                      host.reset(n);
                  }, host);
              }
              return host;
          },
  
          /**
           * 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 get method,
           * allowing Attribute hosts to over-ride either method.
           *
           * See <a href="#method_get">get</a> for argument details.
           *
           * @method _getAttr
           * @protected
           * @chainable
           *
           * @param {String} name The name of the attribute.
           * @return {Any} The value of the attribute.
           */
          _getAttr : function(name) {
              var host = this, // help compression
                  fullName = name,
                  state = host._state,
                  path,
                  getter,
                  val,
                  cfg;
  
              if (name.indexOf(DOT) !== -1) {
                  path = name.split(DOT);
                  name = path.shift();
              }
  
              // On Demand - Should be rare - handles out of order valueFn references
              if (host._tCfgs && host._tCfgs[name]) {
                  cfg = {};
                  cfg[name] = host._tCfgs[name];
                  delete host._tCfgs[name];
                  host._addAttrs(cfg, host._tVals);
              }
  
              // Lazy Init
              if (host._isLazyAttr(name)) {
                  host._addLazyAttr(name);
              }
  
              val = host._getStateVal(name);
              getter = state.get(name, GETTER);
  
              if (getter && !getter.call) {
                  getter = this[getter];
              }
  
              val = (getter) ? getter.call(host, val, fullName) : val;
              val = (path) ? O.getValue(val, path) : val;
  
              return val;
          },
  
          /**
           * 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,
                  state = this._state,
                  stateProxy = this._stateProxy,
                  data = state.data,
                  initialSet,
                  strPath,
                  path,
                  currVal,
                  writeOnce,
                  initializing;
  
              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 (stateProxy && name in stateProxy && !this._state.get(name, BYPASS_PROXY)) {
                  // TODO: Value is always set for proxy. Can we do any better? Maybe take a snapshot as the initial value for the first call to set? 
                  initialSet = false;
              }
  
              if (this._requireAddAttr && !this.attrAdded(name)) {
                  Y.log('Set attribute:' + name + ', aborted; Attribute is not configured', 'warn', 'attribute');
              } else {
  
                  writeOnce = state.get(name, WRITE_ONCE);
                  initializing = state.get(name, INITIALIZING);
  
                  if (!initialSet && !force) {
  
                      if (writeOnce) {
                          Y.log('Set attribute:' + name + ', aborted; Attribute is writeOnce', 'warn', 'attribute');
                          allowSet = false;
                      }
  
                      if (state.get(name, READ_ONLY)) {
                          Y.log('Set attribute:' + name + ', aborted; Attribute is readOnly', 'warn', 'attribute');
                          allowSet = false;
                      }
                  }
  
                  if (!initializing && !force && writeOnce === INIT_ONLY) {
                      Y.log('Set attribute:' + name + ', aborted; Attribute is writeOnce: "initOnly"', 'warn', 'attribute');
                      allowSet = false;
                  }
  
                  if (allowSet) {
                      // Don't need currVal if initialSet (might fail in custom getter if it always expects a non-undefined/non-null value)
                      if (!initialSet) {
                          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 (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 host = this,
                  eventName = attrName + CHANGE,
                  state = host._state,
                  facade;
  
              if (!state.get(attrName, PUBLISHED)) {
                  host.publish(eventName, {
                      queuable:false,
                      defaultTargetOnly: true, 
                      defaultFn:host._defAttrChangeFn, 
                      silent:true,
                      broadcast : state.get(attrName, BROADCAST)
                  });
                  state.add(attrName, PUBLISHED, true);
              }
  
              facade = (opts) ? Y.merge(opts) : host._ATTR_E_FACADE;
  
              // Not using the single object signature for fire({type:..., newVal:...}), since 
              // we don't want to override type. Changed to the fire(type, {newVal:...}) signature.
  
              // facade.type = eventName;
              facade.attrName = attrName;
              facade.subAttrName = subAttrName;
              facade.prevVal = currVal;
              facade.newVal = newVal;
  
              // host.fire(facade);
              host.fire(eventName, 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.get(e.attrName);
              }
          },
  
          /**
           * Gets the stored value for the attribute, from either the 
           * internal state object, or the state proxy if it exits
           * 
           * @method _getStateVal
           * @private
           * @param {String} name The name of the attribute
           * @return {Any} The stored value of the attribute
           */
          _getStateVal : function(name) {
              var stateProxy = this._stateProxy;
              return stateProxy && (name in stateProxy) && !this._state.get(name, BYPASS_PROXY) ? stateProxy[name] : this._state.get(name, VALUE);
          },
  
          /**
           * Sets the stored value for the attribute, in either the 
           * internal state object, or the state proxy if it exits
           *
           * @method _setStateVal
           * @private
           * @param {String} name The name of the attribute
           * @param {Any} value The value of the attribute
           */
          _setStateVal : function(name, value) {
              var stateProxy = this._stateProxy;
              if (stateProxy && (name in stateProxy) && !this._state.get(name, BYPASS_PROXY)) {
                  stateProxy[name] = value;
              } else {
                  this._state.add(name, VALUE, 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 host = this,
                  allowSet = true,
                  state = host._state,
  
                  validator = state.get(attrName, VALIDATOR),
                  setter = state.get(attrName, SETTER),
                  initializing = state.get(attrName, INITIALIZING),
                  prevValRaw = this._getStateVal(attrName),
  
                  name = subAttrName || attrName,
                  retVal,
                  valid;
  
              if (validator) {
                  if (!validator.call) { 
                      // Assume string - trying to keep critical path tight, so avoiding Lang check
                      validator = this[validator];
                  }
                  if (validator) {
                      valid = validator.call(host, newVal, name);
  
                      if (!valid && initializing) {
                          newVal = state.get(attrName, DEF_VALUE);
                          valid = true; // Assume it's valid, for perf.
                      }
                  }
              }
  
              if (!validator || valid) {
                  if (setter) {
                      if (!setter.call) {
                          // Assume string - trying to keep critical path tight, so avoiding Lang check
                          setter = this[setter];
                      }
                      if (setter) {
                          retVal = setter.call(host, 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 === prevValRaw) && !Lang.isObject(newVal)) {
                          Y.log('Attribute: ' + attrName + ', value unchanged:' + newVal, 'warn', 'attribute');
                          allowSet = false;
                      } else {
                          // Store value
                          if (state.get(attrName, INIT_VALUE) === undefined) {
                              state.add(attrName, INIT_VALUE, newVal);
                          }
                          host._setStateVal(attrName, 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, opts) {
              return this._setAttrs(attrs, opts);
          },
  
          /**
           * Implementation behind the public setAttrs method, to set multiple attribute values.
           *
           * @method _setAttrs
           * @protected
           * @param {Object} attrs  An object with attributes name/value pairs.
           * @return {Object} A reference to the host object.
           * @chainable
           */
          _setAttrs : function(attrs, opts) {
              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) {
              return this._getAttrs(attrs);
          },
  
          /**
           * Implementation behind the public getAttrs method, to get multiple attribute values.
           *
           * @method _getAttrs
           * @protected
           * @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 host = this,
                  o = {}, 
                  i, l, attr, val,
                  modifiedOnly = (attrs === true);
  
              attrs = (attrs && !modifiedOnly) ? attrs : O.keys(host._state.data.added);
  
              for (i = 0, l = attrs.length; i < l; i++) {
                  // Go through get, to honor cloning/normalization
                  attr = attrs[i];
                  val = host.get(attr);
  
                  if (!modifiedOnly || host._getStateVal(attr) != host._state.get(attr, INIT_VALUE)) {
                      o[attr] = host.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) {
              var host = this; // help compression
              if (cfgs) {
                  host._tCfgs = cfgs;
                  host._tVals = host._normAttrVals(values);
                  host._addAttrs(cfgs, host._tVals, lazy);
                  host._tCfgs = host._tVals = null;
              }
  
              return host;
          },
  
          /**
           * 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 host = this, // help compression
                  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 = host._getAttrInitVal(attr, attrCfg, host._tVals);
  
                      if (value !== undefined) {
                          attrCfg.value = value;
                      }
  
                      if (host._tCfgs[attr]) {
                          delete host._tCfgs[attr];
                      }
  
                      host.addAttr(attr, attrCfg, lazy);
                  }
              }
          },
  
          /**
           * Utility method to protect an attribute configuration
           * hash, by merging the entire object and the individual 
           * attr config objects. 
           *
           * @method _protectAttrs
           * @protected
           * @param {Object} attrs A hash of attribute to configuration object pairs.
           * @return {Object} A protected version of the attrs argument.
           */
          _protectAttrs : function(attrs) {
              if (attrs) {
                  attrs = Y.merge(attrs);
                  for (var attr in attrs) {
                      if (attrs.hasOwnProperty(attr)) {
                          attrs[attr] = Y.merge(attrs[attr]);
                      }
                  }
              }
              return attrs;
          },
  
          /**
           * Utility method to normalize attribute values. The base implementation 
           * simply merges the hash to protect the original.
           *
           * @method _normAttrVals
           * @param {Object} valueHash An object with attribute name/value pairs
           *
           * @return {Object}
           *
           * @private
           */
          _normAttrVals : function(valueHash) {
              return (valueHash) ? Y.merge(valueHash) : 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 _normAttrVals
           *
           * @return {Any} The initial value of the attribute.
           *
           * @method _getAttrInitVal
           * @private
           */
          _getAttrInitVal : function(attr, cfg, initValues) {
              var val, valFn;
              // init value is provided by the user if it exists, else, provided by the config
              if (!cfg[READ_ONLY] && initValues && initValues.hasOwnProperty(attr)) {
                  val = initValues[attr];
              } else {
                  val = cfg[VALUE];
                  valFn = cfg[VALUE_FN];
   
                  if (valFn) {
                      if (!valFn.call) {
                          valFn = this[valFn];
                      }
                      if (valFn) {
                          val = valFn.call(this);
                      }
                  }
              }
  
              Y.log('initValue for ' + attr + ':' + val, 'info', 'attribute');
  
              return val;
          },
  
          /**
           * Returns an object with the configuration properties (and value)
           * for the given attrubute. If attrName is not provided, returns the
           * configuration properties for all attributes.
           *
           * @method _getAttrCfg
           * @protected
           * @param {String} name Optional. The attribute name. If not provided, the method will return the configuration for all attributes.
           * @return {Object} The configuration properties for the given attribute, or all attributes.
           */
          _getAttrCfg : function(name) {
              var o,
                  data = this._state.data;
  
              if (data) {
                  o = {};
  
                  Y.each(data, function(cfg, cfgProp) {
                      if (name) {
                          if(name in cfg) {
                              o[cfgProp] = cfg[name];
                          }
                      } else {
                          Y.each(cfg, function(attrCfg, attr) {
                             o[attr] = o[attr] || {};
                             o[attr][cfgProp] = attrCfg;
                          });
                      }
                  });
              }
  
              return o;
          },
  
          /**
           * Utility method to set up initial attributes defined during construction, either through the constructor.ATTRS property, or explicitly passed in.
           * 
           * @method _initAttrs
           * @protected
           * @param attrs {Object} The attributes to add during construction (passed through to <a href="#method_addAttrs">addAttrs</a>). These can also be defined on the constructor being augmented with Attribute by defining the ATTRS property on the constructor.
           * @param values {Object} The initial attribute values to apply (passed through to <a href="#method_addAttrs">addAttrs</a>). These are not merged/cloned. The caller is responsible for isolating user provided values if required.
           * @param lazy {boolean} Whether or not to add attributes lazily (passed through to <a href="#method_addAttrs">addAttrs</a>).
           */
          _initAttrs : function(attrs, values, lazy) {
              // ATTRS support for Node, which is not Base based
              attrs = attrs || this.constructor.ATTRS;
      
              var Base = Y.Base;
              if ( attrs && !(Base && Y.instanceOf(this, Base))) {
                  this.addAttrs(this._protectAttrs(attrs), values, lazy);
              }
          }
      };
  
      // Basic prototype augment - no lazy constructor invocation.
      Y.mix(Attribute, EventTarget, false, null, 1);
  
      Y.Attribute = Attribute;
  
  
  }, '3.4.0' ,{requires:['event-custom']});
  