File: attribute/js/Attribute.js

                /**
                 * 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
                 */
            
                /**
                 * <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 AttributeCore
                 * @uses AttributeObservable
                 * @uses EventTarget
                 * @uses AttributeExtras
                 */
                function Attribute() {
                    Y.AttributeCore.apply(this, arguments);
                    Y.AttributeObservable.apply(this, arguments);
                    Y.AttributeExtras.apply(this, arguments);
                }
            
                Y.mix(Attribute, Y.AttributeCore, false, null, 1);
                Y.mix(Attribute, Y.AttributeExtras, false, null, 1);
            
                // Needs to be `true`, to overwrite methods from AttributeCore
                Y.mix(Attribute, Y.AttributeObservable, true, null, 1);
            
                /**
                 * <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
                 * AttributeCore.INVALID_VALUE to prevent invalid values from being stored.</p>
                 *
                 * @property INVALID_VALUE
                 * @type Object
                 * @static
                 * @final
                 */
                Attribute.INVALID_VALUE = Y.AttributeCore.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 = Y.AttributeCore._ATTR_CFG.concat(Y.AttributeObservable._ATTR_CFG);
            
                /**
                 * Utility method to protect an attribute configuration hash, by merging the
                 * entire object and the individual attr config objects.
                 *
                 * @method protectAttrs
                 * @static
                 * @param {Object} attrs A hash of attribute to configuration object pairs.
                 * @return {Object} A protected version of the `attrs` argument.
                 */
                Attribute.protectAttrs = Y.AttributeCore.protectAttrs;
            
                Y.Attribute = Attribute;