/*
YUI 3.10.3 (build 2fb5187)
Copyright 2013 Yahoo! Inc. All rights reserved.
Licensed under the BSD License.
http://yuilibrary.com/license/
*/

YUI.add('attribute-observable', function (Y, NAME) {

    /*For log lines*/
    /*jshint maxlen:200*/


    /**
     * 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-observable` submodule provides augmentable attribute change event support
     * for AttributeCore based implementations.
     *
     * @module attribute
     * @submodule attribute-observable
     */
    var EventTarget = Y.EventTarget,

        CHANGE = "Change",
        BROADCAST = "broadcast";

    /**
     * Provides an augmentable implementation of attribute change events for
     * AttributeCore.
     *
     * @class AttributeObservable
     * @extensionfor AttributeCore
     * @uses EventTarget
     */
    function AttributeObservable() {
        // Perf tweak - avoid creating event literals if not required.
        this._ATTR_E_FACADE = {};

        EventTarget.call(this, {emitFacade:true});
    }

    AttributeObservable._ATTR_CFG = [BROADCAST];

    AttributeObservable.prototype = {

        /**
         * 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);
        },

        /**
         * 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);
        },

        /**
         * Sets multiple attribute values.
         *
         * @method setAttrs
         * @param {Object} attrs  An object with attributes name/value pairs.
         * @param {Object} opts  Properties to mix into the event payload. These are shared and mixed into each set
         * @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.
         * @param {Object} opts  Properties to mix into the event payload. These are shared and mixed into each set
         * @return {Object} A reference to the host object.
         * @chainable
         */
        _setAttrs : function(attrs, opts) {
            var attr;
            for (attr in attrs) {
                if ( attrs.hasOwnProperty(attr) ) {
                    this.set(attr, attrs[attr], 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.
         * @param {Object} [cfg] The attribute config stored in State, if already available.
         */
        _fireAttrChange : function(attrName, subAttrName, currVal, newVal, opts, cfg) {
            var host = this,
                eventName = this._getFullType(attrName + CHANGE),
                state = host._state,
                hasOpts = false,
                facade,
                broadcast,
                e;

            if (!cfg) {
                cfg = state.data[attrName] || {};
            }

            if (!cfg.published) {

                // PERF: Using lower level _publish() for
                // critical path performance
                e = host._publish(eventName);

                e.emitFacade = true;
                e.defaultTargetOnly = true;
                e.defaultFn = host._defAttrChangeFn;

                broadcast = cfg.broadcast;
                if (broadcast !== undefined) {
                    e.broadcast = broadcast;
                }

                cfg.published = true;
            }

            if (opts) {
                facade = Y.merge(opts);
                hasOpts = true;
            } else {
                facade = 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.attrName = attrName;
            facade.subAttrName = subAttrName;
            facade.prevVal = currVal;
            facade.newVal = newVal;

            if (hasOpts) {
                host.fire(eventName, facade, opts);
            } else {
                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, e.details[1])) {
                // Prevent "after" listeners from being invoked since nothing changed.
                e.stopImmediatePropagation();

            } else {
                e.newVal = this.get(e.attrName);
            }
        }
    };

    // Basic prototype augment - no lazy constructor invocation.
    Y.mix(AttributeObservable, EventTarget, false, null, 1);

    Y.AttributeObservable = AttributeObservable;

    /**
    The `AttributeEvents` class extension was deprecated in YUI 3.8.0 and is now
    an alias for the `AttributeObservable` class extension. Use that class
    extnesion instead. This alias will be removed in a future version of YUI.

    @class AttributeEvents
    @uses EventTarget
    @deprecated Use `AttributeObservable` instead.
    @see AttributeObservable
    **/
    Y.AttributeEvents = AttributeObservable;


}, '3.10.3', {"requires": ["event-custom"]});
