Yahoo! UI Library

event  3.0.0b1

Yahoo! UI Library > event > event-dom.js (source view)
Search:
 
Filters
(function() {
/**
 * DOM event listener abstraction layer
 * @module event
 */

/**
 * The event utility provides functions to add and remove event listeners,
 * event cleansing.  It also tries to automatically remove listeners it
 * registers during the unload event.
 *
 * @class Event
 * @static
 */


var add = YUI.Env.add,
remove = YUI.Env.remove,

onLoad = function() {
    YUI.Env.windowLoaded = true;
    Y.Event._load();
    remove(window, "load", onLoad);
},

onUnload = function() {
    Y.Event._unload();
    remove(window, "unload", onUnload);
},

EVENT_READY = 'domready',

COMPAT_ARG = '~yui|2|compat~',

shouldIterate = function(o) {
    try {
         
        // Y.log('node? ' + (o instanceof Y.Node) + ', ' + ((o.size) ? o.size() : ' no size'));
        // if (o instanceof Y.Node) {
            // o.tagName ="adsf";
        // }

        return ( o                     && // o is something
                 typeof o !== "string" && // o is not a string
                 // o.length  && // o is indexed
                 (o.length && ((!o.size) || (o.size() > 1)))  && // o is indexed
                 !o.tagName            && // o is not an HTML element
                 !o.alert              && // o is not a window
                 (o.item || typeof o[0] !== "undefined") );
    } catch(ex) {
        Y.log("collection check failure", "warn", "event");
        return false;
    }

},

Event = function() {

    /**
     * True after the onload event has fired
     * @property _loadComplete
     * @type boolean
     * @static
     * @private
     */
    var _loadComplete =  false,

    /**
     * The number of times to poll after window.onload.  This number is
     * increased if additional late-bound handlers are requested after
     * the page load.
     * @property _retryCount
     * @static
     * @private
     */
    _retryCount = 0,

    /**
     * onAvailable listeners
     * @property _avail
     * @static
     * @private
     */
    _avail = [],

    /**
     * Custom event wrappers for DOM events.  Key is 
     * 'event:' + Element uid stamp + event type
     * @property _wrappers
     * @type Y.Event.Custom
     * @static
     * @private
     */
    _wrappers = {},

    _windowLoadKey = null,

    /**
     * Custom event wrapper map DOM events.  Key is 
     * Element uid stamp.  Each item is a hash of custom event
     * wrappers as provided in the _wrappers collection.  This
     * provides the infrastructure for getListeners.
     * @property _el_events
     * @static
     * @private
     */
    _el_events = {};

    return {

        /**
         * The number of times we should look for elements that are not
         * in the DOM at the time the event is requested after the document
         * has been loaded.  The default is 2000@amp;20 ms, so it will poll
         * for 40 seconds or until all outstanding handlers are bound
         * (whichever comes first).
         * @property POLL_RETRYS
         * @type int
         * @static
         * @final
         */
        POLL_RETRYS: 1000,

        /**
         * The poll interval in milliseconds
         * @property POLL_INTERVAL
         * @type int
         * @static
         * @final
         */
        POLL_INTERVAL: 40,

        /**
         * addListener/removeListener can throw errors in unexpected scenarios.
         * These errors are suppressed, the method returns false, and this property
         * is set
         * @property lastError
         * @static
         * @type Error
         */
        lastError: null,


        /**
         * poll handle
         * @property _interval
         * @static
         * @private
         */
        _interval: null,

        /**
         * document readystate poll handle
         * @property _dri
         * @static
         * @private
         */
         _dri: null,

        /**
         * True when the document is initially usable
         * @property DOMReady
         * @type boolean
         * @static
         */
        DOMReady: false,

        /**
         * @method startInterval
         * @static
         * @private
         */
        startInterval: function() {
            var E = Y.Event;

            if (!E._interval) {
E._interval = setInterval(Y.bind(E._poll, E), E.POLL_INTERVAL);
            }
        },

        /**
         * Executes the supplied callback when the item with the supplied
         * id is found.  This is meant to be used to execute behavior as
         * soon as possible as the page loads.  If you use this after the
         * initial page load it will poll for a fixed time for the element.
         * The number of times it will poll and the frequency are
         * configurable.  By default it will poll for 10 seconds.
         *
         * <p>The callback is executed with a single parameter:
         * the custom object parameter, if provided.</p>
         *
         * @method onAvailable
         *
         * @param {string||string[]}   id the id of the element, or an array
         * of ids to look for.
         * @param {function} fn what to execute when the element is found.
         * @param {object}   p_obj an optional object to be passed back as
         *                   a parameter to fn.
         * @param {boolean|object}  p_override If set to true, fn will execute
         *                   in the context of p_obj, if set to an object it
         *                   will execute in the context of that object
         * @param checkContent {boolean} check child node readiness (onContentReady)
         * @static
         * @deprecated Use Y.on("available")
         */
        // @TODO fix arguments
        onAvailable: function(id, fn, p_obj, p_override, checkContent, compat) {

            var a = Y.Array(id), i;

            // Y.log('onAvailable registered for: ' + id);

            for (i=0; i<a.length; i=i+1) {
                _avail.push({ 
                    id:         a[i], 
                    fn:         fn, 
                    obj:        p_obj, 
                    override:   p_override, 
                    checkReady: checkContent,
                    compat:     compat 
                });
            }
            _retryCount = this.POLL_RETRYS;

            // We want the first test to be immediate, but async
            setTimeout(Y.bind(Y.Event._poll, Y.Event), 0);

            return new Y.EventHandle(); // @TODO by id needs a defered handle
        },

        /**
         * Works the same way as onAvailable, but additionally checks the
         * state of sibling elements to determine if the content of the
         * available element is safe to modify.
         *
         * <p>The callback is executed with a single parameter:
         * the custom object parameter, if provided.</p>
         *
         * @method onContentReady
         *
         * @param {string}   id the id of the element to look for.
         * @param {function} fn what to execute when the element is ready.
         * @param {object}   p_obj an optional object to be passed back as
         *                   a parameter to fn.
         * @param {boolean|object}  p_override If set to true, fn will execute
         *                   in the context of p_obj.  If an object, fn will
         *                   exectute in the context of that object
         *
         * @static
         * @deprecated Use Y.on("contentready")
         */
        // @TODO fix arguments
        onContentReady: function(id, fn, p_obj, p_override, compat) {
            return this.onAvailable(id, fn, p_obj, p_override, true, compat);
        },


        /**
         * Appends an event handler
         *
         * @method attach
         *
         * @param {String}   type     The type of event to append
         * @param {Function} fn        The method the event invokes
         * @param {String|HTMLElement|Array|NodeList} el An id, an element 
         *  reference, or a collection of ids and/or elements to assign the 
         *  listener to.
         * @param {Object}   obj    An arbitrary object that will be 
         *                             passed as a parameter to the handler
         * @param {Boolean|object}  args 0..n arguments to pass to the callback
         * @return {Boolean} True if the action was successful or defered,
         *                        false if one or more of the elements 
         *                        could not have the listener attached,
         *                        or if the operation throws an exception.
         * @static
         */

        attach: function(type, fn, el, obj) {
            return Y.Event._attach(Y.Array(arguments, 0, true));
        },

		_createWrapper: function (el, type, capture, compat, facade) {

            var ek = Y.stamp(el),
	            key = 'event:' + ek + type,
	            cewrapper;


            if (false === facade) {
                key += 'native';
            }
            if (capture) {
                key += 'capture';
            }


            cewrapper = _wrappers[key];
            

            if (!cewrapper) {
                // create CE wrapper
                cewrapper = Y.publish(key, {
                    //silent: true,
                    // host: this,
                    bubbles: false,
                    contextFn: function() {
                        cewrapper.nodeRef = cewrapper.nodeRef || Y.get(cewrapper.el);
                        return cewrapper.nodeRef;
                    }
                });
            
                // for later removeListener calls
                cewrapper.el = el;
                cewrapper.type = type;
                cewrapper.fn = function(e) {
                    cewrapper.fire(Y.Event.getEvent(e, el, (compat || (false === facade))));
                };
            
                if (el == Y.config.win && type == "load") {
                    // window load happens once
                    cewrapper.fireOnce = true;
                    _windowLoadKey = key;
                }
            
                _wrappers[key] = cewrapper;
                _el_events[ek] = _el_events[ek] || {};
                _el_events[ek][key] = cewrapper;
            
                add(el, type, cewrapper.fn, capture);
            }

			return cewrapper;
			
		},

        _attach: function(args, config) {

            var trimmedArgs=args.slice(1),
                compat, E=Y.Event,
                handles, oEl, cewrapper, context, 
                fireNow = false, ret,
                type = args[0],
                fn = args[1],
                el = args[2] || Y.config.win,
                facade = config && config.facade,
                capture = config && config.capture;

            if (trimmedArgs[trimmedArgs.length-1] === COMPAT_ARG) {
                compat = true;
                trimmedArgs.pop();
            }

            if (!fn || !fn.call) {
// throw new TypeError(type + " attach call failed, callback undefined");
Y.log(type + " attach call failed, invalid callback", "error", "event");
                return false;
            }

            // The el argument can be an array of elements or element ids.
            if (shouldIterate(el)) {

                // Y.log('collection: ' + el);
                // Y.log('collection: ' + el.item(0) + ', ' + el.item(1));

                handles=[];
                
                Y.each(el, function(v, k) {
                    args[2] = v;
                    handles.push(E._attach(args, config));
                });

                return (handles.length === 1) ? handles[0] : handles;

            // If the el argument is a string, we assume it is 
            // actually the id of the element.  If the page is loaded
            // we convert el to the actual element, otherwise we 
            // defer attaching the event until the element is
            // ready
            } else if (Y.Lang.isString(el)) {

                // @TODO switch to using DOM directly here
                // oEl = (compat) ? Y.DOM.byId(el) : Y.all(el);
                oEl = (compat) ? Y.DOM.byId(el) : Y.Selector.query(el);

                if (oEl) {

                    if (Y.Lang.isArray(oEl)) {
                        if (oEl.length == 1) {
                            el = oEl[0];
                        } else {
                            args[2] = oEl;
                            return E._attach(args, config);
                        }

                    // HTMLElement
                    } else {
                        // Y.log('no size: ' + oEl + ', ' + type);
                        el = oEl;
                    }

                // Not found = defer adding the event until the element is available
                } else {

                    // Y.log(el + ' not found');

                    return this.onAvailable(el, function() {
                        // Y.log('lazy attach: ' + args);
                        E._attach(args, config);
                    }, E, true, false, compat);
                }
            }

            // Element should be an html element or an array if we get here.
            if (!el) {
                Y.log("unable to attach event " + type, "warn", "event");
                return false;
            }

            // the custom event key is the uid for the element + type

            // allow a node reference to Y.on to work with load time addEventListener check
            // (Node currently only has the addEventListener interface and that may be
            // removed).
            if (Y.Node && el instanceof Y.Node) {
                return el.on.apply(el, args);
            }

 			cewrapper = this._createWrapper(el, type, capture, compat, facade);

            if (el == Y.config.win && type == "load") {

                // if the load is complete, fire immediately.
                // all subscribers, including the current one
                // will be notified.
                if (YUI.Env.windowLoaded) {
                    fireNow = true;
                }
            }

            // switched from obj to trimmedArgs[2] to deal with appened compat param
            // context = trimmedArgs[2] || ((compat) ? el : Y.get(el));
            context = trimmedArgs[2];
            
            // set the context as the second arg to subscribe
            trimmedArgs[1] = context;

            // remove the 'obj' param
            trimmedArgs.splice(2, 1);

            // set context to the Node if not specified
            ret = cewrapper.subscribe.apply(cewrapper, trimmedArgs);

            if (fireNow) {
                cewrapper.fire();
            }

            return ret;

        },

        /**
         * Removes an event listener.  Supports the signature the event was bound
         * with, but the preferred way to remove listeners is using the handle
         * that is returned when using Y.on
         *
         * @method detach
         *
         * @param {String|HTMLElement|Array|NodeList} el An id, an element 
         *  reference, or a collection of ids and/or elements to remove
         *  the listener from.
         * @param {String} type the type of event to remove.
         * @param {Function} fn the method the event invokes.  If fn is
         *  undefined, then all event handlers for the type of event are *  removed.
         * @return {boolean} true if the unbind was successful, false *  otherwise.
         * @static
         */
        detach: function(type, fn, el, obj) {

            var args=Y.Array(arguments, 0, true), compat, i, len, ok,
                id, ce;

            if (args[args.length-1] === COMPAT_ARG) {
                compat = true;
                // args.pop();
            }

            if (type && type.detach) {
                return type.detach();
            }


            // The el argument can be a string
            if (typeof el == "string") {

                // el = (compat) ? Y.DOM.byId(el) : Y.all(el);
                el = (compat) ? Y.DOM.byId(el) : Y.Selector.query(el);
                return Y.Event.detach.apply(Y.Event, args);

            // The el argument can be an array of elements or element ids.
            } else if (shouldIterate(el)) {

                ok = true;
                for (i=0, len=el.length; i<len; ++i) {
                    args[2] = el[i];
                    ok = ( Y.Event.detach.apply(Y.Event, args) && ok );
                }

                return ok;

            }

            if (!type || !fn || !fn.call) {
                return this.purgeElement(el, false, type);
            }

            id = 'event:' + Y.stamp(el) + type;
            ce = _wrappers[id];

            if (ce) {
                return ce.detach(fn);
            } else {
                return false;
            }

        },

        /**
         * Finds the event in the window object, the caller's arguments, or
         * in the arguments of another method in the callstack.  This is
         * executed automatically for events registered through the event
         * manager, so the implementer should not normally need to execute
         * this function at all.
         * @method getEvent
         * @param {Event} e the event parameter from the handler
         * @param {HTMLElement} el the element the listener was attached to
         * @return {Event} the event 
         * @static
         */
        getEvent: function(e, el, noFacade) {
            var ev = e || window.event;

            return (noFacade) ? ev : 
                new Y.DOMEventFacade(ev, el, _wrappers['event:' + Y.stamp(el) + e.type]);
        },

        /**
         * Generates an unique ID for the element if it does not already 
         * have one.
         * @method generateId
         * @param el the element to create the id for
         * @return {string} the resulting id of the element
         * @static
         */
        generateId: function(el) {
            var id = el.id;

            if (!id) {
                id = Y.stamp(el);
                el.id = id;
            }

            return id;
        },

        /**
         * We want to be able to use getElementsByTagName as a collection
         * to attach a group of events to.  Unfortunately, different 
         * browsers return different types of collections.  This function
         * tests to determine if the object is array-like.  It will also 
         * fail if the object is an array, but is empty.
         * @method _isValidCollection
         * @param o the object to test
         * @return {boolean} true if the object is array-like and populated
         * @deprecated was not meant to be used directly
         * @static
         * @private
         */
        _isValidCollection: shouldIterate,

        /**
         * hook up any deferred listeners
         * @method _load
         * @static
         * @private
         */
        _load: function(e) {

            if (!_loadComplete) {

                // Y.log('Load Complete', 'info', 'event');

                _loadComplete = true;

                // Just in case DOMReady did not go off for some reason
                // E._ready();
                if (Y.fire) {
                    Y.fire(EVENT_READY);
                }

                // Available elements may not have been detected before the
                // window load event fires. Try to find them now so that the
                // the user is more likely to get the onAvailable notifications
                // before the window load notification
                Y.Event._poll();

            }
        },

        /**
         * Polling function that runs before the onload event fires, 
         * attempting to attach to DOM Nodes as soon as they are 
         * available
         * @method _poll
         * @static
         * @private
         */
        _poll: function() {

            if (this.locked) {
                return;
            }

            if (Y.UA.ie && !YUI.Env.DOMReady) {
                // Hold off if DOMReady has not fired and check current
                // readyState to protect against the IE operation aborted
                // issue.
                this.startInterval();
                return;
            }

            this.locked = true;

            // Y.log.debug("poll");

            // keep trying until after the page is loaded.  We need to 
            // check the page load state prior to trying to bind the 
            // elements so that we can be certain all elements have been 
            // tested appropriately
            var tryAgain = !_loadComplete, notAvail, executeItem,
                i, len, item, el;

            if (!tryAgain) {
                tryAgain = (_retryCount > 0);
            }

            // onAvailable
            notAvail = [];

            executeItem = function (el, item) {

                var context, ov = item.override;

                if (item.compat) {

                    if (item.override) {
                        if (ov === true) {
                            context = item.obj;
                        } else {
                            context = ov;
                        }
                    } else {
                        context = el;
                    }

                    item.fn.call(context, item.obj);

                } else {
                    context = item.obj || Y.get(el);
                    item.fn.apply(context, (Y.Lang.isArray(ov)) ? ov : []);
                }

            };


            // onAvailable
            for (i=0,len=_avail.length; i<len; ++i) {
                item = _avail[i];
                if (item && !item.checkReady) {

                    // el = (item.compat) ? Y.DOM.byId(item.id) : Y.get(item.id);
                    el = (item.compat) ? Y.DOM.byId(item.id) : Y.Selector.query(item.id, null, true);

                    if (el) {
                        // Y.log('avail: ' + el);
                        executeItem(el, item);
                        _avail[i] = null;
                    } else {
                        // Y.log('NOT avail: ' + el);
                        notAvail.push(item);
                    }
                }
            }

            // onContentReady
            for (i=0,len=_avail.length; i<len; ++i) {
                item = _avail[i];
                if (item && item.checkReady) {

                    // el = (item.compat) ? Y.DOM.byId(item.id) : Y.get(item.id);
                    el = (item.compat) ? Y.DOM.byId(item.id) : Y.Selector.query(item.id, null, true);

                    if (el) {
                        // The element is available, but not necessarily ready
                        // @todo should we test parentNode.nextSibling?
                        if (_loadComplete || (el.get && el.get('nextSibling')) || el.nextSibling) {
                            executeItem(el, item);
                            _avail[i] = null;
                        }
                    } else {
                        notAvail.push(item);
                    }
                }
            }

            _retryCount = (notAvail.length === 0) ? 0 : _retryCount - 1;

            if (tryAgain) {
                // we may need to strip the nulled out items here
                this.startInterval();
            } else {
                clearInterval(this._interval);
                this._interval = null;
            }

            this.locked = false;

            return;

        },

        /**
         * Removes all listeners attached to the given element via addListener.
         * Optionally, the node's children can also be purged.
         * Optionally, you can specify a specific type of event to remove.
         * @method purgeElement
         * @param {HTMLElement} el the element to purge
         * @param {boolean} recurse recursively purge this element's children
         * as well.  Use with caution.
         * @param {string} type optional type of listener to purge. If
         * left out, all listeners will be removed
         * @static
         */
        purgeElement: function(el, recurse, type) {
            // var oEl = (Y.Lang.isString(el)) ? Y.get(el) : el,
            var oEl = (Y.Lang.isString(el)) ?  Y.Selector.query(el, null, true) : el,
                lis = this.getListeners(oEl, type), i, len;
            if (lis) {
                for (i=0,len=lis.length; i<len ; ++i) {
                    lis[i].detachAll();
                }
            }

            if (recurse && oEl && oEl.childNodes) {
                for (i=0,len=oEl.childNodes.length; i<len ; ++i) {
                    this.purgeElement(oEl.childNodes[i], recurse, type);
                }
            }
        },

        /**
         * Returns all listeners attached to the given element via addListener.
         * Optionally, you can specify a specific type of event to return.
         * @method getListeners
         * @param el {HTMLElement|string} the element or element id to inspect 
         * @param type {string} optional type of listener to return. If
         * left out, all listeners will be returned
         * @return {Y.Custom.Event} the custom event wrapper for the DOM event(s)
         * @static
         */           
        getListeners: function(el, type) {
            var ek = Y.stamp(el, true), evts = _el_events[ek],
                results=[] , key = (type) ? 'event:' + ek + type : null;

            if (!evts) {
                return null;
            }

            if (key) {
                if (evts[key]) {
                    results.push(evts[key]);
                }
            } else {
                Y.each(evts, function(v, k) {
                    results.push(v);
                });
            }

            return (results.length) ? results : null;
        },

        /**
         * Removes all listeners registered by pe.event.  Called 
         * automatically during the unload event.
         * @method _unload
         * @static
         * @private
         */
        _unload: function(e) {

            var E = Y.Event;

            Y.each(_wrappers, function(v, k) {
                v.detachAll();
                remove(v.el, v.type, v.fn);
                delete _wrappers[k];
            });

            remove(window, "load", E._load);
            remove(window, "unload", E._unload);
        },

        
        /**
         * Adds a DOM event directly without the caching, cleanup, context adj, etc
         *
         * @method nativeAdd
         * @param {HTMLElement} el      the element to bind the handler to
         * @param {string}      type   the type of event handler
         * @param {function}    fn      the callback to invoke
         * @param {boolen}      capture capture or bubble phase
         * @static
         * @private
         */
        nativeAdd: add,

        /**
         * Basic remove listener
         *
         * @method nativeRemove
         * @param {HTMLElement} el      the element to bind the handler to
         * @param {string}      type   the type of event handler
         * @param {function}    fn      the callback to invoke
         * @param {boolen}      capture capture or bubble phase
         * @static
         * @private
         */
        nativeRemove: remove
    };

}();

Y.Event = Event;


if (Y.config.injected || YUI.Env.windowLoaded) {
    onLoad();
} else {
    add(window, "load", onLoad);
}

// Process onAvailable/onContentReady items when when the DOM is ready in IE
if (Y.UA.ie) {
    Y.on(EVENT_READY, Event._poll, Event, true);
}

add(window, "unload", onUnload);

Event.Custom = Y.CustomEvent;
Event.Subscriber = Y.Subscriber;
Event.Target = Y.EventTarget;
Event.Handle = Y.EventHandle;
Event.Facade = Y.EventFacade;

Event._poll();

})();

Copyright © 2009 Yahoo! Inc. All rights reserved.