Yahoo! UI Library

event  3.3.0pr1

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

/**
 * 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
 */

Y.Env.evt.dom_wrappers = {};
Y.Env.evt.dom_map = {};

var _eventenv = Y.Env.evt,
    config = Y.config,
    win = config.win,
    add = YUI.Env.add,
    remove = YUI.Env.remove,

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

    onUnload = function() {
        Y.Event._unload();
    },

    EVENT_READY = 'domready',

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

    shouldIterate = function(o) {
        try {
            return (o && typeof o !== "string" && Y.Lang.isNumber(o.length) &&
                    !o.tagName && !o.alert);
        } 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 = _eventenv.dom_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 = _eventenv.dom_map;

    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 1000@amp;40 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() {
            if (!Event._interval) {
Event._interval = setInterval(Event._poll, Event.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, availHandle;

            // 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(Event._poll, 0);

            availHandle = new Y.EventHandle({

                _delete: function() {
                    // set by the event system for lazy DOM listeners
                    if (availHandle.handle) {
                        availHandle.handle.detach();
                        return;
                    }

                    var i, j;

                    // otherwise try to remove the onAvailable listener(s)
                    for (i = 0; i < a.length; i++) {
                        for (j = 0; j < _avail.length; j++) {
                            if (a[i] === _avail[j].id) {
                                _avail.splice(j, 1);
                            }
                        }
                    }
                }

            });

            return availHandle;
        },

        /**
         * 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}   obj an optional object to be passed back as
         *                   a parameter to fn.
         * @param {boolean|object}  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, obj, override, compat) {
            return Event.onAvailable(id, fn, obj, override, true, compat);
        },

        /**
         * Adds an event listener
         *
         * @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}   context optional context object
         * @param {Boolean|object}  args 0..n arguments to pass to the callback
         * @return {EventHandle} an object to that can be used to detach the listener
         *
         * @static
         */

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

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

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

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


            cewrapper = _wrappers[key];


            if (!cewrapper) {
                // create CE wrapper
                cewrapper = Y.publish(key, {
                    silent: true,
                    bubbles: false,
                    contextFn: function() {
                        if (compat) {
                            return cewrapper.el;
                        } else {
                            cewrapper.nodeRef = cewrapper.nodeRef || Y.one(cewrapper.el);
                            return cewrapper.nodeRef;
                        }
                    }
                });

                cewrapper.overrides = {};

                // for later removeListener calls
                cewrapper.el = el;
                cewrapper.key = key;
                cewrapper.domkey = ek;
                cewrapper.type = type;
                cewrapper.fn = function(e) {
                    cewrapper.fire(Event.getEvent(e, el, (compat || (false === facade))));
                };
                cewrapper.capture = capture;

                if (el == 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, conf) {

            var compat,
                handles, oEl, cewrapper, context,
                fireNow = false, ret,
                type = args[0],
                fn = args[1],
                el = args[2] || win,
                facade = conf && conf.facade,
                capture = conf && conf.capture,
                overrides = conf && conf.overrides;

            if (args[args.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)) {

                handles=[];

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

                // return (handles.length === 1) ? handles[0] : handles;
                return new Y.EventHandle(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)) {

                // oEl = (compat) ? Y.DOM.byId(el) : Y.Selector.query(el);

                if (compat) {
                    oEl = Y.DOM.byId(el);
                } else {

                    oEl = Y.Selector.query(el);

                    switch (oEl.length) {
                        case 0:
                            oEl = null;
                            break;
                        case 1:
                            oEl = oEl[0];
                            break;
                        default:
                            args[2] = oEl;
                            return Event._attach(args, conf);
                    }
                }

                if (oEl) {

                    el = oEl;

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

                    // Y.log(el + ' not found');
                    ret = Event.onAvailable(el, function() {
                        // Y.log('lazy attach: ' + args);

                        ret.handle = Event._attach(args, conf);

                    }, Event, true, false, compat);

                    return ret;

                }
            }

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

            if (Y.Node && Y.instanceOf(el, Y.Node)) {
                el = Y.Node.getDOMNode(el);
            }

            cewrapper = Event._createWrapper(el, type, capture, compat, facade);
            if (overrides) {
                Y.mix(cewrapper.overrides, overrides);
            }

            if (el == 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;
                }
            }

            if (compat) {
                args.pop();
            }

            context = args[3];

            // set context to the Node if not specified
            // ret = cewrapper.on.apply(cewrapper, trimmedArgs);
            ret = cewrapper._on(fn, context, (args.length > 4) ? args.slice(4) : null);

            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} 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.
         * @param {String|HTMLElement|Array|NodeList|EventHandle} el An
         * event handle, an id, an element reference, or a collection
         * of ids and/or elements to remove the listener from.
         * @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, l, ok, i,
                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);
                if (compat) {
                    el = Y.DOM.byId(el);
                } else {
                    el = Y.Selector.query(el);
                    l = el.length;
                    if (l < 1) {
                        el = null;
                    } else if (l == 1) {
                        el = el[0];
                    }
                }
                // return Event.detach.apply(Event, args);
            }

            if (!el) {
                return false;
            }

            if (el.detach) {
                args.splice(2, 1);
                return el.detach.apply(el, args);
            // The el argument can be an array of elements or element ids.
            } else if (shouldIterate(el)) {
                ok = true;
                for (i=0, l=el.length; i<l; ++i) {
                    args[2] = el[i];
                    ok = ( Y.Event.detach.apply(Y.Event, args) && ok );
                }

                return ok;
            }

            if (!type || !fn || !fn.call) {
                return Event.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 || win.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
                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 (Event.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.
                Event.startInterval();
                return;
            }

            Event.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 i, len, item, el, notAvail, executeItem,
                tryAgain = !_loadComplete;

            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.one(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.one(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.one(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
                Event.startInterval();
            } else {
                clearInterval(Event._interval);
                Event._interval = null;
            }

            Event.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.one(el) : el,
            var oEl = (Y.Lang.isString(el)) ?  Y.Selector.query(el, null, true) : el,
                lis = Event.getListeners(oEl, type), i, len, props, children, child;

            if (recurse && oEl) {
                lis = lis || [];
                children = Y.Selector.query('*', oEl);
                i = 0;
                len = children.length;
                for (; i < len; ++i) {
                    child = Event.getListeners(children[i], type);
                    if (child) {
                        lis = lis.concat(child);
                    }
                }
            }

            if (lis) {
                i = 0;
                len = lis.length;
                for (; i < len; ++i) {
                    props = lis[i];
                    props.detachAll();
                    remove(props.el, props.type, props.fn, props.capture);
                    delete _wrappers[props.key];
                    delete _el_events[props.domkey][props.key];
                }
            }

        },


        /**
         * 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,
                adapters = _eventenv.plugins;

            if (!evts) {
                return null;
            }

            if (key) {
                // look for synthetic events
                if (adapters[type] && adapters[type].eventDef) {
                    key += '_synth';
                }

                if (evts[key]) {
                    results.push(evts[key]);
                }

                // get native events as well
                key += 'native';
                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) {
            Y.each(_wrappers, function(v, k) {
                v.detachAll();
                remove(v.el, v.type, v.fn, v.capture);
                delete _wrappers[k];
                delete _el_events[v.domkey][k];
            });
            remove(win, "unload", onUnload);
        },

        /**
         * 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 (config.injected || YUI.Env.windowLoaded) {
    onLoad();
} else {
    add(win, "load", onLoad);
}

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

add(win, "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 © 2010 Yahoo! Inc. All rights reserved.