Sets up event delegation on a container element. The delegated event + * will use a supplied selector or filtering function to test if the event + * references at least one node that should trigger the subscription + * callback.
+ * + *Selector string filters will trigger the callback if the event originated + * from a node that matches it or is contained in a node that matches it. + * Function filters are called for each Node up the parent axis to the + * subscribing container node, and receive at each level the Node and the event + * object. The function should return true (or a truthy value) if that Node + * should trigger the subscription callback. Note, it is possible for filters + * to match multiple Nodes for a single event. In this case, the delegate + * callback will be executed for each matching Node.
+ * + *For each matching Node, the callback will be executed with its 'this'
+ * object set to the Node matched by the filter (unless a specific context was
+ * provided during subscription), and the provided event's
+ * currentTarget will also be set to the matching Node. The
+ * containing Node from which the subscription was originally made can be
+ * referenced as e.container.
+ *
+ * @method delegate
+ * @param type {String} the event type to delegate
+ * @param fn {Function} the callback function to execute. This function
+ * will be provided the event object for the delegated event.
+ * @param el {String|node} the element that is the delegation container
+ * @param filter {string|Function} a selector that must match the target of the
+ * event or a function to test target and its parents for a match
+ * @param context optional argument that specifies what 'this' refers to.
+ * @param args* 0..n additional arguments to pass on to the callback function.
+ * These arguments will be added after the event object.
+ * @return {EventHandle} the detach handle
+ * @static
+ * @for Event
+ */
+function delegate(type, fn, el, filter) {
+ var args = toArray(arguments, 0, true),
+ query = isString(el) ? el : null,
+ typeBits, synth, container, categories, cat, i, len, handles, handle;
+
+ // Support Y.delegate({ click: fnA, key: fnB }, el, filter, ...);
+ // and Y.delegate(['click', 'key'], fn, el, filter, ...);
+ if (isObject(type)) {
+ handles = [];
+
+ if (isArray(type)) {
+ for (i = 0, len = type.length; i < len; ++i) {
+ args[0] = type[i];
+ handles.push(Y.delegate.apply(Y, args));
+ }
+ } else {
+ // Y.delegate({'click', fn}, el, filter) =>
+ // Y.delegate('click', fn, el, filter)
+ args.unshift(null); // one arg becomes two; need to make space
+
+ for (i in type) {
+ if (type.hasOwnProperty(i)) {
+ args[0] = i;
+ args[1] = type[i];
+ handles.push(Y.delegate.apply(Y, args));
+ }
+ }
+ }
+
+ return new Y.EventHandle(handles);
+ }
+
+ typeBits = type.split(/\|/);
+
+ if (typeBits.length > 1) {
+ cat = typeBits.shift();
+ args[0] = type = typeBits.shift();
+ }
+
+ synth = Y.Node.DOM_EVENTS[type];
+
+ if (isObject(synth) && synth.delegate) {
+ handle = synth.delegate.apply(synth, arguments);
+ }
+
+ if (!handle) {
+ if (!type || !fn || !el || !filter) {
+ return;
+ }
+
+ container = (query) ? Y.Selector.query(query, null, true) : el;
+
+ if (!container && isString(el)) {
+ handle = Y.on('available', function () {
+ Y.mix(handle, Y.delegate.apply(Y, args), true);
+ }, el);
+ }
+
+ if (!handle && container) {
+ args.splice(2, 2, container); // remove the filter
+
+ handle = Y.Event._attach(args, { facade: false });
+ handle.sub.filter = filter;
+ handle.sub._notify = delegate.notifySub;
+ }
+ }
+
+ if (handle && cat) {
+ categories = detachCategories[cat] || (detachCategories[cat] = {});
+ categories = categories[type] || (categories[type] = []);
+ categories.push(handle);
+ }
+
+ return handle;
+}
+
+/**
+Overrides the _notify method on the normal DOM subscription to
+inject the filtering logic and only proceed in the case of a match.
+
+This method is hosted as a private property of the `delegate` method
+(e.g. `Y.delegate.notifySub`)
+
+@method notifySub
+@param thisObj {Object} default 'this' object for the callback
+@param args {Array} arguments passed to the event's fire()
+@param ce {CustomEvent} the custom event managing the DOM subscriptions for
+ the subscribed event on the subscribing node.
+@return {Boolean} false if the event was stopped
+@private
+@static
+@since 3.2.0
+**/
+delegate.notifySub = function (thisObj, args, ce) {
+ // Preserve args for other subscribers
+ args = args.slice();
+ if (this.args) {
+ args.push.apply(args, this.args);
+ }
+
+ // Only notify subs if the event occurred on a targeted element
+ var currentTarget = delegate._applyFilter(this.filter, args, ce),
+ //container = e.currentTarget,
+ e, i, len, ret;
+
+ if (currentTarget) {
+ // Support multiple matches up the the container subtree
+ currentTarget = toArray(currentTarget);
+
+ // The second arg is the currentTarget, but we'll be reusing this
+ // facade, replacing the currentTarget for each use, so it doesn't
+ // matter what element we seed it with.
+ e = args[0] = new Y.DOMEventFacade(args[0], ce.el, ce);
+
+ e.container = Y.one(ce.el);
+
+ for (i = 0, len = currentTarget.length; i < len && !e.stopped; ++i) {
+ e.currentTarget = Y.one(currentTarget[i]);
+
+ ret = this.fn.apply(this.context || e.currentTarget, args);
+
+ if (ret === false) { // stop further notifications
+ break;
+ }
+ }
+
+ return ret;
+ }
+};
+
+/**
+Compiles a selector string into a filter function to identify whether
+Nodes along the parent axis of an event's target should trigger event
+notification.
+
+This function is memoized, so previously compiled filter functions are
+returned if the same selector string is provided.
+
+This function may be useful when defining synthetic events for delegate
+handling.
+
+Hosted as a property of the `delegate` method (e.g. `Y.delegate.compileFilter`).
+
+@method compileFilter
+@param selector {String} the selector string to base the filtration on
+@return {Function}
+@since 3.2.0
+@static
+**/
+delegate.compileFilter = Y.cached(function (selector) {
+ return function (target, e) {
+ return selectorTest(target._node, selector,
+ (e.currentTarget === e.target) ? null : e.currentTarget._node);
+ };
+});
+
+/**
+Regex to test for disabled elements during filtering. This is only relevant to
+IE to normalize behavior with other browsers, which swallow events that occur
+to disabled elements. IE fires the event from the parent element instead of the
+original target, though it does preserve `event.srcElement` as the disabled
+element. IE also supports disabled on ``, but the event still bubbles, so it
+acts more like `e.preventDefault()` plus styling. That issue is not handled here
+because other browsers fire the event on the ``, so delegate is supported in
+both cases.
+
+@property _disabledRE
+@type {RegExp}
+@protected
+@since 3.8.1
+**/
+delegate._disabledRE = /^(?:button|input|select|textarea)$/i;
+
+/**
+Walks up the parent axis of an event's target, and tests each element
+against a supplied filter function. If any Nodes, including the container,
+satisfy the filter, the delegated callback will be triggered for each.
+
+Hosted as a protected property of the `delegate` method (e.g.
+`Y.delegate._applyFilter`).
+
+@method _applyFilter
+@param filter {Function} boolean function to test for inclusion in event
+ notification
+@param args {Array} the arguments that would be passed to subscribers
+@param ce {CustomEvent} the DOM event wrapper
+@return {Node|Node[]|undefined} The Node or Nodes that satisfy the filter
+@protected
+**/
+delegate._applyFilter = function (filter, args, ce) {
+ var e = args[0],
+ container = ce.el, // facadeless events in IE, have no e.currentTarget
+ target = e.target || e.srcElement,
+ match = [],
+ isContainer = false;
+
+ // Resolve text nodes to their containing element
+ if (target.nodeType === 3) {
+ target = target.parentNode;
+ }
+
+ // For IE. IE propagates events from the parent element of disabled
+ // elements, where other browsers swallow the event entirely. To normalize
+ // this in IE, filtering for matching elements should abort if the target
+ // is a disabled form control.
+ if (target.disabled && delegate._disabledRE.test(target.nodeName)) {
+ return match;
+ }
+
+ // passing target as the first arg rather than leaving well enough alone
+ // making 'this' in the filter function refer to the target. This is to
+ // support bound filter functions.
+ args.unshift(target);
+
+ if (isString(filter)) {
+ while (target) {
+ isContainer = (target === container);
+ if (selectorTest(target, filter, (isContainer ? null: container))) {
+ match.push(target);
+ }
+
+ if (isContainer) {
+ break;
+ }
+
+ target = target.parentNode;
+ }
+ } else {
+ // filter functions are implementer code and should receive wrappers
+ args[0] = Y.one(target);
+ args[1] = new Y.DOMEventFacade(e, container, ce);
+
+ while (target) {
+ // filter(target, e, extra args...) - this === target
+ if (filter.apply(args[0], args)) {
+ match.push(target);
+ }
+
+ if (target === container) {
+ break;
+ }
+
+ target = target.parentNode;
+ args[0] = Y.one(target);
+ }
+ args[1] = e; // restore the raw DOM event
+ }
+
+ if (match.length <= 1) {
+ match = match[0]; // single match or undefined
+ }
+
+ // remove the target
+ args.shift();
+
+ return match;
+};
+
+/**
+ * Sets up event delegation on a container element. The delegated event
+ * will use a supplied filter to test if the callback should be executed.
+ * This filter can be either a selector string or a function that returns
+ * a Node to use as the currentTarget for the event.
+ *
+ * The event object for the delegated event is supplied to the callback
+ * function. It is modified slightly in order to support all properties
+ * that may be needed for event delegation. 'currentTarget' is set to
+ * the element that matched the selector string filter or the Node returned
+ * from the filter function. 'container' is set to the element that the
+ * listener is delegated from (this normally would be the 'currentTarget').
+ *
+ * Filter functions will be called with the arguments that would be passed to
+ * the callback function, including the event object as the first parameter.
+ * The function should return false (or a falsey value) if the success criteria
+ * aren't met, and the Node to use as the event's currentTarget and 'this'
+ * object if they are.
+ *
+ * @method delegate
+ * @param type {string} the event type to delegate
+ * @param fn {function} the callback function to execute. This function
+ * will be provided the event object for the delegated event.
+ * @param el {string|node} the element that is the delegation container
+ * @param filter {string|function} a selector that must match the target of the
+ * event or a function that returns a Node or false.
+ * @param context optional argument that specifies what 'this' refers to.
+ * @param args* 0..n additional arguments to pass on to the callback function.
+ * These arguments will be added after the event object.
+ * @return {EventHandle} the detach handle
+ * @for YUI
+ */
+Y.delegate = Y.Event.delegate = delegate;
+
+
+}, '3.10.3', {"requires": ["node-base"]});