2 YUI 3.13.0 (build 508226d)
3 Copyright 2013 Yahoo! Inc. All rights reserved.
4 Licensed under the BSD License.
5 http://yuilibrary.com/license/
8 YUI.add('view', function (Y, NAME) {
11 Represents a logical piece of an application's user interface, and provides a
12 lightweight, overridable API for rendering content and handling delegated DOM
13 events on a container element.
21 Represents a logical piece of an application's user interface, and provides a
22 lightweight, overridable API for rendering content and handling delegated DOM
23 events on a container element.
25 The View class imposes little structure and provides only minimal functionality
26 of its own: it's basically just an overridable API interface that helps you
27 implement custom views.
29 As of YUI 3.5.0, View allows ad-hoc attributes to be specified at instantiation
30 time, so you don't need to subclass `Y.View` to add custom attributes. Just pass
31 them to the constructor:
33 var view = new Y.View({foo: 'bar'});
34 view.get('foo'); // => "bar"
43 View.superclass.constructor.apply(this, arguments);
46 Y.View = Y.extend(View, Y.Base, {
47 // -- Public Properties ----------------------------------------------------
50 Template for this view's container.
52 @property containerTemplate
57 containerTemplate: '<div/>',
60 Hash of CSS selectors mapped to events to delegate to elements matching
63 CSS selectors are relative to the `container` element. Events are attached
64 to the container, and delegation is used so that subscribers are only
65 notified of events that occur on elements inside the container that match
66 the specified selectors. This allows the container's contents to be re-
67 rendered as needed without losing event subscriptions.
69 Event handlers can be specified either as functions or as strings that map
70 to function names on this view instance or its prototype.
72 The `this` object in event handlers will refer to this view instance. If
73 you'd prefer `this` to be something else, use `Y.bind()` to bind a custom
78 var view = new Y.View({
80 // Call `this.toggle()` whenever the element with the id
81 // "toggle-button" is clicked.
82 '#toggle-button': {click: 'toggle'},
84 // Call `this.hoverOn()` when the mouse moves over any element
85 // with the "hoverable" class, and `this.hoverOff()` when the
86 // mouse moves out of any element with the "hoverable" class.
101 Template for this view's contents.
103 This is a convenience property that has no default behavior of its own.
104 It's only provided as a convention to allow you to store whatever you
105 consider to be a template, whether that's an HTML string, a `Y.Node`
106 instance, a Mustache template, or anything else your little heart
109 How this template gets used is entirely up to you and your custom
118 // -- Protected Properties -------------------------------------------------
121 This tells `Y.Base` that it should create ad-hoc attributes for config
122 properties passed to View's constructor. This makes it possible to
123 instantiate a view and set a bunch of attributes without having to subclass
124 `Y.View` and declare all those attributes first.
126 @property _allowAdHocAttrs
132 _allowAdHocAttrs: true,
134 // -- Lifecycle Methods ----------------------------------------------------
135 initializer: function (config) {
136 config || (config = {});
138 // Set instance properties specified in the config.
139 config.containerTemplate &&
140 (this.containerTemplate = config.containerTemplate);
142 config.template && (this.template = config.template);
144 // Merge events from the config into events in `this.events`.
145 this.events = config.events ? Y.merge(this.events, config.events) :
148 // When the container node changes (or when it's set for the first
149 // time), we'll attach events to it, but not until then. This allows the
150 // container to be created lazily the first time it's accessed rather
151 // than always on init.
152 this.after('containerChange', this._afterContainerChange);
156 Destroys this View, detaching any DOM events and optionally also destroying
159 By default, the container node will not be destroyed. Pass an _options_
160 object with a truthy `remove` property to destroy the container as well.
163 @param {Object} [options] Options.
164 @param {Boolean} [options.remove=false] If `true`, this View's container
165 will be removed from the DOM and destroyed as well.
168 destroy: function (options) {
169 // We also accept `delete` as a synonym for `remove`.
170 if (options && (options.remove || options['delete'])) {
171 // Attaching an event handler here because the `destroy` event is
172 // preventable. If we destroyed the container before calling the
173 // superclass's `destroy()` method and the event was prevented, the
174 // class would end up in a broken state.
175 this.onceAfter('destroy', function () {
176 this._destroyContainer();
180 return View.superclass.destroy.call(this);
183 destructor: function () {
185 delete this._container;
188 // -- Public Methods -------------------------------------------------------
191 Attaches delegated event handlers to this view's container element. This
192 method is called internally to subscribe to events configured in the
193 `events` attribute when the view is initialized.
195 You may override this method to customize the event attaching logic.
198 @param {Object} [events] Hash of events to attach. See the docs for the
199 `events` attribute for details on the format. If not specified, this
200 view's `events` property will be used.
204 attachEvents: function (events) {
205 var container = this.get('container'),
206 owns = Y.Object.owns,
207 handler, handlers, name, selector;
211 events || (events = this.events);
213 for (selector in events) {
214 if (!owns(events, selector)) { continue; }
216 handlers = events[selector];
218 for (name in handlers) {
219 if (!owns(handlers, name)) { continue; }
221 handler = handlers[name];
223 // TODO: Make this more robust by using lazy-binding:
224 // `handler = Y.bind(handler, this);`
225 if (typeof handler === 'string') {
226 handler = this[handler];
233 this._attachedViewEvents.push(
234 container.delegate(name, handler, selector, this));
242 Creates and returns a container node for this view.
244 By default, the container is created from the HTML template specified in the
245 `containerTemplate` property, and is _not_ added to the DOM automatically.
247 You may override this method to customize how the container node is created
248 (such as by rendering it from a custom template format). Your method must
249 return a `Y.Node` instance.
252 @param {HTMLElement|Node|String} [container] Selector string, `Y.Node`
253 instance, or DOM element to use at the container node.
254 @return {Node} Node instance of the created container node.
256 create: function (container) {
257 return container ? Y.one(container) :
258 Y.Node.create(this.containerTemplate);
262 Detaches DOM events that have previously been attached to the container by
269 detachEvents: function () {
270 Y.Array.each(this._attachedViewEvents, function (handle) {
276 this._attachedViewEvents = [];
281 Removes this view's container element from the DOM (if it's in the DOM),
282 but doesn't destroy it or any event listeners attached to it.
287 remove: function () {
288 var container = this.get('container');
289 container && container.remove();
296 This method is a noop by default. Override it to provide a custom
297 implementation that renders this view's content and appends it to the
298 container element. Ideally your `render` method should also return `this` as
299 the end to allow chaining, but that's up to you.
301 Since there's no default renderer, you're free to render your view however
302 you see fit, whether that means manipulating the DOM directly, dumping
303 strings into `innerHTML`, or using a template language of some kind.
305 For basic templating needs, `Y.Node.create()` and `Y.Lang.sub()` may
306 suffice, but there are no restrictions on what tools or techniques you can
307 use to render your view. All you need to do is append something to the
308 container element at some point, and optionally append the container
309 to the DOM if it's not there already.
314 render: function () {
318 // -- Protected Methods ----------------------------------------------------
321 Removes the `container` from the DOM and purges all its event listeners.
323 @method _destroyContainer
326 _destroyContainer: function () {
327 var container = this.get('container');
328 container && container.remove(true);
332 Getter for the `container` attribute.
334 @method _getContainer
335 @param {Node|null} value Current attribute value.
336 @return {Node} Container node.
340 _getContainer: function (value) {
341 // This wackiness is necessary to enable fully lazy creation of the
342 // container node both when no container is specified and when one is
343 // specified via a valueFn.
345 if (!this._container) {
347 // Attach events to the container when it's specified via a
348 // valueFn, which won't fire the containerChange event.
349 this._container = value;
352 // Create a default container and set that as the new attribute
353 // value. The `this._container` property prevents infinite
355 value = this._container = this.create();
356 this._set('container', value);
363 // -- Protected Event Handlers ---------------------------------------------
366 Handles `containerChange` events. Detaches event handlers from the old
367 container (if any) and attaches them to the new container.
369 Right now the `container` attr is initOnly so this event should only ever
370 fire the first time the container is created, but in the future (once Y.App
371 can handle it) we may allow runtime container changes.
373 @method _afterContainerChange
377 _afterContainerChange: function () {
378 this.attachEvents(this.events);
385 Container node into which this view's content will be rendered.
387 The container node serves as the host for all DOM events attached by the
388 view. Delegation is used to handle events on children of the container,
389 allowing the container's contents to be re-rendered at any time without
390 losing event subscriptions.
392 The default container is a `<div>` Node, but you can override this in
393 a subclass, or by passing in a custom `container` config value at
394 instantiation time. If you override the default container in a subclass
395 using `ATTRS`, you must use the `valueFn` property. The view's constructor
396 will ignore any assignments using `value`.
398 When `container` is overridden by a subclass or passed as a config
399 option at instantiation time, you can provide it as a selector string, a
400 DOM element, a `Y.Node` instance, or (if you are subclassing and modifying
401 the attribute), a `valueFn` function that returns a `Y.Node` instance.
402 The value will be converted into a `Y.Node` instance if it isn't one
405 The container is not added to the page automatically. This allows you to
406 have full control over how and when your view is actually rendered to
410 @type HTMLElement|Node|String
411 @default Y.Node.create(this.containerTemplate)
415 getter : '_getContainer',
422 Properties that shouldn't be turned into ad-hoc attributes when passed to
425 @property _NON_ATTRS_CFG
440 }, '3.13.0', {"requires": ["base-build", "node-event-delegate"]});