2 Copyright (c) 2009, Yahoo! Inc. All rights reserved.
3 Code licensed under the BSD License:
4 http://developer.yahoo.net/yui/license.txt
8 YUI.add('pluginhost', function(Y) {
11 * Provides the augmentable PluginHost interface, which can be added to any class.
17 * An augmentable class, which provides the augmented class with the ability to host plugins.
18 * It adds <a href="#method_plug">plug</a> and <a href="#method_unplug">unplug</a> methods to the augmented class, which can
19 * be used to add or remove plugins from instances of the class.
22 * <p>Plugins can also be added through the constructor configuration object passed to the host class' constructor using
23 * the "plugins" property. Supported values for the "plugins" property are those defined by the <a href="#method_plug">plug</a> method.
25 * For example the following code would add the AnimPlugin and IOPlugin to Overlay (the plugin host):
27 * var o = new Overlay({plugins: [ AnimPlugin, {fn:IOPlugin, cfg:{section:"header"}}]});
31 * Plug.Host's protected <a href="#method_initPlugins">_initPlugins</a> and <a href="#method_destroyPlugins">_destroyPlugins</a>
32 * methods should be invoked by the host class at the appropriate point in the host's lifecyle.
40 function PluginHost() {
44 PluginHost.prototype = {
47 * Adds a plugin to the host object. This will instantiate the
48 * plugin and attach it to the configured namespace on the host object.
52 * @param p {Function | Object |Array} Accepts the plugin class, or an
53 * object with a "fn" property specifying the plugin class and
54 * a "cfg" property specifying the configuration for the Plugin.
56 * Additionally an Array can also be passed in, with the above function or
57 * object values, allowing the user to add multiple plugins in a single call.
59 * @param config (Optional) If the first argument is the plugin class, the second argument
60 * can be the configuration for the plugin.
61 * @return {Base} A reference to the host object
64 plug: function(p, config) {
66 if (L.isFunction(p)) {
67 this._plug(p, config);
68 } else if (L.isArray(p)) {
69 for (var i = 0, ln = p.length; i < ln; i++) {
73 this._plug(p.fn, p.cfg);
80 * Removes a plugin from the host object. This will destroy the
81 * plugin instance and delete the namepsace from the host object.
84 * @param {String | Function} plugin The namespace of the plugin, or the plugin class with the static NS namespace property defined. If not provided,
85 * all registered plugins are unplugged.
86 * @return {Base} A reference to the host object
89 unplug: function(plugin) {
94 for (ns in this._plugins) {
95 if (this._plugins.hasOwnProperty(ns)) {
104 * Determines if a plugin has plugged into this host.
107 * @param {String} ns The plugin's namespace
108 * @return {boolean} returns true, if the plugin has been plugged into this host, false otherwise.
110 hasPlugin : function(ns) {
111 return (this._plugins[ns] && this[ns]);
115 * Initializes static plugins registered on the host (using the
116 * Base.plug static method) and any plugins passed to the
117 * instance through the "plugins" configuration property.
119 * @method _initPlugins
120 * @param {Config} config The configuration object with property name/value pairs.
123 _initPlugins: function(config) {
124 this._plugins = this._plugins || {};
126 // Class Configuration
127 var classes = (this._getClasses) ? this._getClasses() : [this.constructor],
130 constructor, i, classPlug, classUnplug, pluginClassName;
132 //TODO: Room for optimization. Can we apply statically/unplug in same pass?
133 for (i = classes.length - 1; i >= 0; i--) {
134 constructor = classes[i];
136 classUnplug = constructor._UNPLUG;
138 // subclasses over-write
139 Y.mix(unplug, classUnplug, true);
142 classPlug = constructor._PLUG;
144 // subclasses over-write
145 Y.mix(plug, classPlug, true);
149 for (pluginClassName in plug) {
150 if (plug.hasOwnProperty(pluginClassName)) {
151 if (!unplug[pluginClassName]) {
152 this.plug(plug[pluginClassName]);
157 // User Configuration
158 if (config && config.plugins) {
159 this.plug(config.plugins);
164 * Unplugs and destroys all plugins on the host
165 * @method _destroyPlugins
168 _destroyPlugins: function() {
173 * Private method used to instantiate and attach plugins to the host
176 * @param {Function} PluginClass The plugin class to instantiate
177 * @param {Object} config The configuration object for the plugin
180 _plug: function(PluginClass, config) {
181 if (PluginClass && PluginClass.NS) {
182 var ns = PluginClass.NS;
184 config = config || {};
187 if (this.hasPlugin(ns)) {
189 this[ns].setAttrs(config);
191 // Create new instance
192 this[ns] = new PluginClass(config);
193 this._plugins[ns] = PluginClass;
199 * Unplugs and destroys a plugin already instantiated with the host.
203 * @param {String | Function} plugin The namespace for the plugin, or a plugin class with the static NS property defined.
205 _unplug : function(plugin) {
207 plugins = this._plugins;
209 if (L.isFunction(plugin)) {
211 if (ns && (!plugins[ns] || plugins[ns] !== plugin)) {
229 * Registers plugins to be instantiated at the class level (plugins
230 * which should be plugged into every instance of the class by default).
232 * @method Plugin.Host.plug
235 * @param {Function} hostClass The host class on which to register the plugins
236 * @param {Function | Array} plugin Either the plugin class, an array of plugin classes or an array of objects (with fn and cfg properties defined)
237 * @param {Object} config (Optional) If plugin is the plugin class, the configuration for the plugin
239 PluginHost.plug = function(hostClass, plugin, config) {
240 // Cannot plug into Base, since Plugins derive from Base [ will cause infinite recurrsion ]
243 if (hostClass !== Y.Base) {
244 hostClass._PLUG = hostClass._PLUG || {};
246 if (!L.isArray(plugin)) {
248 plugin = {fn:plugin, cfg:config};
253 for (i = 0, l = plugin.length; i < l;i++) {
255 name = p.NAME || p.fn.NAME;
256 hostClass._PLUG[name] = p;
262 * Unregisters any class level plugins which have been registered by the host class, or any
263 * other class in the hierarchy.
265 * @method Plugin.Host.unplug
268 * @param {Function} hostClass The host class from which to unregister the plugins
269 * @param {Function | Array} plugin The plugin class, or an array of plugin classes
271 PluginHost.unplug = function(hostClass, plugin) {
274 if (hostClass !== Y.Base) {
275 hostClass._UNPLUG = hostClass._UNPLUG || {};
277 if (!L.isArray(plugin)) {
281 for (i = 0, l = plugin.length; i < l; i++) {
284 if (!hostClass._PLUG[name]) {
285 hostClass._UNPLUG[name] = p;
287 delete hostClass._PLUG[name];
293 Y.namespace("Plugin").Host = PluginHost;
296 }, '3.0.0' ,{requires:['yui-base']});