File: pluginhost/js/PluginHost.js
/**
* Provides the augmentable PluginHost interface, which can be added to any class.
* @module pluginhost
*/
/**
* Provides the augmentable PluginHost interface, which can be added to any class.
* @module pluginhost-base
*/
/**
* <p>
* An augmentable class, which provides the augmented class with the ability to host plugins.
* It adds <a href="#method_plug">plug</a> and <a href="#method_unplug">unplug</a> methods to the augmented class, which can
* be used to add or remove plugins from instances of the class.
* </p>
*
* <p>Plugins can also be added through the constructor configuration object passed to the host class' constructor using
* the "plugins" property. Supported values for the "plugins" property are those defined by the <a href="#method_plug">plug</a> method.
*
* For example the following code would add the AnimPlugin and IOPlugin to Overlay (the plugin host):
* <xmp>
* var o = new Overlay({plugins: [ AnimPlugin, {fn:IOPlugin, cfg:{section:"header"}}]});
* </xmp>
* </p>
* <p>
* Plug.Host's protected <a href="#method_initPlugins">_initPlugins</a> and <a href="#method_destroyPlugins">_destroyPlugins</a>
* methods should be invoked by the host class at the appropriate point in the host's lifecyle.
* </p>
*
* @class Plugin.Host
*/
var L = Y.Lang;
function PluginHost() {
this._plugins = {};
}
PluginHost.prototype = {
/**
* Adds a plugin to the host object. This will instantiate the
* plugin and attach it to the configured namespace on the host object.
*
* @method plug
* @chainable
* @param P {Function | Object |Array} Accepts the plugin class, or an
* object with a "fn" property specifying the plugin class and
* a "cfg" property specifying the configuration for the Plugin.
* <p>
* Additionally an Array can also be passed in, with the above function or
* object values, allowing the user to add multiple plugins in a single call.
* </p>
* @param config (Optional) If the first argument is the plugin class, the second argument
* can be the configuration for the plugin.
* @return {Base} A reference to the host object
*/
plug: function(Plugin, config) {
var i, ln, ns;
if (L.isArray(Plugin)) {
for (i = 0, ln = Plugin.length; i < ln; i++) {
this.plug(Plugin[i]);
}
} else {
if (Plugin && !L.isFunction(Plugin)) {
config = Plugin.cfg;
Plugin = Plugin.fn;
}
// Plugin should be fn by now
if (Plugin && Plugin.NS) {
ns = Plugin.NS;
config = config || {};
config.host = this;
if (this.hasPlugin(ns)) {
// Update config
if (this[ns].setAttrs) {
this[ns].setAttrs(config);
}
else {
Y.log("Attempt to replug an already attached plugin, and we can't setAttrs, because it's not Attribute based: " + ns, "warn", "PluginHost");
}
} else {
// Create new instance
this[ns] = new Plugin(config);
this._plugins[ns] = Plugin;
}
}
else {
Y.log("Attempt to plug in an invalid plugin. Host:" + this + ", Plugin:" + Plugin, "error", "PluginHost");
}
}
return this;
},
/**
* Removes a plugin from the host object. This will destroy the
* plugin instance and delete the namespace from the host object.
*
* @method unplug
* @param {String | Function} plugin The namespace of the plugin, or the plugin class with the static NS namespace property defined. If not provided,
* all registered plugins are unplugged.
* @return {Base} A reference to the host object
* @chainable
*/
unplug: function(plugin) {
var ns = plugin,
plugins = this._plugins;
if (plugin) {
if (L.isFunction(plugin)) {
ns = plugin.NS;
if (ns && (!plugins[ns] || plugins[ns] !== plugin)) {
ns = null;
}
}
if (ns) {
if (this[ns]) {
if (this[ns].destroy) {
this[ns].destroy();
}
delete this[ns];
}
if (plugins[ns]) {
delete plugins[ns];
}
}
} else {
for (ns in this._plugins) {
if (this._plugins.hasOwnProperty(ns)) {
this.unplug(ns);
}
}
}
return this;
},
/**
* Determines if a plugin has plugged into this host.
*
* @method hasPlugin
* @param {String} ns The plugin's namespace
* @return {Plugin} Returns a truthy value (the plugin instance) if present, or undefined if not.
*/
hasPlugin : function(ns) {
return (this._plugins[ns] && this[ns]);
},
/**
* Initializes static plugins registered on the host (using the
* Base.plug static method) and any plugins passed to the
* instance through the "plugins" configuration property.
*
* @method _initPlugins
* @param {Object} config The configuration object with property name/value pairs.
* @private
*/
_initPlugins: function(config) {
this._plugins = this._plugins || {};
if (this._initConfigPlugins) {
this._initConfigPlugins(config);
}
},
/**
* Unplugs and destroys all plugins on the host
* @method _destroyPlugins
* @private
*/
_destroyPlugins: function() {
this.unplug();
}
};
Y.namespace("Plugin").Host = PluginHost;