base-componentmgr.js

/**
 * Base Component Manager
 * 
 * Oddnut Software
 * Copyright (c) 2010 Eric Ferraiuolo - http://eric.ferraiuolo.name
 */

var ComponentMgr,
	
	COMPONENTS = 'components',
	
	E_INIT_COMPONENTS = 'initComponents',
	
	L = Y.Lang,
	isString = L.isString,
	isFunction = L.isFunction,
	noop = function(){};
	
// *** Constructor *** //

ComponentMgr = function (config) {
	
	this.publish(E_INIT_COMPONENTS, {
		defaultFn	: this._defInitComponentsFn,
		fireOnce	: true
	});
		
	this.after('init', function(e){
		this.fire(E_INIT_COMPONENTS, { components: [] });
	});
};

// *** Static *** //

// *** Prototype *** //

ComponentMgr.prototype = {
	
	// *** Instance Members *** //
	
	// *** Public Methods *** //
	
	getComponent : function () {
		
		var args = Y.Array(arguments, 0, true),
			components = args.slice(0, -1),
			callback = isFunction(args[args.length-1]) ? args[args.length-1] : noop,
			instances = [],
			requires;
		
		if (components.length < 1) {
			callback.call(this);
			return;
		}
		
		requires = this._getRequires(components);
		
		if (requires.length > 0) {
			
			Y.use.apply(Y, requires.concat(Y.bind(function(Y){
				Y.Array.each(components, function(c){
					instances.push(this._initComponent(c));
				}, this);
				callback.apply(this, instances);
			}, this)));
			
		} else {
			
			Y.Array.each(components, function(c){
				c = this._getComponent(c);
				instances.push(c ? c.instance || null : null);
			}, this);
			callback.apply(this, instances);
			
		}
	},
	
	// *** Private Methods *** //
	
	_getComponent : function (c) {
		
		var components = this[COMPONENTS];
		return ( isString(c) && Y.Object.hasKey(components, c) ? components[c] : Y.Object.hasValue(c) ? c : null );
	},
	
	_getRequires : function (components) {
		
		var requires = [];
		
		Y.Array.each(components, function(c){
			c = this._getComponent(c) || {};
			requires = requires.concat(c.requires || []);
		}, this);
		
		return Y.Array.unique(requires);
	},
	
	_defInitComponentsFn : function (e) {
		
		var components = e.components,
			requires = this._getRequires(components);
			
		Y.use.apply(Y, requires.concat(Y.bind(function(Y){
			Y.Array.each(components, this._initComponent, this);
		}, this)));
	},
	
	_initComponent : function (c) {
		
		c = this._getComponent(c);
		if ( ! c) { return null; }
		
		if ( ! c.instance) {
			var initFn = isFunction(c.initializer) ? c.initializer :
					isString(c.initializer) && isFunction(this[c.initializer]) ? this[c.initializer] : noop;
			try { c.instance = initFn.call(this); } catch(e){}
		}
		
		return c.instance || null;
	}
	
};

Y.BaseComponentMgr = ComponentMgr;

mypage.js

YUI.add('mypage', function(Y){

	function MyPage (config) {
		MyPage.superclass.constructor.apply(this, arguments);
	}
	
	Y.extend(MyPage, Y.Base, {
	
		components : {
			
			myOverlay : {
				requires	: ['overlay', 'gallery-overlay-modal'],
				initializer : function(){
					return (new Y.Overlay({
						width : '500px',
						zInex : 100,
						render : true,
						plugins : [{ fn: Y.Plugin.OverlayModal }]
					}));
				}
			},
			
			mySlider : {
				requires	: ['slider'],
				initializer	: '_initMySlider' 
			}
			
		},
		
		initializer : function (config) {
			
			Y.one('#foo').on('click', function(e){
			
				this.getComponent('mySlider', function(mySlider){
				
					// mySlider component had it's dependencies lazily loaded.
					// mySlider component was lazily initialized.
					// the instance returned by the initializer is cached,
					// repeated calls just quickly return the instance to the callback.
					
					mySlider.set('value', 400);
					
				});
				
			}, this);
			
			Y.one('#bar').on('click', function(e){
			
				this.getComponent('myOverlay', 'mySlider', function(myOverlay, mySlider){
					
					// if mySlider isn't already initialized, then it will be by now.
					
					myOverlay.show();
					mySlider.set('value', 200);
					
				});
			
			}, this);
			
			this.on('initComponents', function(e){
			
				if (Y.one('#foo')) {
					e.components.push('myOverlay');
					// or: e.components.push(this.components.myOverlay);
				}
				
			});
		},
		
		_initMySlider : function () {
		
			return (new Y.Slider({
				min: 0,
				max: 500,
				length: 500,
				render : true
			}));
		}
	
	}, {
	
		NAME : 'myPage'
	
	});
	
	Y.MyPage = Y.Base.mix(MyPage, [Y.BaseComponentMgr]);

}, '1', { requires: ['base', 'base-componentmgr'], optional: ['overlay', 'slider', 'gallery-overlay-modal'] });