JS中装饰器模式的实现

var tree = {};
tree.decorate = function() {
	alert('Make sure the tree won\'t fall');
};
tree.getDecorator = function(deco){
	tree[deco].prototype = this;
	return new tree[deco];
};
tree.RedBalls = function() {
	this.decorate = function() {
		this.RedBalls.prototype.decorate();
		alert('Put on some red balls');
	}
};
tree.BlueBalls = function() {
	this.decorate = function() {
		this.BlueBalls.prototype.decorate();
		alert('Add blue balls');
	}
};
tree.Angel = function() {
	this.decorate = function() {
		this.Angel.prototype.decorate();
		alert('An angel on the top');
	}
};
tree = tree.getDecorator('BlueBalls');
tree = tree.getDecorator('Angel');
tree = tree.getDecorator('RedBalls');
tree.decorate();