Sandboxing pattern & some demo code

Sandboxing.js

(function(_export) {
	var Sandbox = function(modules, callback) {
		if (!(this instanceof Sandbox)) {
			return new Sandbox(modules, callback);
		}
		// modules is an array in this instance:
		for (var i = 0, len = modules.length; i < len; i++) {
			this.Modules[modules[i]](this);
		}
		callback(this);
	};
	Sandbox.prototype.Modules = Sandbox.modules = {};
	_export.Sandbox = Sandbox;
})(this);

Sandbox.modules.people = function(sandbox) {
	sandbox.people = {};
	sandbox.people.all = function(){return 'list of people'};
	sandbox.people.me = function(){return 'logged in user'};
};

Sandbox.modules.pets = function(sandbox) {
	sandbox.pets = {};
	sandbox.pets.dogs = function(){return 'list of dogs'};
	sandbox.pets.cats = function(){return'list of cats'};
};

Sandbox(['people', 'pets'], function(sandbox){
	// i can modify variables
	sandbox.people.me = function(){return 'Jacob'};
	console.log(sandbox);
});

Sandbox(['people'], function(sandbox){
	console.log(sandbox);
});