Example of a possible solution when adding components that require an asynchronous operation to attach to an entity, for example when loading a level.

app.js

require('./thorny/base')('./config/default.json', function ($) {
	// Register a component so we can use it below.
	$.es().registerComponent('load-level', function () {
		return {
			// Used to enable the isReady function.
			asynchronousAttachEvent: 'world-loaded',
			
			// Called in response to .addComponent()
			attach: function (entity, filename) {
				$.ajax({
					url: '...',
					data: {filename: filename},
					success: function (data) {
						// ...
						
						// Mark the end of this request.
						entity.asynchronousTaskComplete();
					}
				});
			}
		};});
	
	// Create the world, and load in two level files.
	$.es().makeEntity()
		.addTag('world')
		.addComponent('load-level', './content/level/fileOne.json')
		.addComponent('load-level', './content/level/fileTwo.json');
	
	$.event().bind('world-loaded', function () {
		// Called once all the asynchronous operations have completed.
		//
		// One possible use would be to spawn monsters/items into the 
		// loaded level.
	});
});