The `Collection` class, which serves as the base class for some of Lithium's data objects
(`RecordSet` and `Document`) provides a way to manage data collections in a very flexible and
intuitive way, using closures and SPL interfaces. The `to()` method allows a `Collection` (or
subclass) to be converted to another format, such as an array. The `Collection` class also allows
other classes to be connected as handlers to convert `Collection` objects to other formats.

The following connects the `Media` class as a format handler, which allows `Collection`s to be
exported to any format with a handler provided by `Media`, i.e. JSON. This enables things like
the following:
{{{
$posts = Post::find('all');
return $posts->to('json');
}}}

{{{

use lithium\util\Collection;

Collection::formats('lithium\net\http\Media');

}}}

This filter is a convenience method which allows you to automatically route requests for static
assets stored within active plugins. For example, given a JavaScript file `bar.js` inside the
`li3_foo` plugin installed in an application, requests to `http://app/path/li3_foo/js/bar.js`
will be routed to `/path/to/app/libraries/plugins/li3_foo/webroot/js/bar.js` on the filesystem.
In production, it is recommended that you disable this filter in favor of symlinking each
plugin's `webroot` directory into your main application's `webroot` directory, or adding routing
rules in your web server's configuration.

{{{

use lithium\action\Dispatcher;
use lithium\action\Response;
use lithium\net\http\Media;

Dispatcher::applyFilter('_callable', function($self, $params, $chain) {
	list($library, $asset) = explode('/', ltrim($params['request']->url, '/'), 2) + array("", "");

	if ($asset && ($path = Media::webroot($library)) && file_exists($file = "{$path}/{$asset}")) {
		return function() use ($file) {
			$info = pathinfo($file);
			$media = Media::type($info['extension']);
			$content = (array) $media['content'];

			return new Response(array(
				'headers' => array('Content-type' => reset($content)),
				'body' => file_get_contents($file)
			));
		};
	}
	return $chain->next($self, $params, $chain);
});

}}}