CakePHP custom Route class that restricts a route to a single extension.

extension_specific_route.php

<?php
/**
 * Custom Route class that restricts a route to a single extension.
 * Enables you to build controller actions that are only applied to specific
 * extensions, e.g., '/posts.json' goes to PostsController::index_json while
 * '/posts' goes to PostsController::index.
 *
 * To use, drop this into app/libs/routes/extension_specific_route.php and add
 * the following to the top of app/config/routes.php:
 *
 * App::import('Lib', 'routes/ExtensionSpecificRoute');
 *
 * To trigger it, specify the routeClass in the route's options array, along
 * with the extension to match in the new key 'ext':
 *
 * Router::connect(
 *     '/posts',
 *     array('controller' => 'posts', 'action' => 'index_json'),
 *     array('routeClass' => 'ExtensionSpecificRoute', 'ext' => 'json')
 * );
 *
 * The 'ext' option can also be an array of multiple extensions (e.g., if you
 * want to use the same controller action for .json and .xml requests.)
 *
 * @author joe bartlett (xo@jdbartlett.com)
 * @license http://www.opensource.org/licenses/mit-license.php MIT License
 * @see CakeRoute
 */
class ExtensionSpecificRoute extends CakeRoute {

/**
 * Checks to see if the given URL can be parsed by this route.
 * If the route can be parsed an array of parameters will be returned; if not,
 * false will be returned. String urls are parsed if they match the 'ext'
 * option specified for this route.
 *
 * @param string $url The url to attempt to parse.
 * @return mixed Boolean false on failure, otherwise an array or parameters
 * @access public
 */
	function parse($url) {
		$params = parent::parse($url);
		
		// Determine the extension to be matched
		if (empty($this->options['ext'])) {
			$ext = array('html');
		} else {
			$ext = (array)$this->options['ext'];
			$ext = array_map('strtolower', $ext);
		}
		
		// Only match URL's using the extension $ext
		if (preg_match('/\\.([\\w]+)$/', $_GET['url'], $matches)) {
			if (!in_array(strtolower($matches[1]), $ext)) {
				return FALSE;
			}
		} elseif (!in_array('html', $ext)) {
			return FALSE;
		}
		
		return parent::parse($url);
	}

}

Why don't you create a full github repository for this?