Controller Extension to add styled error pages

ControllerExtension.php

<?php

class ControllerExtension extends Extension {
	private static $error_codes = array(
		 400 => 'Bad Request',
		 401 => 'Unauthorized',
		 403 => 'Forbidden',
		 404 => 'Not Found',
		 405 => 'Method Not Allowed',
		 406 => 'Not Acceptable',
		 407 => 'Proxy Authentication Required',
		 408 => 'Request Timeout',
		 409 => 'Conflict',
		 410 => 'Gone',
		 411 => 'Length Required',
		 412 => 'Precondition Failed',
		 413 => 'Request Entity Too Large',
		 414 => 'Request-URI Too Long',
		 415 => 'Unsupported Media Type',
		 416 => 'Request Range Not Satisfiable',
		 417 => 'Expectation Failed',
		 500 => 'Internal Server Error',
		 501 => 'Not Implemented',
		 502 => 'Bad Gateway',
		 503 => 'Service Unavailable',
		 504 => 'Gateway Timeout',
		 505 => 'HTTP Version Not Supported',
	);
	
	public function onBeforeHTTPError($code, $request) {
		if (array_key_exists($code,self::$error_codes))
			$title = self::$error_codes[$code];
		else {
			$title = 'Bad Request';
			$code = 400;
		}
		
		$body = $this
			->owner
			->customise(array(
				'Title' => $title,
				'Code' => $code
			))->renderWith(array(
				'Error',
				'Page'
			));
		$response = new SS_HTTPResponse($body,$code,$title);
		
		throw new SS_HTTPResponse_Exception($response, $code);
	}
}