Toggle default prefix functionality within Helper::url()

gistfile1.php

<?php
class AppHelper extends Helper {
	var $maintainPrefix = false;
	
	function url($url = null, $full = false, $maintain = false) {
		if (is_array($url) && !$this->maintainPrefix && !$maintain) {
			$routing = Configure::read('Routing');
			if (!empty($routing['prefixes'])) {
				$prefixes = array_diff_key(array_flip($routing['prefixes']), $url);
				$url = array_merge($url, array_fill_keys(array_keys($prefixes), false)); 
			}
		}	
		return parent::url($url, $full);
	}
}