SubdomainRoute.php

<?php

class SubdomainRoute extends CakeRoute {

/**
 * @var CakeRequest
 */
    private $Request;

/**
 * Length of domain's TLD
 *
 * @var int
 */
    public static $tldLength = 1;

/**
 * Default options
 *
 * @var array
 */
    public $options = array();

/**
 * Constructor for a Route
 *
 * @param string $template Template string with parameter placeholders
 * @param array $defaults Array of defaults for the route.
 * @param array $options Array of additional options for the Route
 */
    public function __construct($template, $defaults = array(), $options = array()) {
        parent::__construct($template, $defaults, $options);

        $this->Request = new CakeRequest();
        $this->options = array_merge(array('protocol' => 'http', 'subdomain' => 'www'), $options);
    }

    public function match($url) {
        $url = parent::match($url);

        return $url;
    }

    protected function _writeUrl($params) {
        $protocol = $this->options['protocol'];
        if (isset($url['protocol'])) {
            $protocol = $url['protocol'];
            unset($url['protocol']);
        }

        $subdomain = $this->options['subdomain'];
        if (isset($url['subdomain'])) {
            $subdomain = $url['subdomain'];
            unset($url['subdomain']);
        }

        $url = parent::_writeUrl($params);
        $domain = $this->_getDomain();
        return "{$protocol}://{$subdomain}.{$domain}{$url}";
    }


    public function parse($url) {
        $url = parent::parse($url);

        if (!in_array($this->options['subdomain'], $this->_getSubdomains())) {
            return false;
        }

        return $url;
    }

/**
 * Gets list of subdomains from current URL
 *
 * @return array Of subdomains
 */
    protected function _getSubdomains() {
        return $this->Request->subdomains(self::$tldLength);
    }

/**
 * Get domain name
 *
 * @return string
 */
    protected function _getDomain() {
        return $this->Request->domain(self::$tldLength);
    }
}