Contao\Environment::url PHP Method

    protected static function url()
    {
        $host = static::get('httpHost');
        $xhost = static::get('httpXForwardedHost');
        // SSL proxy
        if ($xhost != '' && $xhost == \Config::get('sslProxyDomain')) {
            return 'https://' . $xhost . '/' . $host;
        }
        return (static::get('ssl') ? 'https://' : 'http://') . $host;
    }