FOF30\Utils\Ip::detectIP PHP Method

    protected static function detectIP()
    {
        // Normally the $_SERVER superglobal is set
        if (isset($_SERVER)) {
            // Do we have an x-forwarded-for HTTP header (e.g. NginX)?
            if (self::$allowIpOverrides && array_key_exists('HTTP_X_FORWARDED_FOR', $_SERVER)) {
                return $_SERVER['HTTP_X_FORWARDED_FOR'];
            }
            // Do we have a client-ip header (e.g. non-transparent proxy)?
            if (self::$allowIpOverrides && array_key_exists('HTTP_CLIENT_IP', $_SERVER)) {
                return $_SERVER['HTTP_CLIENT_IP'];
            }
            // Normal, non-proxied server or server behind a transparent proxy
            return $_SERVER['REMOTE_ADDR'];
        }
        // This part is executed on PHP running as CGI, or on SAPIs which do
        // not set the $_SERVER superglobal
        // If getenv() is disabled, you're screwed
        if (!function_exists('getenv')) {
            return '';
        }
        // Do we have an x-forwarded-for HTTP header?
        if (self::$allowIpOverrides && getenv('HTTP_X_FORWARDED_FOR')) {
            return getenv('HTTP_X_FORWARDED_FOR');
        }
        // Do we have a client-ip header?
        if (self::$allowIpOverrides && getenv('HTTP_CLIENT_IP')) {
            return getenv('HTTP_CLIENT_IP');
        }
        // Normal, non-proxied server or server behind a transparent proxy
        if (getenv('REMOTE_ADDR')) {
            return getenv('REMOTE_ADDR');
        }
        // Catch-all case for broken servers, apparently
        return '';
    }