protected function getUrlTrackEcommerce($grandTotal, $subTotal = 0.0, $tax = 0.0, $shipping = 0.0, $discount = 0.0)
    {
        if (!is_numeric($grandTotal)) {
            throw new Exception("You must specifiy a grandTotal for the Ecommerce order (or Cart update)");
        }

        $url = $this->getRequest($this->idSite);
        $url .= '&idgoal=0';
        if (!empty($grandTotal)) {
            $grandTotal = $this->forceDotAsSeparatorForDecimalPoint($grandTotal);
            $url .= '&revenue=' . $grandTotal;
        }
        if (!empty($subTotal)) {
            $subTotal = $this->forceDotAsSeparatorForDecimalPoint($subTotal);
            $url .= '&ec_st=' . $subTotal;
        }
        if (!empty($tax)) {
            $tax = $this->forceDotAsSeparatorForDecimalPoint($tax);
            $url .= '&ec_tx=' . $tax;
        }
        if (!empty($shipping)) {
            $shipping = $this->forceDotAsSeparatorForDecimalPoint($shipping);
            $url .= '&ec_sh=' . $shipping;
        }
        if (!empty($discount)) {
            $discount = $this->forceDotAsSeparatorForDecimalPoint($discount);
            $url .= '&ec_dt=' . $discount;
        }
        if (!empty($this->ecommerceItems)) {
            $url .= '&ec_items=' . urlencode(json_encode($this->ecommerceItems));
        }
        $this->ecommerceItems = array();

        return $url;
    }