Referral program

[tsuchiya]

Hello,

In Referral Program, How I Get the value "Total products" in the order and put in this code below?
/modules/referralprogram/ReferralProgramModule.php Line 83

public function registerDiscount($id_customer, $register=false, $id_currency = 0)
   {
       $configurations = Configuration::getMultiple(array(
           'REFERRAL_DISCOUNT_TYPE',
           'REFERRAL_DISCOUNT_VALUE_'.intval($id_currency)
       ));
       $discount = new Discount();
       $discount->id_discount_type = intval($configurations['REFERRAL_DISCOUNT_TYPE']);
       $discount->value = floatval($configurations['REFERRAL_DISCOUNT_VALUE_'.intval($id_currency)]); // change this code to get the value "Total products" on the order

Thank you.