Nvm, got it work finally. -o-
If you send another value, for a discount, through the buy form, you can access it in class_stockitem.php in the getcost function. But this is just to fix the display on the confirmation screen.
PHP Code:
public function getcost($salestax = 0, $quantity = ""){
// Get the total cost of this stock item
$mysidia = Registry::get("mysidia");
if(empty($quantity)) $quantity = $mysidia->input->post("quantity");
$discount = $mysidia->input->post("discount");
$costbeforediscount = $this->price*$quantity*(1+$salestax/100);
$cost = $costbeforediscount * ((100-$discount) / 100);
return $cost;
}
To show users a discounted price, you'll need to do this in the display function of class_itemshop.php -
PHP Code:
# A 5% discount:
$discount = 5;
$price = $item->price * ((100-$discount) / 100);
And replace the $item->price where it would show the item's price when rendering the item to just $price.
To actually make a discount percentage go through in terms of calculations you'll have to modify the purchase() function in class_itemshop.php -
PHP Code:
$cost = $item->getcost($this->salestax, $item->quantity) * ((100-$discount) / 100);
Sorry for the vague ramblings, it's actually the first part I had trouble with (getting the proper amount to show on the confirmation screen), but maybe someone will have gotten something out of rest of this.