/**
* Checks and prepares variables for a quantity change (add, edit, remove) for an Order Item.
* @param Boolean $mustBeExistingItems - if false, the Order Item gets created if it does not exist - if TRUE the order item is searched for and an error shows if there is no Order item.
* @param DataObject $buyable - the buyable (generally a product) being added to the cart
* @param Integer $quantity - number of items add.
* @param Array $parameters - array of parameters to target a specific order item. eg: group=1, length=5*
* @return boolean | DataObject ($orderItem)
*/
protected function prepareOrderItem($mustBeExistingItem = true, $buyable, $parameters = array())
{
if (!$buyable) {
user_error("No buyable was provided", E_USER_WARNING);
}
if (!$buyable->canPurchase()) {
$item = $this->getExistingItem($buyable, $parameters);
if ($item && $item->exists()) {
$item->delete();
$item->destroy();
}
return false;
}
$item = null;
if ($mustBeExistingItem) {
$item = $this->getExistingItem($buyable, $parameters);
} else {
$item = $this->findOrMakeItem($buyable, $parameters);
//find existing order item or make one
}
if (!$item) {
//check for existence of item
return false;
}
return $item;
}
