function setItem($id, $quantity, $add = false) { if ($quantity == 0) { $this->remItem($id); return $quantity; } $quantity = $this->_getAvailable($id, $quantity, $add); if ($add) { if ($quantity) { parent::setItem($id, $quantity, true); } return $quantity; } if ($quantity) { parent::setItem($id, $quantity); return $quantity; } }