A validateLine event occurs when a line in a transaction changes. This change can occur when a shopper adds an item, changes an item’s quantity, or removes an item.

validateLine Function

In all cases, validateLine functions run before a change is made, making them the perfect mechanism for a wide range of preventative actions. For example, you can write a function to prevent shoppers from adding a particular item to their cart or to prevent shoppers from increasing the quantity of a particular item over a certain amount.