I am using a custom field with mutliple checkboxes that add up to create a total cost for the event. The event price is set to 0 as there is no basic fee. I am not using group registration. This works fine as along as the client selects the event and leaves the Quantity at 1 (class=form-control input-mini quantity_box). But if they select quantity > 1 (e.g. they are registering for two) the custom field value does not update in the shopping cart.
I have tried using a custom field calcuation but I don't know how to access the event's quantity value. Hope this makes sense.
I tried this using [FIELD_VALUE]*[CART_NUMBER_REGISTRANTS] as the formula for custom field but it didn't work in checkout. Not a problem as I will just tell registrants not to book more than 1 for this event.
Actually jjust to let you know this actually doesn't work - only if there is a single event registered then [CART_NUMBER_REGISTRANTS] is correct in the formula. If there are 2 events registered and the user updates quantity to 2 in one of them, the [CART_NUMBER_REGISTRANTS]=3 and the calculation fails.
I have reverted to advising client to only use quantity 1 for these events.