Stayntouch PMS Add-On Availability in the Activity Log
The logic behind add-on availability in the Activity Log is as follows.
old_value (shown with a strike): addon_inventory inaddon_settings - total add-on count used on that day + add-on count used by the specified reservation
new_value: addon_inventory inaddon_settings - total add-on count used on that day
In effect, the add-on purchased by the specified reservation will be new_value - old_value. However, if add-on inventory is not specified in the hotel's settings, addon_inventory inaddon_settings - total add-on count used on that day will be treated as zero, so that new_value - old_value will return the add-on purchased by the reservation.
The number you see in the Activity Log is the count of remaining add-ons. The number of add-ons reserved for the reservation can be calculated from the Activity Log.
