I got a real estate Facebook canvas application where people can set their real estate criteria and I send them notifications when new real estates, matching their criteria is available.
The thing is, I check for new real estates every 5 minutes so naturally I don't want to send them a new notification every time a new real estate is found.
Is it possible to see if the user has read my last notification (and if so, send a new one when new real estates are available)?
Preferable I'd want to be able to update the existing notification, from saying "6 new real estates matches your search" to "7 new real estates matches your search".
I have looked around the Facebook API and to me it seems that developers are neither able to update previous notifications nor check the read status of previous notifications. Is that correctly assumed?