Are the ItemRevised notification always delivered in chronological order? For instance, if I revise my item at time x and then revise it at time y, will I always get the notification for x first? If not, how can I tell if the notification is for the latest revision?
It is possible for the notifications to be not delivered in chronological order if the delivery of the first attempt for time x fails. However, irrespective of when the ItemRevised notification is delivered, it will always return the latest item information.
For sending the ItemRevised notification, a call to GetItem is made. There is no field in the response to indicate when the item was last revised, but only that the item was revised. Therefore it is not possible to find out if the notification is for the latest item change.
Also, it is possible for the delivery of notification for time x to fail the first time and notification for time y to be delivered before the second attempt is made for x. However, everytime an attempt is made, a fresh call is made to GetItem and the notification will have the latest item information at the time it is actually delivered. Therefore, even if the notifications are delievered out of chronological order, the information will still be the latest. In our example, if no further changes are made to the item, the notifications for time y and x will contain the same information. Therefore you application will always have the latest revision for the item.