Article # 428, added by Geoworks, historical record
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Sending notification messages to controllers.



Q. I am notifying a controller of a change using a notification. I use
   MSG_META_NOTIFY_WITH_DATA_BLOCK where the block consists of only a
   handle to a memory block containing strings. The handle to the memory
   block containing is the same for each notification. I have noticed
   that after the first notification none of them seem to reach the
   controllers. I believe notifications are cached and duplicates
   discarded although I couldn't confirm this with the manual. Is this
   true? What is the typical way of sending identical notifications to
   a controller so that the controllers get each one?

A. Duplicate status events are ignored. If they are identical, there
   is no need to send multiple ones. If they are not identical, you
   should generate unique notifications.

   By the way, you do not need to use MSG_META_NOTIFY_WITH_DATA_BLOCK directly.
   The normal way controllers get notifications is by adding themselves
   to the necessary GCN list. When a change occurs, the object in which
   the change occurred should then call GCNListSend or send
   MSG_META_GCN_LIST_SEND. The system will then send the
   MSG_META_NOTIFY_WITH_DATA_BLOCK to the objects on the GCN list.