Acknowledge message.
Once the message has been acked, callback will be called. You can then call ack_message_async.end
to get the result of the operation.
A message should be acknowledged once it has been shown to the user by the Handler of the channel. So Observers and Approvers should NOT acknowledge messages themselves. Once a message has been acknowledged, it is removed from the pending-message queue and so the pending_message_removed signal is fired.
You should use the SignalledMessage received from dup_pending_messages or the message_received signal.
| this | |
| message | |
| callback |
a callback to call when the message have been acked |
| user_data |
data to pass to |