In order to receive published messages, application must subscribe to a channel. The subscription API returns a
Channel object which can be used to add messaging callbacks. A callback is used by Backendless to deliver published messages to the client application.
Consider the following example, which demonstrates subscribing to a channel and adding a messaging callback:
Channel channel = await Backendless.messaging.subscribe("that"); Function(String) callback = (chatMessage) => print("got a message: $chatMessage"); channel.addMessageListener(callback);