Receive messages in an open channel

Messages sent from other participants can be received through the onMessageReceived() method in the channel event handler. A BaseMessage object for each received message is one of the following three message types.

To register multiple concurrent handlers, pass a UNIQUE_HANDLER_ID argument as a unique identifier into the addOpenChannelHandler() method.

const channelHandler = new OpenChannelHandler({
    onMessageReceived: (channel, message) => {
        // ...
    }
});

sb.openChannel.addOpenChannelHandler(UNIQUE_HANDLER_ID, channelHandler);

Once a reply is created or deleted from a thread, onThreadInfoUpdated() in OpenChannelHandler is invoked. The method returns a ThreadInfoUpdateEvent object that has the latest information about the thread. This object needs to be applied to the parent message object.

Note: Like other messages, when a reply is created in a channel, the onMessageReceived() method of the channel event handler in client apps will be called.

handler.onThreadInfoUpdated = (channel, threadInfoUpdateEvent) => {
    // Look for a message that has threadInfoUpdateEvent.targetMessageId.
    // Apply the event to the message.
    message.applyThreadInfoUpdateEvent(threadInfoUpdateEvent);
};

If a reply message is created, onMessageReceived() will be called with that reply message. A user will have to find the parent message with the parentMessageID property in that message object.

If the parent message is not in the message view stack and the user wants to get the parent message object, they can do so by calling sb.message.getMessage(params, handler) to retrieve the parent message object.

Once the reply message has been created, the onThreadInfoUpdated() event handler will be called since the thread info has been changed. To update thread information, the user should find the matching parent message with targetMessageID and use the parentMessage.applyThreadInfoUpdateEvent() method.