Chat.tsx - Listen for Online/Offline Users - Ionic Chat App

Chat.tsx

...
const Chat: React.FC = () => {
  ...
  const { cometChat, user, selectedConversation, setCallType } = useContext(Context);
  ...
  useEffect(() => {
    ...
    return () => {
      if (selectedConversation) {
        ...
        if (selectedConversation.contactType === 0) {
          cometChat.removeUserListener(userOnlineListenerId);
        }
        ...
      }
    }
  }, [selectedConversation]);
  ...

  const listenForOnlineUsers = () => {
    cometChat.addUserListener(
      userOnlineListenerId,
      new cometChat.UserListener({
        onUserOnline: (onlineUser: any) => {
          if (onlineUser && onlineUser.uid === selectedConversation.uid) {
            setIsUserOnline(() => true);
          }
        },
        onUserOffline: (offlineUser: any) => {
          if (offlineUser && offlineUser.uid === selectedConversation.uid) {
            setIsUserOnline(() => false);
          }
        }
      })
    );
  };
};
...