main.dart

...
 
  Socket socket;
  
  @override
  void initState() {
    super.initState();
    connectToServer();
  }

  void connectToServer() {
    try {
     
      // Configure socket transports must be sepecified
      socket = io('http://127.0.0.1:3000', <String, dynamic>{
        'transports': ['websocket'],
        'autoConnect': false,
      });
     
      // Connect to websocket
      socket.connect();
     
      // Handle socket events
      socket.on('connect', (_) => print('connect: ${socket.id}'));
      socket.on('location', handleLocationListen);
      socket.on('typing', handleTyping);
      socket.on('message', handleMessage);
      socket.on('disconnect', (_) => print('disconnect'));
      socket.on('fromServer', (_) => print(_));

    } catch (e) {
      print(e.toString());
    }

   
  }
   
  // Send Location to Server
  sendLocation(Map<String, dynamic> data) {
    socket.emit("location", data);
  }
   
  // Listen to Location updates of connected usersfrom server
  handleLocationListen(Map<String, dynamic> data) async {
    print(data);
  }

  // Send update of user's typing status 
  sendTyping(bool typing) {
    socket.emit("typing",
      {
        "id": socket.id,
         "typing": typing,
      });
  }
   
  // Listen to update of typing status from connected users
  void handleTyping(Map<String, dynamic> data) {
    print(data);
  }

  // Send a Message to the server
  sendMessage(String message) {
      socket.emit("message",
        {
          "id": socket.id,
          "message": message, // Message to be sent
          "timestamp": DateTime.now().millisecondsSinceEpoch,
        },
      );
  }

  // Listen to all message events from connected users
  void handleMessage(Map<String, dynamic> data) {
    print(data);
  }


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