CODEWITHSUNDEEP
flutterdartwebsocketsocket.io
Nimish David Mathew
Nimish David Mathew

Reputation: 3168

Socket.io connection works only once

I use this library (socket.io) in my flutter app for instant messaging using web sockets.

There are 2 screens - Home and Chat. After a form input from Home screen, the app navigates to Chat screen, inside initState() method of which, I have written the code to establish the socket connection:

IO.Socket socket;
void initState() {
    socket = IO.io('http://localhost:3000', <String, dynamic>{
        'transports': ['websocket'],
        'query': {
            'timeStamp': new DateTime.now().millisecondsSinceEpoch
        }
    });

    socket.on('connect', (_) {
         print("debug: connected");
    });
});

The connection works the first time I navigate from Home to Chat. But, If I navigate back to the Home page and then come back to Chat, the connection doesn't work. What could be the reason?

This is the code for navigating back to the Home page:

onPressed: () {
                socket.destroy();
                Navigator.pushAndRemoveUntil(
                    context,
                    MaterialPageRoute(
                      builder: (context) => MyHomePage(),
                    ),
                    (x) => false);
              },

No action is done on socket inside the dispose() method of the widget.

Upvotes: 0

Views: 1373

Answers (1)

Nimish David Mathew
Nimish David Mathew

Reputation: 3168

This is because it tries to reuse the same socket for connections to the same host. The solution is to use 'force new connection': true on connection.

socket = IO.io('http://localhost:3000', <String, dynamic>{
    'transports': ['websocket'],
    'force new connection': true,
    'query': {
         'timeStamp': new DateTime.now().millisecondsSinceEpoch
    }
});

Upvotes: 4

Related Questions