如何从对象外部调用函数

Question

I am trying to make a proxy between sockets and websockets. I receive requests on socket server and I want to proxy them to websocket clients, however websocket.ws.send appears to be undefined. What would be the correct way of doing this? How to call ws.send() from outside of the object?

var WebSocketServer = require('ws').Server,
wss = new WebSocketServer({port: 8001}),
var net = require('net')


websocket = wss.on('connection', function(ws) {
    ws.on('message', function(message) {
        console.log('received: %s', message);
    });
    ws.send("NEW USER JOINED");
});


var socketServer = net.createServer(function(socket) {
        socket.on("data", function(data){
                console.log("Received: "+data)
                websocket.ws.send("Message")
        });
});
socketServer.listen(1337, '127.0.0.1');

Answer 1

The problem you have is that ws is a single web socket for one connection. It is not a property on the websocket object, but an argument to a callback you define. Each time someone connects you will get a connection event which will execute your callback, allowing you to bind a function to that specific web socket for the message event.

You either need to store the ws object in a variable that the socket server can access or you could broadcast to all clients.

wss.clients.forEach(function each(client) {
   client.send(data);
});

This will work fine if you only have one client, however if you have multiple connections to both the websocket and socket server then you need to use a method of identifying connections on both so that you can locate the websocket connection you need to send data to.