socket.io and express server not receiving emit from client

问题

The console logs "connection to socket made," so it seems to be connecting, but no events seem to be triggered, even on 'disconnect' inside io.on in the server.

"socket.on" doesn't seem to be working

SERVER SIDE

var server = app.listen(app.get('port'), () => {
  console.log('%s App is running at http://localhost:%d in %s mode', chalk.green('✓'), app.get('port'), app.get('env'));
  console.log('  Press CTRL-C to stop\n');
});

var io = socket(server);

io.on('connection', function(socket){
  console.log('connection to socket made');
  socket.on('chat message', function(msg){
      console.log('message: ' + msg);
    });
});

CLIENT

ul.pages
  li.chat.page
    div.chatArea
      ul.messages
      input.inputMessage(placeholder='Type here...')
  li.login.page
    .form
      h3.title What's your nickname?
      input.usernameInput(type="text", maxlength="14")


script(src="/socket.io/socket.io.js")
script(src="https://code.jquery.com/jquery-1.11.1.js")
script.
    $(function () {
      var socket = io('http://localhost:8080/chat', {transports: ['websocket']});
      $('form').submit(function(){
        socket.emit('chat message', $('#m').val());
        $('#m').val('');
        return false;
      });
    });

回答1:

If anyone has the same problem, I made a simple mistake, though if anyone can explain exactly what's going on, that would be great.

It seems that I wasn't listening on the client for 'connect', so nothing was being called in the client. on top of that I had the jquery selector selecting class of form not a form element.

As soon as I added the socket.on('connect',...) socket.emit was working and I was quickly able to get the jquery statement to work out too.

tldr;

Make sure to turn on the connect event (socket.on('connect',...)) on the client as well.

CLIENT

script.
    $(function () {
      var socket = io('http://localhost:8080', {transports: ['websocket']});
      socket.on('connect', function(){
        console.log("connected on client!");
        socket.emit('chat message', "hello there");
        $('form').submit(function(){
        console.log("form submitted");
          socket.emit('chat message', $('#m').val());
          $('#m').val('');
          return false;
        });
      })

    });

来源：https://stackoverflow.com/questions/49093416/socket-io-and-express-server-not-receiving-emit-from-client

标签

express

Socket.IO

pug