app.js

/** app for groupchat */

const express = require('express');
const app = express();

// serve stuff in static/ folder

app.use(express.static('static/'));

/** Handle websocket chat */

// allow for app.ws routes for websocket routes
const wsExpress = require('express-ws')(app);

const ChatUser = require('./ChatUser');

/** Handle a persistent connection to /chat/[roomName]
 *
 * Note that this is only called *once* per client --- not every time
 * a particular websocket chat is sent.
 *
 * `ws` becomes the socket for the client; it is specific to that visitor.
 * The `ws.send` method is how we'll send messages back to that socket.
 */

app.ws('/chat/:roomName', function(ws, req, next) {
  try {
    const user = new ChatUser(
      ws.send.bind(ws), // fn to call to message this user
      req.params.roomName // name of room for user
    );

    // register handlers for message-received, connection-closed

    ws.on('message', function(data) {
      try {
        user.handleMessage(data);
      } catch (err) {
        console.error(err);
      }
    });

    ws.on('close', function() {
      try {
        user.handleClose();
      } catch (err) {
        console.error(err);
      }
    });
  } catch (err) {
    console.error(err);
  }
});

/** serve homepage --- just static HTML
 *
 * Allow any roomName to come after homepage --- client JS will find the
 * roomname in the URL.
 *
 * */

app.get('/:roomName', function(req, res, next) {
  res.sendFile(`${__dirname}/chat.html`);
});

module.exports = app;