node-es5-chat-server.js

/*
 * A simplistic chat relay server that pools client connections
 * Written with Node, ES5 & using web sockets (Socket.io)
 */
 
var io = require("socket.io");
var socket = io.listen(8001);
var people = [];

// On connection start
socket.on("connection", function (client) {
  connectionId = "";

  client.on("join", function(joinObject) {
    // See if this user exists
    // If not, add them to the people list
    if (!doesUserExist(joinObject)) {
      connectionId = joinObject.userId;
      people.push(joinObject);
      client.emit("update", "You have successfully connected to the server.");
      socket.sockets.emit("update", joinObject.userName + " has just joined.");
      socket.sockets.emit("update-people", people);
    }
  });

  // Send message to everybody
  client.on("send-message", function(messageObject) {
    socket.sockets.emit("message", messageObject);
  });

  // Delete the user off of the people list when disconnecting
  client.on("disconnect", function() {
    socket.sockets.emit("update", people[client.id] + " has left the server.");
    deleteUser(connectionId);
    socket.sockets.emit("update-people", people);
  });
});

// Method for deleting people
function deleteUser(handle) {
  for (var p=0; p<people.length; p++) {
    if (handle==people[p].userId) {
      console.log("Deleting "+handle+" from server.");
      people.splice(p, 1);
    }
  }
}

// Checking for a user existing
function doesUserExist(user) {
  for (var p=0; p<people.length; p++) {
    if (user.userId==people[p].userId) {
      console.log("User "+user.userId+" exists.");
      return true;
      break;
    } else {
      return false;
      break;
    }
  }
}