HTML5 Game Development by Example(Second Edition)

Time for action – sending the drawing through WebSockets

Carry out the following steps:

1. First, we need to modify the server logic. Open the game.js file and add two constants at the beginning of the file, as follows:

   // Constants
   var LINE_SEGMENT = 0;
   var CHAT_MESSAGE = 1;

2. In the Room.prototype.addUser method, add the following code at the beginning of the method:

   this.users.push(user);
   var room = this;
   // tell others that someone joins the room
   var data = {
     dataType: CHAT_MESSAGE,
     sender: "Server",
     message: "Welcome " + user.id 
        + " joining the party. Total connection: " + this.users.length
   };  
   room.sendAll(JSON.stringify(data));

3. We use JSON-formatted string for communicating both drawing actions and chat messages. Add the following code to the user ...