socket.io-mysql-session

Socket-io-mysql-session is a session manager for socket.io and websockets using MySQL as a session store. This was designed specifically for applications that use frameworks like PhoneGap, where cookies are unreliable after the app is compiled.

This is designed as middleware for socket.io. When a socket connects, it creates a new instance of itself and attaches to socket.session. From there, you can interact with the session on the server side.

Default Events

By default, the middleware creates a "getToken" listener. This listener waits for the client to send a "getToken" event along with an object that contains a token. It then tries to load the session. However, if the session cannot be found or is expired, it will create a new session. After all of this is done, it will then emit a "gotToken" with an object that contains a token (either a new one or the one you passed in), and any error messages encountered:

{token: "foo", errors: ""}

Usage - Server Side

To instantiate the session manager and add it to socket io:

Example

var socketSession = require("socket.io-mysql-session"),
    app = express(),
    http = require('http').Server(app),
    Logger = require("filelogger"),                   //filelogger is not required, but supported by the middleware
    logger = new Logger("error", "info", "my.log"),
    io = require("socket.io")(http),
    mysql = require("mysql"),
    options = {
        host: "localhost",
        port: 3306,
        user: "root",
        password: "root",
        database: "foo"
        },
     db = mysql.createConnection(options),
 
//add the middleware
 
io.use(new socketSession({
    db: db,           //MySQL conneciton - required
    logger: logger    //filelogger - optional
    expiration: 3600  //expiration time in seconds - optional - defaults to 86400000
}));
 

Usage - Interaction with the session

To get and set items to the session scope, there are two handy functions included -- get and set. Set will automatically save the session to the database when called.

API

Function	Parameters	Description
set	key, value	Saves into the session at Key, Value -- persists to database, updates expires
get	key	Retrieves Key from the session. If it doesn't exist, returns ""
clearSession		Clears session data from the socket.

Example

io.on("connection", function(socket){
    socket.on("user:login", function(params){
        //do login stuff here with params
        var userId = "id from code above";
        socket.session.set("userId", userId);
    });
 
    socket.on("user:securedEvent", function(params){
        var userId = socket.session.get("userId");
 
        if(userId != ""){
            //do secured user stuff
        } else {
            //throw error
        }
    });
});

Usage: Client Side

Since we're not using cookies, we have to do a little work on the client to initialize the session -- including storing the session token. Since my goal was to use this with a compiled app, local storage seemed like a good choice for the store. All we need to do is emit a "getToken" event and listen for a "gotToken" event.

Example

 
var socket = io("http://your.server.here"),
    token = localStorage.getItem("token") || "";
 
socket.emit("getToken", {token: localStorage.getItem("token") || ""});
 
socket.on("gotToken", function(message){
    console.log(message);
    if(message.token != "") {
        localStorage.setItem("token", message.token);
        token = message.token;
    }
});

That's it. You're now using sessions with websockets :).

Note

This middleware does NOT create its own database table. I'm of the mindeset that apps shouldn't ever have that level of database access, so you need to create it on your own. You'll get the create statement back in error messages if it encounters an error, but here it is:

 
CREATE TABLE `session` (
  `sessionId` varchar(32) COLLATE utf8_bin NOT NULL,
  `expires` int(11) unsigned NOT NULL,
  `data` text COLLATE utf8_bin,
  PRIMARY KEY (`sessionId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;