express-socket.io-session

express-socket.io-session

Share a cookie-based express-session middleware with socket.io

express-socket.io-session works with express > 4.0.0 and socket.io > 1.0.0 and won't be backward compatible.

Help me notice errors or ask me for improvements creating an issue.

Overview

On every socket connection, you'll have the session object at socket.handshake.session That is the same session object req.session you get in your route middleware when your app uses express-session.

Modifying session data inside socket.io event handlers

Don't rely on session data autosaving if you use an async store for express-session.

Use Session.reload() and Session.save() on the socket.handshake.session object inside your socket.io event handlers.

Please, see More about updating and getting session data for better understanding of how to read and update session data inside your socket.io event handlers.

Installation

$ npm install express-socket.io-session

Usage

var session = require("express-session")({
    secret: "my-secret",
    resave: true,
    saveUninitialized: true
});
var sharedsession = require("express-socket.io-session")(session);


app.use(session); // Use express-session middleware for express

io.use(sharedsession(session)); // use shared session middleware for socket.io

Sharing session data with a namespaced socket

io.of('/namespace').use(sharedsession(session));

Using your own custom cookie-parser instance

...
var cookieParser = require("cookie-parser");
...
io.use(sharedsession(session, cookieParser({
    /* your params to cookie-parser* /
}));

Example

$ npm install express socket.io express-session express-socket.io-session

index.js

var app = require('express')(),
  server  = require("http").createServer(app),
  io = require("socket.io")(server),
  session = require("express-session")({
    secret: "my-secret",
    resave: true,
    saveUninitialized: true
  }),
  sharedsession = require("express-socket.io-session");


// Attach session
app.use(session);

// Share session with io sockets

io.use(sharedsession(session));

io.on("connection", function(socket) {
    // Accept a login event with user's data
    socket.on("login", function(userdata) {
        socket.handshake.session.userdata = userdata;
        socket.handshake.session.save();
    });
    socket.on("logout", function(userdata) {
        if (socket.handshake.session.userdata) {
            delete socket.handshake.session.userdata;
            // Save the data to the session store
        socket.handshake.session.save();
        }
    });        
});

server.listen(3000);

More about updating and getting session data

You may be used to express-session behaviour by which, you just modify the session properties and its value gets updated (even with using asynchronous stores like mongodb or redis). express-session achieves that by monkeypatching (and overloading) req.end.

The case here is that socket.io middleware is run only once. On connection handshake. The event handlers you define can't trigger the middleware.

So if you get used to accessing and saving session data inside your event handlers, with the .reload() and .save() from the session object you'll do just fine.

By using express-socket.io-session you'll find these methods in socket.handshake.session.get() and socket.handshake.session.save() when handling an event.

API

This module exports a middleware function for socket.io. This sharedsession function can be used with the io.use() method.

sharedsession( express_session_middleware, [cookieparser_instance] )

• express_session_middleware is required and must be an express middleware function created with the express-session module that allows cookie-based sessions.
• cookieparser_instance is optional. If you don't provide en instance created by cookie-parser, this module creates one for you with defaults.

Inspiration

• socket.io and express 4 sessions
• Socket.io 1.0.5 : How to save session variables?

Although there are a couple of modules that allow you to share session objects between express and socket.io, I wanted to be able to share the modules without affecting regular express-session instantiation.

These modules do the same work but with different approachs on initialization.

• session.socket.io
• socket.io-session-middleware

License

The MIT License (MIT)

Copyright (c) 2014-2015 osk <[e-mail]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.