Book Image

Socket.IO Cookbook

By : Tyson Cadenhead
Book Image

Socket.IO Cookbook

By: Tyson Cadenhead

Overview of this book

Socket.IO is a JavaScript library that provides you with the ability to implement real-time analytics, binary streaming, instant messaging, and document collaboration. It has two parts: a client-side library that runs in the browser, and a server-side library for node.js. Socket.IO is event-driven and primarily uses the WebSocket protocol that allows us to emit data bi-directionally from the server and the client. Socket.IO This book is a complete resource, covering topics from webSocket security to scaling the server-side of a Socket.IO application and everything in between. This book will provide real-world examples of how secure bi-directional, full-duplex connections that can be created using Socket.IO for different environments. It will also explain how the connection vulnerabilities can be resolved for large numbers of users and huge amounts of data/messages. By the end of the book, you will be a competent Socket.IO developer. With the help of the examples and real-world solutions,you will learn to create fast, scalable, and dynamic real-time apps by creating efficient messaging systems between the server side and the client side using Socket.IO.
Table of Contents (15 chapters)
Socket.IO Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Listing rooms the socket is in


Socket.IO provides a dynamic list of the rooms that each socket is a member of. We can retrieve this list and use it as needed.

In this recipe, we will create a list of the rooms that our socket is in. The list will be dynamically updated if the socket leaves any of its rooms.

Getting ready

As usual, this recipe will use jQuery for the DOM manipulation and event delegation.

How to do it…

To list the rooms that your socket is in, follow these steps:

  1. On the server, we will add our socket to three distinct groups by default. We will add an event listener that will request to list the rooms for us. When this event is sent, we will emit a response message that contains socket.rooms, which is an array that Socket.IO builds dynamically as you join and leave rooms. Take a look at the following code:

    io.on('connection', function (socket) {
    
        socket.join('room1');
        socket.join('room2');
        socket.join('room3');
    
        socket.on('list.rooms', function () {
            socket...