Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Building Scalable Apps with Redis and Node.js
  • Table Of Contents Toc
Building Scalable Apps with Redis and Node.js

Building Scalable Apps with Redis and Node.js

By : Johanan
4.3 (9)
close
close
Building Scalable Apps with Redis and Node.js

Building Scalable Apps with Redis and Node.js

4.3 (9)
By: Johanan

Overview of this book

If the phrase scalability sounds alien to you, then this is an ideal book for you. You will not need much Node.js experience as each framework is demonstrated in a way that requires no previous knowledge of the framework. You will be building scalable Node.js applications in no time! Knowledge of JavaScript is required.
Table of Contents (12 chapters)
close
close
11
Index

Using the disconnect event

Our app is only capturing connection and joining events. Remember that the connection happens automatically, as we do not check the client at all. As soon as the client's io.connect() is called, a connection event is fired. Then, when we change the text input, a join event is fired, which goes to all the other clients. Nothing happens when someone leaves.

Socket disconnection events are different than regular HTTP events. Because HTTP is request based, we never really know when someone leaves; we just know what their last request was. Users usually have to take an action to leave, for example, going to the logout page. Socket.IO creates and maintains a persistent connection, so we will know immediately when someone leaves. Let's add it to our application.

We will begin at the backend. Open app.js and add a new listener for the disconnect event:

socket.on('disconnect', function(){
    socket.broadcast.emit('userDisconnect', {username...
Visually different images
CONTINUE READING
83
Tech Concepts
36
Programming languages
73
Tech Tools
Icon Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.
Icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Icon 50+ new titles added per month and exclusive early access to books as they are being written.
Building Scalable Apps with Redis and Node.js
notes
bookmark Notes and Bookmarks search Search in title playlist Add to playlist font-size Font size

Change the font size

margin-width Margin width

Change margin width

day-mode Day/Sepia/Night Modes

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY

Submit Your Feedback

Modal Close icon
Modal Close icon
Modal Close icon