Book Image

Node.js Design Patterns

By : Mario Casciaro
Book Image

Node.js Design Patterns

By: Mario Casciaro

Overview of this book

Node.js is a massively popular software platform that lets you use JavaScript to easily create scalable server-side applications. It allows you to create efficient code, enabling a more sustainable way of writing software made of only one language across the full stack, along with extreme levels of reusability, pragmatism, simplicity, and collaboration. Node.js is revolutionizing the web and the way people and companies create their software. In this book, we will take you on a journey across various ideas and components, and the challenges you would commonly encounter while designing and developing software using the Node.js platform. You will also discover the "Node.js way" of dealing with design and coding decisions. The book kicks off by exploring the fundamental principles and components that define the platform. It then shows you how to master asynchronous programming and how to design elegant and reusable components using well-known patterns and techniques. The book rounds off by teaching you the various approaches to scale, distribute, and integrate your Node.js application.
Table of Contents (16 chapters)
Node.js Design Patterns
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Publish/subscribe pattern


Publish/subscribe (often abbreviated Pub/Sub) is probably the best known one-way messaging pattern. We should already be familiar with it, as it's nothing more than a distributed observer pattern. As in the case of observer, we have a set of subscribers registering their interest in receiving a specific category of messages. On the other side, the publisher produces messages that are distributed across all the relevant subscribers. The following figure shows the two main variations of the pub/sub pattern, the first peer-to-peer, the second using a broker to mediate the communication:

What makes pub/sub so special is the fact that the publisher doesn't know who the recipients of the messages are in advance. As we said, it's the subscriber which has to register its interest to receive a particular message, allowing the publisher to work with an unknown number of receivers. In other words, the two sides of the pub/sub pattern are loosely coupled, which makes this an...