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

Requiring asynchronously initialized modules


In Chapter 1, Node.js Design Fundamentals, when we discussed the fundamental properties of the Node.js module system, we mentioned the fact that require() works synchronously and that module.exports cannot be set asynchronously.

This is one of the main reasons for the existence of synchronous API in the core modules and many npm packages, they are provided more as a convenient alternative, to be used primarily for initialization tasks rather than a substitute for asynchronous API.

Unfortunately, this is not always possible; a synchronous API might not always be available, especially for components using the network during their initialization phase, for example, to perform handshake protocols or to retrieve configuration parameters. This is the case for many database drivers and clients for middleware systems such as message queues.

Canonical solutions

Let's take an example: a module called db, which connects to a remote database. The db module will...