Book Image

Node.js Design Patterns - Third Edition

By : Mario Casciaro, Luciano Mammino
5 (1)
Book Image

Node.js Design Patterns - Third Edition

5 (1)
By: Mario Casciaro, Luciano Mammino

Overview of this book

In this book, we will show you how to implement a series of best practices and design patterns to help you create efficient and robust Node.js applications with ease. We kick off by exploring the basics of Node.js, analyzing its asynchronous event driven architecture and its fundamental design patterns. We then show you how to build asynchronous control flow patterns with callbacks, promises and async/await. Next, we dive into Node.js streams, unveiling their power and showing you how to use them at their full capacity. Following streams is an analysis of different creational, structural, and behavioral design patterns that take full advantage of JavaScript and Node.js. Lastly, the book dives into more advanced concepts such as Universal JavaScript, scalability and messaging patterns to help you build enterprise-grade distributed applications. Throughout the book, you’ll see Node.js in action with the help of several real-life examples leveraging technologies such as LevelDB, Redis, RabbitMQ, ZeroMQ, and many others. They will be used to demonstrate a pattern or technique, but they will also give you a great introduction to the Node.js ecosystem and its set of solutions.
Table of Contents (16 chapters)
Other Books You May Enjoy


Decorator is a structural design pattern that consists in dynamically augmenting the behavior of an existing object. It's different from classical inheritance, because the behavior is not added to all the objects of the same class, but only to the instances that are explicitly decorated.

Implementation-wise, it is very similar to the Proxy pattern, but instead of enhancing or modifying the behavior of the existing interface of an object, it augments it with new functionalities, as described in Figure 8.2:

Figure 8.2: Decorator pattern schematic

In Figure 8.2, the Decorator object is extending the Component object by adding the methodC() operation. The existing methods are usually delegated to the decorated object without further processing but, in some cases, they might also be intercepted and augmented with extra behaviors.

Techniques for implementing decorators

Although proxy and decorator are conceptually two different patterns with different...