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)
14
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15
Index

Piping patterns

As in real-life plumbing, Node.js streams can also be piped together by following different patterns. We can, in fact, merge the flow of two different streams into one, split the flow of one stream into two or more pipes, or redirect the flow based on a condition. In this section, we are going to explore the most important plumbing patterns that can be applied to Node.js streams.

Combining streams

In this chapter, we have stressed the fact that streams provide a simple infrastructure to modularize and reuse our code, but there is one last piece missing in this puzzle: what if we want to modularize and reuse an entire pipeline? What if we want to combine multiple streams so that they look like one from the outside? The following figure shows what this means:

Figure 6.6: Combining streams

From Figure 6.6, we should already get a hint of how this works:

  • When we write into the combined stream, we are actually writing into the first stream...