Book Image

JavaScript Design Patterns

By : Hugo Di Francesco
Book Image

JavaScript Design Patterns

By: Hugo Di Francesco

Overview of this book

Unlock the potential of JavaScript design patterns, the foundation for development teams seeking structured and reusable solutions to common software development challenges in this guide to improving code maintainability, scalability, and performance. Discover how these patterns equip businesses with cleaner and more maintainable code, promote team collaboration, reduce errors, and save time and costs. This book provides a comprehensive view of design patterns in modern (ES6+) JavaScript with real-world examples of their deployment in professional settings. You’ll start by learning how to use creational, structural, and behavioral design patterns in idiomatic JavaScript, and then shift focus to the architecture and UI patterns. Here, you’ll learn how to apply patterns for libraries such as React and extend them further to general web frontend and micro frontend approaches. The last section of the book introduces and illustrates sets of performance and security patterns, including messaging and events, asset and JavaScript loading strategies, and asynchronous programming performance patterns. Throughout the book, examples featuring React and Next.js, in addition to JavaScript and Web API examples, will help you choose and implement proven design patterns across diverse web ecosystems, transforming the way you approach development.
Table of Contents (16 chapters)
Part 1:Design Patterns
Part 2:Architecture and UI Patterns
Part 3:Performance and Security Patterns

Asset Loading Strategies and Executing Code off the Main Thread

There are situations in the life cycle of an application where loading more JavaScript is inevitable. This chapter details techniques to mitigate the impact of such situations. You’ll learn about asset loading optimizations such as a script element’s async, the defer attribute, the impact of type="module", and the link element’s rel (relationship) attribute’s preconnect, preload, and prefetch values. Next, you will further optimize script loading using Next.js’ Script component and its different options. The chapter wraps up with an exploration of reasons to execute JavaScript code off the main thread and an approach to do so.

In this chapter, we’ll cover the following topics:

  • How to control asset loading more granularly with a script’s async and defer attributes, and links with preconnect, preload, and prefetch
  • Further optimization opportunities...