What this book covers

Chapter 1, Working with Creational Design Patterns, covers creational design patterns, which help to organize object creation. We’ll look at implementing the prototype, singleton, and factory patterns in JavaScript.

Chapter 2, Implementing Structural Design Patterns, looks at structural design patterns, which help to organize relationships between entities. We’ll implement the proxy, decorator, flyweight, and adapter patterns in JavaScript.

Chapter 3, Leveraging Behavioral Design Patterns, delves into behavioral design patterns, which help to organize communication between objects. We’ll learn about the observer, state, strategy, and visitor patterns in JavaScript.

Chapter 4, Exploring Reactive View Library Patterns, explores reactive view libraries, such as React, which have taken over the JavaScript application landscape. With these libraries come new patterns to explore, implement, and contrast.

Chapter 5, Rendering Strategies and Page Hydration, takes a look at optimizing page performance, which is a key concern nowadays. It’s a concern both for improving the on-page conversion of customers and search engine optimization, since search engines such as Google take core web vitals into account.

Chapter 6, Micro Frontends, Zones, and Islands Architectures, explores micro frontends. Akin to the microservices movement in the service tier, micro frontends are designed to split a large surface area into smaller chunks that can be worked on and delivered at higher velocity.

Chapter 7, Asynchronous Programming Performance Patterns, looks at how JavaScript’s single-threaded event-loop-based concurrency model is one of its greatest strengths but is often misunderstood or under-leveraged in performance-sensitive situations. Writing asynchronous-handling code in JavaScript in a performant and extensible manner is key to delivering a smooth user experience at scale.

Chapter 8, Event-Driven Programming Patterns, explores how event-driven programming in JavaScript is of paramount importance in security-sensitive applications as it is a way to pass information from and to different web contexts. Event-driven applications can often be optimized to enable better performance and scalability.

Chapter 9, Maximizing Performance – Lazy Loading and Code Splitting, deals with how, in order to maximize the performance of a JavaScript application, reducing the amount of unused JavaScript being loaded and interpreted is key. The techniques that can be brought to bear on this problem are called lazy loading and code splitting.

Chapter 10, Asset-Loading Strategies and Executing Code off the Main Thread, looks at how there are situations in the lifecycle of an application where loading more JavaScript or assets is inevitable. You will learn about asset-loading optimizations in the specific case of JavaScript, as well as other web resources, and finally how to execute JavaScript off the main browser thread.