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)
1
Part 1:Design Patterns
5
Part 2:Architecture and UI Patterns
9
Part 3:Performance and Security Patterns

Visitor in JavaScript

The visitor design pattern concerns itself with being able to add functionality to objects without modifying the structure of them.

With classical inheritance, we often end up with a “base class” that is not used directly; it’s used as an “abstract class,” from which “concrete” classes inherit from our “base class.” For example, with BankAccount and BankAccountWithInterest, our class diagram would look as follows, where BankAccountWithInterest extends BankAccount and overrides setBalance.

Figure 3.2: A class diagram for BankAccountWithInterest inheriting from BankAccount

Figure 3.2: A class diagram for BankAccountWithInterest inheriting from BankAccount

What we can do with the visitor pattern is define BankAccount, which accepts a visitor and an InterestRateVisitor visitor class. As a class diagram, it looks as follows. BankAccount and InterestRateVisitor are not linked via inheritance; they will be linked at runtime when InterestRateVisitor is called...