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

Throttling, debouncing, and batching asynchronous operations

Throttling is an operation in which requests are dropped until a certain time is reached. For example, for a 10 ms throttle timeout, once a request is made, no request in the next 10 ms will be sent. If multiple requests are made between 0 ms and 10 ms, only the last request will be sent after the 10 ms timeout expires.

In JavaScript, such a throttle function can be implemented as follows.

A higher-order function, throttle takes in an fn parameter and returns an executable function with the same input signature as the fn parameter.

When the “throttled” fn function is called, we set isThrottled = true in order to be able to discard calls between the first call and a configured timeout:

function throttle(fn, timeout) {
  let isThrottled = false;
  return (...args) => {
    isThrottled = true;
    return fn(...args);