Book Image

Hands-On JavaScript High Performance

By : Justin Scherer
1 (1)
Book Image

Hands-On JavaScript High Performance

1 (1)
By: Justin Scherer

Overview of this book

High-performance web development is all about cutting through the complexities in different layers of a web app and building services and APIs that improve the speed and performance of your apps on the browser. With emerging web technologies, building scalable websites and sustainable web apps is smoother than ever. This book starts by taking you through the web frontend, popular web development practices, and the latest version of ES and JavaScript. You'll work with Node.js and learn how to build web apps without a framework. The book consists of three hands-on examples that help you understand JavaScript applications at both the server-side and the client-side using Node.js and Svelte.js. Each chapter covers modern techniques such as DOM manipulation and V8 engine optimization to strengthen your understanding of the web. Finally, you’ll delve into advanced topics such as CI/CD and how you can harness their capabilities to speed up your web development dramatically. By the end of this web development book, you'll have understood how the JavaScript landscape has evolved, not just for the frontend but also for the backend, and be ready to use new tools and techniques to solve common web problems.
Table of Contents (15 chapters)

Saving requests for later

So far, we've learned how to intercept requests and either return or even enhance the response from our local system. Now, we will learn how to save requests when we are in offline mode and then send the calls to the server once we appear online.

Let's go ahead and set up a new folder for just this. Follow these steps:

  1. Create a folder called offline_storage and add the following files to it:
  • index.html
  • main.css
  • interactions.js
  • OfflineServiceWorker.js
  1. Add the following boilerplate code to index.html:
<!DOCTYPE html>
<html>
<head><!-- add css file --></head>
<body>
<h1>Offline Storage</h1>
<button id="makeRequest">Request</button>
<table>
<tbody id="body"></tbody>
</table>
<p>Are...