Book Image

Learn ECMAScript - Second Edition

By : MEHUL MOHAN, Narayan Prusty
Book Image

Learn ECMAScript - Second Edition

By: MEHUL MOHAN, Narayan Prusty

Overview of this book

Learn ECMAScript explores implementation of the latest ECMAScript features to add to your developer toolbox, helping you to progress to an advanced level. Learn to add 1 to a variable andsafely access shared memory data within multiple threads to avoid race conditions. You’ll start the book by building on your existing knowledge of JavaScript, covering performing arithmetic operations, using arrow functions and dealing with closures. Next, you will grasp the most commonly used ECMAScript skills such as reflection, proxies, and classes. Furthermore, you’ll learn modularizing the JS code base, implementing JS on the web and how the modern HTML5 + JS APIs provide power to developers on the web. Finally, you will learn the deeper parts of the language, which include making JavaScript multithreaded with dedicated and shared web workers, memory management, shared memory, and atomics. It doesn’t end here; this book is 100% compatible with ES.Next. By the end of this book, you'll have fully mastered all the features of ECMAScript!
Table of Contents (18 chapters)
Title Page
PacktPub.com
Contributors
Preface
Index

Introduction to inline web workers


It is possible to create a web worker from a single file without actually having a separate JS file for your web worker. However, I still recommend that you create a different file for your web workers, for the sake of clarity of code and to make it more modular. Modularity is always preferred in programming.

We can make use of blob URLs to actually point data in memory to a URL, and then load the blob URL instead of an actual file URL. Since this URL is generated dynamically only on the user's computer, you do not need to create a separate file for that particular web worker. Here's how we'll do that:

const blob = new Blob(['(',
function() {
    // web worker code here
}.toString(),
')()'], { type: 'application/javascript' }));

const url = URL.createObjectURL(blob); // gives a url of kind blob:http://....
const awesomeworker = new Worker(url);

It sometimes makes it easy to quickly fire a small web worker. However, this approach won't work for shared web...