Book Image

JavaScript Concurrency

By : Adam Boduch
Book Image

JavaScript Concurrency

By: Adam Boduch

Overview of this book

Concurrent programming may sound abstract and complex, but it helps to deliver a better user experience. With single threaded JavaScript, applications lack dynamism. This means that when JavaScript code is running, nothing else can happen. The DOM can’t update, which means the UI freezes. In a world where users expect speed and responsiveness – in all senses of the word – this is something no developer can afford. Fortunately, JavaScript has evolved to adopt concurrent capabilities – one of the reasons why it is still at the forefront of modern web development. This book helps you dive into concurrent JavaScript, and demonstrates how to apply its core principles and key techniques and tools to a range of complex development challenges. Built around the three core principles of concurrency – parallelism, synchronization, and conservation – you’ll learn everything you need to unlock a more efficient and dynamic JavaScript, to lay the foundations of even better user experiences. Throughout the book you’ll learn how to put these principles into action by using a range of development approaches. Covering everything from JavaScript promises, web workers, generators and functional programming techniques, everything you learn will have a real impact on the performance of your applications. You’ll also learn how to move between client and server, for a more frictionless and fully realized approach to development. With further guidance on concurrent programming with Node.js, JavaScript Concurrency is committed to making you a better web developer. The best developers know that great design is about more than the UI – with concurrency, you can be confident every your project will be expertly designed to guarantee its dynamism and power.
Table of Contents (17 chapters)
JavaScript Concurrency
About the Author
About the Reviewer

Building the UI

We now have an API to target; it's time to start building the user interface for our chat. We'll start by thinking about talking to the API that we've just built, then implementing that piece. Next, we'll build the actual HTML we need to render the three pages used by this application. From here, we'll move onto perhaps the most challenging part of the front end—building the DOM event handlers and manipulators. Finally, we'll see if we can enhance the responsiveness of the application by throwing a web worker into the mix.

Talking to the API

The API communication paths in our UI are inherently concurrent—they send and receive data over a network connection. Therefore, it's in the best interest of our application architecture that we take time to hide the synchronization mechanisms from the rest of the system as best as we can. To communicate with our API, we'll use instances of the XMLHttpRequest class. However, as we've seen in earlier chapters of this book, this class can...