How to Read This Book

This book intends to default to the practical. Everyone learns best by doing, and so each chapter is a series of projects for you to build, each one illustrating a new concept for you to learn. The projects start out small (the first one’s just a stopwatch) but grow in complexity. Before you know it, you’ll be building entire websites backed by the impressive power of RxJS. This is not a book to be read from cover to cover in one sitting; rather it’s a companion, meant to be cracked open on a second monitor as you type away, building out one of the many examples.

If you’re a complete newcomer to the world of observables, I’d recommend starting at the beginning of this book and working your way through. If you’ve subscribed to an observable or two, you may want to skip ahead to Chapter 3, ​Managing Asynchronous Events​, though the interim chapters might be a good refresher.

This book is split into three sections, each building on concepts introduced in the previous sections.

Section 1: Vanilla RxJS

This section starts off with an introduction to observables and how to create them in RxJS. It focuses on teaching the concepts behind RxJS, so that you’re more familiar with what’s going on. You’ll learn the concepts and best practices behind observables while tackling ever-harder examples. This section is framework-agnostic, so it will be equally useful to you regardless of your preferred toolset.

Section 2: RxJS in Angular

As incredible as RxJS is, it works best as a glue that holds the rest of the application together. An application built entirely of glue is not a good application. In this section, you’ll dive into RxJS’ use in Angular, building entire websites. You’ll see how RxJS integrates into Angular to simplify tasks both complicated and repetitive. You’ll also move beyond pure coding to see how RxJS use can enable us to build much more effective user experience. This section ends with a performance profiling task, where you’ll use RxJS to update a page only when it’s absolutely needed.

Section 3: Reactive Game Development

In this final section, you’ll construct your own game based on the Canvas API. Games have an incredible amount of things going on at any given moment, so RxJS is a perfect fit for organizing all of the hectic events that might be triggering. This is also the most advanced section, where you’ll build your own reusable observable operator alongside a from-scratch state management tool.