Preface

React has been my main development tool lately. In my experience both as a developer and a computer user, I found most of what I love in the end is non-heavy stuff. While big names come and go often, there're certain things left behind. For instance, the way to build a website has been reshaped and refined over the past twenty years, but the general process of building it hasn't changed much. You still need to create an HTML file, design the layout, and host it somewhere on a server.

When it comes to the user interface (UI), there's another topic that can benefit you in a similar way. That is state. From jQuery and Angular to React, from the web to other non-desktop platforms (such as Electron or React Native), no matter where you go, there's a technical question that you need to answer now – how does the screen know there's a change to apply? When I was back in college, I never asked this type of question. I generally assumed the computer just worked that way.

Of course, now I know the computer works that way because someone made it. What's fascinating about the UI is when the state gets in the picture. Back in the early days, we didn't talk about state at all. But now state is everywhere, although there's still no textbook definition for it or how we should learn it in the first place. Suffice to say, state is still a relatively young topic in the web development industry.

In this book, I'll attempt, by using React as the underlying technology, to explore and learn how states are introduced and implemented. I hope, by doing that, we will have a better picture in the end to answer the question – how is a render engine driven by states?