Book Image

Mastering Reactive JavaScript

By : Erich de Souza Oliveira
Book Image

Mastering Reactive JavaScript

By: Erich de Souza Oliveira

Overview of this book

If you’re struggling to handle a large amount of data and don’t know how to improve your code readability, then reactive programming is the right solution for you. It lets you describe how your code behaves when changes happen and makes it easier to deal with real-time data. This book will teach you what reactive programming is, and how you can use it to write better applications. The book starts with the basics of reactive programming, what Reactive Extensions is, and how can you use it in JavaScript along with some reactive code using Bacon. Next, you’ll discover what an Observable and an Observer are and when to use them.You'll also find out how you can query data through operators, and how to use schedulers to react to changes. Moving on, you’ll explore the RxJs API, be introduced to the problem of data traffic (backpressure), and see how you can mitigate it. You’ll also learn about other important operators that can help improve your code readability, and you’ll see how to use transducers to compose operators. At the end of the book, you’ll get hands-on experience of using RxJs, and will create a real-time web chat using RxJs on the client and server, providing you with the complete package to master RxJs.
Table of Contents (11 chapters)

Running observables

Dealing with asynchronous computation in JavaScript is a hard task, and this is because all your code runs in a single thread. So, to keep this thread available most operators dealing with I/O use a callback to return the control to your program when the data is available.


The concept of threads and how JavaScript virtual machines work internally goes beyond the scope of this book, and it is not necessary to understand it.

The extensive use of callback functions usually leads to a problem called callback hell, which is basically a code with too many callbacks making it really hard to read from a programmer perspective. To mitigate this problem, promises are now part of the standard JavaScript and are implemented by all modern browsers. As promises are composable by nature, it makes your code cleaner and gives you a safe way out from callback hell.

But promises have only basic constructs to compose with each other, and for this reason RxJS (and most functional reactive...