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)

The fundamentals of RxJS

In Chapter 3, A World Full of Change - Reactive Extentions to the Rescue, we learned about observables and observers; these two objects are the most important part of functional reactive programming. Observables are objects with the capacity to listen to events occurring in an environment and they notify other objects of these events; the objects being notified are called observers and they have the capacity to react to the events propagated by an observable. They can listen for up to three events:

  • onNext(): Triggers when new data is propagated by an observable to this observer
  • onError(): Triggers when an error is propagated by an observable to this observer
  • onCompleted(): Triggers when the observable finishes without any error

RxJS gives us the opportunity to create observables from different sources of data using some built-in functions, but it also lets you create custom observables for any source of data you might need.

Subjects are a special class of objects that...