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)

RxJS Disposable

The Disposable class gives us a method to release allocated resources (database connections, file handlers, and so on). We can do this by calling the dispose() method  of this object.

In this section, we will use the dispose() method to unsubscribe from an observable.

To create a Disposable, we can use the create() function from Rx.Disposable:

var disposable = Rx.Disposable 
        .create(()=>console.log('Releasing allocated resources')); 


If you run this code, it will print the following message in your console:

    Releasing allocated resources

As discussed earlier in this chapter, we can call the dispose() method to unsubscribe from an observable. In some cases, we can even define a Disposable to be used when someone calls the dispose() method from this observable (remember the create() and createWithDisposable() functions to create an observable).

The Disposable class also gives us functions to control groups of Disposable objects. The two most important...