Book Image

Architecting Angular Applications with Redux, RxJS, and NgRx

By : Christoffer Noring
Book Image

Architecting Angular Applications with Redux, RxJS, and NgRx

By: Christoffer Noring

Overview of this book

Managing the state of large-scale web applications is a highly challenging task with the need to align different components, backends, and web workers harmoniously. When it comes to Angular, you can use NgRx, which combines the simplicity of Redux with the reactive programming power of RxJS to build your application architecture, making your code elegant and easy to reason about, debug, and test. In this book, we start by looking at the different ways of architecting Angular applications and some of the patterns that are involved in it. This will be followed by a discussion on one-way data flow, the Flux pattern, and the origin of Redux. The book introduces you to declarative programming or, more precisely, functional programming and talks about its advantages. We then move on to the reactive programming paradigm. Reactive programming is a concept heavily used in Angular and is at the core of NgRx. Later, we look at RxJS, as a library and master it. We thoroughly describe how Redux works and how to implement it from scratch. The two last chapters of the book cover everything NgRx has to offer in terms of core functionality and supporting libraries, including how to build a micro implementation of NgRx. This book will empower you to not only use Redux and NgRx to the fullest, but also feel confident in building your own version, should you need it.
Table of Contents (12 chapters)

Stream in a stream

We have been looking at different operators that change the values being emitted. There is another different aspect to streams: what if you need to create a new stream from an existing stream? Another good question is: when does such a situation usually occur? There are plenty of situations, such as:

  • Based on a stream of keyUp events, do an AJAX call.
  • Count the number of clicks and determine whether the user single, double, or triple-clicked.

You get the idea; we are starting with one type of stream that needs to turn into another type of stream.

Let's first have a look at creating a stream and see what happens when we try to create a stream as the result of using an operator:

let stream$ = Rx.Observable.of(1,2,3)
.map(data => Rx.Observable.of(data));

// Observable, Observable, Observable
stream$.subscribe(data => console.log(data));

At this point...