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)

Creating Observables

Most of the time, when creating Observables, you won't use the create() method to do so. You will use other methods instead. Why is that? Well, an Observable instance usually originates from some asynchronous concept. In the context of using RxJS for creating Angular applications, an Observable instance will be created by doing one of the following things:

  • Creating or fetching data over HTTP with AJAX
  • Listening to input changes with reactive forms
  • Listening to routing changes
  • Listening to UI events
  • Wrapping an asynchronous concept

In RxJS, there are different creation operators that will help you solve these tasks, but the Angular framework might actually create Observables internally. Let's look at some creation operators other than the create() method: