Book Image

Progressive Web Apps with React

By : Scott Domes
Book Image

Progressive Web Apps with React

By: Scott Domes

Overview of this book

For years, the speed and power of web apps has lagged behind native applications. Progressive Web Apps (PWAs) aim to solve this by bridging the gap between the web apps and native apps, delivering a host of exciting features. Simultaneously, React is fast becoming the go-to solution for building modern web UIs, combining ease of development with performance and capability. Using React alongside PWA technology will make it easy for you to build a fast, beautiful, and functional web app. After an introduction and brief overview of the goals of PWAs, the book moves on to setting up the application structure. From there, it covers the Webpack build process and the process of creating React components. You'll learn how to set up the backend database and authentication solution to communicate with Firebase and how to work with React Router. Next, you will create and configure your web app manifest, making your PWA installable on mobile devices. Then you'll get introduced to service workers and see how they work as we configure the app to send push notifications using Firebase Cloud Messaging. We'll also explore the App Shell pattern, a key concept in PWAs and look at its advantages regarding efficient performance. Finally, you'll learn how to add of?ine capabilities to the app with caching and confirm your progress by auditing your PWA with Lighthouse. Also, you'll discover helper libraries and shortcuts that will help you save time and understand the future of PWA development.
Table of Contents (21 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

Class components versus functional components

We just defined React components as functions that return a piece of the UI. This is a useful way of thinking about them, and is certainly true for our App component. However, there's another way of writing React components.

Right now, our App component is a functional component. This means it's literally written as a function, but you can also write components as JavaScript classes. These are called class-based or stateful components (we'll talk about the stateful part in a bit).

JavaScript classes are a new feature of ES6. They work in a similar (but not identical) way to classes in other languages. We won't delve too deep into them here, but for our purpose, you can do the following:

  • Have a class extend another class (and inherit its properties)
  • Create an instance of a class with the new keyword (that is, instantiate it)

Let's see an example by converting our App component into a class-based component.

Every class component must do two things: it...