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

Loading data from Firebase

As we described earlier, we can listen for changes to a particular reference in our database. In other words, we can define a function to run every time firebase.database().ref(‘/messages’) changes, as a new message comes in.

Before we move on, I'd encourage you to consider two things: where we should define this listener, and what the function should do.

See if you can come up with a possible implementation! After you've brainstormed an idea, let's build it.

Here's the thing: we already have a very similar case in our application. Our firebase.auth().onAuthStateChanged in our App#componentDidMount listens for changes in our current user, and updates the state.user of our App.

We will do the exact same thing with our messages reference, though the syntax is a bit different:

class App extends Component {
  state = { user: null, messages: [] }

  componentDidMount() {
    firebase.auth().onAuthStateChanged((user) => {
      if (user) {
        this.setState({ user...