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
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

State in React


Every React component has something called state. You can think of this as the configuration of the component at a certain point of time.

Take, for example, a heart icon that turns red when you click on it, as in the case of Twitter. The button has two states: unclicked and clicked. Clicking on the button causes its state, and thus its appearance, to change.

That's the flow in React; user actions or events cause the component state to change, which causes the component's appearance to change.

The preceding statement comes with an enormous helping of "Well, not always…," but it's a useful starting point to understand state:

User event -> State change -> Appearance change

Let's add some state to our LoginContainer, and then go from there.

State is easy to define; it's an object that is the property of the class. We can define it as shown:

class LoginContainer extends Component {
  state = { text: ‘Hello from state!’ }

   render() {

We always define state at the top of our component...