Book Image

Progressive Web Apps with React

By : Domes
Book Image

Progressive Web Apps with React

By: 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 (15 chapters)

Measuring using the timeline


In this section, we'll look at how to profile our application's performance using the Chrome DevTools, the first of a few tools we'll use to track how our application loads and responds.

Once we have an idea of how it performs, we can improve it according to RAIL principles.

The DevTools are, of course, always under development, so their appearance may differ from the given screenshots. The core functionality should remain the same, however, and so, it's important to pay close attention to the principles at work.

Go to your deployed Firebase application in Chrome and open up DevTools to the Performance tab (I recommend undocking the tools into a separate window via the dropdown menu in the top right, since there’s a lot of content to see); then, refresh the page. After the page finishes loading, you should see something similar to the following:

There's a lot going on here, so let's break it down. We'll start with the Summary tab, the circle graph at the bottom there...