Book Image

React and React Native - Fourth Edition

By : Adam Boduch, Roy Derks, Mikhail Sakhniuk
Book Image

React and React Native - Fourth Edition

By: Adam Boduch, Roy Derks, Mikhail Sakhniuk

Overview of this book

Over the years, React and React Native has proven itself among JavaScript developers as a popular choice for a complete and practical guide to the React ecosystem. This fourth edition comes with the latest features, enhancements, and fixes to align with React 18, while also being compatible with React Native. It includes new chapters covering critical features and concepts in modern cross-platform app development with React. From the basics of React to popular components such as Hooks, GraphQL, and NativeBase, this definitive guide will help you become a professional React developer in a step-by-step manner. You'll begin by learning about the essential building blocks of React components. As you advance through the chapters, you'll work with higher-level functionalities in application development and then put your knowledge to work by developing user interface components for the web and native platforms. In the concluding chapters, you'll learn how to bring your application together with robust data architecture. By the end of this book, you'll be able to build React applications for the web and React Native applications for multiple mobile platforms.
Table of Contents (36 chapters)
1
Part 1 – React
15
Part 2 – React Native
31
Part 3 – React Architecture

Lazy image loading

Sometimes, you don't necessarily want an image to load at the exact moment that it's rendered; for example, you might be rendering something that's not visible on the screen yet. Most of the time, it's perfectly fine to fetch the image source from the network before it's actually visible. But if you're fine-tuning your application and discover that loading lots of images over the network causes performance issues, you can lazily load the source.

I think the more common use case in a mobile context is handling a scenario where you've rendered one or more images where they're visible, but the network is slow to respond. In this case, you will probably want to render a placeholder image so that the user sees something right away, rather than an empty space. So, let's get started:

  1. Firstly, you can implement an abstraction that wraps the actual image that you want to show once it's loaded. Here's the code...