Book Image

React and React Native

By : Adam Boduch
Book Image

React and React Native

By: Adam Boduch

Overview of this book

para 1: Dive into the world of React and create powerful applications with responsive and streamlined UIs! With React best practices for both Android and iOS, this book demonstrates React and React Native in action, helping you to create intuitive and engaging applications. Para 2: React and React Native allow you to build desktop, mobile and native applications for all major platforms. Combined with Flux and Relay, you?ll be able to create powerful and feature-complete applications from just one code base. Para 3: Discover how to build desktop and mobile applications using Facebook?s innovative UI libraries. You?ll also learn how to craft composable UIs using React, and then apply these concepts to building Native UIs using React Native. Finally, find out how you can create React applications which run on all major platforms, and leverage Relay for feature-complete and data-driven applications. Para 4: What?s Inside ? Craft composable UIs using React & build Native UIs using React Native ? Create React applications for major platforms ? Access APIs ? Leverage Relay for data-driven web & native mobile applications
Table of Contents (34 chapters)
React and React Native
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface

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 yet visible on the screen. 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 discovering that loading lots of images over the network causes performance issues, you can lazily load the source.

I think the more common 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 empty space.

To do this, we'll implement an abstraction that wraps the actual image that we want to show once it's loaded. Here's the code:

import React, { Component, PropTypes } from 'react'; 
import { View, Image } from 'react-native...