Book Image

Getting Started with React Native

By : Ethan Holmes, Tom Bray
Book Image

Getting Started with React Native

By: Ethan Holmes, Tom Bray

Overview of this book

React Native is a game-changing approach to hybrid mobile development. Web developers can leverage their existing skills to write mobile applications in JavaScript that are truly native without using cross-compilation or web views. These applications have all of the advantages of those written in Objective-C or Java, combined with the rapid development cycle that JavaScript developers are accustomed to. Web developers who want to develop native mobile applications face a high barrier to entry, because they are forced to learn platform-specific languages and frameworks. Numerous hybrid technologies have tried to simplify this process, but have failed to achieve the performance and appearance that users expect. This book will show you all the advantages of true native development that React Native has without the steep learning curve, leveraging the knowledge you already have. We do this by getting you up and running quickly with a sample application. Next, we’ll introduce you to the fundamentals of creating components and explain how React Native works under the hood. Once you have established a solid foundation, you will dive headfirst into developing a real-world application from start to finish. Along the way, we will demonstrate how to create multiple screens and navigate between them,use layout and style native UI components, and access native APIs such as local storage and geolocation. Finally, we tackle the advanced topic of Native modules, which demonstrates that there are truly no limits to what you can do with React Native.
Table of Contents (15 chapters)


Why are there so many alternatives to using native languages to write mobile apps? And, more importantly, why does the world need yet another approach? Obviously, there must be a problem that hasn't been solved.

Developers want to use just one language to develop for both iOS and Android. Web developers want to reuse their existing JavaScript knowledge and leverage the web frameworks they already know and love. This is why Apache Cordova (PhoneGap) exists. By wrapping a web browser in a native app, developers can package their HTML, CSS, and JavaScript applications in a native shell, but why aren't all mobile applications based on Cordova?

Users expect native performance, with a native user experience. Hybrid apps don't solve the user's problems, they solve the developer's problems. We need a technology that can do both!

React Native changes the game with applications that are truly native. It doesn't use a WebView or transpile JavaScript to native languages. Think of it as native UI components being controlled by a JavaScript brain. The result is a user experience that is indistinguishable from any other native app, and a developer experience that leverages the amazing productivity benefits of JavaScript and the React framework.

Armed with React Native, you'll finally be able to leverage your web development skills in the mobile world without sacrificing quality or performance. It's the Holy Grail, and we're excited to show you what React Native can do and to see what amazing apps you create with it!

What this book covers

Chapter 1, Exploring the Sample Application, is a step-by-step guide to running the sample iOS Application.

Chapter 2, Understanding React Native Fundamentals, covers the basics of React Native and gives brief insight into how the Virtual DOM improves performance. Then there is an introduction to props and state by creating your first component.

Chapter 3, Beginning with the Example Application, begins with generating the project files for iOS and Android. Then it continues with creating the first screens and adding navigation to the application.

Chapter 4, Working with Styles and Layout, covers the ins and outs of laying out and styling content in React Native. Learn how to apply React CSS and Flexbox to your components.

Chapter 5, Displaying and Saving Data, uses ListViews to display data and save notes using the AsyncStorage API.

Chapter 6, Working with Geolocation and Maps, discusses the geolocation API and Map Component.

Chapter 7, Integrating Native Modules, focuses on integrating third party native modules from the React Native community into your applications.

Chapter 8, Releasing the Application, goes through the release process for iOS and Android so you are ready to submit an application to the AppStore or the Google Play Store.

What you need for this book

The software requirements for this book are as follows:

  • Xcode

  • Command Line Tools

  • npm 2.x

  • JDK

  • Android SDK

Who this book is for

This book is for web developers who want to learn to build fast, good-looking, native mobile applications using the skills they already have. If you already have some JavaScript knowledge or are using React on the web, then you will be able to quickly get up and running with React Native for iOS and Android.


In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Open the ReactNotes.xcodeproj in the ios/ folder in Xcode."

A block of code is set as follows:

NSURL *jsCodeLocation;

* Loading JavaScript code - uncomment the one you want.
* Load from development server. Start the server from the repository root:
* $ npm start
* To run on device, change `localhost` to the IP address of your computer
* (you can get this by typing `ifconfig` into the terminal and selecting the
* `inet` value under `en0:`) and make sure your computer and iOS device are
* on the same Wi-Fi network.

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

* Load from pre-bundled file on disk. To re-generate the static bundle
* from the root of your project directory, run
* $ react-native bundle --minify
* see

//jsCodeLocation = [[NSBundle mainBundle] URLForResource:@"main" withExtension:@"jsbundle"];

Any command-line input or output is written as follows:

# cp /usr/src/asterisk-addons/configs/cdr_mysql.conf.sample

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Select Run and under the Info tab change Build Configuration from Release to Debug."


Warnings or important notes appear in a box like this.


Tips and tricks appear like this.

Reader feedback

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Customer support

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.

Downloading the example code

You can download the example code files from your account at for all the Packt Publishing books you have purchased. If you purchased this book elsewhere, you can visit and register to have the files e-mailed directly to you.

Downloading the color images of this book

We also provide you with a PDF file that has color images of the screenshots/diagrams used in this book. The color images will help you better understand the changes in the output. You can download this file from Started with React Native_ColorImages.pdf.


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