Build Cross Platform Mobile Apps Faster with React Native

Introduction

React Native has emerged as a powerful framework for building cross platform mobile apps that run on both iOS and Android. With React Native, you can build mobile apps using only JavaScript and React, sharing most of your code across platforms. Compared to native app development, React Native offers faster development cycles and a unified codebase.

In this article, we'll provide an in-depth guide to building cross platform mobile apps with React Native. We'll cover what React Native is, how to set up your development environment, core React concepts and patterns, debugging and developer tools, building common mobile app features, and finally deploying to app stores. By the end, you'll have a solid foundation for getting started with cross platform mobile app development using React Native. Let's dive in!

Overview of React Native

React Native allows you to build real mobile apps that are indistinguishable from apps built using native SDKs for iOS and Android. Unlike hybrid app frameworks, React Native compiles your JavaScript code into native views, allowing for efficient reuse across platforms without sacrificing performance like web views.

Some key benefits of React Native include:

Key Benefits of React Native

• Cross platform - Write once, render natively on both iOS and Android with minimal platform-specific code. The bridge architecture enables JavaScript execution on native threads for near-native performance.
• Faster development - No need to switch between languages and SDKs. Use familiar React patterns to build UIs faster. Live reloading saves valuable time.
• Reusable components - Components you create can be reused across iOS and Android with little to no changes.
• Huge community - As one of the most popular open source projects, React Native has great support and abundant resources online.

Downsides to Consider

• UI performance - Complex animated UIs can be slower in React Native vs fully native code. But hardware and framework improvements are helping.
• Native access - React Native doesn't expose full native APIs of iOS and Android yet. Some native modules may be needed.
• JavaScript and React - Requires knowledge of these web technologies to get started with React Native.
• Immaturity - React Native is less mature and battle-tested compared to native platforms that have decades of development.

Setting Up Your React Native Environment

To build React Native apps, you'll need to set up your development environment. Here are the main requirements:

• Node.js - Required for using npm and running JavaScript code
• Code editor - Such as Visual Studio Code for writing code
• Xcode - For compiling iOS app binaries
• Android Studio - For Android emulators and building APKs

Once you have these installed, you can use the React Native command line interface to generate new projects and files. Each platform also has additional dependencies like CocoaPods for iOS and JDK for Android.

You'll also want to set up emulators for iOS and Android to test your apps without needing physical devices. The iOS Simulator built into Xcode and Android emulators in Android Studio are great options.

Installing Dependencies

You'll need to install the core React Native packages:

• react - The React framework
• react-native - Main library to build apps
• metro - Bundles JS and serves the app

Plus any iOS or Android specific modules needed. For building real apps, you'll likely also need:

• Redux - For state management
• React Navigation - Routing and navigation

Configuring Native Code Projects

React Native will generate native Xcode and Android Studio projects for you. You'll need to properly link dependencies, and configure app metadata like name, icons, signing certificates etc. per platform before you can build and run the apps natively.

Core Concepts in React Native

If you're familiar with React for web, many concepts in React Native will feel very similar. Let's walk through some of the core ideas and how they apply to mobile app development:

Components

At the core of React Native are components that let you split your app UI into small, reusable pieces. Components can be defined as classes or functions. They receive data through props and use state to manage data that can change.

Handling Styling

React Native uses CSS-like stylesheets to style component views. You'll also heavily use Flexbox for layouts. There are some platform differences between iOS and Android to be aware of when styling.

Navigation with React Navigation

For routing and navigation between screens, React Navigation is a very popular community library. It handles navigation flows, headers, and more across iOS and Android.

Debugging and Developer Tools

React Native provides some great options for inspecting your apps and reducing bugs during development:

React Native Debugger

React Native Debugger is an invaluable tool for inspecting views, network calls, logs and debugging JavaScript code. It also enables hot reloading to view changes instantly.

Expo Client

Expo allows you to quickly build and test React Native apps on devices without needing to generate native binaries. It provides services like push notifications out of the box.

Building Core App Features

Let's go over some common mobile app features and how to implement them in React Native:

User Interface Patterns

You can build mobile UI patterns like forms, lists, and tabs using React Native's core components like TextInput, FlatList and TabView. For navigation, the popular React Navigation library handles routing and navigation between screens.

Device Capabilities

React Native provides access to many device capabilities including Camera, Geolocation, and the Notifications API for push notifications. You can easily leverage these in your apps.

Styling and Animations

React Native offers flexible styling with standard CSS properties. For complex animations, the React Native Reanimated library helps achieve smooth performance.

Deploying to App Stores

Once your app is ready, you'll need to prepare it for deployment to the Apple App Store and Google Play Store:

Generating Builds

You'll need to generate signed release builds for iOS and Android. This requires properly setting up certificates, keys, and provisioning profiles per platform.

Publishing Apps

With release builds in hand, you can submit your app details, media assets and binaries to the app stores. Manage profiles and push updates after launch.

Conclusion

React Native offers an incredible toolset for building cross platform mobile apps faster using JavaScript and React. With some initial configuration, you can build for both major mobile platforms while sharing most code. It provides access to many device capabilities to build fully-featured apps.

While there is a learning curve, the potential time and effort savings from cross platform code reuse makes React Native a compelling choice for many mobile developers. If you're looking to build mobile apps faster and expand reach, take a closer look at React Native. The DevHunt community can help you evaluate if it's a good fit for your next project.