The React Native Developer’s Guide to Building Scalable Cross-Platform Apps

React Native is the preferred choice of many mobile app developers who seek cross-platform compatibility and scalability. An open-source JavaScript framework developed by Meta (Facebook), it entered the market in 2015 and revolutionized the game, enabling developers to create mobile apps compatible with iOS and Android with a single codebase.

In this article, we’ll provide an overview of React Native and explore the benefits of building mobile apps with React Native, two common approaches to React Native mobile app development, and how to build scalable cross-platform apps with it.

Also, we’ll share some best practices for building scalable mobile apps with React Native. So, without further ado, let’s begin. 

Key Takeaways

• Explore the benefits of using React Native and two common approaches to React Native mobile app development.

• Learn a step-by-step guide to building scalable cross-platform mobile apps with React Native. 

• Discover best practices for building scalable cross-platform mobile apps with React Native. 

Understanding React Native

React Native is a lot like React, a JavaScript library for building online applications. With its component-based architecture, it empowers developers to create functional and scalable mobile applications easily and deliver seamless user experience across multiple platforms.

The fact React Native uses JavaScript and is identical to React contributes majorly to its widespread popularity. 

Developers familiar with building web applications with React often don’t think twice before hopping to React Native, as it enables them to build mobile apps without learning everything from scratch. 

Today, mobile app developers use the versatile and flexible framework to create near-native apps functional across iOS and Android platforms with a single codebase. This means less costs, minimal efforts, and better speed-to-market. 

Why Build a React Native App?

In today’s highly competitive market, every app must look and feel like a native app. Users expect seamless experiences and despise mobile apps that are compatible but not functional and look weird.  

That’s where React Native enters the scene. The framework gives developers the functionality they desire and a near-native user experience.

And though it is not technically native, it entails native UI components that make the app look like a native app. Add to the fact it is easy to scale and capable of handling many complexities, it becomes a no-brainer to build a React Native app.

Let’s dive deeper into its architecture, functionalities, and features to understand why React Native is preferred by many to build scalable cross-platform apps.

Advanced Architecture

The real magic lies in its architecture. React Native’s component-based architecture enables sophisticated state management, refined navigation, and native component processing across multiple platforms. 

Then, there are attractive animations that make the apps look native. The secret behind its vast architectural capabilities is that it uses a Javascript thread to connect to and interact with APIs.

This simplifies cross-platform coding and enables developers to use advanced components and seamlessly bridge apps across iOS and Android operating systems.

Hot Reloading 

React Native enables developers to speed up development and test updates live with features like hot reloading. This means you don’t have to reinstall and restart the app after every small change to the code, and you can see how the modification works and looks in real-time.

Code Reusability

React Native follows the motto write once, run anywhere. This implies you can reuse a single code to deploy applications on iOS and Android platforms. The result? Maximum efficiency and reduced development time.

Cross-Platform Functionality

A single codebase for iOS and Android platforms means faster turnaround times, consistent app development, and fewer errors. 

Native Experience

Modern-day users expect a native experience. They want top apps to work seamlessly across multiple platforms without hiccups and blatant inconsistencies. 

The framework’s native UI components solve this issue and enable developers to create mobile apps that satisfy the user’s expectations and offer maximum functionality with minimum inconsistencies.

Excellent Community Support

Every framework needs a solid community to become a hit. React Native also has a strong community through which you can find modules, plugins, and documentation to simplify app development and deliver better user experiences.

Cost-Effective

Last but not least, React Native is a cost-effective option to build scalable mobile apps. A single codebase means less time investment and reduced effort, and that translates to reduced expenses. 

Exploring the React Native Environment

Cross-platform user interfaces, third-party libraries, and native elements make up the React Native ecosystem. Also, many built-in JavaScript modules help make app development a breeze.

However, that’s not it. React Native’s ecosystem also entails developers and contributors who share tools and documentation to evolve the framework and help new developers become pros. 

These resources prove handy for developers, beginners or advanced, as they help streamline development processes and make the apps function supremely.

React Native App Development: Two Approaches

Having explored React Native functionalities and the ecosystem, it is time to explore the common app development approaches. 

Primarily, there are two methods to develop mobile apps with React Native. The first is using React Native CLI, and the other is with the help of tools like Expo.

Using React Native CLI

React Native CLI or Command Line Interface enables developers to create near-native apps seamlessly. You get complete freedom and control while developing the app and can deploy native components to the app using JavaScript and React directly. 

This is the preferred way to create functional and scalable cross-platform mobile applications and involves writing JavaScript code to build the app’s UI and deploy native functionalities. 

Using Expo

React Native also entails a collection of tools called Expo. They aim to make mobile app development more efficient.

Basically, it is a pack of native libraries bundled together for maximum accessibility. The pack is called ExpoKit. And though they make app development simple and enable developers to create straightforward applications seamlessly, it is not ideal for building more complex mobile apps.

Expo has many limitations, such as the lack of available plugins. Thus, this simplicity often comes at the cost of less freedom and control to create original and high-performance mobile apps.

Still, Expo is a quick and effective solution for building prototypes, MVP (Minimum Viable Product), or PoC (Proof of Concept). Put differently, they can be used in the early phases of development, though it is better to eventually switch to React Native CLIs.

The Science Behind React Native

At the core of React Native lies three components: JavaScript thread, Main UI thread, and bridges. The first handles the business logic, the second renders native components on the screen, and the third facilitates the communication between the two threads.

First, React Native components are written in JavaScript. Then, the code employs a bridge to render native platform APIs and deploy features like the GPS or camera. See the example below.

Further, React Native elements display as native UI elements on the framework for a near-native experience, such as Button or TextView on Android and UILabel and UIButton on iOS.

And, to style elements, the framework sticks with a style sheet syntax a lot like Cascading Style Sheets (CSS), which also enables using dynamic themes and styles.

Here’s an example to see the framework in action.

import React, { useState } from ‘react’;

import { View, Text, Button, StyleSheet } from ‘react-native’;

import { RNCamera } from ‘react-native-camera’;

const App = () => {

  const [hasPermission, setHasPermission] = useState(null);

  useEffect(() => {

    (async () => {

      const cameraStatus = await RNCamera.requestCameraPermissionsAsync();

      setHasPermission(cameraStatus === ‘granted’);

    })();

  }, []);

  if (hasPermission === null) {

    return <Text>Requesting camera permission…</Text>;

  }

  if (hasPermission === false) {

    return <Text>Camera permission denied.</Text>;

  }

  return (

    <View style={styles.container}>

      <RNCamera

        style={styles.preview}

        type={RNCamera.Constants.Type.back}

        captureAudio={false}

      />

      <Button title=”Take picture” onPress={() => { /* handle picture taking logic */ }} />

    </View>

  );

};

const styles = StyleSheet.create({

  container: {

    flex: 1,

    justifyContent: ‘center’,

    alignItems: ‘center’,

  },

  preview: {

    width: ‘100%’,

    height: ‘80%’,

  },

});

export default App;

The above example details building a basic camera app in React Native, explaining the use of React components like View, Text, and Button, and how to add features such as permission check and style on-screen elements.

A Step-By-Step Developer’s Guide to Building Scalable Cross-Platform Apps with React Native

Building scalable cross-platform mobile apps with React Native requires setting up the environment correctly, planning the architecture meticulously, and building familiarity with its core features and functionalities to ensure smooth integration and user experience.

Configure Project and Environment

Install Node.js and npm: You need the latest versions of Node.js and npm (Node Package Manager) to utilize the full capabilities of React Native.

# Download the installer from https://nodejs.org/en/

Set Up React Native CLI: The CLI helps streamline project creation and manage development tools to create scalable apps.

npm install -g react-native-cli

Create a New Project: This defines the basic structure for your app, including directories packed with platform-specific code like android/ and ios/ and ones with React Native code like src/. These directories streamline app development by segregating common codes from platform-specific ones. 

npx react-native init YourAppName

IDE Configuration (Optional): Deploy Integrated Development Environments (IDEs) like Visual Studio Code, WebStorm, and Atom. They provide development support and facilitate the development experience.

Plan and Design Architecture 

Define App Requirements: Outline the app’s core functionalities and data requirements. This helps design suitable architecture and create solution-focused apps.

Use Modular Architecture: A modular or component-based architecture breaks down the app’s functionalities into reusable components. These components can be developed, maintained, and tested independently, streamlining maintainability and scalability. 

Select State Management Strategy: Managing the application state effectively across components requires a defined state management strategy. In React Native, you could choose between Context API and Redux. The former works for simple apps, while the more complex ones require a Redux.

Plan Navigation Flow: Navigation planning is critical to delivering seamless user experiences. Evaluate the user journey and navigation between different screens within the app and plan accordingly. 

Integrating React Native Component Navigation

Select Navigation Library: User experience and engagement rely chiefly upon your app’s navigation. So, select the one that aligns with your user’s expectations and requirements. Popular options include tab navigation, stack navigation, and drawer navigation.

Implement Navigation Components: Adhering to the navigation plan, implement the components needed to ensure a seamless experience, such as navigators, screens, and headers.

import * as React from ‘react’;

import { Button, View, Text } from ‘react-native’;

import { createStackNavigator } from ‘@react-navigation/stack’;

const Stack = createStackNavigator();

// Define your screens as React components

const HomeScreen = ({ navigation }) => {

  return (

    <View style={{ flex: 1, alignItems: ‘center’, justifyContent: ‘center’ }}>

      <Text>Home Screen</Text>

      <Button title=”Go to Details” onPress={() => navigation.navigate(‘Details’)} />

    </View>

  );

};

const DetailsScreen = ({ navigation }) => {

  return (

    <View style={{ flex: 1, alignItems: ‘center’, justifyContent: ‘center’ }}>

      <Text>Details Screen</Text>

      <Button title=”Go Back” onPress={() => navigation.goBack()} />

    </View>

  );

};

const App = () => {

  return (

    <NavigationContainer>

      <Stack.Navigator>

        <Stack.Screen name=”Home” component={HomeScreen} options={{ title: ‘My App’ }} />

        <Stack.Screen name=”Details” component={DetailsScreen} />

      </Stack.Navigator>

    </NavigationContainer>

  );

};

export default App;

Use Deep Linking: The feature helps improve accessibility if you desire to navigate the users to external sources, such as social media articles or forms.

Exploring Styling and Layout

Build Visually Appealing Interfaces: Styling and layout are critical to enhancing the user experience and building native-like apps that function consistently across different platforms.

Try Flexbox: A layout model inherited from CSS, Flexbox helps create dynamic and adaptive layouts for your app.

StyleSheet Component: Also, you can deploy the StyleSheet component to ensure consistent styling across various devices and meet users’ expectations. 

Handling Gestures and Touch Events

Maintain Interactivity: Prioritize interactivity and manage user input, adding touchable components and gestures helps enhance the experience.

Add Touchable Components: A quick fix to up responsiveness is by adding touchable components to your app. They efficiently manage user interaction and enhance the overall experience.

import React from ‘react’;

import { View, Text, TouchableOpacity, StyleSheet } from ‘react-native’;

const App = () => {

  const onPressButton = () => {

    console.log(‘Button pressed!’); // Replace with your desired action

  };

  return (

    <View style={styles.container}>

      <Text style={styles.text}>Press the button below!</Text>

      <TouchableOpacity style={styles.button} onPress={onPressButton}>

        <Text style={styles.buttonText}>Click Me</Text>

      </TouchableOpacity>

    </View>

  );

};

const styles = StyleSheet.create({

  container: {

    flex: 1,

    justifyContent: ‘center’,

    alignItems: ‘center’,

  },

  text: {

    fontSize: 20,

    marginBottom: 20,

  },

  button: {

    backgroundColor: ‘#4CAF50’,

    padding: 15,

    borderRadius: 10,

  },

  buttonText: {

    color: ‘white’,

    fontSize: 16,

    textAlign: ‘center’,

  },

});

export default App;

Try Gesture Support: Cross-platform apps entail intuitive and responsive controls to make the user experience elite. Gesture support adds a layer of sophistication mandatory for modern apps.

import React, { useState } from ‘react’;

import { View, Text, PanGestureHandler, Animated } from ‘react-native’;

import { GestureHandlerRootView } from ‘react-native-gesture-handler’;

const App = () => {

  const [translateX, setTranslateX] = useState(new Animated.Value(0));

  const onGestureEvent = Animated.event(

    [{ nativeEvent: { translationX } }],

    { useNativeDriver: true } // Optimize for performance (optional)

  );

  return (

    <GestureHandlerRootView style={{ flex: 1 }}>

      <View style={{ flex: 1, justifyContent: ‘center’, alignItems: ‘center’ }}>

        <Text style={{ fontSize: 20 }}>Drag me!</Text>

        <Animated.View

          style={{

            backgroundColor: ‘skyblue’,

            width: 100,

            height: 100,

            transform: [{ translateX }],

          }}

        />

      </View>

      <PanGestureHandler onGestureEvent={onGestureEvent}>

        {/* Empty view to capture gestures */}

      </PanGestureHandler>

    </GestureHandlerRootView>

  );

};

export default App;

Using Advanced Navigation Techniques

Managing Scalability: Use Advanced navigation techniques to meet users’ expectations as the app scales and grows more complex. 

Implement Nested Navigators: They help maintain a clear, efficient, and logical navigation flow, especially in apps with complex structures.

Integrate Modals: You can facilitate the navigation through interactive elements with modals. They improve user engagement and keep navigation simple.

Incorporating Native Functionalities

Identify Native Requirements: See if your app needs functionalities specific to iOS or Android. This helps integrate platform-specific APIs to make the experience native. For instance, check whether you need to access device sensors or use GPS location services.

Utilize Third-Party Libraries: React Native saves you the hassle of writing platform-specific codes. You can use libraries to bridge the gap between the hybrid framework and native functionalities. Thanks to wrappers, the third-party libraries allow you to access native APIs using JavaScript code.

Use Conditional Rendering: This helps handle platform-specific features and functionalities and ensures seamless integration with native modules.

Streamlining Testing and Debugging

Check Reliability and Stability: Deploy a robust testing and debugging strategy to ensure your app functions reliably and remains stable.

Unit Testing: Test your component independently to check whether the function right in isolation. This helps catch bugs in the early development phase.

Integration Testing: Evaluate how the components interact with each other and external Native APIs or services.

Use React Native Debugger: The debugging tool helps efficiently identify and fix common issues with your app and ensures reliable and stable performance.

Try Testing Libraries: You can switch to external libraries like Jest for more comprehensive coverage. They cover all ends and ensure peak stability and optimum experience.

Best Practices for Building Scalable React Native Apps

Use Component Modularization

Building scalable mobile apps with React Native requires breaking the UI into smaller, reusable components. This helps make maintenance and management simple. 

So, instead of building monolithic components, build components with a clearly defined purpose. You can also use container and presentational components to enhance the modularity. The first handles app logic and the second focuses on rendering UI elements.

Split Code and Try Virtualized Lists

Splitting code is key to ensuring mobile app scalability. The trick is to break the code into smaller bundles. These bundles are relatively smaller and are loaded only when needed, helping reduce initial times and enhance performance, especially across devices with limited bandwidths.

Similarly, virtualized lists help enhance performance by reducing memory consumption. React Native has a component called a FlatList. What does it do? It makes rendering more efficient by rendering only the visible items.

Here’s a code snippet to learn how to use the FlatList component. 

// src/components/ProductListItem.js

import React from ‘react’;

import { Text, Image } from ‘react-native’;

const ProductListItem = ({ product }) => {

    return (

        <View>

            <Image source={{ uri: product.imageUrl }} style={{ width: 100, height: 100 }} />

            <Text>{product.name}</Text>

        </View>

    );

};

export default ProductListItem;

// src/screens/ProductListScreen.js

import React from ‘react’;

import { FlatList } from ‘react-native’;

import ProductListItem from ‘../components/ProductListItem’;

const ProductListScreen = ({ products }) => {

    return (

        <FlatList

            data={products}

            renderItem={({ item }) => <ProductListItem product={item} />}

            keyExtractor={item => item.id}

        />

    );

};

export default ProductListScreen;

Implement Performance Optimization Techniques

Memoization, prop drilling avoidance, and virtualization are some of the many performance optimization techniques you can use while building scalable cross-platform apps. 

Learn and implement these techniques throughout the development process to enhance efficiency and improve user experience. 

Use Over-the-Air (OTA) Updates

React Native enables using third-party services to leverage tools like Over-the-Air (OTA) that allow developers to push updates directly to users’ devices without requiring users to update the app manually. Implement functionalities like OTA to smooth the deployment process and make the user experience elite.

Here’s how you can deploy the tool using a third-party service CodePush.

import React, { useEffect, useState } from ‘react’;

import { View, Text, Button } from ‘react-native’;

import CodePush from ‘code-push’;

const App = () => {

  const [isUpdateAvailable, setIsUpdateAvailable] = useState(false);

  useEffect(() => {

    CodePush.checkForUpdate().then((update) => {

      if (update) {

        setIsUpdateAvailable(true);

      }

    });

  }, []);

  const downloadAndInstallUpdate = () => {

    CodePush.sync({

      deploymentKey: ‘YOUR_DEPLOYMENT_KEY’, // Replace with your actual key

      update⡀ifNeeded: true,

    });

  };

  return (

    <View style={{ flex: 1, justifyContent: ‘center’, alignItems: ‘center’ }}>

      <Text>App Content</Text>

      {isUpdateAvailable && (

        <Button title=”Download and Install Update” onPress={downloadAndInstallUpdate} />

      )}

    </View>

  );

};

export default App;

Conclusion

React Native is preferred by mobile app developers as it resembles React, uses JavaScript and is packed with native UI components.

There are multiple approaches to building apps using React Native, but ultimately, it comes down to decoding your project requirements and selecting the one that fits naturally.

Moreover, building familiarity with its architecture and many features and functionalities is also integral to leveraging the true potential of React Native. 

Used rightly, React Native can help develop scalable cross-platform apps compatible with iOS and Android. However, it is essential to approach app development methodically, plan the process, and keep the user’s expectations and requirements in mind. 

And though scalability is an ongoing process, it is pivotal to ensure you optimize your app for scalability from the get-go by splitting the code and creating bundles to ensure peak performance as the app grows.

We hope the guide helped you understand how to build scalable cross-platform apps using React Native. Remember, the more you code, the better you get. So, put the guide to good use and go build scalable cross-platform apps. 

Frequently Asked Questions

What are the limitations of React Native?

React Native is powerful and can create near-native apps. However, it is not always the ideal solution for more complex apps with extensive native functionalities. Also, some UI elements require serious development effort to make them look native.

Is React Native the best for building cross-platform apps?

Ultimately, it depends on the developer and the project requirements. For those familiar with React, React Native serves as the most natural option. 

What other options are available?

Like React Native, frameworks like Flutter and Xamarin can also build scalable cross-platform apps. Each has its strengths and weaknesses, and selecting the right one requires evaluating your familiarity and project requirements.

What is the future of React Native?

Thanks to its strong community and ecosystem, React Native continues to evolve, unlocking more features and functionalities. And the fact it uses a fundamental language like JavaScript and is backed by Meta (Facebook), it is safe to say the framework will remain highly popular.