Today we will explore how to leverage Expo's capabilities to build a mobile application using our already built Next.js website. But before we start, let us understand the key players involved.

what is nextjs, react native and expo?

Next.js is an open-source web development framework created by the private company Vercel providing React-based web applications with server-side rendering and static website generation. Next.js is widely used by developers because of its high performance, high SEO ranking, efficiency, and great developer experience. Nextjs gives you building blocks to create fast, full-stack web applications. 

React Native is an open-source mobile application framework created by Facebook. It is used to develop applications for Android, Android TV, iOS, macOS, tvOS, Web, and Windows by enabling developers to use React along with native platform capabilities.

react native allows you to use a front end framework (React) to code a mobile app. But it's different from Cordova, Ionic or PhoneGap because those front end frameworks allows you to use HTML, CSS and Javascript to create a native application for a variety of mobile platforms. Cordova takes your web app and renders it within a native WebView.

Expo is a framework and a platform for universal React applications. It is a set of tools and services built around React Native and native platforms that help you develop, build, deploy, and quickly iterate on iOS, Android, and web apps from the same JavaScript/TypeScript codebase. With Expo you have a framework were you have multiple libraries that can help you to develop and distribute the App. 

 A WebView is a large-scale software component that is used to display web content within a native application. Its like a web browser that is embedded within an app. The WebView allows a programmer to write the bulk of the application using HTML, JavaScript and CSS which are the standard Web programming tools.

To start using Expo to build your project is very simple and it won't take you more than 5 minutes.

First you need to create an expo project. Open your code editor terminal (VS Code) and input this command:

npx create-expo-app my-app

replacing "my-app" with your desired project name, Move into the newly created project directory and start the project using this command. 

cd my-app

npm start

It will immediately start the Metro Bundler, and it will display the QR code and sometext like:

 Metro waiting on exp://192.168.0.185:8081

› Scan the QR code above with Expo Go (Android) or the Camera app (iOS)

 you just have to download the expo app from the Play Store (Android) or App Store (iOS). Use the Expo app to scan the displayed QR code.

And that is it! You have successfully set up your Expo project and established a connection with your mobile device. You can change the name of the project in the package.json file.

 Open the App.js file, this file serves as the entry point for your expo application and will contain some pre-written code to start your development process.

Now that we have the Expo project set up, we have to incorporate the react-native-webview component to render our existing Next.js website within the mobile app. Open a separate terminal window within your project directory and execute the following command to install the necessary package:

 npm install react-native-webview

At the top of the App.js file, import the WebView component from the react-native-webview package. Then we have to remove the View component and replace it with an empty react fragment. Inside this fragment, render the WebView component, specifying the URL of your Next.js website as the source prop. The javaScriptEnabled prop is set to true. This ensures that any JavaScript code within your Next.js website executes properly when displayed in the app.

This post must have equipped you with the knowledge on how to use Expo to integrate your pre-built Next.js website into a mobile application. By following these steps, you have successfully created a foundation for delivering your Next.js website through a mobile app.

While this guide focused on the core integration, there are other possibilities to explore! Here are some ideas to enhance your mobile app:

Styling and Customization: Dont forget to customize the appearance and layout of your webview within the app using stylesheets.

Expo Features: Explore the rich set of features offered by Expo, such as push notifications, user authentication, and more, to elevate your mobile app's functionality.

Optimizing for Performance: Consider techniques to optimize the loading speed and responsiveness of your Next.js website within the webview for a seamless user experience.

Remember, this is just the beginning! With your newfound knowledge and the power of Expo, you can craft engaging mobile applications that leverage the strengths of both Next.js and native mobile development.

Stay tuned for future posts where we will go deeper into these exciting areas and explore more advanced Expo functionalities!