Create Native Mobile UI with React Native

Unlocking the Power of Native UI Components in React Native

Are you tired of settling for mediocre UI components in your React Native app? Do you want to unlock the full potential of native components to create a seamless user experience? Look no further! In this article, we’ll dive into the world of native UI components in React Native and explore how to build and use them to take your app to the next level.

What is React Native?

Before we dive into native UI components, let’s take a step back and understand what React Native is. React Native is a JavaScript framework created and maintained by Facebook that allows developers to build natively rendered mobile applications for Android and iOS using JavaScript and React. It’s not just limited to mobile apps; with the help of third-party libraries like react-native-windows, you can also develop desktop applications for macOS and Windows.

What are Native UI Components in React Native?

Under the hood, React Native uses native components like UIView and UIImageView in iOS and exports them to the JavaScript layer. We use these components in our daily development process. For example, when we use the View component in JSX, we’re consuming UIView from iOS in our JavaScript code. Similarly, for the Image component, we use the UIImage component from iOS. All the components we use in React Native have a native declaration.

Creating a Native UI Component: CameraView

Let’s create a native UI component called CameraView that renders a live camera feed from the device camera to the UI and captures images from the camera, saving them to a user’s device. We’ll create a UI similar to the one shown below:

Setting Up the Project

To get started, we need to create a bare React Native project. Open your terminal and change the current working directory to your preferred folder. Then, type the command to create a new React Native project:


npx react-native init <projectName>


Creating a Common Native UI Component for Both Android and iOS

To create a common native UI component for both Android and iOS, we need to modify two files from JavaScript: App.js and CameraView.js.

Creating an Android Native UI Component

According to React Native’s official documentation, there are five steps to creating an Android UI component:

1. Create the ViewManager subclass
2. Implement the createViewInstance method
3. Expose view property setters using @ReactProp (or @ReactPropGroup) annotation
4. Register the manager in createViewManagers of the application package
5. Implement the JavaScript module

We’ll create a Java class that extends the ViewManager subclass, implement the createViewInstance method, and register our viewManager.

Creating an iOS Native UI Component

According to official documentation, we’ll need to complete the following steps to create an iOS native UI component:

1. Subclass RCTViewManager to create a manager for the component
2. Add the RCTEXPORTMODULE() marker macro
3. Implement the -(UIView *)view method

We’ll create a manager class that will export our view and contain logic related to handling events or commands from the JS side. We’ll also create a view that will be sent to the manager class to render.

Accessing the Native UI Component in JavaScript

Finally, we’ll access our native Android UI component using requireNativeComponent from React Native and exporting it as CameraView.

Conclusion

Building and using native UI components in React Native can be incredibly powerful if you’re looking to implement a feature for your React Native application that’s not supported out of the box. It’s also extremely useful if you’re converting your existing native iOS and Android applications to React Native.

By following this guide, you’ll be able to unlock the full potential of native UI components in React Native and take your app to the next level.