Android React Native Application

👉 Overview

👀 What ?

React Native is a JavaScript framework for writing real, natively rendering mobile applications for both iOS and Android. It is based on React, Facebook’s JavaScript library for building user interfaces, but instead of targeting the browser, it targets mobile platforms.

🧐 Why ?

Android React Native Application development is important because it allows developers to write applications for Android using JavaScript, a language many web developers are already familiar with. This means that web developers can transition to mobile development more easily. Additionally, because React Native allows for code reuse across platforms, it significantly shortens development time.

⛏️ How ?

To create an Android React Native application, you first need to set up your development environment. This includes installing Node.js, the React Native command line interface, a Java Development Kit, and Android Studio. Once your environment is set up, you can create a new React Native project by running 'npx react-native init ProjectName'. After creating the project, you can run your React Native application on Android by running 'npx react-native run-android'.

⏳ When ?

React Native was first released by Facebook in 2015. Since then, it has grown in popularity and is now used by many large companies like Facebook, Instagram, Airbnb, and more.

⚙️ Technical Explanations

React Native is a JavaScript framework that allows developers to create mobile applications for both Android and iOS platforms. It leverages JavaScript to control native components via a JavaScript-native (JS-native) bridge.

When a React Native application is built, the JavaScript code is bundled into a file. This bundled file is executed by JavaScriptCore, a JavaScript engine developed by Apple for its Safari web browser. JavaScriptCore can execute JavaScript code outside of the context of a web page, which is critical to React Native's functionality.

The JavaScript code in a React Native app is responsible for controlling the user interface (UI) and for responding to user actions. It does this by sending messages across the JS-native bridge. This bridge is a two-way communication channel between JavaScriptCore and the native side of the application.

On the native side of the bridge, the messages received from JavaScript are translated into commands that can control the UI. This is how JavaScript code can control native components, despite being a separate language. Messages are sent back across the bridge to update the JavaScript side of the app with any native events or data.

This architecture allows for a high degree of code reuse between platforms, making React Native a popular choice for cross-platform mobile app development. It also allows web developers to transition to mobile development more easily, as they can leverage their existing JavaScript knowledge.

React Native was first released by Facebook in 2015 and has since been adopted by many large companies due to its efficiency and ease of use. It continues to be actively developed and maintained by Facebook and the open-source community.

Let's create a simple React Native application that displays a greeting message. Here are the steps:

1. Install the necessary tools: You will need Node.js, the React Native command line interface, a JDK, and Android Studio. You can install Node.js and the React Native CLI with the following commands:

   $ curl -sL <https://deb.nodesource.com/setup_14.x> | sudo -E bash -
   $ sudo apt-get install -y nodejs
   $ npm install -g react-native-cli
   
   

2. Create a new React Native project: Use the command npx react-native init GreetingApp where "GreetingApp" is the name of your new project.

3. Navigate into your project folder: Use the command cd GreetingApp.

4. Open App.js in a text editor: This is the main file where you will write your application code.

5. Replace the existing code in App.js with the following:

   import React from 'react';
   import {Text, View} from 'react-native';
   
   const GreetingApp = () => {
     return (
       <View style={{flex: 1, justifyContent: 'center', alignItems: 'center'}}>
         <Text>Hello, welcome to the GreetingApp!</Text>
       </View>
     );
   };
   
   export default GreetingApp;
   
   

   The Text and View are built-in components provided by React Native. The View acts like a container for other components, and the Text component is used to display some text.

6. Run your React Native application on Android: Use the command npx react-native run-android. This will start a development server and launch the app on your Android emulator.

Remember, the 'GreetingApp' is just a basic example. A real-world React Native application would be much more complex, with multiple screens, state management, and possibly network requests. The above example should, however, give you a good start in understanding how a simple React Native application is structured.