ReactJS - Environment Setup

In this chapter, we will show you how to set up an environment for successful React development. Notice that there are many steps involved but this will help speed up the development process later. We will need NodeJS, so if you don't have it installed, check the link from the following table.

Sr. No.	Software & Description
1	NodeJS and NPM NodeJS is the platform needed for the ReactJS development. Checkout our NodeJS Environment Setup.

Step 1 - Create the Root Folder

The root folder will be named reactApp and we will place it on Desktop. After the folder is created, we need to open it and create empty package.json file inside by running npm init from the command prompt and follow the instructions.

C:\Users\username\Desktop>mkdir reactApp
C:\Users\username\Desktop\reactApp>npm init

Step 2 - Install Global Packages

We will need to install several packages for this setup. We will need some of the babel plugins, so let's first install babel by running the following code in the command prompt window.

C:\Users\username\Desktop\reactApp>npm install -g babel
C:\Users\username\Desktop\reactApp>npm install -g babel-cli

Step 3 - Add Dependencies and Plugins

We will use webpack bundler in these tutorial. Let's install webpack and webpack-dev-server.

C:\Users\username\Desktop\reactApp>npm install webpack --save
C:\Users\username\Desktop\reactApp>npm install webpack-dev-server --save

Since we want to use React, we need to install it first. The --save command will add these packages to package.json file.

C:\Users\username\Desktop\reactApp>npm install react --save
C:\Users\username\Desktop\reactApp>npm install react-dom --save

As already mentioned, we will need some babel plugins, so let's install it too.

C:\Users\username\Desktop\reactApp>npm install babel-core
C:\Users\username\Desktop\reactApp>npm install babel-loader
C:\Users\username\Desktop\reactApp>npm install babel-preset-react
C:\Users\username\Desktop\reactApp>npm install babel-preset-es2015

Step 4 - Create the Files

Let's create several files that we need. It can be added manually or using the command prompt.

C:\Users\username\Desktop\reactApp>touch index.html
C:\Users\username\Desktop\reactApp>touch App.jsx
C:\Users\username\Desktop\reactApp>touch main.js
C:\Users\username\Desktop\reactApp>touch webpack.config.js

Alternative way to create files that we need

C:\Users\username\Desktop\reactApp>type nul >index.html
C:\Users\username\Desktop\reactApp>type nul >App.jsx
C:\Users\username\Desktop\reactApp>type nul >main.js
C:\Users\username\Desktop\reactApp>type nul >webpack.config.js

Step 5 - Set Compiler, Server and Loaders

Open webpack.config.js file and add the following code. We are setting webpack entry point to be main.js. Output path is the place where bundled app will be served. We are also setting the development server to 8080 port. You can choose any port you want.
And lastly, we are setting babel loaders to search for js files, and use es2015 and react presets that we installed before.

webpack.config.js

var config = {
   entry: './main.js',
   output: {
      path:'/',
      filename: 'index.js',
   },
   devServer: {
      inline: true,
      port: 8080
   },
   module: {
      loaders: [
         {
            test: /\.jsx?$/,
            exclude: /node_modules/,
            loader: 'babel-loader',
            query: {
               presets: ['es2015', 'react']
            }
         }
      ]
   }
}
module.exports = config;

Open the package.json and delete "test" "echo \"Error: no test specified\" && exit 1" inside "scripts" object. We are deleting this line since we will not do any testing in this tutorial. Let's add the start command instead.

"start": "webpack-dev-server --hot"

Before the above step, it will required webpack-dev-server. To install webpack-dev-server, use the following command.

C:\Users\username\Desktop\reactApp>npm install webpack-dev-server -g

Now, we can use npm start command to start the server. --hot command will add live reload after something is changed inside our files so we don't need to refresh the browser every time we change our code.

Step 6 - index.html

This is just regular HTML. We are setting div id = "app" as a root element for our app and adding index.js script, which is our bundled app file.

<!DOCTYPE html>
<html lang = "en">

   <head>
      <meta charset = "UTF-8">
      <title>React App</title>
   </head>

   <body>
      <div id = "app"></div>
      <script src = "index.js"></script>
   </body>

</html>

Step 7 - App.jsx and main.js

This is the first React component. We will explain React components in depth in a subsequent chapter. This component will render Hello World!!!.

App.jsx

import React from 'react';

class App extends React.Component {
   render() {
      return (
         <div>
            Hello World!!!
         </div>
      );
   }
}
export default App;

We need to import this component and render it to our root App element, so we can see it in the browser.

main.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.jsx';

ReactDOM.render(<App />, document.getElementById('app'));

Note − Whenever you want to use something, you need to import it first. If you want to make the component usable in other parts of the app, you need to export it after creation and import it in the file where you want to use it.

Step 8 - Running the Server

The setup is complete and we can start the server by running the following command.

C:\Users\username\Desktop\reactApp>npm start

It will show the port we need to open in the browser. In our case, it is http://localhost:8080/. After we open it, we will see the following output.

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