# How to setup a basic webpack, react and babel environment

# How to build a pipeline for a customized "Hello world" with images.

Step 1: Install Node.js

The build pipeline you will be building is based in Node.js so you must ensure in the first instance that you have this installed. For instructions on how to install Node.js you can checkout the SO docs for that here

Step 2: Initialise your project as an node module

Open your project folder on the command line and use the following command:

npm init

For the purposes of this example you can feel free to take the defaults or if you'd like more info on what all this means you can check out this SO doc on setting up package configuration.

Step 3: Install necessary npm packages

Run the following command on the command line to install the packages necessary for this example:

npm install --save react react-dom

Then for the dev dependencies run this command:

npm install --save-dev babel-core babel-preset-react babel-preset-es2015 webpack babel-loader css-loader style-loader file-loader image-webpack-loader 

Finally webpack and webpack-dev-server are things that are worth installing globally rather than as a dependency of your project, if you'd prefer to add it as a dependency then that will work to, I don't. Here is the command to run:

npm install --global webpack webpack-dev-server 

Step 3: Add a .babelrc file to the root of your project

This will setup babel to use the presets you've just installed. Your .babelrc file should look like this:

{
  "presets": ["react", "es2015"]
}

Step 4: Setup project directory structure

Set yourself up a directory stucture that looks like the below in the root of your directory:

|- node_modules
|- src/
  |- components/
  |- images/
  |- styles/
  |- index.html
  |- index.jsx
|- .babelrc
|- package.json

NOTE: The node_modules, .babelrc and package.json should all have already been there from previous steps I just included them so you can see where they fit.

Step 5: Populate the project with the Hello World project files

This isn't really important to the process of building a pipeline so I'll just give you the code for these and you can copy paste them in:

src/components/HelloWorldComponent.jsx

import React, { Component } from 'react';

class HelloWorldComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {name: 'Student'};
    this.handleChange = this.handleChange.bind(this);
  }

  handleChange(e) {
    this.setState({name: e.target.value});
  }

  render() {
    return (
      <div>
        <div className="image-container">
          <img src="./images/myImage.gif" />
        </div>
        <div className="form">
          <input type="text" onChange={this.handleChange} />
          <div>
            My name is {this.state.name} and I'm a clever cloggs because I built a React build pipeline
          </div>
        </div>
      </div>
    );
  }
}

export default HelloWorldComponent;

src/images/myImage.gif

Feel free to substitute this with any image you'd like it's simply there to prove the point that we can bundle up images as well. If you provide your own image and you name it something different then you'll have to update the HelloWorldComponent.jsx to reflect your changes. Equally if you choose an image with a different file extension then you need to modify the test property of the image loader in the webpack.config.js with appropriate regex to match your new file extension..

src/styles/styles.css

.form {
  margin: 25px;
  padding: 25px;
  border: 1px solid #ddd;
  background-color: #eaeaea;
  border-radius: 10px;
}

.form div {
  padding-top: 25px;
}

.image-container {
  display: flex;
  justify-content: center;
}

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Learning to build a react pipeline</title>
</head>
<body>
  <div id="content"></div>
  <script src="app.js"></script>
</body>
</html>

index.jsx

import React from 'react';
import { render } from 'react-dom';
import HelloWorldComponent from './components/HelloWorldComponent.jsx';

require('./images/myImage.gif');
require('./styles/styles.css');
require('./index.html');

render(<HelloWorldComponent />, document.getElementById('content'));

Step 6: Create webpack configuration

Create a file called webpack.config.js in the root of your project and copy this code into it:

webpack.config.js

var path = require('path');

var config = {
  context: path.resolve(__dirname + '/src'),
  entry: './index.jsx',
  output: {
    filename: 'app.js',
    path: path.resolve(__dirname + '/dist'),
  },
  devServer: {
    contentBase: path.join(__dirname + '/dist'),
    port: 3000,
    open: true,
  },
  module: {
    loaders: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        loader: 'babel-loader'
      },
      {
        test: /\.css$/,
        loader: "style!css"
      },
      {
        test: /\.gif$/,
        loaders: [
          'file?name=[path][name].[ext]',
          'image-webpack',
        ]
      },
      { test: /\.(html)$/,
        loader: "file?name=[path][name].[ext]"
      }
    ],
  },
};

module.exports = config;

Step 7: Create npm tasks for your pipeline

To do this you will need to add two properties to the scripts key of the JSON defined in the package.json file in the root of your project. Make your scripts key look like this:


 "scripts": {
    "start": "webpack-dev-server",
    "build": "webpack",
    "test": "echo \"Error: no test specified\" && exit 1"
  },

The test script will have already been there and you can choose whether to keep it or not, it's not important to this example.

Step 8: Use the pipeline

From the command line, if you are in the project root directory you should now be able to run the command:

npm run build

This will bundle up the little application you've built and place it in the dist/ directory that it will create in the root of your project folder.

If you run the command:

npm start

Then the application you've built will be served up in your default web browser inside of a webpack dev server instance.

# Remarks

This build pipeline is not exactly what you would call "production ready" but it does give a solid start for you to add on to it the things that you need in order to get the development experience you're looking for. The approach that some people take (including myself at times) is to take a fully built up pipeline of Yeoman.io or somewhere else and then strip off the things they don't want until it suits there style. There's nothing wrong with this but perhaps with the example above you could opt for the opposite approach and build up from bare bones.

Some things you might like to add are things like a testing framework and coverage statistics like Karma with Mocha or Jasmine. Linting with ESLint. Hot module replacement in webpack-dev-server so that you can get that Ctrl+S, F5 development experience. Also the current pipeline only builds in dev mode so a production build task would be good.

Gotchas!

Notice in the context property of the webpack.config.js we have used the node path module to define our path rather than just concatenating __dirname to the string /src this is because windows hates forward slashses. So to make the solution more cross platform compatible use leverage node to help us.

Explanation of webpack.config.js properties

context

This is the filepath for which webpack will use as it's root path for the purposes of resolving relative file paths. So in index.jsx where we use require('./index.html') that dot actually resolves to the src/ directory because we've defined it as such in this property.

entry

Where webpack looks first to begin bundling the solution. This is why you'll see that in the index.jsx we are stitching together the solution with requires and imports.

output

This is where we define where webpack should be dropping the file files it has found to bundle. We have also defined a name for the file in which our bundled javascript and styles will be dropped.

devServer

These are settings specific to webpack-dev-server. The contentBase defines where the server should make it's root, we've defined the dist/ folder as our base here. The port is the port that the server will be hosted on. open is what is used to instruct webpack-dev-server to open your default browser for you once it's spun up the server.

module > loaders

This defines a mapping for webpack to use so that is knows what to do when it finds different files. The test property gives regex for webpack to use to determine if it should apply this module, in most cases we've matches on file extensions. loader or loaders give the name of the loader module that we'd like to use to load the file into webpack and let that loader take care of the bundling of that file type. There is also a query property on the javascript, this just provides a query string to the loader, so we could have probably used a query property on the html loader as well if we wanted to. It's just a different way of doing things.