babeljs

loklak apps is a website that hosts various apps that are built by using loklak API. It uses static pages and angular.js to make API calls and show results from users. As a part of my GSoC project, I had to introduce the World Mood Tracker app using loklak’s mood API. But since I had planned to work on React, I had to go off from the track of typical app development in loklak apps and integrate a React app in apps.loklak.org. In this blog post, I will be discussing how I introduced a React based app to apps.loklak.org and solved the problem of country-wise visualisation of mood related data on a World map. Setting up development environment inside apps.loklak.org After following the steps to create a new app in apps.loklak.org, I needed to add proper tools and libraries for smooth development of the World Mood Tracker app. In this section, I’ll be explaining the basic configuration that made it possible for a React app to be functional in the angular environment. Pre-requisites The most obvious prerequisite for the project was Node.js. I used node v8.0.0 while development of the app. Instead of npm, I decided to go with yarn because of offline caching and Internet speed issues in India. Webpack and Babel To begin with, I initiated yarn in the app directory inside project and added basic dependencies - $ yarn init $ yarn add webpack webpack-dev-server path $ yarn add babel-loader babel-core babel-preset-es2015 babel-preset-react --dev   Next, I configured webpack to set an entry point and output path for the node project in webpack.config.js - module.exports = { entry: './js/index.js', output: { path: path.resolve('.'), filename: 'index_bundle.js' }, ... }; This would signal to look for ./js/index.js as an entry point while bundling. Similarly, I configured babel for es2015 and React presets - { "presets":[ "es2015", "react" ] }   After this, I was in a state to define loaders for module in webpack.config.js. The loaders would check for /\.js$/ and /\.jsx$/ and assign them to babel-loader (with an exclusion of node_modules). React After configuring the basic presets and loaders, I added React to dependencies of the project - $ yarn add react react-dom   The React related files needed to be in ./js/ directory so that the webpack can bundle it. I used the file to create a simple React app - import React from 'react'; import ReactDOM from 'react-dom'; ReactDOM.render( <div>World Mood Tracker</div>, document.getElementById('app') );   After this, I was in a stage where it was possible to use this app as a part of apps.loklak.org app. But to do this, I first needed to compile these files and bundle them so that the external app can use it. Configuring the build target for webpack In apps.loklak.org, we need to have a file by the name of index.html in the app’s root directory. Here, we also needed to place the bundled js properly so it could be included in index.html at app’s root. HTML Webpack Plugin Using…