Show live departure information for North and South Station (MBTA only).
This React app was bootstrapped with create-react-app.
Some CSS in src/DepartureDisplay.css was leveraged from the React: Up and Running accompanying files repository. All other code was either initially part of the create-react-app bootstrap or entirely written by Joel Sullivan.
The main JavaScript files are src/DepartureDisplay.js and src/DepartureState.js.
The DepartureDisplay class implements the "<DepartureDisplay>" react component. It is fairly simple: it attempts to download the departures CSV file using papaparse (from http://papaparse.com/). It keeps downloading new CSV data every 10 seconds. (It downloads the data via a super-simple PHP proxy script to prevent cross-origin request errors.) On each successful download, it uses the CSV data to create a new DepartureState object, and calls setState to trigger updating of the UI.
The DepartureState class does all of the data extraction and rendering work. It's designed to be easily testable, whereas testing DepartureDisplay would require more work. (Testability was one of the reasons for having this be a separate class.)
The file src/App.js is a modified remnant of the create-react-app boilerplate. It is simply used to display the "Departures" heading and could easily be folded into public/index.html, although that would require migrating the CSS.