server.py

""" Web server based on Flask
Reference: https://github.com/reactjs/react-tutorial/blob/master/server.py
"""

import json
import os
from flask import Flask, Response, request

app = Flask(__name__, static_url_path='', static_folder='public')
app.add_url_rule('/', 'root', lambda: app.send_static_file('index.html'))

@app.route('/comments.json', methods=['GET', 'POST'])
def comments_handler():

  with open('comments.json', 'r') as file:
    comments = json.loads(file.read())

  if request.method == 'POST':
    comments.append(request.form.to_dict())
    with open('comments.json', 'w') as file:
      file.write(json.dumps(comments, indent=2, separators=(',', ': ')))

  return Response(json.dumps(comments), mimetype='application/json', headers={'Cache-Control': 'no-cache'})

if __name__ == '__main__':
  app.run(port=int(os.environ.get('PORT', 3000)), debug=True)