text: from bson import json_util, objectid
  from flask import Flask, g, render_template, request, Response, send_from_directory
  import json
  import os
  from pymongo.mongo_client import MongoClient
  
  app = Flask(__name__)
  app.config.from_pyfile('conveniences.cfg')
  conf = app.config
  
  @app.route('/')
  def index():
      return app.send_static_file("index.html")
  
  @app.route('/<path:resource>')
  def serve_static_resource(resource):
      return send_from_directory('static/', resource)
  
  def get_db():
      if not hasattr(g, 'mongodb_client'):
          g.mongodb_client = get_MongoDB()
      return g.mongodb_client
  
  # This does not work with Python 3
  #@app.teardown_appcontext
  #def close_db(error):
  #    """Closes the database again at the end of the request."""
  #    if hasattr(g, 'mongodb_client'):
  #        g.mongodb_client.close()
  
  def get_MongoDB():
      client = MongoClient(conf['DB_HOST'], conf['DB_PORT'])
      if conf['DB_USER']:
          client[conf['DB_NAME']].authenticate(conf['DB_USER'], conf['DB_PASS'], source='admin')
      db = client[conf['DB_NAME']]
      return db
  
  @app.route("/toilets/within")
  def within():
      db = get_db()
  
      # Get boundary coords - production code would check for invalid values
      lat1 = float(request.args.get('lat1'))
      lon1 = float(request.args.get('lon1'))
      lat2 = float(request.args.get('lat2'))
      lon2 = float(request.args.get('lon2'))
  
      # Make GeoJSON box
      geometry = { "type" : "Polygon", "coordinates" : [[[lon1, lat1], [lon2, lat1], [lon2, lat2], [lon1, lat2], [lon1, lat1]]]}
      # Limit results for large datasets 
      result = db.toilets.find({"geometry.coordinates" : { "$geoWithin" : { "$geometry" : geometry} } }).limit(conf['RESULT_LIMIT'])
      return Response(response=str(json.dumps({'results':list(result)},default=json_util.default)), status=200, mimetype="application/json" )
  
  @app.route("/toilets/near")
  def near():
      db = get_db()
      # Get request parameters - production code would check for invalid values
      lat = float(request.args.get('lat'))
      lon = float(request.args.get('lon'))
  
      # Limit results in case dataset is large
      result = db.toilets.find({"geometry.coordinates" : { "$near" : {"$geometry" : { "type" : "Point" , "coordinates": [ lon , lat ] }}}}).limit(conf['RESULT_LIMIT'])
  
      # Convert results into valid JSON
      return Response(response=str(json.dumps({'results':list(result)},default=json_util.default)), status=200, mimetype="application/json" )
  
  @app.route("/toilets")
  def all_toilets():
      db = get_db()
  
      result = db.toilets.find().limit(conf['RESULT_LIMIT'])
      return Response(response=str(json.dumps({'results':list(result)},default=json_util.default)), status=200, mimetype="application/json" )
  
  if __name__ == "__main__":
      app.run()
  