DT db serialized polygon to geoJSON

convert.coffee

# Convert from SQL serialized format:
parsePolygon = (polygon_s) ->
  for point_s in polygon_s.split('|')
    point_s.split(',').map(parseFloat)


toGeoJSON = (polygon) ->
  # `polygon` is an array of [lat, lng]
  polygon = (point.reverse() for point in polygon)
  polygon.push(polygon[0])

  type       : 'Polygon'
  coordinates: [ polygon ]