Properties Format on Geojson to MongoDB/Mongoengine

Question

I would like to find a solution on what DataField I should give to a geojson with a properties column. Currently a geojson format below would not have any issues since it it would only need the StringField() and PointField().

A geojson format looks like this:

{
name : "Timmy's Taco Truck",
  loc : {
    type : "Point",
    coordinates : [ 37.7577 , -122.4376 ]
  }
}

However for a geojson with this format:

{
   "type" : "Feature",
   "id" : "ID80001",
   "geometry":{"type": "LineString", "coordinates":[[122.332,14.241],[125.332,13.532]]},
   "properties":{ "name":"Dummy Name", "color":"#000000" }
}

Using a model like the one below:

from mongoengine import *
from colorful.fields import RGBColorField

class Geometry(Document):
   type = StringField()
   id = StringField()
   geometry = LineStringField()
   name = StringField() color= RGBColorField() ***OR*** properties = ???

If I use EmbeddedDocumentField and create a separate properties field it would result to "properties": [{"name": "Dummy Name","color": "#000000"}]

not:

"properties": {"name": "Dummy Name","color": "#000000"}

How can I preserve the geojson format in the models?

Answer 1

Try DictField or DynamicDocument.

from mongoengine import *

class Geometry(Document):
   type = StringField()
   id = StringField()
   geometry = LineStringField()
   properties = DictField()


g = Geometry()
# Assuming id is unique
g.properties['id'] = {"name": "Dummy Name","color": "#000000"}
g.save()

db.Geometry.findOne()
{
    "_id": <some_id>
    "properties": {
        "<some_id>": {
            {"name": "Dummy Name","color": "#000000"}
        }
}

or, just access it using index 0 of EmbeddedDocumentField?

print(properties[0])
{"name": "Dummy Name","color": "#000000"}