Serialize models.GeometryCollectionField and m2m spatial relations as GeometryCollection

[duncanwp]

On serializing a GeometryCollection field using a GeoFeatureModelSerializer I seem to get some invalid GeoJSON:

{"id":14,"type":"Feature","geometry":{"type":"GeometryCollection","coordinates":[[[[-62.59810000000004,-3.2129700000000065],[-62.01231356237314,-1.7987564376269107],[-60.598100000000045,-1.2129699999999999],[-59.183886437626946,-1.7987564376269007],[-58.59810000000004,-3.21297],[-59.18388643762694,-4.627183562373094],[-60.59810000000004,-5.21297],[-62.01231356237313,-4.627183562373098],[-62.59810000000004,-3.2129700000000065]]]]},"properties":{"name":"Manacapuru","platform_type":"Ground station","platform_name":null,"region":"SA","public":false}}

Rather than the expected (from GeometryCollection.json):

{"type": "GeometryCollection", "geometries": [{"type": "Polygon", "coordinates": [[[-62.59810000000004, -3.2129700000000065], [-62.01231356237314, -1.7987564376269107], [-60.598100000000045, -1.2129699999999999], [-59.183886437626946, -1.7987564376269007], [-58.59810000000004, -3.21297], [-59.18388643762694, -4.627183562373094], [-60.59810000000004, -5.21297], [-62.01231356237313, -4.627183562373098], [-62.59810000000004, -3.2129700000000065]]]}]}

Are geometry collections supported?

[spatialbits]

heyo, having the exact same problem here.

[nemesifier]

Hello, the GeometryCollection serialization, according to automated tests, works.

If you are getting an unexpected result, please specify how you are generating such a result (show us your code), otherwise we cannot help you.

[spatialbits]

Model:

class Place(models.Model):
    name = models.CharField(max_length=200)
    geometry = models.GeometryCollectionField(srid=4326)

Model Serializer:

class PlaceGeoJSONSerializer(GeoFeatureModelSerializer):
    class Meta:
        model = Place
        fields = ('id', 'name',  'geometry')
        geo_field = 'geometry'

Geojson output:

{
	"id": 6147,
	"type": "Feature",
	"geometry": {
		"type": "GeometryCollection",
		"coordinates": [
			[
				-168.55239868164,
				12.294202377967
			]
		]
	},
	"properties": {
		"name": "Some Place"
	}
}

Looking at the discussion on SO here and geojson spec here it would appear that geometry should be replaced with geometries which should be array of typed geometries.

My particular problem arises when I try to add to a leaflet map.

If I get the geojson straight off the model with instance.geometry.geojson I get:

{
	"type": "GeometryCollection",
	"geometries": [
		{
			"type": "Point",
			"coordinates": [
				-128.55239868164,
				52.294202377966997
			]
		}
	]
}}

[nemesifier]

@spatialbits I think the misunderstanding lies in the fact that models.GeometryCollectionField is not supported, I don't remember it's mentioned anywhere in the tests or in the documentation.

I thought you were referring to having a list of geometries that would then be listed as a GeometryCollection.

[spatialbits]

Well there you go.
Can this be pegged up as a feature request?

[nemesifier]

@spatialbits done