GeoJSON
Serializer¶
GeoDjango provides a specific serializer for the GeoJSON format. See Serializing Django objects for more information on serialization.
The geojson
serializer is not meant for round-tripping data, as it has no
deserializer equivalent. For example, you cannot use loaddata
to
reload the output produced by this serializer. If you plan to reload the
outputted data, use the plain json serializer
instead.
In addition to the options of the json
serializer, the geojson
serializer accepts the following additional option when it is called by
serializers.serialize()
:
geometry_field
: A string containing the name of a geometry field to use for thegeometry
key of the GeoJSON feature. This is only needed when you have a model with more than one geometry field and you don’t want to use the first defined geometry field (by default, the first geometry field is picked).id_field
: A string containing the name of a field to use for theid
key of the GeoJSON feature. By default, the primary key of objects is used.srid
: The SRID to use for thegeometry
content. Defaults to 4326 (WGS 84).
The fields option can be used to limit fields that
will be present in the properties
key, as it works with all other
serializers.
Example:
from django.core.serializers import serialize
from my_app.models import City
serialize("geojson", City.objects.all(), geometry_field="point", fields=["name"])
Would output:
{
"type": "FeatureCollection",
"crs": {"type": "name", "properties": {"name": "EPSG:4326"}},
"features": [
{
"type": "Feature",
"id": 1,
"geometry": {"type": "Point", "coordinates": [-87.650175, 41.850385]},
"properties": {"name": "Chicago"},
}
],
}
When the fields
parameter is not specified, the geojson
serializer adds
a pk
key to the properties
dictionary with the primary key of the
object as the value.