GEO spatial locations

Some search backends support geo spatial searching. In order to take advantage of this we have the drf_haystack.filters.HaystackGEOSpatialFilter.


The HaystackGEOSpatialFilter depends on geopy and libgeos. Make sure to install these libraries in order to use this filter.

$ pip install geopy
$ apt-get install libgeos-c1 (for debian based linux distros)
$ brew install geos (for homebrew on OS X)

The geospatial filter is somewhat special, and for the time being, relies on a few assumptions.

  1. The index model must to have a LocationField (See for example). If your LocationField is named something other than coordinates, subclass the HaystackGEOSpatialFilter and make sure to set the drf_haystack.filters.HaystackGEOSpatialFilter.point_field to the name of the field.
  2. The query must contain a unit parameter where the unit is a valid UNIT in the django.contrib.gis.measure.Distance class.
  3. The query must contain a from parameter which is a comma separated longitude and latitude value.

You may also change the query param from by defining DRF_HAYSTACK_SPATIAL_QUERY_PARAM on your settings.

Example Geospatial view

class DistanceSerializer(serializers.Serializer):
    m = serializers.FloatField()
    km = serializers.FloatField()

class LocationSerializer(HaystackSerializer):

    distance = SerializerMethodField()

    class Meta:
        index_classes = [LocationIndex]
        fields = ["address", "city", "zip_code"]

    def get_distance(self, obj):
        if hasattr(obj, "distance"):
            return DistanceSerializer(obj.distance, many=False).data

class LocationGeoSearchViewSet(HaystackViewSet):

    index_models = [Location]
    serializer_class = LocationSerializer
    filter_backends = [HaystackGEOSpatialFilter]

Example subclassing the HaystackGEOSpatialFilter

Assuming that your LocationField is named location.

from drf_haystack.filters import HaystackGEOSpatialFilter

class CustomHaystackGEOSpatialFilter(HaystackGEOSpatialFilter):
    point_field = 'location'

class LocationGeoSearchViewSet(HaystackViewSet):

    index_models = [Location]
    serializer_class = LocationSerializer
    filter_backends = [CustomHaystackGEOSpatialFilter]

Assuming the above code works as it should, we would be able to do queries like this:


The above query would return all entries with zip_code 0351 within 10 kilometers from the location with latitude 59.744076 and longitude 10.152045.