Order within bounding box from center

apps/search_indexes/filters.py

@@ -1,10 +1,31 @@
 """Search indexes filters."""
 from elasticsearch_dsl.query import Q
-from django_elasticsearch_dsl_drf.filter_backends import SearchFilterBackend, FacetedSearchFilterBackend
+from django_elasticsearch_dsl_drf.filter_backends import SearchFilterBackend, \
+    FacetedSearchFilterBackend, GeoSpatialFilteringFilterBackend
 from search_indexes.utils import OBJECT_FIELD_PROPERTIES
 from six import iteritems
 
 
+class CustomGeoSpatialFilteringFilterBackend(GeoSpatialFilteringFilterBackend):
+    """Automatically adds centering and sorting within bounding box."""
+
+    @staticmethod
+    def calculate_center(a, b):
+        return (a[0] + b[0]) / 2, (a[1] + b[1]) / 2
+
+    def filter_queryset(self, request, queryset, view):
+        ret = super().filter_queryset(request, queryset, view)
+        bb = request.query_params.get('location__geo_bounding_box')
+        if bb:
+            center = self.calculate_center(*map(lambda p: list(map(lambda x: float(x),p.split(','))), bb.split('__')))
+            request.GET._mutable = True
+            request.query_params.update({
+                'ordering': f'location__{center[0]}__{center[1]}__km'
+            })
+            request.GET._mutable = False
+        return ret
+
+
 class CustomFacetedSearchFilterBackend(FacetedSearchFilterBackend):
 
     def __init__(self):

apps/search_indexes/views.py

@@ -103,7 +103,7 @@ class EstablishmentDocumentViewSet(BaseDocumentViewSet):
     filter_backends = [
         FilteringFilterBackend,
         filters.CustomSearchFilterBackend,
-        GeoSpatialFilteringFilterBackend,
+        filters.CustomGeoSpatialFilteringFilterBackend,
         filters.CustomFacetedSearchFilterBackend,
         GeoSpatialOrderingFilterBackend,
     ]
@@ -287,6 +287,12 @@ class EstablishmentDocumentViewSet(BaseDocumentViewSet):
         }
     }
 
+    geo_spatial_ordering_fields = {
+        'location': {
+            'field': 'address.coordinates',
+        },
+    }
+
 
 class MobileEstablishmentDocumentViewSet(EstablishmentDocumentViewSet):
 
@@ -309,7 +315,7 @@ class ProductDocumentViewSet(BaseDocumentViewSet):
         FilteringFilterBackend,
         filters.CustomSearchFilterBackend,
         filters.CustomFacetedSearchFilterBackend,
-        GeoSpatialOrderingFilterBackend,
+        # GeoSpatialOrderingFilterBackend,
     ]
 
     search_fields = {