INTPYTHON-835 Add support for spatial lookups

[NoahStapp]

PR docs: https://django-mongodb-backend--448.org.readthedocs.build/en/448/

[NoahStapp]

All tests (including some simple ones I added due to many of the Django ones requiring features we don't support) passing, marking as ready for an initial review pass.

[Jibola]

Can this just be moved to DistanceGT and DistanceGTE

[NoahStapp]

Can you be more specific? Having it here lets us reduce the code duplication.

[timgraham]

I could see a refactor like this: [Incidentally, is gt vs. gte accounted for elsewhere?)

diff --git a/django_mongodb_backend/gis/operators.py b/django_mongodb_backend/gis/operators.py
index cc24473..3824de5 100644
--- a/django_mongodb_backend/gis/operators.py
+++ b/django_mongodb_backend/gis/operators.py
@@ -52,22 +52,28 @@ class DistanceBase(Operator):
 
     def as_mql(self, field, value, params=None):
         distance = params[0].m if hasattr(params[0], "m") else params[0]
-        if self.name == "distance_gt" or self.name == "distance_gte":
-            cmd = {
-                field: {
-                    "$not": {
-                        "$geoWithin": {
-                            "$centerSphere": [
-                                value["coordinates"],
-                                distance / 6378100,  # radius of earth in meters
-                            ],
-                        }
-                    }
+        return self.get_mql(field, value, distance):
+
+    def get_mql(self, field, value, distance):
+        return  {
+            field: {
+                "$geoWithin": {
+                    "$centerSphere": [
+                        value["coordinates"],
+                        distance / 6378100,  # radius of earth in meters
+                    ],
                 }
             }
+        return self.get_mql(field, value, distance):
+
+    def get_mql(self, field, value, distance):
+        return  {
+            field: {
+                "$geoWithin": {
+                    "$centerSphere": [
+                        value["coordinates"],
+                        distance / 6378100,  # radius of earth in meters
+                    ],
                 }
             }
-        else:
-            cmd = {
-                field: {
+        }
+
+
+class DistanceGT(DistanceBase):
+    name = "distance_gt"
+
+    def get_mql(self, field, value, distance):
+        return {
+            field: {
+                "$not": {
                     "$geoWithin": {
                         "$centerSphere": [
                             value["coordinates"],
@@ -76,14 +82,9 @@ class DistanceBase(Operator):
                     }
                 }
             }
-        return cmd
-
-
-class DistanceGT(DistanceBase):
-    name = "distance_gt"
-
+        }
 
-class DistanceGTE(DistanceBase):
+class DistanceGTE(DistanceGT):
     name = "distance_gte"
 
 

[NoahStapp]

The geospatial functionality supported by the server doesn't allow for a finer-grained gt vs gte filter beyond adding a tiny offset to the given distance. We could add that, but then we are effectively modifying user queries invisibly.

[timgraham]

It seems that only one of gt/gte is really supported then, correct?

[NoahStapp]

Put that way yes, we don't support strict LT or GT. Removing those two operators would be clearer.

[timgraham]

It seems like only one of LT or GT should be "equal to". Since the query condition is negated, both can't include the "equal to" boundary, right?

[NoahStapp]

Good point. We'll have to arbitrarily pick one to be equal to and one to be strictly less/greater. Since greater than is the negation, that will be the strict (no equal to) operation.

[timgraham]

AI (if correct) says "The $geoWithin operator treats its border as inclusive" so I think it would be lte and gt.

[timgraham]

I think saying "geodetic" isn't necessary because MongoDB doesn't support non-geodetic. Also, unlike the SQL implementation, this method isn't used for distance queries, rather it should say "on dwithin queries", I believe.

changes addressed