Ticket #21096: distance-name.diff

django/contrib/gis/db/models/query.py

@@ -85 +85 @@
         """
         return self._geomset_attribute('difference', geom, **kwargs)
 
-    def distance(self, geom, **kwargs):
+    def distance(self, geom, att='distance', **kwargs):
         """
         Returns the distance from the given geographic field name to the
-        given geometry in a `distance` attribute on each element of the
-        GeoQuerySet.
+        given geometry in an attribute named `att` on each element of the 
+        GeoQuerySet, `distance` by default.
 
         Keyword Arguments:
-         `spheroid`  => If the geometry field is geodetic and PostGIS is
-                        the spatial database, then the more accurate
-                        spheroid calculation will be used instead of the
-                        quicker sphere calculation.
+         `spheroid`   => If the geometry field is geodetic and PostGIS is
+                         the spatial database, then the more accurate
+                         spheroid calculation will be used instead of the
+                         quicker sphere calculation.
+ 
+         `tolerance`  => Used only for Oracle. The tolerance is
+                         in meters -- a default of 5 centimeters (0.05)
+                         is used.
 
-         `tolerance` => Used only for Oracle. The tolerance is
-                        in meters -- a default of 5 centimeters (0.05)
-                        is used.
+         `field_name` => Explicitly set the geometry field name, by default 
+                         it uses the first it finds on the model
         """
-        return self._distance_attribute('distance', geom, **kwargs)
+        return self._distance_attribute('distance', geom, att=att, **kwargs)
 
     def envelope(self, **kwargs):
         """
@@ -573 +576 @@
         return self.extra(select={model_att : fmt % settings['procedure_args']},
                           select_params=settings['select_params'])
 
-    def _distance_attribute(self, func, geom=None, tolerance=0.05, spheroid=False, **kwargs):
+    def _distance_attribute(self, func, geom=None, tolerance=0.05, spheroid=False, att=None, **kwargs):
         """
         DRY routine for GeoQuerySet distance attribute routines.
         """
@@ -716 +719 @@
             # The geometry is passed in as a parameter because we handled
             # transformation conditions in this routine.
             s['select_params'] = [backend.Adapter(geom)]
-        return self._spatial_attribute(func, s, **kwargs)
+        return self._spatial_attribute(att or func, s, **kwargs)
 
     def _geom_attribute(self, func, tolerance=0.05, **kwargs):
         """