Fixed #24214 -- Added GIS functions to replace geoqueryset's methods

Thanks Simon Charette and Tim Graham for the reviews.

django/contrib/gis/db/backends/base/features.py

@@ -1,3 +1,4 @@
+import re
 from functools import partial
 
 from django.contrib.gis.db.models import aggregates
@@ -59,11 +60,11 @@ def supports_relate_lookup(self):
     # `has_<name>_method` (defined in __init__) which accesses connection.ops
     # to determine GIS method availability.
     geoqueryset_methods = (
-        'area', 'centroid', 'difference', 'distance', 'distance_spheroid',
-        'envelope', 'force_rhr', 'geohash', 'gml', 'intersection', 'kml',
-        'length', 'num_geom', 'perimeter', 'point_on_surface', 'reverse',
-        'scale', 'snap_to_grid', 'svg', 'sym_difference', 'transform',
-        'translate', 'union', 'unionagg',
+        'area', 'bounding_circle', 'centroid', 'difference', 'distance',
+        'distance_spheroid', 'envelope', 'force_rhr', 'geohash', 'gml',
+        'intersection', 'kml', 'length', 'mem_size', 'num_geom', 'num_points',
+        'perimeter', 'point_on_surface', 'reverse', 'scale', 'snap_to_grid',
+        'svg', 'sym_difference', 'transform', 'translate', 'union', 'unionagg',
     )
 
     # Specifies whether the Collect and Extent aggregates are supported by the database
@@ -86,5 +87,13 @@ def __init__(self, *args):
             setattr(self.__class__, 'has_%s_method' % method,
                     property(partial(BaseSpatialFeatures.has_ops_method, method=method)))
 
+    def __getattr__(self, name):
+        m = re.match(r'has_(\w*)_function$', name)
+        if m:
+            func_name = m.group(1)
+            if func_name not in self.connection.ops.unsupported_functions:
+                return True
+        return False
+
     def has_ops_method(self, method):
         return getattr(self.connection.ops, method, False)

django/contrib/gis/db/backends/base/operations.py

@@ -22,6 +22,7 @@ class BaseSpatialOperations(object):
     geometry = False
 
     area = False
+    bounding_circle = False
     centroid = False
     difference = False
     distance = False
@@ -30,7 +31,6 @@ class BaseSpatialOperations(object):
     envelope = False
     force_rhr = False
     mem_size = False
-    bounding_circle = False
     num_geom = False
     num_points = False
     perimeter = False
@@ -48,6 +48,22 @@ class BaseSpatialOperations(object):
     # Aggregates
     disallowed_aggregates = ()
 
+    geom_func_prefix = ''
+
+    # Mapping between Django function names and backend names, when names do not
+    # match; used in spatial_function_name().
+    function_names = {}
+
+    # Blacklist/set of known unsupported functions of the backend
+    unsupported_functions = {
+        'Area', 'AsGeoHash', 'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG',
+        'BoundingCircle', 'Centroid', 'Difference', 'Distance', 'Envelope',
+        'ForceRHR', 'Intersection', 'Length', 'MemSize', 'NumGeometries',
+        'NumPoints', 'Perimeter', 'PointOnSurface', 'Reverse', 'Scale',
+        'SnapToGrid', 'SymDifference', 'Transform', 'Translate',
+        'Union',
+    }
+
     # Serialization
     geohash = False
     geojson = False
@@ -108,9 +124,14 @@ def check_expression_support(self, expression):
     def spatial_aggregate_name(self, agg_name):
         raise NotImplementedError('Aggregate support not implemented for this spatial backend.')
 
+    def spatial_function_name(self, func_name):
+        if func_name in self.unsupported_functions:
+            raise NotImplementedError("This backend doesn't support the %s function." % func_name)
+        return self.function_names.get(func_name, self.geom_func_prefix + func_name)
+
     # Routines for getting the OGC-compliant models.
     def geometry_columns(self):
-        raise NotImplementedError('subclasses of BaseSpatialOperations must a provide geometry_columns() method')
+        raise NotImplementedError('Subclasses of BaseSpatialOperations must provide a geometry_columns() method.')
 
     def spatial_ref_sys(self):
         raise NotImplementedError('subclasses of BaseSpatialOperations must a provide spatial_ref_sys() method')

django/contrib/gis/db/backends/postgis/adapter.py

@@ -8,12 +8,13 @@
 
 
 class PostGISAdapter(object):
-    def __init__(self, geom):
+    def __init__(self, geom, geography=False):
         "Initializes on the geometry."
         # Getting the WKB (in string form, to allow easy pickling of
         # the adaptor) and the SRID from the geometry.
         self.ewkb = bytes(geom.ewkb)
         self.srid = geom.srid
+        self.geography = geography
         self._adapter = Binary(self.ewkb)
 
     def __conform__(self, proto):
@@ -44,4 +45,7 @@ def prepare(self, conn):
     def getquoted(self):
         "Returns a properly quoted string for use in PostgreSQL/PostGIS."
         # psycopg will figure out whether to use E'\\000' or '\000'
-        return str('ST_GeomFromEWKB(%s)' % self._adapter.getquoted().decode())
+        return str('%s(%s)' % (
+            'ST_GeogFromWKB' if self.geography else 'ST_GeomFromEWKB',
+            self._adapter.getquoted().decode())
+        )

django/contrib/gis/db/backends/postgis/operations.py

@@ -88,6 +88,13 @@ class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
         'distance_lte': PostGISDistanceOperator(func='ST_Distance', op='<=', geography=True),
     }
 
+    unsupported_functions = set()
+    function_names = {
+        'BoundingCircle': 'ST_MinimumBoundingCircle',
+        'MemSize': 'ST_Mem_Size',
+        'NumPoints': 'ST_NPoints',
+    }
+
     def __init__(self, connection):
         super(PostGISOperations, self).__init__(connection)