Simplified handling of GIS lookup params.

4 files changed, 33 insertions, 71 deletions

diff --git a/django/contrib/gis/db/backends/postgis/operations.py b/django/contrib/gis/db/backends/postgis/operations.py
index da673312db..2d27be14ca 100644
--- a/django/contrib/gis/db/backends/postgis/operations.py
+++ b/django/contrib/gis/db/backends/postgis/operations.py
@@ -42,17 +42,11 @@ class PostGISOperator(SpatialOperator):
         return super().as_sql(connection, lookup, template_params, *args)
 
     def check_raster(self, lookup, template_params):
-        # Get rhs value.
-        if isinstance(lookup.rhs, (tuple, list)):
-            rhs_val = lookup.rhs[0]
-            spheroid = lookup.rhs[-1] == 'spheroid'
-        else:
-            rhs_val = lookup.rhs
-            spheroid = False
+        spheroid = lookup.rhs_params and lookup.rhs_params[-1] == 'spheroid'
 
         # Check which input is a raster.
         lhs_is_raster = lookup.lhs.field.geom_type == 'RASTER'
-        rhs_is_raster = isinstance(rhs_val, GDALRaster)
+        rhs_is_raster = isinstance(lookup.rhs, GDALRaster)
 
         # Look for band indices and inject them if provided.
         if lookup.band_lhs is not None and lhs_is_raster:
@@ -90,7 +84,7 @@ class PostGISDistanceOperator(PostGISOperator):
         if not lookup.lhs.output_field.geography and lookup.lhs.output_field.geodetic(connection):
             template_params = self.check_raster(lookup, template_params)
             sql_template = self.sql_template
-            if len(lookup.rhs) == 3 and lookup.rhs[-1] == 'spheroid':
+            if len(lookup.rhs_params) == 2 and lookup.rhs_params[-1] == 'spheroid':
                 template_params.update({
                     'op': self.op,
                     'func': connection.ops.spatial_function_name('DistanceSpheroid'),
diff --git a/django/contrib/gis/db/models/fields.py b/django/contrib/gis/db/models/fields.py
index a639f3c176..9f8c5a1e16 100644
--- a/django/contrib/gis/db/models/fields.py
+++ b/django/contrib/gis/db/models/fields.py
@@ -6,7 +6,6 @@ from django.contrib.gis.db.models.proxy import SpatialProxy
 from django.contrib.gis.gdal.error import GDALException
 from django.contrib.gis.geometry.backend import Geometry, GeometryException
 from django.core.exceptions import ImproperlyConfigured
-from django.db.models.expressions import Expression
 from django.db.models.fields import Field
 from django.utils.translation import gettext_lazy as _
 
@@ -181,24 +180,7 @@ class BaseSpatialField(Field):
                 raise ValueError("Couldn't create spatial object from lookup value '%s'." % value)
 
     def get_prep_value(self, value):
-        """
-        Spatial lookup values are either a parameter that is (or may be
-        converted to) a geometry or raster, or a sequence of lookup values
-        that begins with a geometry or raster. Set up the geometry or raster
-        value properly and preserves any other lookup parameters.
-        """
-        value = super().get_prep_value(value)
-
-        # For IsValid lookups, boolean values are allowed.
-        if isinstance(value, (Expression, bool)):
-            return value
-        elif isinstance(value, (tuple, list)):
-            obj = value[0]
-            seq_value = True
-        else:
-            obj = value
-            seq_value = False
-
+        obj = super().get_prep_value(value)
         # When the input is not a geometry or raster, attempt to construct one
         # from the given string input.
         if isinstance(obj, Geometry):
@@ -221,13 +203,7 @@ class BaseSpatialField(Field):
 
         # Assigning the SRID value.
         obj.srid = self.get_srid(obj)
-
-        if seq_value:
-            lookup_val = [obj]
-            lookup_val.extend(value[1:])
-            return tuple(lookup_val)
-        else:
-            return obj
+        return obj
 
 
 class GeometryField(GeoSelectFormatMixin, BaseSpatialField):
diff --git a/django/contrib/gis/db/models/lookups.py b/django/contrib/gis/db/models/lookups.py
index 42089f64d2..12caf80359 100644
--- a/django/contrib/gis/db/models/lookups.py
+++ b/django/contrib/gis/db/models/lookups.py
@@ -18,9 +18,21 @@ class GISLookup(Lookup):
     band_rhs = None
     band_lhs = None
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+    def __init__(self, lhs, rhs):
+        rhs, *self.rhs_params = rhs if isinstance(rhs, (list, tuple)) else [rhs]
+        super().__init__(lhs, rhs)
         self.template_params = {}
+        self.process_rhs_params()
+
+    def process_rhs_params(self):
+        if self.rhs_params:
+            # Check if a band index was passed in the query argument.
+            if len(self.rhs_params) == (2 if self.lookup_name == 'relate' else 1):
+                self.process_band_indices()
+            elif len(self.rhs_params) > 1:
+                raise ValueError('Tuple too long for lookup %s.' % self.lookup_name)
+        elif isinstance(self.lhs, RasterBandTransform):
+            self.process_band_indices(only_lhs=True)
 
     def process_band_indices(self, only_lhs=False):
         """
@@ -39,20 +51,11 @@ class GISLookup(Lookup):
         else:
             self.band_lhs = 1
 
-        self.band_rhs = self.rhs[1]
-        if len(self.rhs) == 1:
-            self.rhs = self.rhs[0]
-        else:
-            self.rhs = (self.rhs[0], ) + self.rhs[2:]
+        self.band_rhs, *self.rhs_params = self.rhs_params
 
     def get_db_prep_lookup(self, value, connection):
         # get_db_prep_lookup is called by process_rhs from super class
-        if isinstance(value, (tuple, list)):
-            # First param is assumed to be the geometric object
-            params = [connection.ops.Adapter(value[0])] + list(value)[1:]
-        else:
-            params = [connection.ops.Adapter(value)]
-        return ('%s', params)
+        return ('%s', [connection.ops.Adapter(value)] + (self.rhs_params or []))
 
     def process_rhs(self, compiler, connection):
         if isinstance(self.rhs, Query):
@@ -72,16 +75,6 @@ class GISLookup(Lookup):
             return connection.ops.get_geom_placeholder(self.lhs.output_field, geom, compiler) % sql, []
         elif isinstance(self.rhs, Expression):
             raise ValueError('Complex expressions not supported for spatial fields.')
-        elif isinstance(self.rhs, (list, tuple)):
-            geom = self.rhs[0]
-            # Check if a band index was passed in the query argument.
-            if ((len(self.rhs) == 2 and not self.lookup_name == 'relate') or
-                    (len(self.rhs) == 3 and self.lookup_name == 'relate')):
-                self.process_band_indices()
-            elif len(self.rhs) > 2:
-                raise ValueError('Tuple too long for lookup %s.' % self.lookup_name)
-        elif isinstance(self.lhs, RasterBandTransform):
-            self.process_band_indices(only_lhs=True)
 
         rhs, rhs_params = super().process_rhs(compiler, connection)
         rhs = connection.ops.get_geom_placeholder(self.lhs.output_field, geom, compiler)
@@ -275,14 +268,14 @@ class RelateLookup(GISLookup):
     pattern_regex = re.compile(r'^[012TF\*]{9}$')
 
     def get_db_prep_lookup(self, value, connection):
-        if len(value) != 2:
+        if len(self.rhs_params) != 1:
             raise ValueError('relate must be passed a two-tuple')
         # Check the pattern argument
         backend_op = connection.ops.gis_operators[self.lookup_name]
         if hasattr(backend_op, 'check_relate_argument'):
-            backend_op.check_relate_argument(value[1])
+            backend_op.check_relate_argument(self.rhs_params[0])
         else:
-            pattern = value[1]
+            pattern = self.rhs_params[0]
             if not isinstance(pattern, str) or not self.pattern_regex.match(pattern):
                 raise ValueError('Invalid intersection matrix pattern "%s".' % pattern)
         return super().get_db_prep_lookup(value, connection)
@@ -302,20 +295,20 @@ class DistanceLookupBase(GISLookup):
     distance = True
     sql_template = '%(func)s(%(lhs)s, %(rhs)s) %(op)s %(value)s'
 
-    def process_rhs(self, compiler, connection):
-        if not isinstance(self.rhs, (tuple, list)) or not 2 <= len(self.rhs) <= 4:
+    def process_rhs_params(self):
+        if not 1 <= len(self.rhs_params) <= 3:
             raise ValueError("2, 3, or 4-element tuple required for '%s' lookup." % self.lookup_name)
-        elif len(self.rhs) == 4 and not self.rhs[3] == 'spheroid':
+        elif len(self.rhs_params) == 3 and self.rhs_params[2] != 'spheroid':
             raise ValueError("For 4-element tuples the last argument must be the 'spheroid' directive.")
 
         # Check if the second parameter is a band index.
-        if len(self.rhs) > 2 and not self.rhs[2] == 'spheroid':
+        if len(self.rhs_params) > 1 and self.rhs_params[1] != 'spheroid':
             self.process_band_indices()
 
-        params = [connection.ops.Adapter(self.rhs[0])]
-
+    def process_rhs(self, compiler, connection):
+        params = [connection.ops.Adapter(self.rhs)]
         # Getting the distance parameter in the units of the field.
-        dist_param = self.rhs[1]
+        dist_param = self.rhs_params[0]
         if hasattr(dist_param, 'resolve_expression'):
             dist_param = dist_param.resolve_expression(compiler.query)
             sql, expr_params = compiler.compile(dist_param)
@@ -323,7 +316,7 @@ class DistanceLookupBase(GISLookup):
             params.extend(expr_params)
         else:
             params += connection.ops.get_distance(
-                self.lhs.output_field, (dist_param,) + self.rhs[2:],
+                self.lhs.output_field, self.rhs_params,
                 self.lookup_name,
             )
         rhs = connection.ops.get_geom_placeholder(self.lhs.output_field, params[0], compiler)
diff --git a/tests/gis_tests/rasterapp/test_rasterfield.py b/tests/gis_tests/rasterapp/test_rasterfield.py
index 4fba577f5e..710305fe62 100644
--- a/tests/gis_tests/rasterapp/test_rasterfield.py
+++ b/tests/gis_tests/rasterapp/test_rasterfield.py
@@ -271,10 +271,9 @@ class RasterFieldTest(TransactionTestCase):
 
     def test_lookup_input_tuple_too_long(self):
         rast = GDALRaster(json.loads(JSON_RASTER))
-        qs = RasterModel.objects.filter(rast__bbcontains=(rast, 1, 2))
         msg = 'Tuple too long for lookup bbcontains.'
         with self.assertRaisesMessage(ValueError, msg):
-            qs.count()
+            RasterModel.objects.filter(rast__bbcontains=(rast, 1, 2))
 
     def test_lookup_input_band_not_allowed(self):
         rast = GDALRaster(json.loads(JSON_RASTER))