Fixed #23757 -- Added 3D introspection support to Spatialite backend

Thanks Tim Graham for the review.

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

@@ -14,6 +14,8 @@ class BaseSpatialFeatures(object):
     # Does the backend introspect GeometryField to its subtypes?
     supports_geometry_field_introspection = True
 
+    # Does the backend support storing 3D geometries?
+    supports_3d_storage = False
     # Reference implementation of 3D functions is:
     # http://postgis.net/docs/PostGIS_Special_Functions_Index.html#PostGIS_3D_Functions
     supports_3d_functions = False

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

@@ -4,5 +4,6 @@ from django.db.backends.postgresql_psycopg2.features import \
 
 
 class DatabaseFeatures(BaseSpatialFeatures, Psycopg2DatabaseFeatures):
+    supports_3d_storage = True
     supports_3d_functions = True
     supports_left_right_lookups = True

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

 from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
+from django.contrib.gis.geos import geos_version
 from django.db.backends.sqlite3.features import \
     DatabaseFeatures as SQLiteDatabaseFeatures
 from django.utils.functional import cached_property
@@ -15,3 +16,7 @@ class DatabaseFeatures(BaseSpatialFeatures, SQLiteDatabaseFeatures):
         # which can result in a significant performance improvement when
         # creating the database.
         return self.connection.ops.spatial_version >= (4, 1, 0)
+
+    @cached_property
+    def supports_3d_storage(self):
+        return geos_version() >= '3.3'

django/contrib/gis/db/backends/spatialite/introspection.py

@@ -41,7 +41,13 @@ class SpatiaLiteIntrospection(DatabaseIntrospection):
 
             # OGRGeomType does not require GDAL and makes it easy to convert
             # from OGC geom type name to Django field.
-            field_type = OGRGeomType(row[2]).django
+            ogr_type = row[2]
+            if isinstance(ogr_type, six.integer_types) and ogr_type > 1000:
+                # Spatialite versions >= 4 use the new SFSQL 1.2 offsets
+                # 1000 (Z), 2000 (M), and 3000 (ZM) to indicate the presence of
+                # higher dimensional coordinates (M not yet supported by Django).
+                ogr_type = ogr_type % 1000 + OGRGeomType.wkb25bit
+            field_type = OGRGeomType(ogr_type).django
 
             # Getting any GeometryField keyword arguments that are not the default.
             dim = row[0]
@@ -49,7 +55,7 @@ class SpatiaLiteIntrospection(DatabaseIntrospection):
             field_params = {}
             if srid != 4326:
                 field_params['srid'] = srid
-            if isinstance(dim, six.string_types) and 'Z' in dim:
+            if (isinstance(dim, six.string_types) and 'Z' in dim) or dim == 3:
                 field_params['dim'] = 3
         finally:
             cursor.close()

tests/gis_tests/geo3d/tests.py

@@ -74,7 +74,7 @@ bbox_data = (
 
 
 @skipUnless(HAS_GDAL, "GDAL is required for Geo3DTest.")
-@skipUnlessDBFeature("gis_enabled", "supports_3d_functions")
+@skipUnlessDBFeature("gis_enabled", "supports_3d_storage")
 class Geo3DTest(TestCase):
     """
     Only a subset of the PostGIS routines are 3D-enabled, and this TestCase
@@ -189,6 +189,7 @@ class Geo3DTest(TestCase):
         ref_json_regex = re.compile(r'^{"type":"Point","coordinates":\[-95.363151,29.763374,18(\.0+)?\]}$')
         self.assertTrue(ref_json_regex.match(h.geojson))
 
+    @skipUnlessDBFeature("supports_3d_functions")
     def test_union(self):
         """
         Testing the Union aggregate of 3D models.
@@ -207,6 +208,7 @@ class Geo3DTest(TestCase):
         # Ordering of points in the resulting geometry may vary between implementations
         self.assertSetEqual({p.ewkt for p in ref_union}, {p.ewkt for p in union})
 
+    @skipUnlessDBFeature("supports_3d_functions")
     @ignore_warnings(category=RemovedInDjango20Warning)
     def test_extent(self):
         """
@@ -227,6 +229,7 @@ class Geo3DTest(TestCase):
         self.assertIsNone(City3D.objects.none().extent3d())
         self.assertIsNone(City3D.objects.none().aggregate(Extent3D('point'))['point__extent3d'])
 
+    @skipUnlessDBFeature("supports_3d_functions")
     def test_perimeter(self):
         """
         Testing GeoQuerySet.perimeter() on 3D fields.
@@ -244,6 +247,7 @@ class Geo3DTest(TestCase):
                                Polygon3D.objects.perimeter().get(name='3D BBox').perimeter.m,
                                tol)
 
+    @skipUnlessDBFeature("supports_3d_functions")
     def test_length(self):
         """
         Testing GeoQuerySet.length() on 3D fields.
@@ -276,6 +280,7 @@ class Geo3DTest(TestCase):
                                InterstateProj3D.objects.length().get(name='I-45').length.m,
                                tol)
 
+    @skipUnlessDBFeature("supports_3d_functions")
     def test_scale(self):
         """
         Testing GeoQuerySet.scale() on Z values.
@@ -287,6 +292,7 @@ class Geo3DTest(TestCase):
             for city in City3D.objects.scale(1.0, 1.0, zscale):
                 self.assertEqual(city_dict[city.name][2] * zscale, city.scale.z)
 
+    @skipUnlessDBFeature("supports_3d_functions")
     def test_translate(self):
         """
         Testing GeoQuerySet.translate() on Z values.

tests/gis_tests/inspectapp/models.py

@@ -14,3 +14,11 @@ class AllOGRFields(models.Model):
     point = models.PointField()
 
     objects = models.GeoManager()
+
+
+class Fields3D(models.Model):
+    point = models.PointField(dim=3)
+    line = models.LineStringField(dim=3)
+    poly = models.PolygonField(dim=3)
+
+    objects = models.GeoManager()

tests/gis_tests/inspectapp/tests.py

@@ -27,9 +27,11 @@ class InspectDbTests(TestCase):
         Test the geo-enabled inspectdb command.
         """
         out = StringIO()
-        call_command('inspectdb',
-                 table_name_filter=lambda tn: tn.startswith('inspectapp_'),
-                 stdout=out)
+        call_command(
+            'inspectdb',
+            table_name_filter=lambda tn: tn == 'inspectapp_allogrfields',
+            stdout=out
+        )
         output = out.getvalue()
         if connection.features.supports_geometry_field_introspection:
             self.assertIn('geom = models.PolygonField()', output)
@@ -39,6 +41,25 @@ class InspectDbTests(TestCase):
             self.assertIn('point = models.GeometryField(', output)
         self.assertIn('objects = models.GeoManager()', output)
 
+    @skipUnlessDBFeature("supports_3d_storage")
+    def test_3d_columns(self):
+        out = StringIO()
+        call_command(
+            'inspectdb',
+            table_name_filter=lambda tn: tn == 'inspectapp_fields3d',
+            stdout=out
+        )
+        output = out.getvalue()
+        if connection.features.supports_geometry_field_introspection:
+            self.assertIn('point = models.PointField(dim=3)', output)
+            self.assertIn('line = models.LineStringField(dim=3)', output)
+            self.assertIn('poly = models.PolygonField(dim=3)', output)
+        else:
+            self.assertIn('point = models.GeometryField(', output)
+            self.assertIn('line = models.GeometryField(', output)
+            self.assertIn('poly = models.GeometryField(', output)
+        self.assertIn('objects = models.GeoManager()', output)
+
 
 @skipUnless(HAS_GDAL, "OGRInspectTest needs GDAL support")
 @skipUnlessDBFeature("gis_enabled")