Fixed #27973 -- Fixed GeoJSON representation of LinearRing and custom GEOSGeometry subclasses.

django/contrib/gis/geos/collections.py

@@ -15,6 +15,7 @@ from django.contrib.gis.geos.polygon import Polygon
 
 
 class GeometryCollection(GEOSGeometry):
+    _json_type = 'GeometryCollection'
     _typeid = 7
 
     def __init__(self, *args, **kwargs):
@@ -106,11 +107,13 @@ class GeometryCollection(GEOSGeometry):
 # MultiPoint, MultiLineString, and MultiPolygon class definitions.
 class MultiPoint(GeometryCollection):
     _allowed = Point
+    _json_type = 'MultiPoint'
     _typeid = 4
 
 
 class MultiLineString(LinearGeometryMixin, GeometryCollection):
     _allowed = (LineString, LinearRing)
+    _json_type = 'MultiLineString'
     _typeid = 5
 
     @property
@@ -122,6 +125,7 @@ class MultiLineString(LinearGeometryMixin, GeometryCollection):
 
 class MultiPolygon(GeometryCollection):
     _allowed = Polygon
+    _json_type = 'MultiPolygon'
     _typeid = 6
 
 

django/contrib/gis/geos/geometry.py

@@ -415,7 +415,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
         """
         Return GeoJSON representation of this Geometry.
         """
-        return json.dumps({'type': self.__class__.__name__, 'coordinates': self.coords})
+        return json.dumps({'type': self._json_type, 'coordinates': self.coords})
     geojson = json
 
     @property

django/contrib/gis/geos/linestring.py

@@ -8,6 +8,7 @@ from django.contrib.gis.shortcuts import numpy
 
 class LineString(LinearGeometryMixin, GEOSGeometry):
     _init_func = capi.create_linestring
+    _json_type = 'LineString'
     _minlength = 2
     has_cs = True
 

django/contrib/gis/geos/point.py

@@ -7,6 +7,7 @@ from django.contrib.gis.geos.geometry import GEOSGeometry
 
 
 class Point(GEOSGeometry):
+    _json_type = 'Point'
     _minlength = 2
     _maxlength = 3
     has_cs = True

django/contrib/gis/geos/polygon.py

@@ -7,6 +7,7 @@ from django.contrib.gis.geos.linestring import LinearRing
 
 
 class Polygon(GEOSGeometry):
+    _json_type = 'Polygon'
     _minlength = 1
 
     def __init__(self, *args, **kwargs):

tests/gis_tests/geos_tests/test_geos.py

@@ -372,6 +372,12 @@ class GEOSTest(SimpleTestCase, TestDataMixin):
             with self.assertRaisesMessage(ValueError, 'LinearRing requires at least 4 points, got 1.'):
                 LinearRing(numpy.array([(0, 0)]))
 
+    def test_linearring_json(self):
+        self.assertJSONEqual(
+            LinearRing((0, 0), (0, 1), (1, 1), (0, 0)).json,
+            '{"coordinates": [[0, 0], [0, 1], [1, 1], [0, 0]], "type": "LineString"}',
+        )
+
     def test_polygons_from_bbox(self):
         "Testing `from_bbox` class method."
         bbox = (-180, -90, 180, 90)
@@ -1269,6 +1275,10 @@ class GEOSTest(SimpleTestCase, TestDataMixin):
         self.assertEqual(type(ext_poly), ExtendedPolygon)
         # ExtendedPolygon.__str__ should be called (instead of Polygon.__str__).
         self.assertEqual(str(ext_poly), "EXT_POLYGON - data: 3 - POLYGON ((0 0, 0 1, 1 1, 0 0))")
+        self.assertJSONEqual(
+            ext_poly.json,
+            '{"coordinates": [[[0, 0], [0, 1], [1, 1], [0, 0]]], "type": "Polygon"}',
+        )
 
     def test_geos_version(self):
         """Testing the GEOS version regular expression."""