Merge f642734 into 7a4c222

django_group_by/group.py

@@ -61,9 +61,17 @@ def _set_values(self):
                     pass
 
                 else:
-                    # It is a model, build instance from data
+                    # Model, first shorten field name
                     k = k.replace('__', '_')
-                    v = rel_model(**v)
+
+                    # Now init instance if required (not if we got ID None)
+                    if 'id' in v and v['id'] is None:
+                        # This means we grouped by ID, if it's none then FK is None
+                        v = None
+
+                    else:
+                        # Either we have ID or we didn't group by ID, use instance
+                        v = rel_model(**v)
 
             # Set value
             setattr(self, k, v)

setup.py

@@ -20,7 +20,7 @@
     name='django_group_by',
 
     # https://packaging.python.org/en/latest/single_source_version.html
-    version='0.2.1',
+    version='0.2.2',
 
     description='Group by arbitrary model fields',
     long_description=long_description,
@@ -48,9 +48,7 @@
     packages=find_packages(exclude=['contrib', 'docs', 'test_app']),
 
     # https://packaging.python.org/en/latest/requirements.html
-    install_requires=[
-        'django>=1.8,<1.9.99'
-    ],
+    install_requires=[],
     extras_require={},
     package_data={},
 
@@ -63,5 +61,5 @@
     entry_points={},
 
     # Django test suite
-    test_suite='runtests.run_tests'
+    test_suite='runtests.run_tests',
 )

test_app/models.py

@@ -14,7 +14,7 @@ class Book(models.Model):
 
 class Author(models.Model):
     name = models.CharField(max_length=50)
-    nationality = models.ForeignKey('Nation')
+    nationality = models.ForeignKey('Nation', null=True)
 
 
 class Genre(models.Model):

test_app/tests.py

@@ -46,7 +46,13 @@ def test_init(self):
         with self.assertRaises(AttributeError):
             agg.genre
 
-        # Provide also related models
+        # FK None (all fields None, including ID), should not init model
+        values.update({'author__id': None, 'author__name': None})
+        agg = AggregatedGroup(Book, values)
+        self.assertEqual(agg.author, None)
+
+        # Change to FK values, without ID
+        values.pop('author__id')
         values.update({'author__name': 'Terry Pratchett', 'genre__name': 'Fantasy'})
         agg = AggregatedGroup(Book, values)
         self.assertEqual(type(agg.author), Author)
@@ -92,7 +98,7 @@ def test_group_by(self):
         BookFactory.create(author=author1, title='The Light Fantastic')
 
         # Create another book with same title, but different author
-        author2 = AuthorFactory.create(nationality__name='United States')
+        author2 = AuthorFactory.create(nationality=None)
         BookFactory.create(author=author2, title='The Colour of Magic')
 
         # Group by author, should return two with only author set
@@ -125,7 +131,8 @@ def test_group_by(self):
                 group.genre
 
         # Group by nationality, only attr author_nationality is included
-        res = Book.objects.group_by('author__nationality').order_by('author__nationality').distinct()
+        # Note: invert order because None goes first
+        res = Book.objects.group_by('author__nationality').order_by('-author__nationality').distinct()
         self.assertEqual(res.count(), 2)
         tp, oth = res.all()
         self.assertEqual(tp.author_nationality, author1.nationality)
@@ -134,8 +141,7 @@ def test_group_by(self):
             tp.title
         with self.assertRaises(AttributeError):
             tp.author
-        self.assertEqual(oth.author_nationality, author2.nationality)
-        self.assertEqual(oth.author_nationality.name, 'United States')
+        self.assertEqual(oth.author_nationality, None)
         with self.assertRaises(AttributeError):
             oth.title
         with self.assertRaises(AttributeError):