on_delete param where needed due to django 2 requirements

added support for querying a model with objects that may be a proxy model, fixed and added tests

a few style changes

examples/starwars/models.py

@@ -5,7 +5,13 @@ from django.db import models
 
 class Character(models.Model):
     name = models.CharField(max_length=50)
-    ship = models.ForeignKey('Ship', blank=True, null=True, related_name='characters')
+    ship = models.ForeignKey(
+        'Ship',
+        blank=True,
+        null=True,
+        on_delete=models.SET_NULL,
+        related_name='characters'
+    )
 
     def __str__(self):
         return self.name
@@ -13,7 +19,10 @@ class Character(models.Model):
 
 class Faction(models.Model):
     name = models.CharField(max_length=50)
-    hero = models.ForeignKey(Character)
+    hero = models.ForeignKey(
+        Character,
+        on_delete=models.SET_NULL,
+    )
 
     def __str__(self):
         return self.name
@@ -21,7 +30,11 @@ class Faction(models.Model):
 
 class Ship(models.Model):
     name = models.CharField(max_length=50)
-    faction = models.ForeignKey(Faction, related_name='ships')
+    faction = models.ForeignKey(
+        Faction,
+        on_delete=models.SET_NULL,
+        related_name='ships'
+    )
 
     def __str__(self):
         return self.name

graphene_django/tests/models.py

@@ -15,7 +15,11 @@ class Pet(models.Model):
 
 class FilmDetails(models.Model):
     location = models.CharField(max_length=30)
-    film = models.OneToOneField('Film', related_name='details')
+    film = models.OneToOneField(
+        'Film',
+        on_delete=models.CASCADE,
+        related_name='details'
+    )
 
 
 class Film(models.Model):
@@ -30,15 +34,49 @@ class Reporter(models.Model):
     pets = models.ManyToManyField('self')
     a_choice = models.CharField(max_length=30, choices=CHOICES)
 
+    reporter_type = models.IntegerField(
+        'Reporter Type',
+        null=True,
+        blank=True,
+        choices=[(1, u'Regular'), (2, u'CNN Reporter')] )
+
     def __str__(self):              # __unicode__ on Python 2
         return "%s %s" % (self.first_name, self.last_name)
 
+    def __init__(self, *args, **kwargs):
+        """
+        Override the init method so that during runtime, Django
+        can know that this object can be a CNNReporter by casting
+        it to the proxy model. Otherwise, as far as Django knows,
+        when a CNNReporter is pulled from the database, it is still
+        of type Reporter. This was added to test proxy model support.
+        """
+        super(Reporter, self).__init__(*args, **kwargs)
+        if self.reporter_type == 2:  # quick and dirty way without enums
+            self.__class__ = CNNReporter
+
+class CNNReporter(Reporter):
+    """
+    This class is a proxy model for Reporter, used for testing
+    proxy model support
+    """
+    class Meta:
+        proxy = True
+
 
 class Article(models.Model):
     headline = models.CharField(max_length=100)
     pub_date = models.DateField()
-    reporter = models.ForeignKey(Reporter, related_name='articles')
+    reporter = models.ForeignKey(
-    editor = models.ForeignKey(Reporter, related_name='edited_articles_+')
+        Reporter,
+        on_delete=models.SET_NULL,
+        related_name='articles'
+    )
+    editor = models.ForeignKey(
+        Reporter,
+        on_delete=models.SET_NULL,
+        related_name='edited_articles_+'
+    )
     lang = models.CharField(max_length=2, help_text='Language', choices=[
         ('es', 'Spanish'),
         ('en', 'English')

graphene_django/tests/test_query.py

@@ -13,7 +13,11 @@ from ..compat import MissingType, JSONField
 from ..fields import DjangoConnectionField
 from ..types import DjangoObjectType
 from ..settings import graphene_settings
-from .models import Article, Reporter
+from .models import (
+    Article,
+    CNNReporter,
+    Reporter,
+)
 
 pytestmark = pytest.mark.django_db
 
@@ -689,6 +693,7 @@ def test_should_query_dataloader_fields():
         email='johndoe@example.com',
         a_choice=1
     )
+
     Article.objects.create(
         headline='Article Node 1',
         pub_date=datetime.date.today(),
@@ -780,3 +785,139 @@ def test_should_handle_inherited_choices():
     '''
     result = schema.execute(query)
     assert not result.errors
+
+
+def test_proxy_model_support():
+    """
+    This test asserts that we can query for all Reporters,
+    even if some are of a proxy model type at runtime.
+    """
+    class ReporterType(DjangoObjectType):
+
+        class Meta:
+            model = Reporter
+            interfaces = (Node, )
+            use_connection = True
+
+    reporter_1 = Reporter.objects.create(
+        first_name='John',
+        last_name='Doe',
+        email='johndoe@example.com',
+        a_choice=1
+    )
+
+    reporter_2 = CNNReporter.objects.create(
+        first_name='Some',
+        last_name='Guy',
+        email='someguy@cnn.com',
+        a_choice=1,
+        reporter_type=2,  # set this guy to be CNN
+    )
+
+    class Query(graphene.ObjectType):
+        all_reporters = DjangoConnectionField(ReporterType)
+
+    schema = graphene.Schema(query=Query)
+    query = '''
+        query ProxyModelQuery {
+            allReporters {
+                edges {
+                    node {
+                        id
+                    }
+                }
+            }
+        }
+    '''
+
+    expected = {
+        'allReporters': {
+            'edges': [{
+                'node': {
+                    'id': 'UmVwb3J0ZXJUeXBlOjE=',
+                },
+            },
+            {
+                'node': {
+                    'id': 'UmVwb3J0ZXJUeXBlOjI=',
+                },
+            }
+            ]
+        }
+    }
+
+    result = schema.execute(query)
+    assert not result.errors
+    assert result.data == expected
+
+
+def test_proxy_model_fails():
+    """
+    This test asserts that if you try to query for a proxy model,
+    that query will fail with:
+        GraphQLError('Expected value of type "CNNReporterType" but got: 
+            CNNReporter.',)
+
+    This is because a proxy model has the identical model definition
+    to its superclass, and defines its behavior at runtime, rather than
+    at the database level. Currently, filtering objects of the proxy models'
+    type isn't supported. It would require a field on the model that would
+    represent the type, and it doesn't seem like there is a clear way to
+    enforce this pattern across all projects
+    """
+    class CNNReporterType(DjangoObjectType):
+
+        class Meta:
+            model = CNNReporter
+            interfaces = (Node, )
+            use_connection = True
+
+    reporter_1 = Reporter.objects.create(
+        first_name='John',
+        last_name='Doe',
+        email='johndoe@example.com',
+        a_choice=1
+    )
+
+    reporter_2 = CNNReporter.objects.create(
+        first_name='Some',
+        last_name='Guy',
+        email='someguy@cnn.com',
+        a_choice=1,
+        reporter_type=2,  # set this guy to be CNN
+    )
+
+    class Query(graphene.ObjectType):
+        all_reporters = DjangoConnectionField(CNNReporterType)
+
+    schema = graphene.Schema(query=Query)
+    query = '''
+        query ProxyModelQuery {
+            allReporters {
+                edges {
+                    node {
+                        id
+                    }
+                }
+            }
+        }
+    '''
+
+    expected = {
+        'allReporters': {
+            'edges': [{
+                'node': {
+                    'id': 'UmVwb3J0ZXJUeXBlOjE=',
+                },
+            },
+            {
+                'node': {
+                    'id': 'UmVwb3J0ZXJUeXBlOjI=',
+                },
+            }
+            ]
+        }
+    }
+
+    result = schema.execute(query)
+    assert result.errors

graphene_django/tests/test_schema.py

@@ -35,6 +35,7 @@ def test_should_map_fields_correctly():
         'email',
         'pets',
         'a_choice',
+        'reporter_type'
     ]
 
     assert sorted(fields[-2:]) == [

graphene_django/tests/test_types.py

@@ -58,7 +58,7 @@ def test_django_get_node(get):
 def test_django_objecttype_map_correct_fields():
     fields = Reporter._meta.fields
     fields = list(fields.keys())
-    assert fields[:-2] == ['id', 'first_name', 'last_name', 'email', 'pets', 'a_choice']
+    assert fields[:-2] == ['id', 'first_name', 'last_name', 'email', 'pets', 'a_choice', 'reporter_type']
     assert sorted(fields[-2:]) == ['articles', 'films']
 
 
@@ -124,6 +124,7 @@ type Reporter {
   email: String!
   pets: [Reporter]
   aChoice: ReporterAChoice!
+  reporterType: ReporterReporterType
   articles(before: String, after: String, first: Int, last: Int): ArticleConnection
 }
 
@@ -132,6 +133,11 @@ enum ReporterAChoice {
   A_2
 }
 
+enum ReporterReporterType {
+  A_1
+  A_2
+}
+
 type RootQuery {
   node(id: ID!): Node
 }

graphene_django/types.py

@@ -108,7 +108,8 @@ class DjangoObjectType(ObjectType):
             raise Exception((
                 'Received incompatible instance "{}".'
             ).format(root))
-        model = root._meta.model
+
+        model = root._meta.model._meta.concrete_model
         return model == cls._meta.model
 
     @classmethod