Improved ObjectType instances

README.md

@@ -51,8 +51,6 @@ class Query(graphene.ObjectType):
     @resolve_only_args
     def resolve_human(self, id):
         return wrap_character(getHuman(id))
-        if human:
-            return Human(human)
 
     @resolve_only_args
     def resolve_droid(self, id):
@@ -91,9 +89,7 @@ class Ship(relay.Node):
 
     @classmethod
     def get_node(cls, id):
-        ship = getShip(id)
-        if ship:
-            return Ship(ship)
+        return Ship(getShip(id))
 
 
 class Faction(relay.Node):
@@ -107,9 +103,7 @@ class Faction(relay.Node):
 
     @classmethod
     def get_node(cls, id):
-        faction = getFaction(id)
-        if faction:
-            return Faction(faction)
+        return Faction(getFaction(id)
 
 
 class Query(graphene.ObjectType):

graphene/core/schema.py

@@ -43,10 +43,11 @@ class Schema(object):
         return self._types[type_name]
 
     def execute(self, request='', root=None, vars=None, operation_name=None):
+        root = root or object()
         return graphql(
             self._schema,
             request=request,
-            root=root or self.query(),
+            root=self.query(root),
             vars=vars,
             operation_name=operation_name
         )

graphene/core/types.py

@@ -83,6 +83,13 @@ class ObjectTypeMeta(type):
 
 
 class ObjectType(six.with_metaclass(ObjectTypeMeta)):
+    def __new__(cls, instance=None, *args, **kwargs):
+        if cls._meta.interface:
+            raise Exception("An interface cannot be initialized")
+        if instance == None:
+            return None
+        return super(ObjectType, cls).__new__(cls, instance, *args, **kwargs)
+
     def __init__(self, instance=None):
         signals.pre_init.send(self.__class__, instance=instance)
         self.instance = instance
@@ -136,6 +143,7 @@ class Interface(ObjectType):
         interface = True
         proxy = True
 
+
 @signals.init_schema.connect
 def add_types_to_schema(schema):
     own_schema = schema

tests/starwars_relay/schema.py

@@ -14,9 +14,7 @@ class Ship(relay.Node):
 
     @classmethod
     def get_node(cls, id):
-        ship = getShip(id)
-        if ship:
-            return Ship(ship)
+        return Ship(getShip(id))
 
 
 class Faction(relay.Node):
@@ -30,9 +28,7 @@ class Faction(relay.Node):
 
     @classmethod
     def get_node(cls, id):
-        faction = getFaction(id)
-        if faction:
-            return Faction(faction)
+        return Faction(getFaction(id))
 
 
 class Query(graphene.ObjectType):