Simplified interface logic

graphene/types/field.py

@@ -115,7 +115,7 @@ class Field(AbstractField, GraphQLField, OrderedType):
         return self.copy_and_extend(self)
 
     @classmethod
-    def copy_and_extend(cls, field, type=None, args=None, resolver=None, source=None, deprecation_reason=None, name=None, description=None, required=False, _creation_counter=False, **extra_args):
+    def copy_and_extend(cls, field, type=None, args=None, resolver=None, source=None, deprecation_reason=None, name=None, description=None, required=False, _creation_counter=False, parent=None, attname=None, **extra_args):
         if isinstance(field, Field):
             type = type or field._type
             resolver = resolver or field._resolver
@@ -123,8 +123,8 @@ class Field(AbstractField, GraphQLField, OrderedType):
             name = name or field._name
             required = required or field.required
             _creation_counter = field.creation_counter if _creation_counter is False else None
-            attname = field.attname
-            parent = field.parent
+            attname = attname or field.attname
+            parent = parent or field.parent
         else:
             # If is a GraphQLField
             type = type or field.type
@@ -133,8 +133,8 @@ class Field(AbstractField, GraphQLField, OrderedType):
             name = field.name
             required = None
             _creation_counter = None
-            attname = name
-            parent = None
+            attname = attname or name
+            parent = parent
 
         new_field = cls(
             type=type,

graphene/types/interface.py

@@ -2,42 +2,74 @@ import six
 
 from graphql import GraphQLInterfaceType
 from .definitions import FieldsMeta, ClassTypeMeta, GrapheneGraphQLType
-
+from .options import Options
+from ..utils.is_base_type import is_base_type
 
 class GrapheneInterfaceType(GrapheneGraphQLType, GraphQLInterfaceType):
     pass
 
 
-class InterfaceTypeMeta(FieldsMeta, ClassTypeMeta):
+class InterfaceTypeMeta(type):
 
-    def get_options(cls, meta):
-        return cls.options_class(
-            meta,
+    def __new__(cls, name, bases, attrs):
+        super_new = super(InterfaceTypeMeta, cls).__new__
+
+        # Also ensure initialization is only performed for subclasses of Model
+        # (excluding Model class itself).
+        if not is_base_type(bases, InterfaceTypeMeta):
+            return super_new(cls, name, bases, attrs)
+
+        options = Options(
+            attrs.pop('Meta', None),
             name=None,
             description=None,
             graphql_type=None,
             abstract=False
         )
 
-    def construct(cls, bases, attrs):
-        if not cls._meta.abstract:
-            local_fields = cls._extract_local_fields(attrs)
-            if not cls._meta.graphql_type:
-                cls._meta.graphql_type = GrapheneInterfaceType(
-                    graphene_type=cls,
-                    name=cls._meta.name or cls.__name__,
-                    description=cls._meta.description or cls.__doc__,
-                    fields=cls._fields(bases, attrs, local_fields),
-                )
-            else:
-                assert not local_fields, "Can't mount Fields in an Interface with a defined graphql_type"
+        from ..utils.get_fields import get_fields
 
-        return super(InterfaceTypeMeta, cls).construct(bases, attrs)
+        fields = get_fields(Interface, attrs, bases)
+        attrs = attrs_without_fields(attrs, fields)
+        cls = super_new(cls, name, bases, dict(attrs, _meta=options))
+
+        if not options.graphql_type:
+            fields = copy_fields(fields)
+            options.graphql_type = GrapheneInterfaceType(
+                graphene_type=cls,
+                name=options.name or cls.__name__,
+                description=options.description or cls.__doc__,
+                fields=fields,
+            )
+        else:
+            assert not fields, "Can't mount Fields in an Interface with a defined graphql_type"
+            fields = copy_fields(options.graphql_type.get_fields())
+
+        for attname, field in fields.items():
+            field.parent = cls
+            # setattr(cls, field.name, field)
+
+        return cls
+
+
+def attrs_without_fields(attrs, fields):
+    fields_names = fields.keys()
+    return {k: v for k, v in attrs.items() if k not in fields_names}
+
+
+def copy_fields(fields):
+    from collections import OrderedDict
+    from .field import Field
+
+    _fields = []
+    for attname, field in fields.items():
+        field = Field.copy_and_extend(field, attname=attname)
+        _fields.append(field)
+
+    return OrderedDict((f.name, f) for f in sorted(_fields))
 
 
 class Interface(six.with_metaclass(InterfaceTypeMeta)):
-    class Meta:
-        abstract = True
 
     def __init__(self, *args, **kwargs):
         from .objecttype import ObjectType

graphene/types/objecttype.py

@@ -46,7 +46,7 @@ def get_interfaces(cls, interfaces):
         yield graphql_type
 
 
-class ObjectTypeMeta(InterfaceTypeMeta):
+class ObjectTypeMeta(FieldsMeta, ClassTypeMeta, InterfaceTypeMeta):
 
     def get_options(cls, meta):
         return cls.options_class(

graphene/utils/get_fields.py

@@ -0,0 +1,48 @@
+from collections import OrderedDict
+
+from .get_graphql_type import get_graphql_type
+from .is_graphene_type import is_graphene_type
+from ..types.field import Field, InputField
+from ..types.unmountedtype import UnmountedType
+
+
+def get_fields_from_attrs(in_type, attrs):
+    for attname, value in list(attrs.items()):
+        is_field = isinstance(value, (Field, InputField))
+        is_field_proxy = isinstance(value, UnmountedType)
+        if not (is_field or is_field_proxy):
+            continue
+        field = value.as_mounted(in_type) if is_field_proxy else value
+        yield attname, field
+
+
+def get_fields_from_types(bases):
+    fields = set()
+    for _class in bases:
+        for attname, field in get_graphql_type(_class).get_fields().items():
+            if attname in fields:
+                continue
+            fields.add(attname)
+            yield attname, field
+
+
+def get_fields(in_type, attrs, bases):
+    fields = []
+
+    graphene_bases = tuple(
+        base._meta.graphql_type for base in bases if is_graphene_type(base) and not base._meta.abstract
+    )
+
+    extended_fields = list(get_fields_from_types(graphene_bases))
+    local_fields = list(get_fields_from_attrs(in_type, attrs))
+
+    field_names = set(f[0] for f in local_fields)
+    for name, extended_field in extended_fields:
+        if name in field_names:
+            continue
+        fields.append((name, extended_field))
+        field_names.add(name)
+
+    fields.extend(local_fields)
+
+    return OrderedDict(fields)

graphene/utils/is_base_type.py

@@ -0,0 +1,2 @@
+def is_base_type(bases, _type):
+    return any(b for b in bases if isinstance(b, _type))

graphene/utils/is_graphene_type.py

@@ -7,6 +7,8 @@ from ..types.enum import Enum
 
 
 def is_graphene_type(_type):
+    if _type in [Interface]:
+        return False
     return inspect.isclass(_type) and issubclass(_type, (
         Interface,
         ObjectType,