Improved interface fields getter

graphene/relay/node.py

@@ -12,17 +12,16 @@ class NodeMeta(InterfaceTypeMeta):
     def construct_graphql_type(cls, bases):
         pass
 
-    def construct(cls, *args, **kwargs):
-        constructed = super(NodeMeta, cls).construct(*args, **kwargs)
-        if not cls._meta.graphql_type:
-            node_interface, node_field = node_definitions(
-                cls.get_node,
-                interface_class=partial(GrapheneInterfaceType, graphene_type=cls),
-                field_class=Field
-            )
-            cls._meta.graphql_type = node_interface
-            cls._Field = node_field
-        return constructed
+    def construct(cls, bases, attrs):
+        cls.get_node = attrs.pop('get_node')
+        node_interface, node_field = node_definitions(
+            cls.get_node,
+            interface_class=partial(GrapheneInterfaceType, graphene_type=cls),
+            field_class=Field
+        )
+        cls._meta.graphql_type = node_interface
+        cls._Field = node_field
+        return super(NodeMeta, cls).construct(bases, attrs)
 
     @property
     def Field(cls):

graphene/types/interface.py

@@ -1,3 +1,6 @@
+from itertools import chain
+from functools import partial
+from collections import OrderedDict
 import six
 
 from graphql import GraphQLInterfaceType
@@ -20,18 +23,33 @@ class InterfaceTypeMeta(ClassTypeMeta):
         )
 
     def construct_graphql_type(cls, bases):
+        pass
+
+    def _build_field_map(cls, local_fields, bases):
+        from ..utils.extract_fields import get_base_fields
+        extended_fields = get_base_fields(bases)
+        fields = chain(extended_fields, local_fields)
+        return OrderedDict((f.name, f) for f in fields)
+
+    def construct(cls, bases, attrs):
         if not cls._meta.graphql_type and not cls._meta.abstract:
             from ..utils.is_graphene_type import is_graphene_type
+            from ..utils.extract_fields import extract_fields
+
             inherited_types = [
                 base._meta.graphql_type for base in bases if is_graphene_type(base)
             ]
+            inherited_types = filter(None, inherited_types)
+
+            local_fields = list(extract_fields(attrs))
 
             cls._meta.graphql_type = GrapheneInterfaceType(
                 graphene_type=cls,
                 name=cls._meta.name or cls.__name__,
                 description=cls._meta.description or cls.__doc__,
-                fields=FieldMap(cls, bases=filter(None, inherited_types)),
+                fields=partial(cls._build_field_map, local_fields, inherited_types),
             )
+        return super(InterfaceTypeMeta, cls).construct(bases, attrs)
 
 
 class Interface(six.with_metaclass(InterfaceTypeMeta)):

graphene/utils/extract_fields.py

@@ -0,0 +1,35 @@
+import copy
+from .get_graphql_type import get_graphql_type
+
+from ..types.field import Field
+from ..types.proxy import TypeProxy
+
+
+def extract_fields(attrs):
+    fields = set()
+    _fields = list()
+    for attname, value in list(attrs.items()):
+        is_field = isinstance(value, Field)
+        is_field_proxy = isinstance(value, TypeProxy)
+        if not (is_field or is_field_proxy):
+            continue
+
+        field = value.as_field() if is_field_proxy else copy.copy(value)
+        field.attname = attname
+        fields.add(attname)
+        del attrs[attname]
+        _fields.append(field)
+
+    return sorted(_fields)
+
+
+def get_base_fields(bases):
+    fields = set()
+    for _class in bases:
+        for attname, field in get_graphql_type(_class).get_fields().items():
+            if attname in fields:
+                continue
+            field = copy.copy(field)
+            field.name = attname
+            fields.add(attname)
+            yield field

graphene/utils/tests/test_extract_fields.py

@@ -0,0 +1,41 @@
+from collections import OrderedDict
+from graphql import GraphQLField, GraphQLString, GraphQLInterfaceType, GraphQLInt, GraphQLFloat
+from ..extract_fields import extract_fields, get_base_fields
+
+from ...types import Field, String, Argument
+
+
+def test_extract_fields_attrs():
+    attrs = {
+        'field_string': Field(String),
+        'string': String(),
+        'other': None,
+        'argument': Argument(String),
+        'graphql_field': GraphQLField(GraphQLString)
+    }
+    extracted_fields = list(extract_fields(attrs))
+    assert [f.name for f in extracted_fields] == ['fieldString', 'string']
+    assert sorted(attrs.keys()) == ['argument', 'graphql_field', 'other']
+
+
+def test_extract_fields():
+    int_base = GraphQLInterfaceType('IntInterface', fields=OrderedDict([
+        ('int', GraphQLField(GraphQLInt)),
+        ('num', GraphQLField(GraphQLInt)),
+        ('extra', GraphQLField(GraphQLInt))
+    ]))
+    float_base = GraphQLInterfaceType('IntInterface', fields=OrderedDict([
+        ('float', GraphQLField(GraphQLFloat)),
+        ('num', GraphQLField(GraphQLFloat)),
+        ('extra', GraphQLField(GraphQLFloat))
+    ]))
+
+    bases = (int_base, float_base)
+    base_fields = list(get_base_fields(bases))
+    assert [f.name for f in base_fields] == ['int', 'num', 'extra', 'float']
+    assert [f.type for f in base_fields] == [
+        GraphQLInt,
+        GraphQLInt,
+        GraphQLInt,
+        GraphQLFloat,
+    ]