Improved Mutations Input args

graphene/core/fields.py

@@ -124,6 +124,13 @@ class Field(object):
                 ','.join(extra_args.keys())
             ))
 
+        args = self.args
+
+        object_type = self.get_object_type(schema)
+        if object_type and object_type._meta.mutation:
+            assert not self.args, 'Arguments provided for mutations are defined in Input class in Mutation'
+            args = object_type.input_type.fields_as_arguments(schema)
+
         internal_type = self.internal_type(schema)
         if not internal_type:
             raise Exception("Internal type for field %s is None" % self)
@@ -141,7 +148,7 @@ class Field(object):
         return GraphQLField(
             internal_type,
             description=description,
-            args=self.args,
+            args=args,
             resolver=resolver,
         )
 

graphene/core/types.py

@@ -5,7 +5,8 @@ from collections import OrderedDict
 
 from graphql.core.type import (
     GraphQLObjectType,
-    GraphQLInterfaceType
+    GraphQLInterfaceType,
+    GraphQLArgument
 )
 
 from graphene import signals
@@ -58,6 +59,10 @@ class ObjectTypeMeta(type):
 
         if new_class._meta.mutation:
             assert hasattr(new_class, 'mutate'), "All mutations must implement mutate method"
+            Input = getattr(new_class, 'Input', None)
+            if Input:
+                input_type = type('{}Input'.format(new_class._meta.type_name), (Input, ObjectType), Input.__dict__)
+                setattr(new_class, 'input_type', input_type)
 
         new_class.add_extra_fields()
 
@@ -141,6 +146,11 @@ class BaseObjectType(object):
         if self.instance:
             return getattr(self.instance, name)
 
+    @classmethod
+    def fields_as_arguments(cls, schema):
+        return OrderedDict([(f.field_name, GraphQLArgument(f.internal_type(schema)))
+                            for f in cls._meta.fields])
+
     @classmethod
     def resolve_objecttype(cls, schema, instance, *_):
         return instance

tests/core/test_mutations.py

@@ -12,14 +12,14 @@ class Query(graphene.ObjectType):
 class ChangeNumber(graphene.Mutation):
     '''Result mutation'''
     class Input:
-        id = graphene.IntField(required=True)
+        to = graphene.IntField()
 
     result = graphene.StringField()
 
     @classmethod
     def mutate(cls, instance, args, info):
         global my_id
-        my_id = my_id + 1
+        my_id = args.get('to', my_id + 1)
         return ChangeNumber(result=my_id)
 
 
@@ -30,7 +30,13 @@ class MyResultMutation(graphene.ObjectType):
 schema = Schema(query=Query, mutation=MyResultMutation)
 
 
-def test_mutate():
+def test_mutation_input():
+    assert ChangeNumber.input_type
+    assert ChangeNumber.input_type._meta.type_name == 'ChangeNumberInput'
+    assert list(ChangeNumber.input_type._meta.fields_map.keys()) == ['to']
+
+
+def test_execute_mutations():
     query = '''
     mutation M{
       first: changeNumber {
@@ -39,6 +45,9 @@ def test_mutate():
       second: changeNumber {
         result
       }
+      third: changeNumber(to: 5) {
+        result
+      }
     }
     '''
     expected = {
@@ -47,6 +56,9 @@ def test_mutate():
         },
         'second': {
             'result': '2',
+        },
+        'third': {
+            'result': '5',
         }
     }
     result = schema.execute(query, root=object())