Add convert_choices_to_enum option on DjangoObjectType Meta class (#674)

* Add convert_choices_to_enum meta option

* Add tests

* Run black

* Update documentation

* Add link to Django choices documentation

* Add test and documentation note

That setting to an empty list is the same as setting the value as False

* Fix Django warning in tests

* rst is not markdown

Author: jkimbo

docs/queries.rst

@@ -92,6 +92,71 @@ You can completely overwrite a field, or add new fields, to a ``DjangoObjectType
             return 'hello!'
 
 
+Choices to Enum conversion
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By default Graphene-Django will convert any Django fields that have `choices`_
+defined into a GraphQL enum type.
+
+.. _choices: https://docs.djangoproject.com/en/2.2/ref/models/fields/#choices
+
+For example the following ``Model`` and ``DjangoObjectType``:
+
+.. code:: python
+
+   class PetModel(models.Model):
+      kind = models.CharField(max_length=100, choices=(('cat', 'Cat'), ('dog', 'Dog')))
+
+   class Pet(DjangoObjectType):
+      class Meta:
+         model = PetModel
+
+Results in the following GraphQL schema definition:
+
+.. code::
+
+   type Pet {
+     id: ID!
+     kind: PetModelKind!
+   }
+
+   enum PetModelKind {
+     CAT
+     DOG
+   }
+
+You can disable this automatic conversion by setting
+``convert_choices_to_enum`` attribute to ``False`` on the ``DjangoObjectType``
+``Meta`` class.
+
+.. code:: python
+
+   class Pet(DjangoObjectType):
+      class Meta:
+         model = PetModel
+         convert_choices_to_enum = False
+
+.. code::
+
+   type Pet {
+     id: ID!
+     kind: String!
+   }
+
+You can also set ``convert_choices_to_enum`` to a list of fields that should be
+automatically converted into enums:
+
+.. code:: python
+
+   class Pet(DjangoObjectType):
+      class Meta:
+         model = PetModel
+         convert_choices_to_enum = ['kind']
+
+**Note:** Setting ``convert_choices_to_enum = []`` is the same as setting it to
+``False``.
+
+
 Related models
 --------------
 

graphene_django/converter.py

@@ -52,13 +52,15 @@ def get_choices(choices):
             yield name, value, description
 
 
-def convert_django_field_with_choices(field, registry=None):
+def convert_django_field_with_choices(
+    field, registry=None, convert_choices_to_enum=True
+):
     if registry is not None:
         converted = registry.get_converted_field(field)
         if converted:
             return converted
     choices = getattr(field, "choices", None)
-    if choices:
+    if choices and convert_choices_to_enum:
         meta = field.model._meta
         name = to_camel_case("{}_{}".format(meta.object_name, field.name))
         choices = list(get_choices(choices))

graphene_django/tests/test_converter.py

@@ -196,6 +196,23 @@ class Meta:
     convert_django_field_with_choices(field)
 
 
+def test_field_with_choices_convert_enum_false():
+    field = models.CharField(
+        help_text="Language", choices=(("es", "Spanish"), ("en", "English"))
+    )
+
+    class TranslatedModel(models.Model):
+        language = field
+
+        class Meta:
+            app_label = "test"
+
+    graphene_type = convert_django_field_with_choices(
+        field, convert_choices_to_enum=False
+    )
+    assert isinstance(graphene_type, graphene.String)
+
+
 def test_should_float_convert_float():
     assert_conversion(models.FloatField, graphene.Float)
 

graphene_django/tests/test_types.py

@@ -1,6 +1,11 @@
+from collections import OrderedDict, defaultdict
+from textwrap import dedent
+
+import pytest
+from django.db import models
 from mock import patch
 
-from graphene import Interface, ObjectType, Schema, Connection, String
+from graphene import Connection, Field, Interface, ObjectType, Schema, String
 from graphene.relay import Node
 
 from .. import registry
@@ -224,3 +229,111 @@ class Meta:
 
     fields = list(Reporter._meta.fields.keys())
     assert "email" not in fields
+
+
+class TestDjangoObjectType:
+    @pytest.fixture
+    def PetModel(self):
+        class PetModel(models.Model):
+            kind = models.CharField(choices=(("cat", "Cat"), ("dog", "Dog")))
+            cuteness = models.IntegerField(
+                choices=((1, "Kind of cute"), (2, "Pretty cute"), (3, "OMG SO CUTE!!!"))
+            )
+
+        yield PetModel
+
+        # Clear Django model cache so we don't get warnings when creating the
+        # model multiple times
+        PetModel._meta.apps.all_models = defaultdict(OrderedDict)
+
+    def test_django_objecttype_convert_choices_enum_false(self, PetModel):
+        class Pet(DjangoObjectType):
+            class Meta:
+                model = PetModel
+                convert_choices_to_enum = False
+
+        class Query(ObjectType):
+            pet = Field(Pet)
+
+        schema = Schema(query=Query)
+
+        assert str(schema) == dedent(
+            """\
+        schema {
+          query: Query
+        }
+
+        type Pet {
+          id: ID!
+          kind: String!
+          cuteness: Int!
+        }
+
+        type Query {
+          pet: Pet
+        }
+        """
+        )
+
+    def test_django_objecttype_convert_choices_enum_list(self, PetModel):
+        class Pet(DjangoObjectType):
+            class Meta:
+                model = PetModel
+                convert_choices_to_enum = ["kind"]
+
+        class Query(ObjectType):
+            pet = Field(Pet)
+
+        schema = Schema(query=Query)
+
+        assert str(schema) == dedent(
+            """\
+        schema {
+          query: Query
+        }
+
+        type Pet {
+          id: ID!
+          kind: PetModelKind!
+          cuteness: Int!
+        }
+
+        enum PetModelKind {
+          CAT
+          DOG
+        }
+
+        type Query {
+          pet: Pet
+        }
+        """
+        )
+
+    def test_django_objecttype_convert_choices_enum_empty_list(self, PetModel):
+        class Pet(DjangoObjectType):
+            class Meta:
+                model = PetModel
+                convert_choices_to_enum = []
+
+        class Query(ObjectType):
+            pet = Field(Pet)
+
+        schema = Schema(query=Query)
+
+        assert str(schema) == dedent(
+            """\
+        schema {
+          query: Query
+        }
+
+        type Pet {
+          id: ID!
+          kind: String!
+          cuteness: Int!
+        }
+
+        type Query {
+          pet: Pet
+        }
+        """
+        )

graphene_django/types.py

@@ -18,7 +18,9 @@
     from typing import Type
 
 
-def construct_fields(model, registry, only_fields, exclude_fields):
+def construct_fields(
+    model, registry, only_fields, exclude_fields, convert_choices_to_enum
+):
     _model_fields = get_model_fields(model)
 
     fields = OrderedDict()
@@ -33,7 +35,18 @@ def construct_fields(model, registry, only_fields, exclude_fields):
             # in there. Or when we exclude this field in exclude_fields.
             # Or when there is no back reference.
             continue
-        converted = convert_django_field_with_choices(field, registry)
+
+        _convert_choices_to_enum = convert_choices_to_enum
+        if not isinstance(_convert_choices_to_enum, bool):
+            # then `convert_choices_to_enum` is a list of field names to convert
+            if name in _convert_choices_to_enum:
+                _convert_choices_to_enum = True
+            else:
+                _convert_choices_to_enum = False
+
+        converted = convert_django_field_with_choices(
+            field, registry, convert_choices_to_enum=_convert_choices_to_enum
+        )
         fields[name] = converted
 
     return fields
@@ -63,6 +76,7 @@ def __init_subclass_with_meta__(
         connection_class=None,
         use_connection=None,
         interfaces=(),
+        convert_choices_to_enum=True,
         _meta=None,
         **options
     ):
@@ -90,7 +104,10 @@ def __init_subclass_with_meta__(
             )
 
         django_fields = yank_fields_from_attrs(
-            construct_fields(model, registry, only_fields, exclude_fields), _as=Field
+            construct_fields(
+                model, registry, only_fields, exclude_fields, convert_choices_to_enum
+            ),
+            _as=Field,
         )
 
         if use_connection is None and interfaces: