Add Django form-based mutations

Author: Grant McConnaughey

graphene_django/forms/__init__.py

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+from .forms import GlobalIDFormField, GlobalIDMultipleChoiceField

graphene_django/forms/converter.py

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+from django import forms
+from django.core.exceptions import ImproperlyConfigured
+from graphene_django.utils import import_single_dispatch
+import graphene
+
+
+singledispatch = import_single_dispatch()
+
+
+def convert_form_to_input_type(form_class):
+    form = form_class()
+
+    items = {
+        name: convert_form_field(field)
+        for name, field in form.fields.items()
+    }
+
+    return type(
+        '{}Input'.format(form.__class__.__name__),
+        (graphene.InputObjectType, ),
+        items
+    )
+
+
+@singledispatch
+def get_graphene_type_from_form_field(field):
+    raise ImproperlyConfigured(
+        "Don't know how to convert the form field %s (%s) "
+        "to Graphene type" % (field, field.__class__)
+    )
+
+
+def convert_form_field(field, is_input=True):
+    """
+    Converts a Django form field to a graphql field and marks the field as
+    required if we are creating an input type and the field itself is required
+    """
+
+    graphql_type = get_graphene_type_from_form_field(field)
+
+    kwargs = {
+        'description': field.help_text,
+        'required': is_input and field.required,
+    }
+
+    # if it is a tuple or a list it means that we are returning
+    # the graphql type and the child type
+    if isinstance(graphql_type, (list, tuple)):
+        kwargs['of_type'] = graphql_type[1]
+        graphql_type = graphql_type[0]
+
+    return graphql_type(**kwargs)
+
+
+@get_graphene_type_from_form_field.register(forms.CharField)
+@get_graphene_type_from_form_field.register(forms.ChoiceField)
+def convert_form_field_to_string(field):
+    return graphene.String
+
+
+@get_graphene_type_from_form_field.register(forms.IntegerField)
+def convert_form_field_to_int(field):
+    return graphene.Int
+
+
+@get_graphene_type_from_form_field.register(forms.BooleanField)
+def convert_form_field_to_bool(field):
+    return graphene.Boolean
+
+
+@get_graphene_type_from_form_field.register(forms.FloatField)
+@get_graphene_type_from_form_field.register(forms.DecimalField)
+def convert_form_field_to_float(field):
+    return graphene.Float
+
+
+@get_graphene_type_from_form_field.register(forms.DateField)
+@get_graphene_type_from_form_field.register(forms.DateTimeField)
+def convert_form_field_to_datetime(field):
+    return graphene.types.datetime.DateTime
+
+
+@get_graphene_type_from_form_field.register(forms.TimeField)
+def convert_form_field_to_time(field):
+    return graphene.types.datetime.Time
+
+
+@get_graphene_type_from_form_field.register(forms.MultipleChoiceField)
+def convert_form_field_to_list_of_string(field):
+    return (graphene.List, graphene.String)

graphene_django/forms.py renamed to graphene_django/forms/forms.py

@@ -0,0 +1,157 @@
+from functools import partial
+
+import six
+import graphene
+from graphene import Field, Argument
+from graphene.types.mutation import MutationMeta
+from graphene.types.objecttype import ObjectTypeMeta
+from graphene.types.options import Options
+from graphene.types.utils import get_field_as, merge
+from graphene.utils.is_base_type import is_base_type
+from graphene_django.registry import get_global_registry
+
+from .converter import convert_form_to_input_type
+from .types import ErrorType
+
+
+class FormMutationMeta(MutationMeta):
+    def __new__(cls, name, bases, attrs):
+        if not is_base_type(bases, FormMutationMeta):
+            return type.__new__(cls, name, bases, attrs)
+
+        options = Options(
+            attrs.pop('Meta', None),
+            name=name,
+            description=attrs.pop('__doc__', None),
+            form_class=None,
+            input_field_name='input',
+            local_fields=None,
+            only_fields=(),
+            exclude_fields=(),
+            interfaces=(),
+            registry=None
+        )
+
+        if not options.form_class:
+            raise Exception('Missing form_class')
+
+        cls = ObjectTypeMeta.__new__(
+            cls, name, bases, dict(attrs, _meta=options)
+        )
+
+        options.fields = merge(
+            options.interface_fields, options.base_fields, options.local_fields,
+            {'errors': get_field_as(cls.errors, Field)}
+        )
+
+        cls.Input = convert_form_to_input_type(options.form_class)
+
+        field_kwargs = {cls.options.input_field_name: Argument(cls.Input, required=True)}
+        cls.Field = partial(
+            Field,
+            cls,
+            resolver=cls.mutate,
+            **field_kwargs
+        )
+
+        return cls
+
+
+class BaseFormMutation(graphene.Mutation):
+
+    @classmethod
+    def mutate(cls, root, args, context, info):
+        form = cls.get_form(root, args, context, info)
+
+        if form.is_valid():
+            return cls.perform_mutate(form, info)
+        else:
+            errors = [
+                ErrorType(field=key, messages=value)
+                for key, value in form.errors.items()
+            ]
+            return cls(errors=errors)
+
+    @classmethod
+    def perform_mutate(cls, form, info):
+        form.save()
+        return cls(errors=[])
+
+    @classmethod
+    def get_form(cls, root, args, context, info):
+        form_data = args.get(cls._meta.input_field_name)
+        kwargs = cls.get_form_kwargs(root, args, context, info)
+        return cls._meta.form_class(data=form_data, **kwargs)
+
+    @classmethod
+    def get_form_kwargs(cls, root, args, context, info):
+        return {}
+
+
+class FormMutation(six.with_metaclass(FormMutationMeta, BaseFormMutation)):
+
+    errors = graphene.List(ErrorType)
+
+
+class ModelFormMutationMeta(MutationMeta):
+    def __new__(cls, name, bases, attrs):
+        if not is_base_type(bases, ModelFormMutationMeta):
+            return type.__new__(cls, name, bases, attrs)
+
+        options = Options(
+            attrs.pop('Meta', None),
+            name=name,
+            description=attrs.pop('__doc__', None),
+            form_class=None,
+            input_field_name='input',
+            return_field_name=None,
+            model=None,
+            local_fields=None,
+            only_fields=(),
+            exclude_fields=(),
+            interfaces=(),
+            registry=None
+        )
+
+        if not options.form_class:
+            raise Exception('Missing form_class')
+
+        cls = ObjectTypeMeta.__new__(
+            cls, name, bases, dict(attrs, _meta=options)
+        )
+
+        options.fields = merge(
+            options.interface_fields, options.base_fields, options.local_fields,
+            {'errors': get_field_as(cls.errors, Field)}
+        )
+
+        cls.Input = convert_form_to_input_type(options.form_class)
+
+        field_kwargs = {cls.options.input_field_name: Argument(cls.Input, required=True)}
+        cls.Field = partial(
+            Field,
+            cls,
+            resolver=cls.mutate,
+            **field_kwargs
+        )
+
+        cls.model = options.model or options.form_class.Meta.model
+        cls.return_field_name = cls._meta.return_field_name or cls.model._meta.model_name
+
+        registry = get_global_registry()
+        model_type = registry.get_type_for_model(cls.model)
+
+        options.fields[cls.return_field_name] = graphene.Field(model_type)
+
+        return cls
+
+
+class ModelFormMutation(six.with_metaclass(ModelFormMutationMeta, BaseFormMutation)):
+
+    errors = graphene.List(ErrorType)
+
+    @classmethod
+    def perform_mutate(cls, form, info):
+        obj = form.save()
+        kwargs = {cls.return_field_name: obj}
+        return cls(errors=[], **kwargs)

graphene_django/forms/mutation.py

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+import copy
+
+from django import forms
+from py.test import raises
+
+import graphene
+
+from ..converter import convert_form_field
+
+
+def _get_type(form_field, **kwargs):
+    # prevents the following error:
+    # AssertionError: The `source` argument is not meaningful when applied to a `child=` field.
+    # Remove `source=` from the field declaration.
+    # since we are reusing the same child in when testing the required attribute
+
+    if 'child' in kwargs:
+        kwargs['child'] = copy.deepcopy(kwargs['child'])
+
+    field = form_field(**kwargs)
+
+    return convert_form_field(field)
+
+
+def assert_conversion(form_field, graphene_field, **kwargs):
+    graphene_type = _get_type(form_field, help_text='Custom Help Text', **kwargs)
+    assert isinstance(graphene_type, graphene_field)
+
+    graphene_type_required = _get_type(
+        form_field, help_text='Custom Help Text', required=True, **kwargs
+    )
+    assert isinstance(graphene_type_required, graphene_field)
+
+    return graphene_type
+
+
+def test_should_unknown_form_field_raise_exception():
+    with raises(Exception) as excinfo:
+        convert_form_field(None)
+    assert 'Don\'t know how to convert the form field' in str(excinfo.value)
+
+
+def test_should_charfield_convert_string():
+    assert_conversion(forms.CharField, graphene.String)
+
+
+def test_should_timefield_convert_time():
+    assert_conversion(forms.TimeField, graphene.types.datetime.Time)
+
+
+def test_should_email_convert_string():
+    assert_conversion(forms.EmailField, graphene.String)
+
+
+def test_should_slug_convert_string():
+    assert_conversion(forms.SlugField, graphene.String)
+
+
+def test_should_url_convert_string():
+    assert_conversion(forms.URLField, graphene.String)
+
+
+def test_should_choicefield_convert_string():
+    assert_conversion(forms.ChoiceField, graphene.String, choices=[])
+
+
+def test_should_regexfield_convert_string():
+    assert_conversion(forms.RegexField, graphene.String, regex='[0-9]+')
+
+
+def test_should_uuidfield_convert_string():
+    assert_conversion(forms.UUIDField, graphene.String)
+
+
+def test_should_integer_convert_int():
+    assert_conversion(forms.IntegerField, graphene.Int)
+
+
+def test_should_boolean_convert_boolean():
+    assert_conversion(forms.BooleanField, graphene.Boolean)
+
+
+def test_should_float_convert_float():
+    assert_conversion(forms.FloatField, graphene.Float)
+
+
+def test_should_decimal_convert_float():
+    assert_conversion(forms.DecimalField, graphene.Float, max_digits=4, decimal_places=2)
+
+
+def test_should_filepath_convert_string():
+    assert_conversion(forms.FilePathField, graphene.String, path='/')
+
+
+def test_should_multiplechoicefield_convert_to_list_of_string():
+    field = assert_conversion(forms.MultipleChoiceField, graphene.List, choices=[1, 2, 3])
+
+    assert field.of_type == graphene.String

graphene_django/forms/tests/__init__.py

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+from django import forms
+from py.test import raises
+
+from graphene_django.tests.models import Pet
+from ..mutation import FormMutation, ModelFormMutation
+
+
+class MyForm(forms.Form):
+    text = forms.CharField()
+
+
+class PetForm(forms.ModelForm):
+
+    class Meta:
+        model = Pet
+        fields = ('name',)
+
+
+def test_needs_form_class():
+    with raises(Exception) as exc:
+        class MyMutation(FormMutation):
+            pass
+
+    assert exc.value.args[0] == 'Missing form_class'
+
+
+def test_has_fields():
+    class MyMutation(FormMutation):
+        class Meta:
+            form_class = MyForm
+
+    assert 'errors' in MyMutation._meta.fields
+
+
+def test_has_input_fields():
+    class MyMutation(FormMutation):
+        class Meta:
+            form_class = MyForm
+
+    assert 'text' in MyMutation.Input._meta.fields
+
+
+def test_model_form():
+    class PetMutation(ModelFormMutation):
+        class Meta:
+            form_class = PetForm
+
+    assert PetMutation.model == Pet
+    assert PetMutation.return_field_name == 'pet'