graphene-django/graphene_django/types.py

127 lines
4.2 KiB
Python

from collections import OrderedDict
import six
from django.utils.functional import SimpleLazyObject
from graphene import Field, ObjectType
from graphene.types.objecttype import ObjectTypeMeta
from graphene.types.options import Options
from graphene.types.utils import merge, yank_fields_from_attrs
from graphene.utils.is_base_type import is_base_type
from .converter import convert_django_field_with_choices
from .registry import Registry, get_global_registry
from .utils import (DJANGO_FILTER_INSTALLED, get_model_fields,
is_valid_django_model)
def construct_fields(options):
_model_fields = get_model_fields(options.model)
only_fields = options.only_fields
exclude_fields = options.exclude_fields
fields = OrderedDict()
for field in _model_fields:
name = field.name
is_not_in_only = only_fields and name not in options.only_fields
is_already_created = name in options.fields
is_excluded = name in exclude_fields or is_already_created
# https://docs.djangoproject.com/en/1.10/ref/models/fields/#django.db.models.ForeignKey.related_query_name
is_no_backref = str(name).endswith('+')
if is_not_in_only or is_excluded or is_no_backref:
# We skip this field if we specify only_fields and is not
# 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, options.registry)
if not converted:
continue
fields[name] = converted
return fields
class DjangoObjectTypeMeta(ObjectTypeMeta):
@staticmethod
def __new__(cls, name, bases, attrs):
# Also ensure initialization is only performed for subclasses of
# DjangoObjectType
if not is_base_type(bases, DjangoObjectTypeMeta):
return type.__new__(cls, name, bases, attrs)
defaults = dict(
name=name,
description=attrs.pop('__doc__', None),
model=None,
local_fields=None,
only_fields=(),
exclude_fields=(),
interfaces=(),
registry=None
)
if DJANGO_FILTER_INSTALLED:
# In case Django filter is available, then
# we allow more attributes in Meta
defaults.update(
filter_fields=(),
)
options = Options(
attrs.pop('Meta', None),
**defaults
)
if not options.registry:
options.registry = get_global_registry()
assert isinstance(options.registry, Registry), (
'The attribute registry in {}.Meta needs to be an instance of '
'Registry, received "{}".'
).format(name, options.registry)
assert is_valid_django_model(options.model), (
'You need to pass a valid Django Model in {}.Meta, received "{}".'
).format(name, options.model)
cls = ObjectTypeMeta.__new__(cls, name, bases, dict(attrs, _meta=options))
options.registry.register(cls)
options.django_fields = yank_fields_from_attrs(
construct_fields(options),
_as=Field,
)
options.fields = merge(
options.interface_fields,
options.django_fields,
options.base_fields,
options.local_fields
)
return cls
class DjangoObjectType(six.with_metaclass(DjangoObjectTypeMeta, ObjectType)):
def resolve_id(self, args, context, info):
return self.pk
@classmethod
def is_type_of(cls, root, context, info):
if isinstance(root, SimpleLazyObject):
root._setup()
root = root._wrapped
if isinstance(root, cls):
return True
if not is_valid_django_model(type(root)):
raise Exception((
'Received incompatible instance "{}".'
).format(root))
model = root._meta.model
return model == cls._meta.model
@classmethod
def get_node(cls, id, context, info):
try:
return cls._meta.model.objects.get(pk=id)
except cls._meta.model.DoesNotExist:
return None