graphene/graphene/contrib/django/fields.py
2015-10-10 14:56:18 -07:00

93 lines
3.0 KiB
Python

from graphene.core.fields import (
ListField
)
from graphene import relay
from graphene.core.fields import Field, LazyField
from graphene.utils import cached_property, memoize, LazyMap
from graphene.relay.types import BaseNode
from django.db.models.query import QuerySet
from django.db.models.manager import Manager
@memoize
def get_type_for_model(schema, model):
schema = schema
types = schema.types.values()
for _type in types:
type_model = hasattr(_type, '_meta') and getattr(
_type._meta, 'model', None)
if model == type_model:
return _type
def lazy_map(value, func):
if isinstance(value, Manager):
value = value.get_queryset()
if isinstance(value, QuerySet):
return LazyMap(value, func)
return value
class DjangoConnectionField(relay.ConnectionField):
def wrap_resolved(self, value, instance, args, info):
schema = info.schema.graphene_schema
return lazy_map(value, self.get_object_type(schema))
class LazyListField(ListField):
def resolve(self, instance, args, info):
schema = info.schema.graphene_schema
resolved = super(LazyListField, self).resolve(instance, args, info)
return lazy_map(resolved, self.get_object_type(schema))
class ConnectionOrListField(LazyField):
@memoize
def get_field(self, schema):
model_field = self.field_type
field_object_type = model_field.get_object_type(schema)
if field_object_type and issubclass(field_object_type, BaseNode):
field = DjangoConnectionField(model_field)
else:
field = LazyListField(model_field)
field.contribute_to_class(self.object_type, self.name)
return field
class DjangoModelField(Field):
def __init__(self, model, *args, **kwargs):
super(DjangoModelField, self).__init__(None, *args, **kwargs)
self.model = model
def resolve(self, instance, args, info):
resolved = super(DjangoModelField, self).resolve(instance, args, info)
schema = info.schema.graphene_schema
_type = self.get_object_type(schema)
assert _type, ("Field %s cannot be retrieved as the "
"ObjectType is not registered by the schema" % (
self.field_name
))
return _type(resolved)
@memoize
def internal_type(self, schema):
_type = self.get_object_type(schema)
if not _type and self.object_type._meta.only_fields:
raise Exception(
"Model %r is not accessible by the schema. "
"You can either register the type manually "
"using @schema.register. "
"Or disable the field %s in %s" % (
self.model,
self.field_name,
self.object_type
)
)
return _type and _type.internal_type(schema) or Field.SKIP
def get_object_type(self, schema):
return get_type_for_model(schema, self.model)