graphene/graphene-django/graphene_django/utils.py
2016-06-21 23:42:38 -07:00

82 lines
2.3 KiB
Python

import inspect
from django.db import models
from django.db.models.manager import Manager
# from graphene.utils import LazyList
class LazyList(object):
pass
from .compat import RelatedObject
try:
import django_filters # noqa
DJANGO_FILTER_INSTALLED = True
except (ImportError, AttributeError):
# AtributeError raised if DjangoFilters installed with a incompatible Django Version
DJANGO_FILTER_INSTALLED = False
def get_reverse_fields(model):
for name, attr in model.__dict__.items():
# Django =>1.9 uses 'rel', django <1.9 uses 'related'
related = getattr(attr, 'rel', None) or \
getattr(attr, 'related', None)
if isinstance(related, RelatedObject):
# Hack for making it compatible with Django 1.6
new_related = RelatedObject(related.parent_model, related.model, related.field)
new_related.name = name
yield new_related
elif isinstance(related, models.ManyToOneRel):
yield related
elif isinstance(related, models.ManyToManyRel) and not related.symmetrical:
yield related
def maybe_queryset(value):
if isinstance(value, Manager):
value = value.get_queryset()
return value
def get_model_fields(model):
reverse_fields = get_reverse_fields(model)
all_fields = sorted(list(model._meta.fields) +
list(model._meta.local_many_to_many))
all_fields += list(reverse_fields)
return all_fields
def get_related_model(field):
if hasattr(field, 'rel'):
# Django 1.6, 1.7
return field.rel.to
return field.related_model
def is_valid_django_model(model):
return inspect.isclass(model) and issubclass(model, models.Model)
def import_single_dispatch():
try:
from functools import singledispatch
except ImportError:
singledispatch = None
if not singledispatch:
try:
from singledispatch import singledispatch
except ImportError:
pass
if not singledispatch:
raise Exception(
"It seems your python version does not include "
"functools.singledispatch. Please install the 'singledispatch' "
"package. More information here: "
"https://pypi.python.org/pypi/singledispatch"
)
return singledispatch