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from .models import SortableMixin, SortableForeignKey
def check_inheritance(cls):
return issubclass(type(cls), SortableMixin)
def get_is_sortable(objects):
if objects.count() < 2:
return False
if not check_inheritance(objects[:1][0]):
return False
return True
def is_self_referential(cls):
cls_type = type(cls)
sortable_subclass = check_inheritance(cls_type)
sortable_foreign_key_subclass = issubclass(cls_type, SortableForeignKey)
if sortable_foreign_key_subclass and not sortable_subclass:
return True
return False
def check_model_is_sortable(cls):
if cls:
if check_inheritance(cls):
if is_self_referential(cls):
objects = cls.model.objects
else:
objects = cls.objects
return get_is_sortable(objects.all())
return False
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