from collections import OrderedDict
from rest_framework.fields import empty
from django.utils.functional import cached_property
class Mixin(object):
ordered = False
def __init__(self, *args, **kwargs):
self.ordered = kwargs.pop('ordered', self.ordered)
super(Mixin, self).__init__(*args, **kwargs)
def obj_to_representation(self, obj):
data = [(f, getattr(obj, f.field_name)) for
f in self.repr_fields]
if self.ordered:
return OrderedDict(
[(f.field_name, f.to_representation(val) if val else None)
for f, val in data])
else:
return dict(
[(f.field_name, f.to_representation(val) if val else None)
for f, val in data])
def dict_to_representation(self, d):
data = [(f, d.get(f.field_name, None)) for
f in self.repr_fields]
if self.ordered:
return OrderedDict(
[(f.field_name, f.to_representation(val) if val else None)
for f, val in data])
else:
return dict(
[(f.field_name, f.to_representation(val) if val else None)
for f, val in data])
@cached_property
def repr_fields(self):
return [field for field in self.fields.values()
if (not field.read_only) or (field.default is not empty)]
obj_to_representation = Mixin.obj_to_representation
dict_to_representation = Mixin.dict_to_representation
