mirror of
https://github.com/django/django.git
synced 2024-12-23 17:46:27 +00:00
5ed20b3aa3
Allows model fields to override the descriptor class used on the model instance attribute.
27 lines
832 B
Python
27 lines
832 B
Python
from django.db import models
|
|
from django.db.models.query_utils import DeferredAttribute
|
|
|
|
|
|
class CustomTypedField(models.TextField):
|
|
def db_type(self, connection):
|
|
return 'custom_field'
|
|
|
|
|
|
class CustomDeferredAttribute(DeferredAttribute):
|
|
def __get__(self, instance, cls=None):
|
|
self._count_call(instance, 'get')
|
|
return super().__get__(instance, cls)
|
|
|
|
def __set__(self, instance, value):
|
|
self._count_call(instance, 'set')
|
|
instance.__dict__[self.field.attname] = value
|
|
|
|
def _count_call(self, instance, get_or_set):
|
|
count_attr = '_%s_%s_count' % (self.field.attname, get_or_set)
|
|
count = getattr(instance, count_attr, 0)
|
|
setattr(instance, count_attr, count + 1)
|
|
|
|
|
|
class CustomDescriptorField(models.CharField):
|
|
descriptor_class = CustomDeferredAttribute
|