/Python/Django/Unique mark boolean django model field

Unique mark boolean django model field

#FIELDS.py

from django.db.models import BooleanField


class UniqueBooleanField(BooleanField):
    def pre_save(self, model_instance, add):
        objects = model_instance.__class__.objects
        # If True then set all others as False
        if getattr(model_instance, self.attname):
            objects.update(**{self.attname: False})
        # If no true object exists that isnt saved model, save as True
        elif not objects.exclude(id=model_instance.id)\
                        .filter(**{self.attname: True}):
            return True
        return getattr(model_instance, self.attname)

# To use with South
from south.modelsinspector import add_introspection_rules
add_introspection_rules([], ["^project\.apps\.fields\.UniqueBooleanField"])


#Models.py
from django.db import models

from project.apps.fields import UniqueBooleanField


class UniqueBooleanModel(models.Model):
    unique_boolean = UniqueBooleanField()

    def __unicode__(self):
        return str(self.unique_boolean)

Source: stackoverflow.com

Similar codes

9 votes354 views2 answers
Django import Q
Python Django
0 vote335 views1 answer
Django model meta ordering multiple ordering
Python Django
0 vote364 views1 answer
Lose your django secret key
Python Django
0 vote372 views1 answer
Views.py django
Python Django
0 vote360 views1 answer
Staff user is not restricting permission in django
Python Django
0 vote487 views2 answers
Django admin image
Python Django
2 votes382 views1 answer
Django get current date
Python Django
3 votes364 views2 answers
Django change user password
Python Django
0 vote335 views1 answer
Django retrieveupdatedestroyapiview
Python Django
0 vote426 views1 answer
How to export schema in graphene django
Python Django