/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

6 votes317 views2 answers
Kill port django
Python Django
1 vote322 views1 answer
How to create staff account in django
Python Django
0 vote287 views1 answer
Django forms request
Python Django
0 vote303 views1 answer
How to work with django ornm __in
Python Django
5 votes308 views4 answers
Import user in django
Python Django
0 vote261 views1 answer
How to resize image with pillow in django
Python Django
0 vote274 views2 answers
Style django forms with crisp
Python Django
2 votes273 views1 answer
Django queryset get all distinct
Python Django
1 vote307 views2 answers
Django template iterate dict
Python Django
0 vote302 views2 answers
Generate-thumbnails-in-django-with-pil
Python Django