/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 votes162 views2 answers
Kill port django
Python Django
-1 vote173 views1 answer
Django filter on related field
Python Django
3 votes161 views2 answers
Django radio button
Python Django
0 vote156 views1 answer
Django cms api create page
Python Django
0 vote194 views2 answers
Form.as_p in django
Python Django
0 vote180 views2 answers
Create blog in django
Python Django
1 vote153 views1 answer
Import "django.core.urlresolvers" could not be resolved
Python Django
4 votes226 views2 answers
Django composite primary key
Python Django
0 vote166 views1 answer
Custom django password checker
Python Django
1 vote165 views3 answers
Accessing data on django sessionstore
Python Django