Provides a BitField like class (using a BigIntegerField) for your Django models.
(If you're upgrading from a version before 1.2 the API has changed greatly and is backwards incompatible!)
- Django >= 1.4
- PostgreSQL (see notes)
Notes:
- SQLite does not support save operations using a
Bit
(per the example under Usage). - MySQL fails on most queries related to BitField's.
Install it with pip (or easy_install):
pip install django-bitfield
First you'll need to attach a BitField to your class. This acts as a BigIntegerField (BIGINT) in your database:
from bitfield import BitField
class MyModel(models.Model):
flags = BitField(flags=(
'awesome_flag',
'flaggy_foo',
'baz_bar',
))
Flags can also be defined with labels:
class MyModel(models.Model):
flags = BitField(flags=(
('awesome_flag', 'Awesome Flag!'),
('flaggy_foo', 'Flaggy Foo'),
('baz_bar', 'Baz (bar)'),
))
Now you can use the field using very familiar Django operations:
# Create the model
o = MyModel.objects.create(flags=0)
# Add awesome_flag (does not work in SQLite)
MyModel.objects.filter(pk=o.pk).update(flags=F('flags').bitor(MyModel.flags.awesome_flag))
# Set flags manually to [awesome_flag, flaggy_foo]
MyModel.objects.filter(pk=o.pk).update(flags=MyModel.flags.awesome_flag | MyModel.flags.flaggy_foo)
# Remove awesome_flag (does not work in SQLite)
MyModel.objects.filter(pk=o.pk).update(flags=F('flags').bitand(~MyModel.flags.awesome_flag))
# Find by awesome_flag
MyModel.objects.filter(flags=MyModel.flags.awesome_flag)
# Exclude by awesome_flag
MyModel.objects.filter(flags=~MyModel.flags.awesome_flag)
# Test awesome_flag
if o.flags.awesome_flag:
print "Happy times!"
# List all flags on the field
for f in o.flags:
print f
# Get a flag label
print o.flags.get_label('awesome_flag')
Enjoy!
To use the widget in the admin, you'll need to update your ModelAdmin. Add the following lines to your ModelAdmin:
formfield_overrides = {
BitField: {'widget': BitFieldCheckboxSelectMultiple},
}
Make sure you've imported the classes by adding these lines to the top of the file:
from bitfield import BitField
from bitfield.forms import BitFieldCheckboxSelectMultiple
There is also a BitFieldListFilter
list filter (Django 1.4 or newer). To use it set list_filter
ModelAdmin option:
list_filter = (
('flags', BitFieldListFilter,)
)
BitFieldListFilter is in bitfield.admin
module:
from bitfield.admin import BitFieldListFilter