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!)
We needed the get_set_bits()
due to its usage throughout several other packages.
It was easier to fork this one package and add it back in than change all the other
packages.
- Django >= 1.8
- 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