Tracking dirty fields on a Django model instance.
$ pip install django-dirtyfieldsor if you're interested in developing it
$ virtualenv --no-site-packages ve/
$ source ve/bin/activate
(ve)$ pip install -r requirements.pip
(ve)$ python setup.py develop
(ve)$ cd example_app && ./manage.py test testing_appMakes a Mixing available that will give you the methods:
- is_dirty()
- get_dirty_fields()
from django.db import models
from dirtyfields import DirtyFieldsMixin
class TestModel(DirtyFieldsMixin, models.Model):
"""A simple test model to test dirty fields mixin with"""
boolean = models.BooleanField(default=True)
characters = models.CharField(blank=True, max_length=80)(ve)$ ./manage.py shell
>>> from testing_app.models import TestModel
>>> tm = TestModel(boolean=True,characters="testing")
>>> tm.save()
>>> tm.is_dirty()
False
>>> tm.get_dirty_fields()
{}
>>> tm.boolean = False
>>> tm.is_dirty()
True
>>> tm.get_dirty_fields()
{'boolean': True}
>>> tm.characters = "have changed"
>>> tm.is_dirty()
True
>>> tm.get_dirty_fields()
{'boolean': True, 'characters': 'testing'}
>>> tm.save()
>>> tm.is_dirty()
False
>>> tm.get_dirty_fields()
{}
>>> When using signals, especially pre_save, it is useful to be able to see what fields have changed or not. A signal could change its behaviour depending on whether a specific field has changed, whereas otherwise, you only could work on the event that the model's save() method had been called.
This code has largely be adapted from what was made available at Stack Overflow.