Quick Start¶

Add the Mixin to Your Model¶

To track dirty fields on a model, inherit from DirtyFieldsMixin:

# myapp/models.py  (`myapp` must be in INSTALLED_APPS — otherwise Django raises app_label errors)
from django.db import models
from filthyfields import DirtyFieldsMixin

class ExampleModel(DirtyFieldsMixin, models.Model):
    boolean = models.BooleanField(default=True)
    characters = models.CharField(blank=True, max_length=80)

Mixin Order

DirtyFieldsMixin must come before models.Model in the inheritance list.

Check if a Model is Dirty¶

Use is_dirty() to check if any fields have been modified:

>>> model = ExampleModel.objects.create(boolean=True, characters="first value")
>>> model.is_dirty()
False

>>> model.boolean = False
>>> model.is_dirty()
True

Get Dirty Fields¶

Use get_dirty_fields() to get a dictionary of changed fields with their original values:

>>> model = ExampleModel.objects.create(boolean=True, characters="first value")
>>> model.boolean = False
>>> model.characters = "second value"

>>> model.get_dirty_fields()
{'boolean': True, 'characters': 'first value'}

The returned dictionary maps field names to their original (database) values, not the new values.

Save and Reset¶

After saving, the dirty state is cleared:

>>> model.is_dirty()
True
>>> model.save()
>>> model.is_dirty()
False
>>> model.get_dirty_fields()
{}