django-openutils 0.1.0

Practical Django model utilities.

django-openutils

Practical Django model utilities. Currently ships ModelDiffMixin for tracking field changes.

Installation

pip install django-openutils

ModelDiffMixin

A model mixin that tracks field changes via __dict__ snapshotting. Uses concrete field attnames (e.g. author_id not author) so FK fields are compared by PK value without extra DB queries. Deferred fields are excluded from tracking.

Usage

from django.db import models
from django_openutils.mixins import ModelDiffMixin


class MyModel(ModelDiffMixin, models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField()

obj = MyModel.objects.create(name="Alice", email="[e-mail]")
obj.has_unsaved_changes  # False

obj.name = "Bob"
obj.has_unsaved_changes  # True
obj.unsaved_fields       # dict_keys(['name'])
obj.get_unsaved_field_diff("name")  # ('Alice', 'Bob')

obj.save()
obj.has_unsaved_changes  # False
obj.has_updated_fields   # True
obj.recent_updates       # {'name': ('Alice', 'Bob')}

API

Property / Method	Description
unsaved_changes	Dict of {field: (old, new)} for in-memory changes not yet saved
has_unsaved_changes	True if any fields differ from the last save/load
unsaved_fields	Keys of unsaved_changes
get_unsaved_field_diff(field)	Returns (old, new) tuple or None
recent_updates	Dict of {field: (old, new)} from the last save() call
has_updated_fields	True if recent_updates is non-empty
updated_fields	Keys of recent_updates

License

MIT - see LICENSE for details.