django-fsm-freeze 0.1.7

django-fsm data immutability support

django fsm data immutability support

django-fsm-freeze provides a django model mixin for data immutability based on django-fsm.

Installation

pip install django-fsm-freeze

Usage

• Add FreezableFSMModelMixin to your django-fsm model
• Specify the FROZEN_IN_STATES in which the object should be frozen, meaning the value of its fields/attributes cannot be changed.
• (optional) Customize the NON_FROZEN_FIELDS for mutability

When an object is in a frozen state, by default all of its fields are immutable, except for the state field which needs to be mutable for django-fsm to work.

In case we still want to mutate certain fields when the object is frozen, we can override the NON_FROZEN_FIELDS to allow it. When overriding the NON_FROZEN_FIELDS, be careful to include state for the reason mentioned above.

from django.db import models
from django_fsm import FSMField

from django_fsm_freeze.models import FreezableFSMModelMixin

class MyDjangoFSMModel(FreezableFSMModelMixin, models.Model):

    # In this example, when object is in the 'active' state, it is immutable.
    FROZEN_IN_STATES = ('active', )

    NON_FROZEN_FIELDS = FreezableFSMModelMixin.NON_FROZEN_FIELDS + (
        'a_mutable_field',
    )
    # This field is mutable even when the object is in the frozen state.
    a_mutable_field = models.BooleanField()

    # django-fsm specifics: state, transitions, etc.
    state = FSMField(default='new')
    # ...

See example usage also in https://github.com/ming-tung/django-fsm-freeze/blob/main/mytest/models.py