Django finite state machine implementation

New approach to the finite state machines, the idea is to avoid declaring machine logic on models, instead, create machines.py file in your app and define your example state handler:

from django_state_machines.logic import BaseStateHandler

class TestHandler(BaseStateHandler):
    def accept(self, **kwargs):
        pass

    def reject(self, **kwargs):
        print('reject')

    def add_transitions(self):
        self.add_transition(trigger='accept', start_state='notaccepted', end_state='accepted')
        self.add_transition(trigger='reject', start_state='notaccepted', end_state='rejected')

and for the model:

from django_state_machines.fields import StateMachineCharField
from test_app.machines import TestHandler


class Test(models.Model):
    state = StateMachineCharField(
        max_length=50,
        handler=TestHandler,
        state_choices=(
            ('accepted', 'Accepted state', 'accepted'),
            ('notaccepted', 'Not accepted state', 'notaccepted'),
            ('rejected', 'Rejected state', 'rejected'),

        ))

Installation

$ pip install django-state-machines