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Integrations

Django integration

When used in a Django App, this library implements an auto-discovery hook similar to how Django's built-in admin autodiscover.

This library attempts to import an statemachine or statemachines module in each installed application. Such modules are expected to register StateMachine classes to be used with the {ref}MachineMixin.

When using `python-statemachine` to control the state of a Django model, we advise keeping the
{ref}`StateMachine` definitions on their own modules.

So as circular references may occur, and as a way to help you organize your
code, if you put state machines on modules named as mentioned above inside installed
Django Apps, these {ref}`StateMachine` classes will be automatically
imported and registered.

This is only an advice, nothing stops you do declare your state machine alongside your models.

Example

Given this StateMachine:

# campaign/statemachines.py

from statemachine import StateMachine
from statemachine import State
from statemachine.mixins import MachineMixin


class CampaignMachineWithKeys(StateMachine):
    "A workflow machine"
    draft = State('Draft', initial=True, value=1)
    producing = State('Being produced', value=2)
    closed = State('Closed', value=3)
    cancelled = State('Cancelled', value=4)

    add_job = draft.to.itself() | producing.to.itself()
    produce = draft.to(producing)
    deliver = producing.to(closed)
    cancel = cancelled.from_(draft, producing)

Integrate with your model:

# campaign/models.py

from django.db import models

class Campaign(models.Model, MachineMixin):
    state_machine_name = 'campaign.statemachines.CampaignMachineWithKeys'
    state_machine_attr = 'sm'
    state_field_name = 'step'

    name = models.CharField(max_length=30)
    step = models.IntegerField()
Learn more about using the [](mixins.md#machinemixin).