djangorestframework-fsm

Automatically hook your Django-FSM transitions up to Django REST Framework

Based on drf-fsm-transitions which is very outdated and does not support a lot of the functionality described below

Installation

pip install djangorestframework-fsm

Usage

When declaring your viewset, simply mix in the result of get_drf_fsm_mixin

from rest_framework import viewsets
from djangorestframework_fsm.viewset_mixins import get_drf_fsm_mixin

from .models import Article


class ArticleViewSet(
    get_drf_fsm_mixin(Article, fieldname='state'),
    viewsets.ModelViewSet,
):
    queryset = Article.objects.all()

You can customise the field name as show above. By default, it uses state

if Article had 2 transitions, delete and publish, the following API calls would be set up

• POST /api/article/1234/delete/
• POST /api/article/1234/publish/

In addition, a possible transitions endpoint is provided

• GET /api/article/1234/possible-transitions/ -> returns the transitions that satisfy fsm's can_proceed

Custom transition arguments

Passing custom arguments to each transition can be done by specifying them in the get_{}_kwargs method:

class ArticleViewSet(
    get_drf_fsm_mixin(Article, fieldname='state'),
    viewsets.ModelViewSet,
):
    queryset = Article.objects.all()
    
    def get_publish_kwargs(self):
        return {
            'publisher_address': self.request.data.get('publisher_address', ''),
        }

This will in turn call the Article.publish method with the publisher_address argument

In addition, djangorestframework-fsm automatically calls the transition method with a by argument if the method accepts one unless it's overriden in the get_{}_kwargs viewset method

Saving

By default, the model instance will be saved after the transition has been successfully called. This can be disabled with the save_after_transition attribute

class ArticleViewSet(
    get_drf_fsm_mixin(Article),
    viewsets.ModelViewSet,
):
    queryset = Article.objects.all()
    save_after_transition = False

Permissions

Custom permissions should be defined on the model's transition method