Task based reusable workflow library for django
Ad-hoc business process automation framework for Django.
The process logic defined with django-viewflow is concentrated in one clearly defined flow. You can organize your views, background jobs, user permission checking in a simple, intuitive django-friendly way.
django-viewflow allows to implement such process, just in about hundred lines of code, and you would still have pure django views for that.
Full documentation is available at http://kmmbvnr.github.io/django-viewflow/
django-viewflow requires Python 3.3 or greater and django 1.7:
pip install django-viewflow
And add it into INSTALLED_APPS settings
INSTALLED_APPS = ( ... viewflow, )
Let’s define basic Hello Process where one could start hello world request, another person approves it, and as soon as the request is approved it should be send into background.
Start with process database model definition
from django.db import models from viewflow.models import Process class HelloworldProcess(Process): text = models.ChatField(max_lenght=150, blank=True, null=True) approved = models.BooleanField(default=False) class Meta: permissions = [ ('can_start_request', 'Can start hello world request'), ('can_approve_request', 'Can approve hello world request') ]
Define the actual task that says Hello to the World in task.py
import os from celery import shared_task from viewflow.flow import flow_job @shared_task(bind=True) @flow_job() def send_hello_world_request(self, activation): with open(os.devnull, "w") as world: world.write(activation.process.text)
To make the above code work just put the following flow definition in flows.py module from your django application.
from viewflow import flow from viewflow.base import this, Flow from viewflow.views import ProcessView class HelloWorldFlow(Flow): start = flow.Start(StartView, fields=["text"]) \ .Permission('helloworld.can_start_request') \ .Activate(this.hello_world) approve = flow.View(ProcessView, fields=["approve"]) \ .Permission('helloworld.can_approve_request') .Next(this.check_approve) check_approve = flow.If(cond=lambda p: p.approved) \ .OnTrue(this.send) \ .OnFalse(this.end) send = flow.Job(send_hello_world_request) \ .Next(this.end) end = flow.End()
Flow class contains all urls required for the task processing.
from django.conf.urls import patterns, url, include from .flows import HelloWorldFlow urlpatterns = patterns('', url(r'^helloworld/', include(HelloWorldFlow.instance.urls)))
That’s all you need to setup this flow.
Next, you can see how to define custom views, and meet other concepts of django-viewflow at http://kmmbvnr.github.io/django-viewflow/
More examples are available in the tests/examples directory.
- Initial public prototype
- Basic set of tasks support (View, Job, If/Switch, Split/Join)