Activity based reusable workflow library for django
Project description
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/
Installation
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,
)
Quick start
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, lock
from viewflow.base import this, Flow
from viewflow.views import ProcessView
from .models import HelloWorldProcess
class HelloWorldFlow(Flow):
process_cls = HelloWorldProcess
lock_impl = lock.select_for_update_lock
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.
License
Change log
0.2.0 2014-06-02
Back reference for task owner for next tasks assignment
Auto create for task permissions support
Basic django admin interace
Exception handling during flow task activation and for broken celery jobs
0.1.0 2014-05-01
Initial public prototype
Basic set of tasks support (View, Job, If/Switch, Split/Join)
Project details
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