django-river 3.3.0

Django Workflow Library

Django River

River is an open source workflow framework for Django which supports on the fly changes instead of hard-coding states, transitions and authorization rules.

The main goal of developing this framework is to be able to modify literally everything about the workflows on the fly. This means that all the elements in a workflow like states, transitions or authorizations rules are editable at any time so that no changes requires a re-deploying of your application anymore.

Playground: There is a fake jira example repository as a playground of django-river. https://github.com/javrasya/fakejira

Donations

This is a fully open source project and it can be better with your donations.

If you are using django-river to create a commercial product, please consider becoming our sponsor , patron or donate over PayPal

Documentation

Online documentation is available at http://django-river.rtfd.org/

Advance Admin

A very modern admin with some user friendly interfaces that is called River Admin has been published.

Requirements

• Python (3.5 (for Django 2.2 only), 3.6, 3.7, 3.8)

• Django (2.2, 3.0, 3.1)

• Django = 2.2 is supported for Python >= 3.5

• Django >= 3.0 is supported for Python >= 3.6

Supported (Tested) Databases:

PostgreSQL	Tested	Support
9	✅	✅
10	✅	✅
11	✅	✅
12	✅	✅

MySQL	Tested	Support
5.6	✅	❌
5.7	✅	❌
8.0	✅	✅

MSSQL	Tested	Support
19	✅	✅
17	✅	✅

Usage

1. Install and enable it

   pip install django-river

   INSTALLED_APPS=[
       ...
       river
       ...
   ]

2. Create your first state machine in your model and migrate your db

   from django.db import models
   from river.models.fields.state import StateField
   
   class MyModel(models.Model):
       my_state_field = StateField()

3. Create all your states on the admin page

4. Create a workflow with your model ( MyModel - my_state_field ) information on the admin page

5. Create your transition metadata within the workflow created earlier, source and destination states

6. Create your transition approval metadata within the workflow created earlier and authorization rules along with their priority on the admin page

7. Enjoy your django-river journey.

   my_model=MyModel.objects.get(....)
   
   my_model.river.my_state_field.approve(as_user=transactioner_user)
   my_model.river.my_state_field.approve(as_user=transactioner_user, next_state=State.objects.get(label='re-opened'))
   
   # and much more. Check the documentation

Note

Whenever a model object is saved, it’s state field will be initialized with the state is given at step-4 above by django-river.

Hooking Up With The Events

django-river provides you to have your custom code run on certain events. And since version v2.1.0 this has also been supported for on the fly changes. You can create your functions and also the hooks to a certain events by just creating few database items. Let’s see what event types that can be hooked a function to;

• An approval is approved

• A transition goes through

• The workflow is complete

For all these event types, you can create a hooking with a given function which is created separately and preliminary than the hookings for all the workflow objects you have or you will possible have, or for a specific workflow object. You can also hook up before or after the events happen.

1. Create Function

This will be the description of your functions. So you define them once and you can use them with multiple hooking up. Just go to /admin/river/function/ admin page and create your functions there. django-river function admin support python code highlights.

INSTALLED_APPS=[
    ...
    codemirror2
    river
    ...
]

Here is an example function;

from datetime import datetime

def handle(context):
    print(datetime.now())

Important: YOUR FUNCTION SHOULD BE NAMED AS handle. Otherwise django-river won’t execute your function.

django-river will pass a context down to your function in order for you to know why the function is triggered or for which object or so. And the context will look different for different type of events. Please see detailed context documentation to know more on what you would get from context in your functions.

You can find an advance function example on the link.

2. Hook It Up

The hookings in django-river can be created both specifically for a workflow object or for a whole workflow. django-river comes with some model objects and admin interfaces which you can use to create the hooks.

• To create one for whole workflow regardless of what the workflow object is, go to

  • /admin/river/onapprovedhook/ to hook up to an approval

  • /admin/river/ontransithook/ to hook up to a transition

  • /admin/river/oncompletehook/ to hook up to the completion of the workflow

• To create one for a specific workflow object you should use the admin interface for the workflow object itself. One amazing feature of django-river is now that it creates a default admin interface with the hookings for your workflow model class. If you have already defined one, django-river enriches your already defined admin with the hooking section. It is default disabled. To enable it just define RIVER_INJECT_MODEL_ADMIN to be True in the settings.py.

Note: They can programmatically be created as well since they are model objects. If it is needed to be at workflow level, just don’t provide the workflow object column. If it is needed to be for a specific workflow object then provide it.

Here are the list of hook models;

• OnApprovedHook

• OnTransitHook

• OnCompleteHook

Before Reporting A Bug

django-river has behavioral tests that are very easy to read and write. One can easily set up one and see if everything is running as expected. Please look at other examples (that are the files with .feature postfix) under features folder that you can get all the inspiration and create one for yourself before you open an issue Then refer to your behavioral test to point out what is not function as expected to speed the process up for your own sake. It is even better to name it with your issue number so we can persist it in the repository.

Migrations

2.X.X to 3.0.0

django-river v3.0.0 comes with quite number of migrations, but the good news is that even though those are hard to determine kind of migrations, it comes with the required migrations out of the box. All you need to do is to run;

python manage.py migrate river

3.1.X to 3.2.X

django-river started to support Microsoft SQL Server 17 and 19 after version 3.2.0 but the previous migrations didn’t get along with it. We needed to reset all the migrations to have fresh start. If you have already migrated to version 3.1.X all you need to do is to pull your migrations back to the beginning.

python manage.py migrate --fake river zero
python manage.py migrate --fake river

FAQ

Have a look at FAQ

Contributors

Code Contributors

This project exists thanks to all the people who contribute :rocket: :heart:

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Individuals

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License

This software is licensed under the New BSD License. See the LICENSE file in the top distribution directory for the full license text.