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Django Workflow Library

Project description

Django River
============

|Build Status| |Coverage Status| |Documentation Status|

River is a open source workflow system for ``Django`` which support on
the fly changes on every item in workflow instead of hardcoding states
and transitions.

Main goal of developing this framework is **to be able to edit any
workflow item on the fly.** This means, all elements in workflow like
states, transitions, user authorizations(permission), group
authorization are editable. To do this, all data about the workflow item
is persisted into DB. **Hence, they can be changed without touching the
code and re-deploying your application.**

There is ordering aprovments for a transition functionality in
``django-river``. It also provides skipping specific transition of a
specific objects.

Documentation
-------------

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

Installation
------------

- Install it

.. code:: bash

pip install django-river

- Configure settings

.. code:: python

INSTALLED_APP=[
...
river
...
]

- Migrate your application

.. code:: bash

python manage.py migrate

- In your model class which will be processing in workflow;

.. code:: python

from django.db import models
from river.models.fields.state import StateField

class MyModel(models.Model):
my_state_field = StateField()

That's it. Whenever your new model object is saved, it's state field
will be initialized according to given meta data about workflow. To know
how to do your workflow confirmation(states, transitions, permissions
etc.), see the next part.

Usage for End User
------------------

1. Define your states.
2. Define your state transitions.
3. Define your approvement meta which contains permissions and groups
authorization for transitions. Approvement order is also given here.

We are now ready to workflowing :)

Whenever an object of MyModel is inserted in your system, all its
workflow initialization is done by ``django-river``.

Usage for Developer
-------------------

Signals:
~~~~~~~~

**``pre_transition``**: it is fired before any transition occured.

+----------------------+-----------------------------------------+
| Args | Description |
+======================+=========================================+
| workflow\_object | Your object on transition |
+----------------------+-----------------------------------------+
| field | Field which you registered object for |
+----------------------+-----------------------------------------+
| source\_state | Transition source state object |
+----------------------+-----------------------------------------+
| destination\_state | Transition destination state object |
+----------------------+-----------------------------------------+
| appovement | Approvement object |
+----------------------+-----------------------------------------+

**``post_transition``**: it is fired before any transition occured.

+----------------------+-----------------------------------------+
| Args | Description |
+======================+=========================================+
| workflow\_object | Your object on transition |
+----------------------+-----------------------------------------+
| field | Field which you registered object for |
+----------------------+-----------------------------------------+
| source\_state | Transition source state object |
+----------------------+-----------------------------------------+
| destination\_state | Transition destination state object |
+----------------------+-----------------------------------------+
| appovement | Approvement object |
+----------------------+-----------------------------------------+

**``pre_approved``**: it is fired before any approvement occured.
Transition does not have to be occured.

+--------------------+-----------------------------------------+
| Args | Description |
+====================+=========================================+
| workflow\_object | Your object approved |
+--------------------+-----------------------------------------+
| field | Field which you registered object for |
+--------------------+-----------------------------------------+
| appovement | Approvement object |
+--------------------+-----------------------------------------+
| track | Approvement track object |
+--------------------+-----------------------------------------+

**``post_approved``**: it is fired before any approvement occured.
Transition does not have to be occured.

+--------------------+-----------------------------------------+
| Args | Description |
+====================+=========================================+
| workflow\_object | Your object approved |
+--------------------+-----------------------------------------+
| field | Field which you registered object for |
+--------------------+-----------------------------------------+
| appovement | Approvement object |
+--------------------+-----------------------------------------+
| track | Approvement track object |
+--------------------+-----------------------------------------+

**``pre_final``**: it is fired before any workflow is completed.

+--------------------+-----------------------------------------+
| Args | Description |
+====================+=========================================+
| workflow\_object | Your object on final |
+--------------------+-----------------------------------------+
| field | Field which you registered object for |
+--------------------+-----------------------------------------+

**``post_final``**: it is fired before any workflow is completed.

+--------------------+-----------------------------------------+
| Args | Description |
+====================+=========================================+
| workflow\_object | Your object on final |
+--------------------+-----------------------------------------+
| field | Field which you registered object for |
+--------------------+-----------------------------------------+

Handlers:
~~~~~~~~~

Handlers are different from ``django-river`` signals. These are for
spesific object, spesific source\_state, spesific destination\_state
etc. It is fired when the condition is matched.

####\ ``PreCompletedHandler``:
------------------------------

Before an object is on final state, if the condition is match; means
object is suitable, it is fired;

.. code:: python

from river.handlers.completed import PreCompletedHandler

def handler(my_object,field,*args,**kwargs):
do_something_with(object,field)

PreCompletedHandler.register(handler,my_object,'my_state_field')

**``register`` method parameter**

+--------------------+-----------------------------------------+------------+
| Args | Description | |
+====================+=========================================+============+
| workflow\_object | Your object | Required |
+--------------------+-----------------------------------------+------------+
| field | Field which you registered object for | Required |
+--------------------+-----------------------------------------+------------+

####\ ``PostCompletedHandler``:
-------------------------------

After an object is on final state, if the condition is match; means
object is suitable, it is fired;

.. code:: python

from river.handlers.completed import PostCompletedHandler

def handler(my_object,field,*args,**kwargs):
do_something_with(object,field)

PostCompletedHandler.register(handler,my_object,'my_state_field')

**``register`` method parameter**

+--------------------+-----------------------------------------+------------+
| Args | Description | |
+====================+=========================================+============+
| workflow\_object | Your object | Required |
+--------------------+-----------------------------------------+------------+
| field | Field which you registered object for | Required |
+--------------------+-----------------------------------------+------------+

####\ ``PreTransitionHandler``:
-------------------------------

Before any transition occurred, if the condition is match; means object,
source\_state,destination state are suitable, it is fired;

.. code:: python

from river.handlers.transition import PreTransitionHandler

def handler(my_object,field,*args,**kwargs):
do_something_with(object,field)

PreTransitionHandler.register(handler,my_object,'my_state_field')

**``register`` method parameter**

+---------------------+-----------------------------------------+------------+
| Args | Description | |
+=====================+=========================================+============+
| workflow\_object | Your object | Required |
+---------------------+-----------------------------------------+------------+
| field | Field which you registered object for | Required |
+---------------------+-----------------------------------------+------------+
| source\_state | Source state of the tranition | Optional |
+---------------------+-----------------------------------------+------------+
| desination\_satte | Destinatio state of the tranition | Optional |
+---------------------+-----------------------------------------+------------+

####\ ``PostTransitionHandler``:
--------------------------------

After any transition occurred, if the condition is match; means object,
source\_state,destination state are suitable, it is fired;

.. code:: python

from river.handlers.transition import PostTransitionHandler

def handler(my_object,field,*args,**kwargs):
do_something_with(object,field)

PostTransitionHandler.register(handler,my_object,'my_state_field')

**``register`` method parameter**

+---------------------+-----------------------------------------+------------+
| Args | Description | |
+=====================+=========================================+============+
| workflow\_object | Your object | Required |
+---------------------+-----------------------------------------+------------+
| field | Field which you registered object for | Required |
+---------------------+-----------------------------------------+------------+
| source\_state | Source state of the tranition | Optional |
+---------------------+-----------------------------------------+------------+
| desination\_satte | Destinatio state of the tranition | Optional |
+---------------------+-----------------------------------------+------------+

Models:
-------

States:
^^^^^^^

Indicates states in your state machine.

Transitions:
^^^^^^^^^^^^

These are transition between your states. **There must be only one
initial state** which is in a transition as destination state but no
source state to make ``django-river`` find it on object creation.

Approvement Meta:
^^^^^^^^^^^^^^^^^

These are approvement meta of transitions that describes which user
permission or user group will be allowed to approve the transition.
These are kind of template for approvements will be created for each
object. An order can also be given here for the transition. This means,
If you want to order approvement for a transition, you can define it.
Assume **s1** and **s2** are our states and there is a transition
defined between them and we have two approvement meta on this
transition. They shall be for\ **permission1** and **permission2**. If
you want object is on approval first **permission1** and after it is
approved by permission1, then it is on approval the second permission
which is **permission2**, you can do it with ``djang-river`` by defining
order in this model.

Approvement
^^^^^^^^^^^

There are state machines paths which is needed to be approved for every
particular object. Approvements are generated on your model object
creation by using ``approvement meta``. This is whole path for the
created object. Do not add or edit this model data unless you don't need
specific objects editing like skiping, overriding permissions and
groups.

.. |Build Status| image:: https://travis-ci.org/javrasya/django-river.svg
:target: https://travis-ci.org/javrasya/django-river
.. |Coverage Status| image:: https://coveralls.io/repos/javrasya/django-river/badge.svg?branch=master&service=github
:target: https://coveralls.io/github/javrasya/django-river?branch=master
.. |Documentation Status| image:: https://readthedocs.org/projects/django-river/badge/?version=latest
:target: https://readthedocs.org/projects/django-river/?badge=latest

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