django-concurrency 2.0

Optimistic lock implementation for Django. Prevents users from doing concurrent editing.

==================
Django Concurrency
==================


.. image:: https://badge.fury.io/py/django-concurrency.svg
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:alt: PyPI package


django-concurrency is an optimistic lock [1]_ implementation for Django.

Supported Django versions: 1.8.x, 1.9.x, 1.10.x., 1.11.x, 2.x

It prevents users from doing concurrent editing in Django both from UI and from a
django command.


How it works
------------
sample code::

from django.db import models
from concurrency.fields import IntegerVersionField

class ConcurrentModel( models.Model ):
version = IntegerVersionField( )
name = models.CharField(max_length=100)

Now if you try::

a = ConcurrentModel.objects.get(pk=1)
a.name = '1'

b = ConcurrentModel.objects.get(pk=1)
b.name = '2'

a.save()
b.save()

you will get a ``RecordModifiedError`` on ``b.save()``


Similar projects
----------------

Other projects that handle concurrent editing are `django-optimistic-lock`_ and `django-locking`_ anyway concurrency is "a batteries included" optimistic lock management system, here some features not available elsewhere:

* can be applied to any model; not only your code (ie. django.contrib.auth.Group)
* handle `list-editable`_ ChangeList. (handle `#11313 <https://code.djangoproject.com/ticket/11313>`_)
* manage concurrency conflicts in admin's actions
* can intercept changes performend out of the django app (ie using pgAdmin, phpMyAdmin, Toads) (using `TriggerVersionField`_)
* can be disabled if needed (see `disable_concurrency`_)
* `ConditionalVersionField`_ to handle complex business rules


Links
~~~~~

+--------------------+----------------+--------------+------------------------+
| Stable | |master-build| | |master-cov| | |
+--------------------+----------------+--------------+------------------------+
| Development | |dev-build| | |dev-cov| | |
+--------------------+----------------+--------------+------------------------+
| Project home page: |https://github.com/saxix/django-concurrency |
+--------------------+---------------+----------------------------------------+
| Issue tracker: |https://github.com/saxix/django-concurrency/issues?sort |
+--------------------+---------------+----------------------------------------+
| Download: |http://pypi.python.org/pypi/django-concurrency/ |
+--------------------+---------------+----------------------------------------+
| Documentation: |https://django-concurrency.readthedocs.org/en/latest/ |
+--------------------+---------------+--------------+-------------------------+

.. |master-build| image:: https://secure.travis-ci.org/saxix/django-concurrency.svg?branch=master
:target: http://travis-ci.org/saxix/django-concurrency/

.. |master-cov| image:: https://codecov.io/gh/saxix/django-concurrency/branch/master/graph/badge.svg
:target: https://codecov.io/gh/saxix/django-concurrency

.. |master-doc| image:: https://readthedocs.org/projects/django-concurrency/badge/?version=stable
:target: http://django-concurrency.readthedocs.io/en/stable/

.. |dev-build| image:: https://secure.travis-ci.org/saxix/django-concurrency.svg?branch=develop
:target: http://travis-ci.org/saxix/django-concurrency/

.. |dev-cov| image:: https://codecov.io/gh/saxix/django-concurrency/branch/develop/graph/badge.svg
:target: https://codecov.io/gh/saxix/django-concurrency

.. |dev-doc| image:: https://readthedocs.org/projects/django-concurrency/badge/?version=stable
:target: http://django-concurrency.readthedocs.io/en/stable/



.. |wheel| image:: https://img.shields.io/pypi/wheel/django-concurrency.svg

_list-editable: https://django-concurrency.readthedocs.org/en/latest/admin.html#list-editable


.. _django-locking: https://github.com/stdbrouw/django-locking

.. _django-optimistic-lock: https://github.com/gavinwahl/django-optimistic-lock

.. _TriggerVersionField: https://django-concurrency.readthedocs.org/en/latest/fields.html#triggerversionfield

.. _ConditionalVersionField: https://django-concurrency.readthedocs.org/en/latest/fields.html#conditionalversionfield

.. _disable_concurrency: https://django-concurrency.readthedocs.org/en/latest/api.html?#disable-concurrency



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