Metadata-Version: 2.1
Name: django-fsa
Version: 2.7.1
Summary: Django friendly finite state machine support, forked from django-fsm
Home-page: http://github.com/mdziwny/django-fsm
Author: Antoine Fontaine
Author-email: antoine.fontaine@gmail.com
License: MIT License
Description: Django friendly finite state machine support
        ============================================
        
        This is a friendly fork which aims to ensure that the tests are passing with
        the new python and django versions, the original django-fsm was written by
        Mikhail Podgurskiy (kmmbvnr@gmail.com), https://github.com/viewflow/django-fsm
        
        |Build Status|
        
        django-fsm adds simple declarative states management for django models.
        
        If you need parallel task execution, view and background task code reuse
        over different flows - check my new project django-viewflow:
        
        https://github.com/viewflow/viewflow
        
        
        Instead of adding some state field to a django model, and managing its
        values by hand, you could use FSMState field and mark model methods with
        the ``transition`` decorator. Your method could contain the side-effects
        of the state change.
        
        Nice introduction is available here:
        https://gist.github.com/Nagyman/9502133
        
        You may also take a look at django-fsm-admin project containing a mixin
        and template tags to integrate django-fsm state transitions into the
        django admin.
        
        https://github.com/gadventures/django-fsm-admin
        
        Transition logging support could be achived with help of django-fsm-log
        package
        
        https://github.com/gizmag/django-fsm-log
        
        FSM really helps to structure the code, especially when a new developer
        comes to the project. FSM is most effective when you use it for some
        sequential steps.
        
        
        Installation
        ------------
        
        .. code:: bash
        
            $ pip install django-fsm
        
        Or, for the latest git version
        
        .. code:: bash
        
            $ pip install -e git://github.com/kmmbvnr/django-fsm.git#egg=django-fsm
        
        The library has full Python 3 support
        
        Usage
        -----
        
        Add FSMState field to your model
        
        .. code:: python
        
            from django_fsm import FSMField, transition
        
            class BlogPost(models.Model):
                state = FSMField(default='new')
        
        Use the ``transition`` decorator to annotate model methods
        
        .. code:: python
        
            @transition(field=state, source='new', target='published')
            def publish(self):
                """
                This function may contain side-effects,
                like updating caches, notifying users, etc.
                The return value will be discarded.
                """
        
        ``source`` parameter accepts a list of states, or an individual state.
        You can use ``*`` for source, to allow switching to ``target`` from any
        state. The ``field`` parameter accepts both a string attribute name or an
        actual field instance.
        
        If calling publish() succeeds without raising an exception, the state
        field will be changed, but not written to the database.
        
        .. code:: python
        
            from django_fsm import can_proceed
        
            def publish_view(request, post_id):
                post = get_object__or_404(BlogPost, pk=post_id)
                if not can_proceed(post.publish):
                    raise PermissionDenied
        
                post.publish()
                post.save()
                return redirect('/')
        
        If some conditions are required to be met before changing the state, use
        the ``conditions`` argument to ``transition``. ``conditions`` must be a
        list of functions taking one argument, the model instance. The function
        must return either ``True`` or ``False`` or a value that evaluates to
        ``True`` or ``False``. If all functions return ``True``, all conditions
        are considered to be met and the transition is allowed to happen. If one
        of the functions returns ``False``, the transition will not happen.
        These functions should not have any side effects.
        
        You can use ordinary functions
        
        .. code:: python
        
            def can_publish(instance):
                # No publishing after 17 hours
                if datetime.datetime.now().hour > 17:
                    return False
                return True
        
        Or model methods
        
        .. code:: python
        
            def can_destroy(self):
                return self.is_under_investigation()
        
        Use the conditions like this:
        
        .. code:: python
        
            @transition(field=state, source='new', target='published', conditions=[can_publish])
            def publish(self):
                """
                Side effects galore
                """
        
            @transition(field=state, source='*', target='destroyed', conditions=[can_destroy])
            def destroy(self):
                """
                Side effects galore
                """
        
        You could instantiate a field with protected=True option, that prevents
        direct state field modification.
        
        .. code:: python
        
            class BlogPost(models.Model):
                state = FSMField(default='new', protected=True)
        
            model = BlogPost()
            model.state = 'invalid' # Raises AttributeError
        
        Note that calling
        `refresh_from_db <https://docs.djangoproject.com/en/1.8/ref/models/instances/#django.db.models.Model.refresh_from_db>`_
        on a model instance with a protected FSMField will cause an exception.
        
        `target`
        ~~~~~~~~
        
        `target` state parameter could point to a specific state or `django_fsm.State` implementation
        
        .. code:: python
                  
            from django_fsm import FSMField, transition, RETURN_VALUE, GET_STATE
            @transition(field=state,
                        source='*',
                        target=RETURN_VALUE('for_moderators', 'published'))
            def publish(self, is_public=False):
                return 'for_moderators' if is_public else 'published'
        
            @transition(
                field=state,
                source='for_moderators',
                target=GET_STATE(
                    lambda self, allowed: 'published' if allowed else 'rejected',
                    states=['published', 'rejected']))
            def moderate(self, allowed):
                self.allowed=allowed
        
        
        ``custom`` properties
        ~~~~~~~~~~~~~~~~~~~~~
        
        Custom properties can be added by providing a dictionary to the
        ``custom`` keyword on the ``transition`` decorator.
        
        .. code:: python
        
            @transition(field=state,
                        source='*',
                        target='onhold',
                        custom=dict(verbose='Hold for legal reasons'))
            def legal_hold(self):
                """
                Side effects galore
                """
        
        ``on_error`` state
        ~~~~~~~~~~~~~~~~~~
        
        In case of transition method would raise exception, you can provide
        specific target state
        
        .. code:: python
        
            @transition(field=state, source='new', target='published', on_error='failed')
            def publish(self):
               """
               Some exception could happen here
               """
        
        ``state_choices``
        ~~~~~~~~~~~~~~~~~
        
        Instead of passing two elements list ``choices`` you could use three
        elements ``state_choices``, the last element states for string reference
        to model proxy class.
        
        Base class instance would be dynamically changed to corresponding Proxy
        class instance, depending on the state. Even for queryset results, you
        will get Proxy class instances, even if QuerySet executed on base class.
        
        Check the `test
        case <https://github.com/kmmbvnr/django-fsm/blob/master/tests/testapp/tests/test_state_transitions.py>`__
        for example usage. Or read about `implementation
        internals <http://schinckel.net/2013/06/13/django-proxy-model-state-machine/>`__
        
        Permissions
        ~~~~~~~~~~~
        
        It is common to have permissions attached to each model transition.
        ``django-fsm`` handles this with ``permission`` keyword on the
        ``transition`` decorator. ``permission`` accepts a permission string, or
        callable that expects ``instance`` and ``user`` arguments and returns
        True if user can perform the transition.
        
        .. code:: python
        
            @transition(field=state, source='*', target='publish',
                        permission=lambda instance, user: not user.has_perm('myapp.can_make_mistakes'))
            def publish(self):
                pass
        
            @transition(field=state, source='*', target='publish',
                        permission='myapp.can_remove_post')
            def remove(self):
                pass
        
        You can check permission with ``has_transition_permission`` method
        
        .. code:: python
        
            from django_fsm import has_transition_perm
            def publish_view(request, post_id):
                post = get_object_or_404(BlogPost, pk=post_id)
                if not has_transition_perm(post.publish, request.user):
                    raise PermissionDenied
        
                post.publish()
                post.save()
                return redirect('/')
        
        Model methods
        ~~~~~~~~~~~~~
        
        ``get_all_FIELD_transitions`` Enumerates all declared transitions
        
        ``get_available_FIELD_transitions`` Returns all transitions data
        available in current state
        
        ``get_available_user_FIELD_transitions`` Enumerates all transitions data
        available in current state for provided user
        
        Foreign Key constraints support
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        If you store the states in the db table you could use FSMKeyField to
        ensure Foreign Key database integrity.
        
        In your model :
        
        .. code:: python
        
            class DbState(models.Model):
                id = models.CharField(primary_key=True, max_length=50)
                label = models.CharField(max_length=255)
        
                def __unicode__(self):
                    return self.label
        
        
            class BlogPost(models.Model):
                state = FSMKeyField(DbState, default='new')
        
                @transition(field=state, source='new', target='published')
                def publish(self):
                    pass
        
        In your fixtures/initial\_data.json :
        
        .. code:: json
        
            [
                {
                    "pk": "new",
                    "model": "myapp.dbstate",
                    "fields": {
                        "label": "_NEW_"
                    }
                },
                {
                    "pk": "published",
                    "model": "myapp.dbstate",
                    "fields": {
                        "label": "_PUBLISHED_"
                    }
                }
            ]
        
        Note : source and target parameters in @transition decorator use pk
        values of DBState model as names, even if field "real" name is used,
        without \_id postfix, as field parameter.
        
        Integer Field support
        ~~~~~~~~~~~~~~~~~~~~~
        
        You can also use ``FSMIntegerField``. This is handy when you want to use
        enum style constants.
        
        .. code:: python
        
            class BlogPostStateEnum(object):
                NEW = 10
                PUBLISHED = 20
                HIDDEN = 30
        
            class BlogPostWithIntegerField(models.Model):
                state = FSMIntegerField(default=BlogPostStateEnum.NEW)
        
                @transition(field=state, source=BlogPostStateEnum.NEW, target=BlogPostStateEnum.PUBLISHED)
                def publish(self):
                    pass
        
        Signals
        ~~~~~~~
        
        ``django_fsm.signals.pre_transition`` and
        ``django_fsm.signals.post_transition`` are called before and after
        allowed transition. No signals on invalid transition are called.
        
        Arguments sent with these signals:
        
        **sender** The model class.
        
        **instance** The actual instance being proceed
        
        **name** Transition name
        
        **source** Source model state
        
        **target** Target model state
        
        Optimistic locking
        ------------------
        
        ``django-fsm`` provides optimistic locking mixin, to avoid concurrent
        model state changes. If model state was changed in database
        ``django_fsm.ConcurrentTransition`` exception would be raised on
        model.save()
        
        .. code:: python
        
            from django_fsm import FSMField, ConcurrentTransitionMixin
        
            class BlogPost(ConcurrentTransitionMixin, models.Model):
                state = FSMField(default='new')
        
        For guaranteed protection against race conditions caused by concurrently
        executed transitions, make sure:
        
        - Your transitions do not have any side effects except for changes in the database,
        - You always run the save() method on the object within ``django.db.transaction.atomic()`` block.
        
        Following these recommendations, you can rely on
        ConcurrentTransitionMixin to cause a rollback of all the changes that
        have been executed in an inconsistent (out of sync) state, thus
        practically negating their effect.
        
        Drawing transitions
        -------------------
        
        Renders a graphical overview of your models states transitions
        
        You need ``pip install graphviz>=0.4`` library and add ``django_fsm`` to
        your ``INSTALLED_APPS``:
        
        .. code:: python
        
            INSTALLED_APPS = (
                ...
                'django_fsm',
                ...
            )
        
        .. code:: bash
        
            # Create a dot file
            $ ./manage.py graph_transitions > transitions.dot
        
            # Create a PNG image file only for specific model
            $ ./manage.py graph_transitions -o blog_transitions.png myapp.Blog
        
        Changelog
        ---------
        
        django-fsm 2.6.0 2017-06-08
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        - Fix django 1.11 compatibility
        - Fix TypeError in `graph_transitions` command when using django's lazy translations
        
        
        django-fsm 2.7.0 2019-02-14
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        - Add tests for Python 3.7, remove tests for deprecated Python versions (2.6 and 3.3)
        - Add tests for Django 2.0 and 2.1, remove tests for deprecated Django versions (1.6, 1.7, 1.8 and 1.10)
        - Fix the tests on TravisCI
        
        django-fsm 2.7.1 2019-03-04
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        - Delivery on Pypi
        
        
        .. |Build Status| image:: https://travis-ci.org/MDziwny/django-fsm.svg?branch=develop
           :target: https://travis-ci.org/MDziwny/django-fsm.svg
        
Keywords: django
Platform: any
Classifier: Development Status :: 5 - Production/Stable
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Framework :: Django
Classifier: Framework :: Django :: 1.11
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Framework :: Django
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Description-Content-Type: text/x-rst
