Django-pgtrigger

Feature

- Multiple database support [Wes Kendall, b09ba73]

Supports multiple-database functionality in all core functions and management commands.
By default, all functions and management commands operate over all databases in a
multi-database setup. This behavior can be overridden with the ``--database`` flag.

When calling ``manage.py migrate``, only the database being migrated will have
relevant triggers installed. This fits into how Django supports multi-database
migrations.

Bug

- Fixed possibility of duplicate trigger function names [Wes Kendall, b9b1552]

django-pgtrigger previously enforced that no model could have the
same trigger name, however, the trigger function being called
is a globally unique name that needs to be checked.

django-pgtrigger now adds a hash to the trigger function and
installed trigger name based on the registered model. This
prevents a global collision for trigger functions.

Note that this change will make it appear like no triggers
are installed. Upgrading to this version will involve dropping
and re-creating existing triggers.

Api-Break

- Trigger management commands [Wes Kendall, be26d33]

Adds the ability to manage triggers by name
with the ``manage.py pgtrigger`` management command. This
change includes the following subcommands:

- ``manage.py pgtrigger ls``: List all triggers, their installation
status, and whether they are enabled or disabled.
- ``manage.py pgtrigger install``: Install triggers.
- ``manage.py pgtrigger uninstall``: Uninstall triggers.
- ``manage.py pgtrigger enable``: Enable triggers.
- ``manage.py pgtrigger disable``: Disable triggers.
- ``manage.py pgtrigger prune``: Prune triggers.

Because of this change, names are now enforced for every trigger
and must be unique for every model. Users that wish to
upgrade to this version must now supply a ``name`` keyword
argument to their triggers.

Docs were updated with references to the new management commands.

Feature

- Extend the ``pgtrigger.SoftDelete`` trigger to support more field types. [Wes Kendall, 4dd8cf8]

``pgtrigger.SoftDelete`` takes an optional "value" argument to assign to
the soft-deleted attribute upon deletion. This allows for more flexibility
in soft-delete models that might, for example, set a ``CharField`` to
"inactive".
- ``pgtrigger.FSM`` enforces a finite state machine on a field. [Wes Kendall, bd3980e]

The ``pgtrigger.FSM`` trigger allows a user to configure a field and
a set of valid transitions for the field. An error will be raised
if any transitions happen that are not part of the valid transitions
list.

The docs were updated with an example of how to use ``pgtrigger.FSM``.

Trivial

- Added trigger cookbook example for how to track history and model changes. [Wes Kendall, 114a70a]
- Add "versioning" example to trigger cookbook. [Wes Kendall, 842ad5b]
- Added trigger cookbook example of freezing a published model [Wes Kendall, 994e9da]

Feature

- Added ``pgtrigger.ignore`` for dynamically ignoring triggers. [Wes Kendall, b3557bb]

``pgtrigger.ignore`` can be used to ignore triggers per thread of
execution. Docs were updated with examples of how to use
``pgtrigger.ignore`` and how to utilize it to create
"official" interfaces.
- Allow custom naming of triggers [Wes Kendall, 864d653]

Triggers can be given a "name" attribute that is used when generating
the trigger and obtaining it from the registry. This will not only
make trigger management in the future easier, but it will also make
it possible to dynamically ignore specific triggers registered to
models.

Feature

- Added "Referencing" construct for statement-level triggers. [Wes Kendall, 20d958e]

The ``pgtrigger.Referencing`` construct allows one to reference
transition tables in statement-level triggers.
- Added statement-level triggers. [Wes Kendall, c0cc365]

django-pgtrigger now has a "level" construct for specifying
row and statement-level triggers. All triggers default to being
row-level triggers.

Trivial

- Support the "INSTEAD OF" construct for views on SQL triggers. [Wes Kendall, 79f9d54]
- Updated docs and added a quick start section [Wes Kendall, 9ce7b29]