django-pluggableappsettings 1.1.5

A convenience class for providing default values for a django app setting.

|PyPI version| |Build Status| |Coverage Status| |Downloads| |Supported
Python versions| |Supported Python versions| |License| |Codacy Badge|
|Requirements Status|\ |Requirements Status|

django-pluggableappsettings
===========================

This app provides a baseclass to easily realize AppSettings for any
django project. The advantage of using an AppSettings class lies in the
possibility for the programmer to assign default values for settings if
the setting is not present in the main settings.py

Requirements:
-------------

- Django >= 1.6

Quick start
-----------

1. Install django-pluggableappsettings

- From the pip repository:
``pip install django-pluggableappsettings``
- or directly from github:
\`\ ``pip install git+git://github.com/NB-Dev/django-pluggableappsettings.git``

2. Create your AppSettings class in any of your project's files. E.g. in
'app\_settings.py'.

3. Define your settings by setting the class attributes as one of the
provided settings types

::

from django_pluggableappsettings import AppSettings, Setting

class MyAppSettings(AppSettings):
MY_SETTING = Setting('DEFAULT_VALUE')

4. Access the setting from anywhere:

::

from app_settings import MyAppSettings
setting = MyAppSettings.MY_SETTING

Provided Setting Types
----------------------

Different setting types are provided with the package:

Setting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The most basic setting that looks up the setting's value from the
``settings.py`` usually the attribute name is used for the detection.
If, however, the ``settings_name`` parameter is given, this name is used
instead for the lookup in the ``settings.py``. It simply returns the
value from the settings.py or, if that is not set, the default value. If
no default value is provided and the setting is not set in your
settings.py, an ``AttributeError`` is thrown. Also a list of aliases can
be passed to allow for multiple names of one setting (e.g. for backwards
compatibility)

CalledOnceSetting(default\_value, setting\_name, aliases, force\_callable=False)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Checks whether the value is callable and calls it once before returning.
Subsequent accesses to this setting return the cached return value of
the first call. If ``force_callable`` is ``True``, the setting throws a
``ValueError`` if the value of the setting is not callable.

CalledEachTimeSetting(default\_value, setting\_name, aliases, force\_callable=False)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Checks whether the value is callable. If so, the callable is called each
time when the setting is accessed. If ``force_callable`` is ``True``,
the setting throws a ``ValueError`` if the value of the setting is not
callable.

ClassSetting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Behaves as a Setting but accepts only Classes or dotted paths to classes
as values. If the value is a dotted path, the path is translated to a
class before returning, so the returned value is always a class.

IntSetting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Accepts only values that are of type int or can be casted to type int

FloatSetting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Accepts only values of type float of values that can be casted to type
float

StringSetting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Accepts only strings as value

IterableSetting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Makes sure that the value is an iterable

TypedSetting(default\_value, setting\_name, aliases)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A class that checks whether the given value is of a certain type and
optionally allows casting the value to that type. Used as a base class
for all type checking classes and can be easily subclassed to allow
checking of various value types.

To create your own type checking setting simply subclass this type and
set the class attributes ``_setting_type`` and ``_cast_value`` according
to your needs. The ``_setting_type`` attribute specifies the desired
type while the ``_cast_value`` attribute specifies whether the value
should be casted to the ``_setting_type``. A ``_cast_value`` of ``True``
essentially results in a call of ``value = _setting_type(value)``.

E.g. The ``IntSetting`` is defined as follows:

::

class IntSetting(TypedSetting):
"""
An integer setting
"""
_setting_type = int
_cast_value = True

If you need more elaborate casting functions, you can overwrite the
``cast_value(self, value)`` function of your type which should return
the casted value.

Accessing Values
----------------

You can access any setting by simply importing your AppSettings class
and accessing the corresponding attribute.

Tests with AppSettings
----------------------

The package provides a convenient ``override_appsettings`` decorator /
context manager to allow for the temporary override of AppSettings
values. It is used just like Django's ``override_settings`` decorator
but with an extra argument: The AppSettings-Class that is to be altered
has to be passed in as first argument. Following should be keyword,
value arguments where the keyword is the name of the setting to be
overridden and the value is the desired return value.

E.g.:

::

from django_pluggableappsettings.test.utils import override_appsettings
from myapp.appsettings import MyAppSettings

class SomeTestCase(TestCase):
@override_appsettings(MyAppSettings, SETTING='new_value')
def test_decorated(self):
MyAppSettings.SETTING # This returns 'new_value'

def test_context_manager(self):
with override_appsettings(MyAppSettings, SETTING='new_value'):
MyAppSettings.SETTING # This returns 'new_value'

Running the tests
-----------------

The included tests can be run standalone by running the
``tests/runtests.py`` script. You need to have Django and mock installed
for them to run. If you also want to run coverage, you need to install
it before running the tests

CHANGELOG
---------

v 1.1.5 (2017-05-19)
~~~~~~~~~~~~~~~~~~~~

- Version bump as I forgot to convert the readme. Added a publish.py to
automate publishing in future.

v. 1.1.4 (2017-05-19)
~~~~~~~~~~~~~~~~~~~~~

- Adding tests for Django 1.10 and 1.11.

v. 1.1.3 (2016-01-27)
~~~~~~~~~~~~~~~~~~~~~

- Adding the possibility to look for a settings value under a different
name in the ``settings.py`` by usage of the ``settings_name``
parameter
- Fixing a bug that caused all ``AppSettings`` instances to share the
same cache of loaded settings. This could cause the settings to be
overridden by other settings

v. 1.1.2 (2016-01-15)
~~~~~~~~~~~~~~~~~~~~~

- Adding an ``override_appsettings`` decorator / context manager to
allow the overriding of AppSettings values in test
- Added the possibility to retrieve non-\ ``Setting`` attributes from
the ``AppSettings`` class to allow for custom attributes or custom
functions.

v.1.1.1
~~~~~~~

- I screwed up with pypi and need to bump the version number - Sorry

v.1.1.0
~~~~~~~

- Changing structure of Setting class to being able to add repeatedly
called functions as setting.

**Warning**: This breaks compatibility of custom settings classes. To
fix this, simply rename the ``get`` method of your custom classes to
``_get`` - Added a ``CalledEachTimeSetting`` that takes a callable that
is called each time the setting's value is accessed - Renamed the
``CallableSetting`` to ``CalledOnceSetting`` to make the differentiation
to the ``CalledEachTimeSetting`` clearer. The old name will stay as an
alias for now. - The ``CalledEachTimeSetting`` and the
``CalledOnceSetting`` take an ``force_callable`` kwarg to set whether
the value of the setting is enforced to be callable or not.

v.1.0.0
~~~~~~~

- Releasing first stable version

v.0.2.3
~~~~~~~

- Added 'aliases' parameter to ``Setting`` to allow multiple names for
one setting (e.g. for backwards compatibility)

v.0.2.2
~~~~~~~

- Extended code to also work with Python 3

v.0.2.1
~~~~~~~

- Added ``TypedSetting`` Setting type which allows for the setting to
be typechecked
- Added ``IntSetting``, ``FloatSetting``, ``StringSetting`` and
``ÌterableSetting``` as subtypes of ```TypedSetting``

v.0.2.0
~~~~~~~

- Added the changelog
- Redesign of settings to allow different types of settings that can
now also provide type checking.
- Settings are now explicitly defined and no ``_DEFAULT_`` prefix is
needed anymore
- Also no staticmethod decorator is needed anymore

ToDos:
------

- Allow the easy definition of multiple allowed setting types so that a
setting could e.g. accept either string or an Integer
- Allow the chaining of callables with typed settings to check that the
return value of a callable is of the correct type

Maintainers
-----------

This Project is maintaned by `Northbridge Development Konrad & Schneider
GbR <http://www.northbridge-development.de>`__ Softwareentwicklung

.. |PyPI version| image:: https://img.shields.io/pypi/v/django-pluggableappsettings.svg
:target: http://badge.fury.io/py/django-pluggableappsettings
.. |Build Status| image:: https://travis-ci.org/NB-Dev/django-pluggableappsettings.svg?branch=master
:target: https://travis-ci.org/NB-Dev/django-pluggableappsettings
.. |Coverage Status| image:: https://coveralls.io/repos/NB-Dev/django-pluggableappsettings/badge.svg?branch=master&service=github
:target: https://coveralls.io/github/NB-Dev/django-pluggableappsettings?branch=master
.. |Downloads| image:: https://img.shields.io/pypi/dm/django-pluggableappsettings.svg
:target: https://pypi.python.org/pypi/django-pluggableappsettings/
.. |Supported Python versions| image:: https://img.shields.io/pypi/pyversions/django-pluggableappsettings.svg
:target: https://pypi.python.org/pypi/django-pluggableappsettings/
.. |Supported Python versions| image:: https://img.shields.io/badge/Django-1.6%2C%201.7%2C%201.8%2C%201.9%2C%201.10%2C%201.11-brightgreen.svg
:target: https://pypi.python.org/pypi/django-pluggableappsettings/
.. |License| image:: https://img.shields.io/pypi/l/django-pluggableappsettings.svg
:target: https://pypi.python.org/pypi/django-pluggableappsettings/
.. |Codacy Badge| image:: https://api.codacy.com/project/badge/grade/79d4fa62bb77478392d9535067d010c6
:target: https://www.codacy.com/app/tim_11/django-pluggableappsettings
.. |Requirements Status| image:: https://requires.io/github/NB-Dev/django-pluggableappsettings/requirements.svg?branch=master
:target: https://requires.io/github/NB-Dev/django-pluggableappsettings/requirements/?branch=master