django-app-settings 0.3.0

Installation

pip install django-app-settings

Documentation

On ReadTheDocs

Development

To run all the tests: tox. See CONTRIBUTING.

Quick usage

# Define your settings class
import appsettings


class MySettings(appsettings.AppSettings):
    boolean_setting = appsettings.BooleanSetting(default=False)
    required_setting = appsettings.StringSetting(required=True)
    named_setting = appsettings.IntegerSetting(name='integer_setting')
    prefixed_setting = appsettings.ListSetting(prefix='my_app_')

    class Meta:
        setting_prefix = 'app_'


# Related settings in settings.py
APP_INTEGER_SETTING = -24
MY_APP_PREFIXED_SETTING = []


# Instantiate your class wherever you need to
appconf = MySettings()
assert appconf.boolean_setting is False  # True (default value)
assert appconf.required_setting == 'hello'  # raises AttributeError
assert appconf.named_setting < 0  # True
assert appconf.prefixed_setting  # False (empty list)


# Values are cached to avoid perf issues
with override_settings(APP_REQUIRED_SETTING='hello',
                       APP_INTEGER_SETTING=0):
    # ...but cache is cleaned on Django's setting_changed signal
    assert appconf.required_setting == 'hello'  # True
    assert appconf.named_setting < 0  # False


# You can still access settings through the class itself (values not cached)
print(MySettings.boolean_setting.get_value())  # explicit call
print(MySettings.boolean_setting.value)  # with property


# Run type checking and required presence on all settings at once
MySettings.check()  # raises Django's ImproperlyConfigured (missing required_setting)
# MySettings.check() is best called in django.apps.AppConfig's ready method

You can easily create your own Setting classes for more complex settings.

import re
import appsettings


class RegexSetting(appsettings.Setting):
    def checker(self, name, value):
        re_type = type(re.compile(r'^$'))
        if not isinstance(value, (re_type, str)):
            # raise whatever exception
            raise ValueError('%s must be a a string or a compiled regex '
                             '(use re.compile)' % name)

    def transform(self, value):
        # ensure it always returns a compiled regex
        if isinstance(value, str):
            value = re.compile(value)
        return value

Please check the documentation to see even more advanced usage.

License

Software licensed under ISC license.

0.3.0 (2017-11-30)

Going from alpha to beta status. Logic has been reworked.

• An instance of a subclass of AppSettings will now dynamically get settings values from project settings, and cache them. This allows to use the instance the same way in code and tests, without performance loss. See issue #16.

• Cache is invalidated when Django sends a setting_changed signal (i.e. when using TestCase or override_settings). See issue #16.

• Setting main class now accepts callable as default value, and two new parameters to keep control on its behavior: call_default, which tells if the default value should be called (if callable) or not, and transform_default, which tells if the default value should be transformed as well by the transform method. See issue #17.

• Settings type checkers now have custom parameters like max_length, empty or key_type, that can be passed directly through the settings classes as keyword arguments. Check the documentation for more information.

• Settings classes have been rewritten more explicitly, using class inheritance instead of hard-to-debug generators. Composed types like float lists or boolean sets have been removed in favor of more flexible list, set and tuple types which now accept an optional item_type parameter.

• ImportedObjectSetting has been renamed ObjectSetting, and now supports object paths down to arbitrary level of nesting. Before, it only supported object paths down to classes or functions, now you can for example give it the path to a constant in a class within a class, itself contained in a module within a package. It will work as long a the deepest module is importable through importlib.import_module and each object down to the last is obtainable through getattr method.

Many thanks to ziima for having shared good ideas and thoughts!

0.2.5 (2017-06-02)

• Add six dependency (now required).

• Rename Int settings to Integer, and Bool ones to Boolean.

• Remove metaclass generated getters and checkers.

0.2.4 (2017-05-02)

• Settings are not checked when they default to the provided default value.

• Settings classes received better default values corresponding to their types.

0.2.3 (2017-05-02)

• Add full_name property to Setting class.

• Add required parameter to Setting class (default False).

0.2.2 (2017-04-17)

• Import settings classes in main module to simplify imports.

0.2.1 (2017-04-17)

• Add PositiveInt and PositiveFloat settings.

• Add support for Django 1.11.

• Implement basic settings classes.

0.2.0 (2017-04-17)

• Implement basic Setting class.

• Pin dependencies.

• Change distribution name to app-settings.

0.1.0 (2017-03-23)

• Alpha release on PyPI.