Factor out some common pieces of django.conf.LazySettings. (cf307124) · Commits · Dom Sekotill / django

django/conf/init.py

+7 −28

Original line number	Diff line number	Diff line
		@@ -8,40 +8,19 @@ a list of all possible variables.

		import os
		import time # Needed for Windows

		from django.conf import global_settings
		from django.utils.functional import LazyObject

		ENVIRONMENT_VARIABLE = "DJANGO_SETTINGS_MODULE"

		class LazySettings(object):
		class LazySettings(LazyObject):
		"""
		A lazy proxy for either global Django settings or a custom settings object.
		The user can manually configure settings prior to using them. Otherwise,
		Django uses the settings module pointed to by DJANGO_SETTINGS_MODULE.
		"""
		def __init__(self):
		# _target must be either None or something that supports attribute
		# access (getattr, hasattr, etc).
		self._target = None

		def __getattr__(self, name):
		if self._target is None:
		self._import_settings()
		if name == '__members__':
		# Used to implement dir(obj), for example.
		return self._target.get_all_members()
		return getattr(self._target, name)

		def __setattr__(self, name, value):
		if name == '_target':
		# Assign directly to self.__dict__, because otherwise we'd call
		# __setattr__(), which would be an infinite loop.
		self.__dict__['_target'] = value
		else:
		if self._target is None:
		self._import_settings()
		setattr(self._target, name, value)

		def _import_settings(self):
		def _setup(self):
		"""
		Load the settings module pointed to by the environment variable. This
		is used the first time we need any settings at all, if the user has not
		@@ -56,7 +35,7 @@ class LazySettings(object):
		# problems with Python's interactive help.
		raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE)

		self._target = Settings(settings_module)
		self._wrapped = Settings(settings_module)

		def configure(self, default_settings=global_settings, **options):
		"""
		@@ -69,13 +48,13 @@ class LazySettings(object):
		holder = UserSettingsHolder(default_settings)
		for name, value in options.items():
		setattr(holder, name, value)
		self._target = holder
		self._wrapped = holder

		def configured(self):
		"""
		Returns True if the settings have already been configured.
		"""
		return bool(self._target)
		return bool(self._wrapped)
		configured = property(configured)

		class Settings(object):

django/utils/functional.py

+36 −0

Original line number	Diff line number	Diff line
		@@ -251,3 +251,39 @@ def allow_lazy(func, *resultclasses):
		return func(args, *kwargs)
		return lazy(func, resultclasses)(args, **kwargs)
		return wraps(func)(wrapper)

		class LazyObject(object):
		"""
		A wrapper for another class that can be used to delay instantiation of the
		wrapped class.

		This is useful, for example, if the wrapped class needs to use Django
		settings at creation time: we want to permit it to be imported without
		accessing settings.
		"""
		def __init__(self):
		self._wrapped = None

		def __getattr__(self, name):
		if self._wrapped is None:
		self._setup()
		if name == "__members__":
		# Used to implement dir(obj)
		return self._wrapped.get_all_members()
		return getattr(self._wrapped, name)

		def __setattr__(self, name, value):
		if name == "_wrapped":
		# Assign to __dict__ to avoid infinite __setattr__ loops.
		self.__dict__["_wrapped"] = value
		else:
		if self._wrapped is None:
		self._setup()
		setattr(self._wrapped, name, value)

		def _setup(self):
		"""
		Must be implemented by subclasses to initialise the wrapped object.
		"""
		raise NotImplementedError

tests/regressiontests/comment_tests/tests/app_api_tests.py

+1 −1

Original line number	Diff line number	Diff line
		@@ -41,7 +41,7 @@ class CustomCommentTest(CommentTestCase):
		del settings.INSTALLED_APPS[-1]
		settings.COMMENTS_APP = self.old_comments_app
		if settings.COMMENTS_APP is None:
		delattr(settings._target, 'COMMENTS_APP')
		delattr(settings._wrapped, 'COMMENTS_APP')

		def testGetCommentApp(self):
		from regressiontests.comment_tests import custom_comments