""" Settings and configuration for Django. Values will be read from the module specified by the DJANGO_SETTINGS_MODULE environment variable, and then from django.conf.global_settings; see the global settings file for a list of all possible variables. """ import importlib import os import time import warnings from django.conf import global_settings from django.core.exceptions import ImproperlyConfigured from django.utils.deprecation import RemovedInDjango110Warning from django.utils.functional import LazyObject, empty ENVIRONMENT_VARIABLE = "DJANGO_SETTINGS_MODULE" 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 _setup(self, name=None): """ 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 previously configured the settings manually. """ settings_module = os.environ.get(ENVIRONMENT_VARIABLE) if not settings_module: desc = ("setting %s" % name) if name else "settings" raise ImproperlyConfigured( "Requested %s, but settings are not configured. " "You must either define the environment variable %s " "or call settings.configure() before accessing settings." % (desc, ENVIRONMENT_VARIABLE)) self._wrapped = Settings(settings_module) def __getattr__(self, name): if self._wrapped is empty: self._setup(name) return getattr(self._wrapped, name) def configure(self, default_settings=global_settings, **options): """ Called to manually configure the settings. The 'default_settings' parameter sets where to retrieve any unspecified values from (its argument must support attribute access (__getattr__)). """ if self._wrapped is not empty: raise RuntimeError('Settings already configured.') holder = UserSettingsHolder(default_settings) for name, value in options.items(): setattr(holder, name, value) self._wrapped = holder @property def configured(self): """ Returns True if the settings have already been configured. """ return self._wrapped is not empty class BaseSettings(object): """ Common logic for settings whether set by a module or by the user. """ def __setattr__(self, name, value): if name in ("MEDIA_URL", "STATIC_URL") and value and not value.endswith('/'): raise ImproperlyConfigured("If set, %s must end with a slash" % name) object.__setattr__(self, name, value) class Settings(BaseSettings): def __init__(self, settings_module): # update this dict from global settings (but only for ALL_CAPS settings) for setting in dir(global_settings): if setting.isupper(): setattr(self, setting, getattr(global_settings, setting)) # store the settings module in case someone later cares self.SETTINGS_MODULE = settings_module mod = importlib.import_module(self.SETTINGS_MODULE) tuple_settings = ( "ALLOWED_INCLUDE_ROOTS", "INSTALLED_APPS", "TEMPLATE_DIRS", "LOCALE_PATHS", ) self._explicit_settings = set() for setting in dir(mod): if setting.isupper(): setting_value = getattr(mod, setting) if (setting in tuple_settings and not isinstance(setting_value, (list, tuple))): raise ImproperlyConfigured("The %s setting must be a list or a tuple. " "Please fix your settings." % setting) setattr(self, setting, setting_value) self._explicit_settings.add(setting) if not self.SECRET_KEY: raise ImproperlyConfigured("The SECRET_KEY setting must not be empty.") if ('django.contrib.auth.middleware.AuthenticationMiddleware' in self.MIDDLEWARE_CLASSES and 'django.contrib.auth.middleware.SessionAuthenticationMiddleware' not in self.MIDDLEWARE_CLASSES): warnings.warn( "Session verification will become mandatory in Django 1.10. " "Please add 'django.contrib.auth.middleware.SessionAuthenticationMiddleware' " "to your MIDDLEWARE_CLASSES setting when you are ready to opt-in after " "reading the upgrade considerations in the 1.8 release notes.", RemovedInDjango110Warning ) if hasattr(time, 'tzset') and self.TIME_ZONE: # When we can, attempt to validate the timezone. If we can't find # this file, no check happens and it's harmless. zoneinfo_root = '/usr/share/zoneinfo' if (os.path.exists(zoneinfo_root) and not os.path.exists(os.path.join(zoneinfo_root, *(self.TIME_ZONE.split('/'))))): raise ValueError("Incorrect timezone setting: %s" % self.TIME_ZONE) # Move the time zone info into os.environ. See ticket #2315 for why # we don't do this unconditionally (breaks Windows). os.environ['TZ'] = self.TIME_ZONE time.tzset() def is_overridden(self, setting): return setting in self._explicit_settings class UserSettingsHolder(BaseSettings): """ Holder for user configured settings. """ # SETTINGS_MODULE doesn't make much sense in the manually configured # (standalone) case. SETTINGS_MODULE = None def __init__(self, default_settings): """ Requests for configuration variables not in this class are satisfied from the module specified in default_settings (if possible). """ self.__dict__['_deleted'] = set() self.default_settings = default_settings def __getattr__(self, name): if name in self._deleted: raise AttributeError return getattr(self.default_settings, name) def __setattr__(self, name, value): self._deleted.discard(name) super(UserSettingsHolder, self).__setattr__(name, value) def __delattr__(self, name): self._deleted.add(name) if hasattr(self, name): super(UserSettingsHolder, self).__delattr__(name) def __dir__(self): return list(self.__dict__) + dir(self.default_settings) def is_overridden(self, setting): deleted = (setting in self._deleted) set_locally = (setting in self.__dict__) set_on_default = getattr(self.default_settings, 'is_overridden', lambda s: False)(setting) return (deleted or set_locally or set_on_default) settings = LazySettings()