|
| 1 | +""" |
| 2 | +Settings and configuration for Django. |
| 3 | +
|
| 4 | +Values will be read from the module specified by the DJANGO_SETTINGS_MODULE environment |
| 5 | +variable, and then from django.conf.global_settings; see the global settings file for |
| 6 | +a list of all possible variables. |
| 7 | +""" |
| 8 | + |
| 9 | +import os |
| 10 | +import re |
| 11 | +import time # Needed for Windows |
| 12 | + |
| 13 | +from django.conf import global_settings |
| 14 | +from django.utils.functional import LazyObject |
| 15 | +from django.utils import importlib |
| 16 | + |
| 17 | +ENVIRONMENT_VARIABLE = "DJANGO_SETTINGS_MODULE" |
| 18 | + |
| 19 | +class LazySettings(LazyObject): |
| 20 | + """ |
| 21 | + A lazy proxy for either global Django settings or a custom settings object. |
| 22 | + The user can manually configure settings prior to using them. Otherwise, |
| 23 | + Django uses the settings module pointed to by DJANGO_SETTINGS_MODULE. |
| 24 | + """ |
| 25 | + def _setup(self): |
| 26 | + """ |
| 27 | + Load the settings module pointed to by the environment variable. This |
| 28 | + is used the first time we need any settings at all, if the user has not |
| 29 | + previously configured the settings manually. |
| 30 | + """ |
| 31 | + try: |
| 32 | + settings_module = os.environ[ENVIRONMENT_VARIABLE] |
| 33 | + if not settings_module: # If it's set but is an empty string. |
| 34 | + raise KeyError |
| 35 | + except KeyError: |
| 36 | + # NOTE: This is arguably an EnvironmentError, but that causes |
| 37 | + # problems with Python's interactive help. |
| 38 | + raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE) |
| 39 | + |
| 40 | + self._wrapped = Settings(settings_module) |
| 41 | + |
| 42 | + def configure(self, default_settings=global_settings, **options): |
| 43 | + """ |
| 44 | + Called to manually configure the settings. The 'default_settings' |
| 45 | + parameter sets where to retrieve any unspecified values from (its |
| 46 | + argument must support attribute access (__getattr__)). |
| 47 | + """ |
| 48 | + if self._wrapped != None: |
| 49 | + raise RuntimeError, 'Settings already configured.' |
| 50 | + holder = UserSettingsHolder(default_settings) |
| 51 | + for name, value in options.items(): |
| 52 | + setattr(holder, name, value) |
| 53 | + self._wrapped = holder |
| 54 | + |
| 55 | + def configured(self): |
| 56 | + """ |
| 57 | + Returns True if the settings have already been configured. |
| 58 | + """ |
| 59 | + return bool(self._wrapped) |
| 60 | + configured = property(configured) |
| 61 | + |
| 62 | +class Settings(object): |
| 63 | + def __init__(self, settings_module): |
| 64 | + # update this dict from global settings (but only for ALL_CAPS settings) |
| 65 | + for setting in dir(global_settings): |
| 66 | + if setting == setting.upper(): |
| 67 | + setattr(self, setting, getattr(global_settings, setting)) |
| 68 | + |
| 69 | + # store the settings module in case someone later cares |
| 70 | + self.SETTINGS_MODULE = settings_module |
| 71 | + |
| 72 | + try: |
| 73 | + mod = importlib.import_module(self.SETTINGS_MODULE) |
| 74 | + except ImportError, e: |
| 75 | + raise ImportError, "Could not import settings '%s' (Is it on sys.path? Does it have syntax errors?): %s" % (self.SETTINGS_MODULE, e) |
| 76 | + |
| 77 | + # Settings that should be converted into tuples if they're mistakenly entered |
| 78 | + # as strings. |
| 79 | + tuple_settings = ("INSTALLED_APPS", "TEMPLATE_DIRS") |
| 80 | + |
| 81 | + for setting in dir(mod): |
| 82 | + if setting == setting.upper(): |
| 83 | + setting_value = getattr(mod, setting) |
| 84 | + if setting in tuple_settings and type(setting_value) == str: |
| 85 | + setting_value = (setting_value,) # In case the user forgot the comma. |
| 86 | + setattr(self, setting, setting_value) |
| 87 | + |
| 88 | + # Expand entries in INSTALLED_APPS like "django.contrib.*" to a list |
| 89 | + # of all those apps. |
| 90 | + new_installed_apps = [] |
| 91 | + for app in self.INSTALLED_APPS: |
| 92 | + if app.endswith('.*'): |
| 93 | + app_mod = importlib.import_module(app[:-2]) |
| 94 | + appdir = os.path.dirname(app_mod.__file__) |
| 95 | + app_subdirs = os.listdir(appdir) |
| 96 | + app_subdirs.sort() |
| 97 | + name_pattern = re.compile(r'[a-zA-Z]\w*') |
| 98 | + for d in app_subdirs: |
| 99 | + if name_pattern.match(d) and os.path.isdir(os.path.join(appdir, d)): |
| 100 | + new_installed_apps.append('%s.%s' % (app[:-2], d)) |
| 101 | + else: |
| 102 | + new_installed_apps.append(app) |
| 103 | + self.INSTALLED_APPS = new_installed_apps |
| 104 | + |
| 105 | + if hasattr(time, 'tzset'): |
| 106 | + # Move the time zone info into os.environ. See ticket #2315 for why |
| 107 | + # we don't do this unconditionally (breaks Windows). |
| 108 | + os.environ['TZ'] = self.TIME_ZONE |
| 109 | + time.tzset() |
| 110 | + |
| 111 | + def get_all_members(self): |
| 112 | + return dir(self) |
| 113 | + |
| 114 | +class UserSettingsHolder(object): |
| 115 | + """ |
| 116 | + Holder for user configured settings. |
| 117 | + """ |
| 118 | + # SETTINGS_MODULE doesn't make much sense in the manually configured |
| 119 | + # (standalone) case. |
| 120 | + SETTINGS_MODULE = None |
| 121 | + |
| 122 | + def __init__(self, default_settings): |
| 123 | + """ |
| 124 | + Requests for configuration variables not in this class are satisfied |
| 125 | + from the module specified in default_settings (if possible). |
| 126 | + """ |
| 127 | + self.default_settings = default_settings |
| 128 | + |
| 129 | + def __getattr__(self, name): |
| 130 | + return getattr(self.default_settings, name) |
| 131 | + |
| 132 | + def get_all_members(self): |
| 133 | + return dir(self) + dir(self.default_settings) |
| 134 | + |
| 135 | +settings = LazySettings() |
| 136 | + |
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