Source Code for Package django.conf

  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 time     # Needed for Windows 
 11  from django.conf import global_settings 
 12   
 13  ENVIRONMENT_VARIABLE = "DJANGO_SETTINGS_MODULE" 
 14   
 15 -class LazySettings(object): 
 16      """ 
 17      A lazy proxy for either global Django settings or a custom settings object. 
 18      The user can manually configure settings prior to using them. Otherwise, 
 19      Django uses the settings module pointed to by DJANGO_SETTINGS_MODULE. 
 20      """ 
 21 -    def __init__(self): 
 22          # _target must be either None or something that supports attribute 
 23          # access (getattr, hasattr, etc). 
 24          self._target = None 
 25   
 26 -    def __getattr__(self, name): 
 27          if self._target is None: 
 28              self._import_settings() 
 29          if name == '__members__': 
 30              # Used to implement dir(obj), for example. 
 31              return self._target.get_all_members() 
 32          return getattr(self._target, name) 
 33   
 34 -    def __setattr__(self, name, value): 
 35          if name == '_target': 
 36              # Assign directly to self.__dict__, because otherwise we'd call 
 37              # __setattr__(), which would be an infinite loop. 
 38              self.__dict__['_target'] = value 
 39          else: 
 40              if self._target is None: 
 41                  self._import_settings() 
 42              setattr(self._target, name, value) 
 43   
 44 -    def _import_settings(self): 
 45          """ 
 46          Load the settings module pointed to by the environment variable. This 
 47          is used the first time we need any settings at all, if the user has not 
 48          previously configured the settings manually. 
 49          """ 
 50          try: 
 51              settings_module = os.environ[ENVIRONMENT_VARIABLE] 
 52              if not settings_module: # If it's set but is an empty string. 
 53                  raise KeyError 
 54          except KeyError: 
 55              # NOTE: This is arguably an EnvironmentError, but that causes 
 56              # problems with Python's interactive help. 
 57              raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE) 
 58   
 59          self._target = Settings(settings_module) 
 60   
 61 -    def configure(self, default_settings=global_settings, **options): 
 62          """ 
 63          Called to manually configure the settings. The 'default_settings' 
 64          parameter sets where to retrieve any unspecified values from (its 
 65          argument must support attribute access (__getattr__)). 
 66          """ 
 67          if self._target != None: 
 68              raise RuntimeError, 'Settings already configured.' 
 69          holder = UserSettingsHolder(default_settings) 
 70          for name, value in options.items(): 
 71              setattr(holder, name, value) 
 72          self._target = holder 
 73   
 74 -class Settings(object): 
 75 -    def __init__(self, settings_module): 
 76          # update this dict from global settings (but only for ALL_CAPS settings) 
 77          for setting in dir(global_settings): 
 78              if setting == setting.upper(): 
 79                  setattr(self, setting, getattr(global_settings, setting)) 
 80   
 81          # store the settings module in case someone later cares 
 82          self.SETTINGS_MODULE = settings_module 
 83   
 84          try: 
 85              mod = __import__(self.SETTINGS_MODULE, {}, {}, ['']) 
 86          except ImportError, e: 
 87              raise ImportError, "Could not import settings '%s' (Is it on sys.path? Does it have syntax errors?): %s" % (self.SETTINGS_MODULE, e) 
 88   
 89          # Settings that should be converted into tuples if they're mistakenly entered 
 90          # as strings. 
 91          tuple_settings = ("INSTALLED_APPS", "TEMPLATE_DIRS") 
 92   
 93          for setting in dir(mod): 
 94              if setting == setting.upper(): 
 95                  setting_value = getattr(mod, setting) 
 96                  if setting in tuple_settings and type(setting_value) == str: 
 97                      setting_value = (setting_value,) # In case the user forgot the comma. 
 98                  setattr(self, setting, setting_value) 
 99   
100          # Expand entries in INSTALLED_APPS like "django.contrib.*" to a list 
101          # of all those apps. 
102          new_installed_apps = [] 
103          for app in self.INSTALLED_APPS: 
104              if app.endswith('.*'): 
105                  appdir = os.path.dirname(__import__(app[:-2], {}, {}, ['']).__file__) 
106                  for d in os.listdir(appdir): 
107                      if d.isalpha() and os.path.isdir(os.path.join(appdir, d)): 
108                          new_installed_apps.append('%s.%s' % (app[:-2], d)) 
109              else: 
110                  new_installed_apps.append(app) 
111          self.INSTALLED_APPS = new_installed_apps 
112   
113          if hasattr(time, 'tzset'): 
114              # Move the time zone info into os.environ. See ticket #2315 for why 
115              # we don't do this unconditionally (breaks Windows). 
116              os.environ['TZ'] = self.TIME_ZONE 
117              time.tzset() 
118   
119 -    def get_all_members(self): 
120          return dir(self) 
121   
122 -class UserSettingsHolder(object): 
123      """ 
124      Holder for user configured settings. 
125      """ 
126      # SETTINGS_MODULE doesn't make much sense in the manually configured 
127      # (standalone) case. 
128      SETTINGS_MODULE = None 
129   
130 -    def __init__(self, default_settings): 
131          """ 
132          Requests for configuration variables not in this class are satisfied 
133          from the module specified in default_settings (if possible). 
134          """ 
135          self.default_settings = default_settings 
136   
137 -    def __getattr__(self, name): 
138          return getattr(self.default_settings, name) 
139   
140 -    def get_all_members(self): 
141          return dir(self) + dir(self.default_settings) 
142   
143  settings = LazySettings() 
144