python/lib/django_1_4/django/core/exceptions.py

   1 """
   2 Global Django exception and warning classes.
   3 """
   4
   5 class DjangoRuntimeWarning(RuntimeWarning):
   6     pass
   7
   8 class ObjectDoesNotExist(Exception):
   9     "The requested object does not exist"
  10     silent_variable_failure = True
  11
  12 class MultipleObjectsReturned(Exception):
  13     "The query returned multiple objects when only one was expected."
  14     pass
  15
  16 class SuspiciousOperation(Exception):
  17     "The user did something suspicious"
  18     pass
  19
  20 class PermissionDenied(Exception):
  21     "The user did not have permission to do that"
  22     pass
  23
  24 class ViewDoesNotExist(Exception):
  25     "The requested view does not exist"
  26     pass
  27
  28 class MiddlewareNotUsed(Exception):
  29     "This middleware is not used in this server configuration"
  30     pass
  31
  32 class ImproperlyConfigured(Exception):
  33     "Django is somehow improperly configured"
  34     pass
  35
  36 class FieldError(Exception):
  37     """Some kind of problem with a model field."""
  38     pass
  39
  40 NON_FIELD_ERRORS = '__all__'
  41 class ValidationError(Exception):
  42     """An error while validating data."""
  43     def __init__(self, message, code=None, params=None):
  44         import operator
  45         from django.utils.encoding import force_unicode
  46         """
  47         ValidationError can be passed any object that can be printed (usually
  48         a string), a list of objects or a dictionary.
  49         """
  50         if isinstance(message, dict):
  51             self.message_dict = message
  52             # Reduce each list of messages into a single list.
  53             message = reduce(operator.add, message.values())
  54
  55         if isinstance(message, list):
  56             self.messages = [force_unicode(msg) for msg in message]
  57         else:
  58             self.code = code
  59             self.params = params
  60             message = force_unicode(message)
  61             self.messages = [message]
  62
  63     def __str__(self):
  64         # This is needed because, without a __str__(), printing an exception
  65         # instance would result in this:
  66         # AttributeError: ValidationError instance has no attribute 'args'
  67         # See http://www.python.org/doc/current/tut/node10.html#handling
  68         if hasattr(self, 'message_dict'):
  69             return repr(self.message_dict)
  70         return repr(self.messages)
  71
  72     def __repr__(self):
  73         if hasattr(self, 'message_dict'):
  74             return 'ValidationError(%s)' % repr(self.message_dict)
  75         return 'ValidationError(%s)' % repr(self.messages)
  76
  77     def update_error_dict(self, error_dict):
  78         if hasattr(self, 'message_dict'):
  79             if error_dict:
  80                 for k, v in self.message_dict.items():
  81                     error_dict.setdefault(k, []).extend(v)
  82             else:
  83                 error_dict = self.message_dict
  84         else:
  85             error_dict[NON_FIELD_ERRORS] = self.messages
  86         return error_dict
  87