Browse files

Fixed non-standard introspection support in LazyObject.

LazyObject called a public method ``get_all_members`` on wrapped objects in
order to allow introspection.  This could easily cause name clashes with
existing methods on wrapped objects, and so has been changed to use the
standard methods.  This could be slightly backwards-incompatible, in obscure
cases, if the undocumented LazyObject has been used externally.

git-svn-id: bcc190cf-cafb-0310-a4f2-bffc1f526a37
  • Loading branch information...
spookylukey committed Oct 19, 2009
1 parent 22be3d7 commit c6e8e5d9f068210d25f501b2aae4192d1c01185c
Showing with 39 additions and 11 deletions.
  1. +4 −4 django/conf/
  2. +0 −4 django/core/files/
  3. +7 −3 django/utils/
  4. +28 −0 docs/releases/1.2-alpha.txt
@@ -108,9 +108,6 @@ def __init__(self, settings_module):
os.environ['TZ'] = self.TIME_ZONE
def get_all_members(self):
return dir(self)
class UserSettingsHolder(object):
Holder for user configured settings.
@@ -129,8 +126,11 @@ def __init__(self, default_settings):
def __getattr__(self, name):
return getattr(self.default_settings, name)
def get_all_members(self):
def __dir__(self):
return dir(self) + dir(self.default_settings)
# For Python < 2.6:
__members__ = property(lambda self: self.__dir__())
settings = LazySettings()
@@ -118,10 +118,6 @@ def url(self, name):
raise NotImplementedError()
# Needed by django.utils.functional.LazyObject (via DefaultStorage).
def get_all_members(self):
return self.__members__
class FileSystemStorage(Storage):
Standard filesystem storage
@@ -266,9 +266,6 @@ def __init__(self):
def __getattr__(self, name):
if self._wrapped is None:
if name == "__members__":
# Used to implement dir(obj)
return self._wrapped.get_all_members()
return getattr(self._wrapped, name)
def __setattr__(self, name, value):
@@ -286,6 +283,13 @@ def _setup(self):
raise NotImplementedError
# introspection support:
__members__ = property(lambda self: self.__dir__())
def __dir__(self):
if self._wrapped is None:
return dir(self._wrapped)
class SimpleLazyObject(LazyObject):
@@ -0,0 +1,28 @@
Backwards-incompatible changes
``LazyObject`` is an undocumented utility class used for lazily wrapping other
objects of unknown type. In Django 1.1 and earlier, it handled introspection in
a non-standard way, depending on wrapped objects implementing a public method
``get_all_members()``. Since this could easily lead to name clashes, it has been
changed to use the standard method, involving ``__members__`` and ``__dir__()``.
If you used ``LazyObject`` in your own code, and implemented the
``get_all_members()`` method for wrapped objects, you need to make the following
* If your class does not have special requirements for introspection (i.e. you
have not implemented ``__getattr__()`` or other methods that allow for
attributes not discoverable by normal mechanisms), you can simply remove the
``get_all_members()`` method. The default implementation on ``LazyObject``
will do the right thing.
* If you have more complex requirements for introspection, first rename the
``get_all_members()`` method to ``__dir__()``. This is the standard method,
from Python 2.6 onwards, for supporting introspection. If you are require
support for Python < 2.6, add the following code to the class::
__members__ = property(lambda self: self.__dir__())

0 comments on commit c6e8e5d

Please sign in to comment.