[Zope3-Users] Re: OrderedContainer.keys() does not return newely added key in ObjectAddedEvent

[Philipp von Weitershausen]

Alek Kowalczyk wrote:
> Hi,
> 
> I have subscribed to the ObjectAddedEvent for my OrderedContainer.
> There is the a strange behavior in the event handler:
> - myObj is my contained object
> - myObj.__parent__ is my OrderedContainer.
> 
> 1. this returns True when called in the event handler:
> myObj.__name__ in myObj.__parent__
> 2. this returns False when called in the event handler:
> myObj.__name__ in myObj.__parent__.keys()
> 
> Code inspection of OrderedContainer.__setitem__ shows the following:
> 1. first call setitem, which triggers event as side effect
> setitem(self, self._data.__setitem__, key, object)
> 
> 2. after that add key to the _order, which is returned by keys() method:
> if not existed:
>    self._order.append(key)
> 
> Is it bug or just works-as-designed? 
> I think that this behavior is improper or at least confusing a bit. 
> Event should be called *after* 
> the keys() method is able to return list with added object, so that:
> (myObj.__name__ in myObj.__parent__) == 
> (myObj.__name__ in myObj.__parent__.keys())

Yes. I think

         if not existed:
             self._order.append(key)

should be executed before

         setitem(self, self._data.__setitem__, key, object)

Perhaps you can round up a patch, including a test that tests this from 
an event handler perspective? You can submit the patch and the original 
bug report to the Zope 3 bug collector 
(http://www.zope.org/Collectors/Zope3-dev).


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