[Zope3-Users] UnpickleableError when adding object with reference

[Thierry Florac]

Le mardi 15 janvier 2008 à 07:05 -0500, john saponara a écrit :
> I add a Limoservice object, then inside that object add a Car; then I 
> add a Driver (which contains a Car), and the AddForm offers a dropdown 
> with '(no value)' and my Car object.  If I select the car from the 
> dropdown I get an error:
> 
> UnpickleableError: Cannot pickle <type 'zope.security._proxy._Proxy'> 
> objects
> 
> Whereas if I leave the dropdown at '(no value)', the error does not 
> occur.  What am I doing wrong?  (See attached error.txt for full error.)

Hi, 
As explained into error message, you can't store security proxied
objects into ZODB : you have to remove proxy before they can be stored.

What I generally do is just something like this :

  ...
  from zope.security.proxy import removeSecurityProxy

  class Driver(Contained):
    implements(IDriver,ILimoserviceContained)
    _car = None

    def _getCar(self):
      return self._car

    def _setCar(self, value):
      self._car = removeSecurityProxy(value)

    car = property(_getCar,_setCar)
  ...

Like that, any way the car property is modified, it's automatically
unproxied and can be stored safely.


  Thierry Florac
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