[ZODB-Dev] Why does this useage of __setstate__ fail?

[Mika, David P (GE, Research)]

Thanks David,
 
Yes, that does work.  I am trying to keep the persistence machinery in
the persistent classes themselves.  Notice with the subsequent statement

 
   newuser.setColor('red')
 
----------------------------------------
class User(Persistent):
...
   def setColor(self, color):
        self.color.setColor(color)
        #self._p_changed = True
        transaction.commit()
 
the _p_changed should be set (implicitly), and then all changes fixed
with the transaction.commit() in that method--this doesn't seem to be
the case.  I can uncomment the _p_changed = True line in the setColor
method and get the desired result, but I don't see why this is required,
after all, the color attribute is a Persistent class in itself.  I
suppose because the Persistent class was added in the __setstate__ it
has not fully been bootstrapped at this point and needs a little help.
(the _p_changed=True is not needed when color is a bonafide attribute)
 
One final observation:  if I instead put the self._p_changed = True
statement in the setColor method of the Color class, it doesn't produce
the desired persistency.  This is somehow related to the bootstrapping
mystery.
 
Thanks,
Dave
 
________________________________

From: David Binger [mailto:dbinger at mems-exchange.org] 
Sent: Thursday, January 17, 2008 1:23 PM

You need to saved the user object with the color attribute.
The __setstate__ is just giving you the unsaved one every time.
Add 'newuser._p_changed = 1'  after the first 
assert statement below and it will be saved along with
your change to the Color instance.

On Jan 17, 2008, at 11:21 AM, Mika, David P (GE, Research) wrote:


	    def test_2_setstate(self):
	        print 'in test2'
	        newuser = self.userdb[self.id]
	        # setstate is called subsequently
	        assert hasattr(newuser, 'color')
	        assert newuser.getColor() == 'blue'
	        newuser.setColor('red')
	        assert newuser.getColor() == 'red'  


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