[Zope] Re: [Zope-CMF] Persistent dictionaries

[Thomas Olsen]

On Friday 24 August 2001 23:46, Dieter Maurer wrote:
>  >         self._attributes = {'value':'','html':'','alignment':''}
>
> From here on "self._attributes" is no longer a PersistentMapping
> but a normal Python dictionary.
> Internal modifications do not trigger the persistence machinery.
> They would, if "_attributes" were still a PersistentMapping....

Doh - didn't think of that...

Anyway - I'm lying on the coach with the flu right now so my brain is even 
duller than usual :-) Something I don't quite understand about the python 
classes: 

Say you have an instance of a class MyClass with attributes myattr1 and 
myattr2; then you change the class definition for MyClass adding myattr3.
If attributes are stored in dictionary __dict__ isn't it possible simply to 
do:

def __getattr__(self, name): # or maybe __setstate__(self):
    if not self.hasattr(name):
        # add attribute name
        self.__dict__[name] = ""

Shouldn't this add the attribute to the class instance?
-- 
Regards,
	Thomas Olsen

http://www.tanghus.dk