[Zope3-dev] Re: Do not serialize one attribute

[Rocky Burt]

On Thu, 2006-14-12 at 23:04 +0100, Florian Lindner wrote:
> I have a object, derived from Persistent when contain one attribute which is 
> not serializable and that's not a problem for me, but Zope complains about 
> that.
> Can I mark this attribute somehow as "not to serialize" and make Zope call a 
> member function when it has unserialized this object so I can reinstantiate 
> this attribute?

It *sounds* like you want _v_ attributes.  So you should probably do
something like this...

class MyClass(persistent.Persistent):
    @property
    def myattr(self):
        if not hasattr(self, '_v_myattr'):
            self._v_myattr = somecalculatedvalue
        return self._v_myattr

so then you can do:
myobj = MyClass()
print myobj.myattr
This will give you the content you want but you don't have to worry
about it getting persisted.

Regards,
Rocky

ps. I'm pulling over my zope2 knowledge here so if I did something a
little naive, please forgive me :)

-- 
Rocky Burt
ServerZen Software -- http://www.serverzen.com
News About The Server (blog) -- http://www.serverzen.net
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