[ZPatterns] Why is class_default_for_ method unbound?

[Itai Tavor]

>At 12:10 PM 8/21/01 +1000, Itai Tavor wrote:
>>I got the following DataSkin class (Zope 2.3.2, ZPatterns 0.4.3p1):
>>
>>class MyClass(DataSkin):
>>
>>      def class_default_for_method1(self, REQUEST):
>>         """ Display something """
>>         ...
>>
>>Calling http://mysite/myinstance/method1 returns:
>>
>>Error Type: TypeError
>>Error Value: unbound Python method must be called with MyClass 1st argument
>>
>>Why is method1 unbound? Why does it behave any different than a 
>>method defined as def method1(self, REQUEST)? And what do I do to 
>>make this method work?
>
>Congratulations, you just found a long-buried bug in DynPersist.c, 
>that hasn't hit anybody else yet (including me).

Yeepee! Do I get a ZPatterns T-shirt?

It bothers me that nobody else ever hit this problem. So nobody ever 
had the need to use class_default_ for web-callable methods. That 
must mean I'm structuring my apps badly...

>   I just looked over the code and realized that DynPersist only 
>calls the "__of__" method of an object returned from __get_attr__, 
>and does not perform instance method binding.  This works correctly 
>with methods that are Zope objects, just not methods that are Python 
>functions or unbound methods.  There is a workaround, but of course 
>I really should fix DynPersist.c, and will attempt to do so.  Here's 
>the (untested) workaround:
>
>import MethodObject
>
>class Method(MethodObject.Method):
>
>     def __init__(self,func):
>         self.func = func
>         self.func_code = func.func_code
>         self.func_defaults = func.func_defaults
>
>     def __call__(self,*args,**kw):
>         return apply(self.func,args,kw)
>
>
>
>class MyClass(DataSkin):
>
>     def class_default_for_method1(self, REQUEST):
>         ...
>
>     class_default_for_method1 = Method(class_default_for_method1)
>
>
>This should turn the Python function into a Zope "method" object 
>with the right magic.  Sorry about the difficulty, I'll take a look 
>and see if there's a way to fix DynPersist.c to do the right thing 
>with "unbound method" objects.

Doesn't work, unfortunately. Returns same error.

BTW, sorry I keep sending HTML in my postings... the price you pay 
for using a beta email client on a beta OS :-(
-- 
--
Itai Tavor                      -- "Je sautille, donc je suis."    --
itai@optusnet.com.au            --               - Kermit the Frog --
--                                                                 --
-- "If you haven't got your health, you haven't got anything"      --