openerp-expert-framework team mailing list archive

[Xavier Morel <xmo@xxxxxxxxxxx>]

On 2011-07-04, at 17:19 , Leonardo Santagada wrote:
> 2011/7/4 Olivier Dony <odo@xxxxxxxxxxx>:
>> 1) fields.function() does not take a "method" parameter anymore [1]. It
>> was useless and every field was passing method=True. It is possible to
>> pass a normal function too, it simply needs to have the proper signature
>> (see the docstring). Don't forget to run 'bzr pull' on the server,
>> otherwise the trunk addons will not work anymore.
>> And please do not use the "method" parameter anymore in trunk! (it's
>> ignored, though, so it's backwards compatible)
> 
> I saw the changeset[1], but why not introspect the function to know if
> it is a method or a function?
Because technically, the callable passed is never a method (unless you're
doing pretty strange stuff with it): it has not yet been collected and 
converted by the class statement (that only happens after the class body
has finished executing), so it's always a function taking an arbitrary
object as its first argument (the object happens to be the current class
instance, so it looks like it's a method form within it):

    >>> store = None
    >>> def set_store(callable):
    ...     global store
    ...     store = callable
    ... 
    >>> class Foo(object):
    ...     def some_method(self):
    ...             print 4
    ...     set_store(some_method)
    ... 
    >>> Foo.some_method
    <unbound method Foo.some_method>
    >>> Foo().some_method
    <bound method Foo.some_method of <__main__.Foo object at 0x1004cd910>>
    >>> store
    <function some_method at 0x1004b92a8>

The value of `store` is what is really stored in function fields: a function,
which takes one argument, which happens to be called `self`.