[Zope] Product refreshing in Zope 2.9

[Peter Bengtsson]

I've noticed another strange behaviour with the Acquisition module in
Zope 2.9 that might give us some clues as to why refreshing doesn't
work.

Imagine some code that looks like this::

from Acquisition import aq_parent

class MyProduct(Folder):
    def index_html(self):
        print type(aq_parent) is None
        return "Hello World!"

The first time I run this, it prints "False" to stdout because
ac_parent is of course a function.
BUT, if I refresh the product (no change made to the source) and run
this index_html() again it instead prints "True" because ac_parent has
become None.
Isn't that odd?

Again, this is easily reproducable with
http://www.peterbe.com/zope/2.9-refresh-reproduction/MyProduct.tgz

Any idea anyone?



On 1/27/06, Dieter Maurer <dieter at handshake.de> wrote:
> Peter Bengtsson wrote at 2006-1-27 16:42 +0000:
> > ...
> >But, in that example they are using Five and I'm not. I've just got a
> >Zope 2.9 install and a python product that I started on before Five
> >even existed. Does that give us any hope for non-Five python products?
> >Anybody?
>
> I cannot believe that they were able to break refreshability
> of "normal" (non Five) products.
>
> Refreshing essentially works by removing the modules belonging
> to the product from "sys.module" and then reimporting the product.
>
> This may fail when product defined objects are held in registries
> (such as adapters) and are not overridden when the product is
> reimported. Maybe, such cases occur often with Five.
>
> Without Five, it is rather rare (product objects are often registered
> but usually, the reimport overrides the old no longer working entries).
>
> >I've tried pressing the little "Refresh" button in Control_Panel and
> >sure enough, the product is reloaded (I put some print statements in
> >the .py file) but not refreshed.
>
> "reloaded but not refreshed" means what?
>
> --
> Dieter
>


--
Peter Bengtsson,
work www.fry-it.com
home www.peterbe.com
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