[Zope-CMF] Patch for more forward-compatible APB

[Tres Seaver]

On Fri, 2003-04-18 at 13:05, Sidnei da Silva wrote:
> On Fri, Apr 18, 2003 at 12:04:15PM -0400, Tres Seaver wrote:
> | I don't mind the parts of the patch which surface the "readable" bits of
> | a dict;  however, I don't think I want to encourage anybody to assume
> | that modifying the object through '__setitem__' / 'update' is
> | supported.  Does Plone actually need that, or were you just being
> | thorough?
> 
> For __setitem__ yes. There is some code in Plone and other products
> that does:
> 
> actions = types_tool._cloneActions()
> for action in actions:
>   if action['id'] == 'view':
>      action['action'] = 'folder_listing'
> types_tool._actions = tuple(actions)
> 
> (or something to that effect).

First, I presume that this code is actually manipulating the type
information objects' actions, rather than the tool actions;  the tool
actions have not been dictionaries ever, I think.  Second,
this is specifically the kind of usage I'd like to suppress:  it is
subverting the TIs own handling of actions.  I *especially* dislike the
last line there:  it breaks encapsulation at least two ways (the name of
the attribute, plus its representation as a tuple).

If we *do* add your full patch, I would expect it to be immediately
deprecated:  I don't want to introduce gratuitous breakage into Plone or
other projects, but I do want to discourage that kind of "monkey patch"
coding in the future.

> Notice that im restricting the values that can be read and set to a
> small set ( _props ), and that __setitem__ behaves differently for
> 'action', because it needs special treatment when being set.
> 
> | > In the way, I also added a few __traceback_info__ to make debugging
> | > easier.
> | 
> | Yep, no problem there.
> | 
> | BTW, I vastly prefer to read unified diff.  My ~/.cvsrc looks like:
> | 
> |   $ cat .cvsrc
> |   -z7
> |   diff -u
> 
> Hey, nice tip! 

Tres.
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Tres Seaver                                tseaver@zope.com
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