[Zope-dev] Acquisition Filtered Folder stuff

[Dieter Maurer]

Chris Withers writes:
 > Dieter Maurer wrote:
 > > You may be successful, if you override "__of__".
 > > It is this method that (usually) builds the acquisition wrapper.
 > 
 > When does it not build the wrapper?
If it is not the "__of__" defined by "Acquisition.{Im,Ex}plicit",
it may not build acquisition wrappers.
E.g. the "__of__" of "ComputedAttribute" does not.

 > > The easiest way, of course, is to derive the class from
 > > "Acquisition.Explicit" with higher priority (more to the left)
 > > than from "Acquisition.Implicit".
 > 
 > Hmmm... then maybe use the acquire() method to get hold of names that can be
 > acquired, in the __getattr__ method?
Read the "Acquisition" documentation:

   With explicit acquisition, you can declare that some attributes
   should be acquired implicitly.

Of course, you can do it in "__getattr__", too.

 > There is a more fundamental problem here though; If you limit acquisition to a
 > specified list of names, what do you do about all the stuff Zope normally
 > silently acquires, like the security context, the REQUEST, etc?
I expect, that the security context is explicitly acquired
(not sure).

For "REQUEST" and some essential other objects, you can declare
them to be implicitly acquired.

 > It would be great if you could make it work along the lines of "acquire all the
 > Zope internal stuff, but beyond that, only acquire if the name is in this list".
 > But how would we define "all the Zope internal stuff" and how would we implement
 > the logic? 
The first question may have some surprises. The second should not be too
difficult.

 > Hurm... this sounds like a problem of Fultonesque proportions :-S
Maybe, we wait a bit. As I heard, DC is thinking about making
acquisition explicit rathen than implicit.


Dieter