[Zope3-dev] Important Heads Up: I'm making IResult private

[Chris McDonough]

On Dec 26, 2005, at 8:51 AM, Jim Fulton wrote:

> Chris McDonough wrote:
>> FWIW, It would be nice to have some API to return large amounts  
>> of  content which doesn't live in ZODB without returning an  
>> *actual* file  object.  A real world use case: In a Zope2  
>> application, I depend on  being able to return  a "streamiterator"  
>> which does decryption as it  streams.  I cannot write this data  
>> temporarily to disk for business  reasons (it's encrypted for a  
>> reason),
>
> Even on a unix-based platform on which the file is removed before  
> data are
> written to it?

For this project, yes, given that the project owners believe their  
business model depends on "no sensitive unencrypted data ever being  
written to persistent storage (even temporarily)".  I've even gone as  
far as to replace the logic in fieldstorage/zserver to encrypt data  
that would have been written to a plain tempfile as it is inputted  
from the UA as a result.

This is of course an edge case example and I don't expect others to  
have the same kind of requirements.  I've already needed to  
monkeypatch Zope 2 to get it to do what was required of it for  
*input* data, so I could of course continue to maintain code to do  
this for Z3.

That said, Z2 defines a marker interface named IStreamIterator that  
can be implemented by things returned to the publisher; these are  
handled specially by the publisher.

> > so I wrap a file pointer in
>> something that implements a stream iterator; it decrypts as it's   
>> iterated.
>> I don't know if you have this in mind still.
>
> No, I didn't.  We need to have something like this.  Let's figure  
> out what
> it is over the next release cycle.  In the mean time, an IResult-based
> framework is still lurking in 3.2.  You can use it if you don't  
> mind changing
> later.  (Note that the adapter is now looked up for the original  
> result, and the
> request, rather than just the original result.)

That's fine; I'm not using the Z3 publisher for this particular  
project anyway.  This is more of an example use case where a special  
interface would be nice to retain (although the IResults thing looks  
kinda complicated; a simple marker interface indicating the object is  
iterable would be better I think).  It of course makes sense to be  
able to return "plain" files to the publisher without needing to  
decorate them with any special interface, though, too.

- C