[Zope3-dev] Re: Re-revisiting IResult (for in-Zope pipelining)

[Gary Poster]

On Jul 13, 2007, at 5:40 AM, Lennart Regebro wrote:

> Hi all!
>
> On 4/16/07, Gary Poster <gary at zope.com> wrote:
>> The work that Jim Washington and David Pratt have started recently to
>> make lxml an XHTML generator/ZPT replacement [#1]_ has really excited
>> me.  It would be *great* with in-Zope pipelines [#2]_.
>
> I'm here at the grok-sprint at EuroPython and we are looking into
> getting a pipeline hooked in to add theming to HTML output. [The idea
> of this is to add the theming, that is design, viewlets and so on, by
> imposing it on the HTML output, instead of including it from the
> template. This would open up for template independency, or even
> skipping templates completely for simple HTML and instead just
> outputting it.]
>
> We are looking for recommendations and visions on how to do this
> pipelining with IResults, because it's not entirely clear to us at the
> moment. Main worries are the questions of how to differ between
> results that need to be themed and those who don't,

I thought you'd return different objects, and rely on adapters.  I'm  
a bit surprised at the question, actually--what have I missed?

> and also IResult
> seems to have to handle the encoding itself, which means we need to
> duplicate the encoding that is already going on in setResults.

I think the responsibility is appropriate: IResult should be  
responsible for encoding, because who knows what it wants to return.

Perhaps the factoring could be improved in the future, so that the  
encoding code could be a function that setResults uses, and your  
custom IResult adapter can too.  For now, it hardly seems like a show- 
stopper.

> I have earlier (before IResult being made public) made a quick hack
> that inserts theming earlier in the process by replacing the
> BrowserPublication, maybe that's a better way to put theming?

Doesn't appeal to me--feels like the hack that we did for  
zc.resourcelibrary, in which the change to the system is much, much  
too heavyweight (someday we'll convert it to using IResult, I  
suspect)--but you're doing it. :-)

Gary