[Twisted-web] Twisted.web2

[Donovan Preston]

On Sep 15, 2004, at 12:26 PM, William Dode wrote:

> James Y Knight <foom at fuhm.net> writes:
>
> ...
>
>> 3) For distribution: twisted.web2 depends on Nevow (for static
>> directory listings, and error pages), so will be distributed with
>> it. Nevow recommends Twisted but does not require it for simple cases
>> (e.g. flattening to a string from a CGI script), so there can also be
>> a limited-functionality distribution of standalone Nevow.
>
> What about the wsgi spec ?
> http://www.python.org/peps/pep-0333.html
>
> It could be great if the server could not depend on any framework (i
> mean nevow).

The server would depend on Nevow in order to generate the HTML for 
various automatically generated pages, such as directory listings. I 
suggested to James that having a standalone twisted.web server that 
didn't depend on Nevow and wasn't capable of generating any pages 
itself would be possible, but James didn't think it was worth the 
effort.

The WSGI spec is unsuitable for use with asynchronous servers and 
applications. Basically, once the application callable returns, the 
server (or "gateway" as wsgi calls it) must consider the page finished 
rendering.

I have implemented a simple WSGI application callable in Nevow svn 
head, which will take a Page and synchronously render it. However, 
unless there is a way for the application to continue rendering after 
it has returned, I don't think this will be much use beyond just simple 
CGI style apps.

I haven't mentioned anything about this to any WSGI list yet because I 
don't have a solution or a proposal. My initial thought is to have the 
start_response callable return a tuple of (write, finish) callables, 
instead of just write as it does now. I'm not yet sure this will 
actually work, though, so I'll have to give it further thought.

dp