[Web-SIG] Adding wsgiref to stdlib

Fri Apr 28 22:19:26 CEST 2006

It still looks like an application of WSGI, not part of a reference
implementation. Multiple apps looks like an advanced topic to me; more
something that the infrastructure (Apache server or whatever) ought to
take care of.

I don't expect you to agree with me. But I don't expect you to be able
to convince me either. Maybe you can convince Phillip; I'm going to
try to sit on my hands now.

--Guido

On 4/28/06, Ian Bicking <ianb at colorstudy.com> wrote:
> Guido van Rossum wrote:
> >> I think another useful addition would be some prefix-based dispatcher,
> >> similar to paste.urlmap (but probably a bit simpler):
> >> http://svn.pythonpaste.org/Paste/trunk/paste/urlmap.py
> >
> >
> > IMO this is getting into framework design. Perhaps something like this
> > could be added in 2.6?
>
> I don't think it's frameworky.  It could be used to build a very
> primitive framework, but even then it's not a particularly useful
> starting point.
>
> In Paste this would generally be used below any framework (or above I
> guess, depending on which side is "up").  You'd pass /blog to a blog
> app, /cms to a cms app, etc.  WSGI already is very specific about what
> needs to be done when doing this dispatching (adjusting SCRIPT_NAME and
> PATH_INFO), and that's all that the dispatching needs to do.
>
> The applications themselves are written in some framework with internal
> notions of URL dispatching, but this doesn't infringe upon those.
> (Unless the framework doesn't respect SCRIPT_NAME and PATH_INFO; but
> that's their problem, as the dispatcher is just using what's already
> allowed for in the WSGI spec.)  It also doesn't overlap with frameworks,
> as prefix-based dispatching isn't really that useful in a framework.
>
> The basic implementation is:
>
> class PrefixDispatch(object):
>      def __init__(self):
>          self.applications = {}
>      def add_application(self, prefix, app):
>          self.applications[prefix] = app
>      def __call__(self, environ, start_response):
>          apps = sorted(self.applications.items(),
>                        key=lambda x: -len(x[0]))
>          path_info = environ.get('PATH_INFO', '')
>          for prefix, app in apps:
>              if not path_info.startswith(prefix):
>                  continue
>              environ['SCRIPT_NAME'] = environ.get('SCRIPT_NAME', '')+prefix
>              environ['PATH_INFO'] = environ.get('PATH_INFO',
> '')[len(prefix):]
>              return app(environ, start_response)
>          start_response('404 Not Found', [('Content-type', 'text/html')])
>          return ['<html><body><h1>Not Found</h1></body></html>']
>
>
> There's a bunch of checks that should take place (most related to /'s),
> and the not found response should be configurable (probably as an
> application that can be passed in as an argument).  But that's most of
> what it should do.
>
>
> --
> Ian Bicking  /  ianb at colorstudy.com  /  http://blog.ianbicking.org
>

--
--Guido van Rossum (home page: http://www.python.org/~guido/)