Mini framework v2

apper.py

import re

import webob
import webob.exc


class Servlet(object):

    name = None

    def __init__(self, request, response):
        super(Servlet, self).__init__()
        self.request = request
        self.response = response

    def routes(self):
        raise NotImplementedError

    def __call__(self):
        for method, path, action in self.routes():
            if method != self.request.method:
                continue

            matches = re.match('^' + path + '/?$', self.request.path_info[1:])

            if matches:
                return action(**matches.groupdict())

        raise webob.exc.HTTPNotFound


class Apper(object):

    def __init__(self, *servlets):
        super(Apper, self).__init__()
        self.servlets = {}

        for servlet in servlets:
            assert servlet.name not in self.servlets
            self.servlets[servlet.name] = servlet

    def __call__(self, environ, start_response):
        request = webob.Request(environ)
        response = webob.Response(request=request)

        servlet_name = request.path_info_pop()

        try:
            if servlet_name not in self.servlets:
                raise webob.exc.HTTPNotFound

            servlet = self.servlets[servlet_name](request, response)

            retval = servlet()

            if isinstance(retval, basestring):
                response.body = retval
            else:
                response.app_iter = retval
        except webob.exc.WSGIHTTPException as e:
            return request.get_response(e)(environ, start_response)
        else:
            return response(environ, start_response)

sample.py

import simplejson
from wsgiref.simple_server import make_server

import webob.exc

from apper import Apper, Servlet


class Home(Servlet):

    name = ""

    def routes(self):
        return [
            ('GET', r"", self.home)
        ]

    def home(self):
        return """
<h1>Welcome!</h1>
<form action="/hello" method="post">
Name: <input type="text" name="name" />
<input type="submit" value="Go!" />
</form>
"""


class Hello(Servlet):

    name = "hello"

    def routes(self):
        return [
            ('GET', r"(?P<name>.+)", self.hello),
            ('POST', r"", self.hello_post)
        ]

    def hello(self, name):
        return "Hello, %s!" % name

    def hello_post(self):
        if not self.request.POST.get('name'):
            raise webob.exc.HTTPNotFound

        name = self.request.POST['name']
        raise webob.exc.HTTPSeeOther(location="/hello/%s" % name)

app = Apper(Home, Hello)

make_server('0.0.0.0', 8000, app).serve_forever()