# -*- coding: utf-8 -*-
"""
webapp2_extras.routes
=====================
Extra route classes for webapp2.
:copyright: 2011 by tipfy.org.
:license: Apache Sotware License, see LICENSE for details.
"""
import re
import urllib
from webob import exc
import webapp2
class MultiRoute(object):
"""Base class for routes with nested routes."""
routes = None
children = None
match_children = None
build_children = None
def __init__(self, routes):
self.routes = routes
def get_children(self):
if self.children is None:
self.children = []
for route in self.routes:
for r in route.get_routes():
self.children.append(r)
for rv in self.children:
yield rv
def get_match_children(self):
if self.match_children is None:
self.match_children = []
for route in self.get_children():
for r in route.get_match_routes():
self.match_children.append(r)
for rv in self.match_children:
yield rv
def get_build_children(self):
if self.build_children is None:
self.build_children = {}
for route in self.get_children():
for n, r in route.get_build_routes():
self.build_children[n] = r
for rv in self.build_children.iteritems():
yield rv
get_routes = get_children
get_match_routes = get_match_children
get_build_routes = get_build_children
class DomainRoute(MultiRoute):
"""A route used to restrict route matches to a given domain or subdomain.
For example, to restrict routes to a subdomain of the appspot domain::
app = WSGIApplication([
DomainRoute('<subdomain>.app-id.appspot.com', [
Route('/foo', 'FooHandler', 'subdomain-thing'),
]),
Route('/bar', 'BarHandler', 'normal-thing'),
])
The template follows the same syntax used by :class:`webapp2.Route` and
must define named groups if any value must be added to the match results.
In the example above, an extra `subdomain` keyword is passed to the
handler, but if the regex didn't define any named groups, nothing would
be added.
"""
def __init__(self, template, routes):
"""Initializes a URL route.
:param template:
A route template to match against ``environ['SERVER_NAME']``.
See a syntax description in :meth:`webapp2.Route.__init__`.
:param routes:
A list of :class:`webapp2.Route` instances.
"""
super(DomainRoute, self).__init__(routes)
self.template = template
def get_match_routes(self):
# This route will do pre-matching before matching the nested routes!
yield self
def match(self, request):
# Use SERVER_NAME to ignore port number that comes with request.host?
# host_match = self.regex.match(request.host.split(':', 1)[0])
host_match = self.regex.match(request.environ['SERVER_NAME'])
if host_match:
args, kwargs = webapp2._get_route_variables(host_match)
return _match_routes(self.get_match_children, request, None,
kwargs)
@webapp2.cached_property
def regex(self):
regex, reverse_template, args_count, kwargs_count, variables = \
webapp2._parse_route_template(self.template,
default_sufix='[^\.]+')
return regex
class NamePrefixRoute(MultiRoute):
"""The idea of this route is to set a base name for other routes::
app = WSGIApplication([
NamePrefixRoute('user-', [
Route('/users/<user:\w+>/', UserOverviewHandler, 'overview'),
Route('/users/<user:\w+>/profile', UserProfileHandler,
'profile'),
Route('/users/<user:\w+>/projects', UserProjectsHandler,
'projects'),
]),
])
The example above is the same as setting the following routes, just more
convenient as you can reuse the name prefix::
app = WSGIApplication([
Route('/users/<user:\w+>/', UserOverviewHandler, 'user-overview'),
Route('/users/<user:\w+>/profile', UserProfileHandler,
'user-profile'),
Route('/users/<user:\w+>/projects', UserProjectsHandler,
'user-projects'),
])
"""
_attr = 'name'
def __init__(self, prefix, routes):
"""Initializes a URL route.
:param prefix:
The prefix to be prepended.
:param routes:
A list of :class:`webapp2.Route` instances.
"""
super(NamePrefixRoute, self).__init__(routes)
self.prefix = prefix
# Prepend a prefix to a route attribute.
for route in self.get_routes():
setattr(route, self._attr, prefix + getattr(route, self._attr))
class HandlerPrefixRoute(NamePrefixRoute):
"""Same as :class:`NamePrefixRoute`, but prefixes the route handler."""
_attr = 'handler'
class PathPrefixRoute(NamePrefixRoute):
"""Same as :class:`NamePrefixRoute`, but prefixes the route path.
For example, imagine we have these routes::
app = WSGIApplication([
Route('/users/<user:\w+>/', UserOverviewHandler,
'user-overview'),
Route('/users/<user:\w+>/profile', UserProfileHandler,
'user-profile'),
Route('/users/<user:\w+>/projects', UserProjectsHandler,
'user-projects'),
])
We could refactor them to reuse the common path prefix::
app = WSGIApplication([
PathPrefixRoute('/users/<user:\w+>', [
Route('/', UserOverviewHandler, 'user-overview'),
Route('/profile', UserProfileHandler, 'user-profile'),
Route('/projects', UserProjectsHandler, 'user-projects'),
]),
])
This is not only convenient, but also performs better: the nested routes
will only be tested if the path prefix matches.
"""
_attr = 'template'
def __init__(self, prefix, routes):
"""Initializes a URL route.
:param prefix:
The prefix to be prepended. It must start with a slash but not
end with a slash.
:param routes:
A list of :class:`webapp2.Route` instances.
"""
assert prefix.startswith('/') and not prefix.endswith('/'), \
'Path prefixes must start with a slash but not end with a slash.'
super(PathPrefixRoute, self).__init__(prefix, routes)
def get_match_routes(self):
# This route will do pre-matching before matching the nested routes!
yield self
def match(self, request):
if not self.regex.match(urllib.unquote(request.path)):
return None
return _match_routes(self.get_match_children, request)
@webapp2.cached_property
def regex(self):
regex, reverse_template, args_count, kwargs_count, variables = \
webapp2._parse_route_template(self.prefix + '<:/.*>')
return regex
class RedirectRoute(webapp2.Route):
"""A convenience route class for easy redirects.
It adds redirect_to, redirect_to_name and strict_slash options to
:class:`webapp2.Route`.
"""
def __init__(self, template, handler=None, name=None, defaults=None,
build_only=False, handler_method=None, methods=None,
schemes=None, redirect_to=None, redirect_to_name=None,
strict_slash=False):
"""Initializes a URL route. Extra arguments compared to
:meth:`webapp2.Route.__init__`:
:param redirect_to:
A URL string or a callable that returns a URL. If set, this route
is used to redirect to it. The callable is called passing
``(handler, *args, **kwargs)`` as arguments. This is a
convenience to use :class:`RedirectHandler`. These two are
equivalent::
route = Route('/foo', handler=webapp2.RedirectHandler,
defaults={'_uri': '/bar'})
route = Route('/foo', redirect_to='/bar')
:param redirect_to_name:
Same as `redirect_to`, but the value is the name of a route to
redirect to. In the example below, accessing '/hello-again' will
redirect to the route named 'hello'::
route = Route('/hello', handler=HelloHandler, name='hello')
route = Route('/hello-again', redirect_to_name='hello')
:param strict_slash:
If True, redirects access to the same URL with different trailing
slash to the strict path defined in the route. For example, take
these routes::
route = Route('/foo', FooHandler, strict_slash=True)
route = Route('/bar/', BarHandler, strict_slash=True)
Because **strict_slash** is True, this is what will happen:
- Access to ``/foo`` will execute ``FooHandler`` normally.
- Access to ``/bar/`` will execute ``BarHandler`` normally.
- Access to ``/foo/`` will redirect to ``/foo``.
- Access to ``/bar`` will redirect to ``/bar/``.
"""
super(RedirectRoute, self).__init__(
template, handler=handler, name=name, defaults=defaults,
build_only=build_only, handler_method=handler_method,
methods=methods, schemes=schemes)
if strict_slash and not name:
raise ValueError('Routes with strict_slash must have a name.')
self.strict_slash = strict_slash
self.redirect_to_name = redirect_to_name
if redirect_to is not None:
assert redirect_to_name is None
self.handler = webapp2.RedirectHandler
self.defaults['_uri'] = redirect_to
def get_match_routes(self):
"""Generator to get all routes that can be matched from a route.
:yields:
This route or all nested routes that can be matched.
"""
if self.redirect_to_name:
main_route = self._get_redirect_route(name=self.redirect_to_name)
else:
main_route = self
if not self.build_only:
if self.strict_slash is True:
if self.template.endswith('/'):
template = self.template[:-1]
else:
template = self.template + '/'
yield main_route
yield self._get_redirect_route(template=template)
else:
yield main_route
def _get_redirect_route(self, template=None, name=None):
template = template or self.template
name = name or self.name
defaults = self.defaults.copy()
defaults.update({
'_uri': self._redirect,
'_name': name,
})
new_route = webapp2.Route(template, webapp2.RedirectHandler,
defaults=defaults)
return new_route
def _redirect(self, handler, *args, **kwargs):
# Get from request because args is empty if named routes are set?
# args, kwargs = (handler.request.route_args,
# handler.request.route_kwargs)
kwargs.pop('_uri', None)
kwargs.pop('_code', None)
return handler.uri_for(kwargs.pop('_name'), *args, **kwargs)
def _match_routes(iter_func, request, extra_args=None, extra_kwargs=None):
"""Tries to match a route given an iterator."""
method_not_allowed = False
for route in iter_func():
try:
match = route.match(request)
if match:
route, args, kwargs = match
if extra_args:
args += extra_args
if extra_kwargs:
kwargs.update(extra_kwargs)
return route, args, kwargs
except exc.HTTPMethodNotAllowed:
method_not_allowed = True
if method_not_allowed:
raise exc.HTTPMethodNotAllowed()