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Append OR remove slash in django - like APPEND_SLASH but smarter.
from django import http
from django.utils.http import urlquote
from django import urls
from django.conf import settings
from django.utils.deprecation import MiddlewareMixin
class AppendOrRemoveSlashMiddleware(MiddlewareMixin):
"""Like django's built in APPEND_SLASH functionality, but also works in
reverse. Eg. will remove the slash if a slash-appended url won't resolve,
but its non-slashed counterpart will.
Additionally, if a 404 error is raised within a view for a non-slashed url,
and APPEND_SLASH is True, and the slash-appended url resolves, the
middleware will redirect. (The default APPEND_SLASH behaviour only catches
Resolver404, so wouldn't work in this case.)
See for more information."""
def process_request(self, request):
"""Returns a redirect if adding/removing a slash is appropriate. This
works in the same way as the default APPEND_SLASH behaviour but in
either direction."""
# check if the url is valid
urlconf = getattr(request, 'urlconf', None)
if not _is_valid_path(request.path_info, urlconf):
# if not, check if adding/removing the trailing slash helps
if request.path_info.endswith('/'):
new_path = request.path_info[:-1]
new_path = request.path_info + '/'
if _is_valid_path(new_path, urlconf):
# if the new url is valid, redirect to it
return http.HttpResponsePermanentRedirect(
generate_url(request, new_path))
def process_response(self, request, response):
"""If a 404 is raised within a view, try appending/removing the slash
(based on the setting) and redirecting if the new url is
if response.status_code == 404:
if not request.path_info.endswith('/') and settings.APPEND_SLASH:
new_path = request.path_info + '/'
elif request.path_info.endswith('/') and not settings.APPEND_SLASH:
new_path = request.path_info[:-1]
new_path = None
if new_path:
urlconf = getattr(request, 'urlconf', None)
if _is_valid_path(new_path, urlconf):
return http.HttpResponsePermanentRedirect(
generate_url(request, new_path))
return response
def generate_url(request, path):
if request.get_host():
new_url = "%s://%s%s" % (request.is_secure() and 'https' or 'http',
new_url = urlquote(path)
if request.GET:
new_url += '?' + request.META['QUERY_STRING']
return new_url
def _is_valid_path(path, urlconf=None):
Returns True if the given path resolves against the default URL resolver,
False otherwise.
urls.resolve(path, urlconf)
return True
except urls.Resolver404:
return False

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phoebebright commented Jun 19, 2013

Just what I needed. Thanks.

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