--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/middleware/common.py Fri Jul 18 18:22:23 2008 +0000
@@ -0,0 +1,134 @@
+import md5
+import re
+
+from django.conf import settings
+from django import http
+from django.core.mail import mail_managers
+from django.utils.http import urlquote
+from django.core import urlresolvers
+
+class CommonMiddleware(object):
+ """
+ "Common" middleware for taking care of some basic operations:
+
+ - Forbids access to User-Agents in settings.DISALLOWED_USER_AGENTS
+
+ - URL rewriting: Based on the APPEND_SLASH and PREPEND_WWW settings,
+ this middleware appends missing slashes and/or prepends missing
+ "www."s.
+
+ - If APPEND_SLASH is set and the initial URL doesn't end with a
+ slash, and it is not found in urlpatterns, a new URL is formed by
+ appending a slash at the end. If this new URL is found in
+ urlpatterns, then an HTTP-redirect is returned to this new URL;
+ otherwise the initial URL is processed as usual.
+
+ - ETags: If the USE_ETAGS setting is set, ETags will be calculated from
+ the entire page content and Not Modified responses will be returned
+ appropriately.
+ """
+
+ def process_request(self, request):
+ """
+ Check for denied User-Agents and rewrite the URL based on
+ settings.APPEND_SLASH and settings.PREPEND_WWW
+ """
+
+ # Check for denied User-Agents
+ if 'HTTP_USER_AGENT' in request.META:
+ for user_agent_regex in settings.DISALLOWED_USER_AGENTS:
+ if user_agent_regex.search(request.META['HTTP_USER_AGENT']):
+ return http.HttpResponseForbidden('<h1>Forbidden</h1>')
+
+ # Check for a redirect based on settings.APPEND_SLASH
+ # and settings.PREPEND_WWW
+ host = request.get_host()
+ old_url = [host, request.path]
+ new_url = old_url[:]
+
+ if (settings.PREPEND_WWW and old_url[0] and
+ not old_url[0].startswith('www.')):
+ new_url[0] = 'www.' + old_url[0]
+
+ # Append a slash if APPEND_SLASH is set and the URL doesn't have a
+ # trailing slash and there is no pattern for the current path
+ if settings.APPEND_SLASH and (not old_url[1].endswith('/')):
+ try:
+ urlresolvers.resolve(request.path)
+ except urlresolvers.Resolver404:
+ new_url[1] = new_url[1] + '/'
+ if settings.DEBUG and request.method == 'POST':
+ raise RuntimeError, (""
+ "You called this URL via POST, but the URL doesn't end "
+ "in a slash and you have APPEND_SLASH set. Django can't "
+ "redirect to the slash URL while maintaining POST data. "
+ "Change your form to point to %s%s (note the trailing "
+ "slash), or set APPEND_SLASH=False in your Django "
+ "settings.") % (new_url[0], new_url[1])
+
+ if new_url != old_url:
+ # Redirect if the target url exists
+ try:
+ urlresolvers.resolve(new_url[1])
+ except urlresolvers.Resolver404:
+ pass
+ else:
+ if new_url[0]:
+ newurl = "%s://%s%s" % (
+ request.is_secure() and 'https' or 'http',
+ new_url[0], urlquote(new_url[1]))
+ else:
+ newurl = urlquote(new_url[1])
+ if request.GET:
+ newurl += '?' + request.GET.urlencode()
+ return http.HttpResponsePermanentRedirect(newurl)
+
+ return None
+
+ def process_response(self, request, response):
+ "Check for a flat page (for 404s) and calculate the Etag, if needed."
+ if response.status_code == 404:
+ if settings.SEND_BROKEN_LINK_EMAILS:
+ # If the referrer was from an internal link or a non-search-engine site,
+ # send a note to the managers.
+ domain = request.get_host()
+ referer = request.META.get('HTTP_REFERER', None)
+ is_internal = _is_internal_request(domain, referer)
+ path = request.get_full_path()
+ if referer and not _is_ignorable_404(path) and (is_internal or '?' not in referer):
+ ua = request.META.get('HTTP_USER_AGENT', '<none>')
+ ip = request.META.get('REMOTE_ADDR', '<none>')
+ mail_managers("Broken %slink on %s" % ((is_internal and 'INTERNAL ' or ''), domain),
+ "Referrer: %s\nRequested URL: %s\nUser agent: %s\nIP address: %s\n" \
+ % (referer, request.get_full_path(), ua, ip))
+ return response
+
+ # Use ETags, if requested.
+ if settings.USE_ETAGS:
+ if response.has_header('ETag'):
+ etag = response['ETag']
+ else:
+ etag = md5.new(response.content).hexdigest()
+ if response.status_code >= 200 and response.status_code < 300 and request.META.get('HTTP_IF_NONE_MATCH') == etag:
+ cookies = response.cookies
+ response = http.HttpResponseNotModified()
+ response.cookies = cookies
+ else:
+ response['ETag'] = etag
+
+ return response
+
+def _is_ignorable_404(uri):
+ "Returns True if a 404 at the given URL *shouldn't* notify the site managers"
+ for start in settings.IGNORABLE_404_STARTS:
+ if uri.startswith(start):
+ return True
+ for end in settings.IGNORABLE_404_ENDS:
+ if uri.endswith(end):
+ return True
+ return False
+
+def _is_internal_request(domain, referer):
+ "Return true if the referring URL is the same domain as the current request"
+ # Different subdomains are treated as different domains.
+ return referer is not None and re.match("^https?://%s/" % re.escape(domain), referer)