--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/middleware.py	Sat May 05 17:10:48 2012 -0500
@@ -0,0 +1,72 @@
+"""Common middleware for the entire project."""
+import datetime
+import logging
+
+from django.db import IntegrityError
+from django.contrib.auth import logout
+from django.conf import settings
+
+from core.functions import get_ip
+from core.whos_online import report_user, report_visitor
+
+
+class InactiveUserMiddleware(object):
+    """
+    This middleware ensures users with is_active set to False get their
+    session destroyed and are treated as logged out.
+    This middleware should come after the 'django.contrib.auth.middleware.
+    AuthenticationMiddleware' in settings.py.
+    Idea taken from: http://djangosnippets.org/snippets/1105/
+    """
+
+    def process_view(self, request, view_func, view_args, view_kwargs):
+        if request.user.is_authenticated() and not request.user.is_active:
+            logout(request)
+
+
+ONLINE_COOKIE = 'sg101_online'  # online cookie name
+ONLINE_TIMEOUT = 5 * 60         # online cookie lifetime in seconds
+
+
+class WhosOnline(object):
+    """
+    This middleware class keeps track of which registered users have
+    been seen recently, and the number of unique unregistered users.
+    This middleware should come after the authentication middleware,
+    as we count on the user attribute being attached to the request.
+    """
+
+    def process_response(self, request, response):
+        """
+        Keep track of who is online.
+        """
+        # Note that some requests may not have a user attribute
+        # as these may have been redirected in the middleware chain before
+        # the auth middleware got a chance to run. If this is the case, just
+        # bail out. We also ignore AJAX requests.
+
+        if not hasattr(request, 'user') or request.is_ajax():
+            return response
+
+        if request.user.is_authenticated():
+            if request.COOKIES.get(ONLINE_COOKIE) is None:
+                # report that we've seen the user
+                report_user(request.user.username)
+
+                # set a cookie to expire
+                response.set_cookie(ONLINE_COOKIE, '1', max_age=ONLINE_TIMEOUT)
+        else:
+            if request.COOKIES.get(settings.CSRF_COOKIE_NAME) is not None:
+                # We have a non-authenticated user that has cookies enabled. This
+                # means we can track them.
+                if request.COOKIES.get(ONLINE_COOKIE) is None:
+                    # see if we can get the IP address
+                    ip = get_ip(request)
+                    if ip:
+                        # report that we've seen this visitor
+                        report_visitor(ip)
+
+                        # set a cookie to expire
+                        response.set_cookie(ONLINE_COOKIE, '1', max_age=ONLINE_TIMEOUT)
+
+        return response