Add docstring to middleware

1 files changed, 14 insertions, 0 deletions

diff --git a/yaksh/middleware/one_session_per_user.py b/yaksh/middleware/one_session_per_user.py
index f382652..92e888d 100644
--- a/yaksh/middleware/one_session_per_user.py
+++ b/yaksh/middleware/one_session_per_user.py
@@ -5,9 +5,23 @@ from yaksh.models import ConcurrentUser
 
 
 class OneSessionPerUserMiddleware(object):
+    """
+    Middleware to handle multiple logins with same credentials
+        - Creates a Database entry to record the current user and active session key
+        - Checks if the current user has already been logged in. If True, the new session
+          key is stored with respect to the user and the old session key is deleted,
+          effectively terminating the older session for the same user.
+        - The concurrentuser attribute of the User model refers to the ConcurrentUser
+          model object and not the concurrent_user field due to behaviour described 
+          in the Documentation
+          Link: https://docs.djangoproject.com/en/1.5/topics/auth/customizing/#extending-the-existing-user-model)
+    """
     def process_request(self, request):
         if isinstance(request.user, User):
             current_key = request.session.session_key
+            # 
+            # Documentation: 
+            # https://docs.djangoproject.com/en/1.5/topics/auth/customizing/#extending-the-existing-user-model
             if hasattr(request.user, 'concurrentuser'):
                 active_key = request.user.concurrentuser.session_key
                 if active_key != current_key: