#NEWLINE# @ login_required #NEWLINE# def add_subscription( request , topic_id ) : #NEWLINE# #INDENT# topic = get_object_or_404 ( perms . filter_topics ( request . user , Topic . objects . all ( ) ) , pk = topic ) #NEWLINE# if ( not perms . may_subscribe_topic ( request . user , topic ) ) : #NEWLINE# #INDENT# raise PermissionDenied #NEWLINE# #UNINDENT# topic . subscribers . add ( request . user ) #NEWLINE# return HttpResponseRedirect ( topic . get_absolute_url ( ) )