--- loncom/auth/lonroles.pm	2008/10/20 03:25:48	1.209
+++ loncom/auth/lonroles.pm	2008/11/12 20:01:09	1.210
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # User Roles Screen
 #
-# $Id: lonroles.pm,v 1.209 2008/10/20 03:25:48 raeburn Exp $
+# $Id: lonroles.pm,v 1.210 2008/11/12 20:01:09 jms Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -27,6 +27,103 @@
 #
 ###
 
+=pod
+
+=head1 NAME
+
+Apache::lonroles - User Roles Screen
+
+=head1 SYNOPSIS
+
+Invoked by /etc/httpd/conf/srm.conf:
+
+ <Location /adm/roles>
+ PerlAccessHandler       Apache::lonacc
+ SetHandler perl-script
+ PerlHandler Apache::lonroles
+ ErrorDocument     403 /adm/login
+ ErrorDocument	  500 /adm/errorhandler
+ </Location>
+
+=head1 OVERVIEW
+
+=head2 Choosing Roles
+
+C<lonroles> is a handler that allows a user to switch roles in
+mid-session. LON-CAPA attempts to work with "No Role Specified", the
+default role that a user has before selecting a role, as widely as
+possible, but certain handlers for example need specification which
+course they should act on, etc. Both in this scenario, and when the
+handler determines via C<lonnet>'s C<&allowed> function that a certain
+action is not allowed, C<lonroles> is used as error handler. This
+allows the user to select another role which may have permission to do
+what they were trying to do. C<lonroles> can also be accessed via the
+B<CRS> button in the Remote Control. 
+
+=begin latex
+
+\begin{figure}
+\begin{center}
+\includegraphics[width=0.45\paperwidth,keepaspectratio]{Sample_Roles_Screen}
+  \caption{\label{Sample_Roles_Screen}Sample Roles Screen} 
+\end{center}
+\end{figure}
+
+=end latex
+
+=head2 Role Initialization
+
+The privileges for a user are established at login time and stored in the session environment. As a consequence, a new role does not become active till the next login. Handlers are able to query for privileges using C<lonnet>'s C<&allowed> function. When a user first logs in, their role is the "common" role, which means that they have the sum of all of their privileges. During a session it might become necessary to choose a particular role, which as a consequence also limits the user to only the privileges in that particular role.
+
+=head1 INTRODUCTION
+
+This module enables a user to select what role he wishes to
+operate under (instructor, student, teaching assistant, course
+coordinator, etc).  These roles are pre-established by the actions
+of upper-level users.
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org.
+
+=head1 HANDLER SUBROUTINE
+
+This routine is called by Apache and mod_perl.
+
+=over 4
+
+=item *
+
+Roles Initialization (yes/no)
+
+=item *
+
+Get Error Message from Environment
+
+=item *
+
+Who is this?
+
+=item *
+
+Generate Page Output
+
+=item *
+
+Choice or no choice
+
+=item *
+
+Table
+
+=item *
+
+Privileges
+
+=back
+
+=cut
+
+
 package Apache::lonroles;
 
 use strict;