--- loncom/auth/lonroles.pm 2000/02/22 21:36:44 1.1
+++ loncom/auth/lonroles.pm 2012/08/15 16:56:52 1.273
@@ -1,54 +1,2631 @@
# The LearningOnline Network with CAPA
# User Roles Screen
-# (Directory Indexer
-# (Login Screen
-# 5/21/99,5/22,5/25,5/26,5/31,6/2,6/10,7/12,7/14 Gerd Kortemeyer)
-# 11/23 Gerd Kortemeyer)
-# 1/14 Gerd Kortemeyer
#
+# $Id: lonroles.pm,v 1.273 2012/08/15 16:56:52 raeburn Exp $
+#
+# Copyright Michigan State University Board of Trustees
+#
+# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
+#
+# LON-CAPA is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# LON-CAPA is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with LON-CAPA; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+#
+# /home/httpd/html/adm/gpl.txt
+#
+# http://www.lon-capa.org/
+#
+###
+
+=pod
+
+=head1 NAME
+
+Apache::lonroles - User Roles Screen
+
+=head1 SYNOPSIS
+
+Invoked by /etc/httpd/conf/srm.conf:
+
+
+ PerlAccessHandler Apache::lonacc
+ SetHandler perl-script
+ PerlHandler Apache::lonroles
+ ErrorDocument 403 /adm/login
+ ErrorDocument 500 /adm/errorhandler
+
+
+=head1 OVERVIEW
+
+=head2 Choosing Roles
+
+C 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's C<&allowed> function that a certain
+action is not allowed, C 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.
+
+=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'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;
-use Apache::lonnet();
+use Apache::lonnet;
+use Apache::lonuserstate();
use Apache::Constants qw(:common);
-use CGI::Cookie();
+use Apache::File();
+use Apache::lonmenu;
+use Apache::loncommon;
+use Apache::lonhtmlcommon;
+use Apache::lonannounce;
+use Apache::lonlocal;
+use Apache::lonpageflip();
+use Apache::lonnavdisplay();
+use Apache::loncoursequeueadmin;
+use GDBM_File;
+use LONCAPA qw(:DEFAULT :match);
+use HTML::Entities;
+
+
+sub redirect_user {
+ my ($r,$title,$url,$msg) = @_;
+ $msg = $title if (! defined($msg));
+ &Apache::loncommon::content_type($r,'text/html');
+ &Apache::loncommon::no_cache($r);
+ $r->send_http_header;
+
+ # Breadcrumbs
+ my $brcrum = [{'href' => $url,
+ 'text' => 'Switching Role'},];
+ my $start_page = &Apache::loncommon::start_page('Switching Role',undef,
+ {'redirect' => [1,$url],
+ 'bread_crumbs' => $brcrum,});
+ my $end_page = &Apache::loncommon::end_page();
+
+# Note to style police:
+# This must only replace the spaces, nothing else, or it bombs elsewhere.
+ $url=~s/ /\%20/g;
+ $r->print(<$msg
+$end_page
+ENDREDIR
+ return;
+}
+
+sub error_page {
+ my ($r,$error,$dest)=@_;
+ &Apache::loncommon::content_type($r,'text/html');
+ &Apache::loncommon::no_cache($r);
+ $r->send_http_header;
+ return OK if $r->header_only;
+ # Breadcrumbs
+ my $brcrum = [{'href' => $dest,
+ 'text' => 'Problems during Course Initialization'},];
+ $r->print(&Apache::loncommon::start_page('Problems during Course Initialization',
+ undef,
+ {'bread_crumbs' => $brcrum,})
+ );
+ $r->print(
+ ''.
+ '