--- loncom/interface/Attic/lonchart.pm	2001/10/19 22:03:05	1.8
+++ loncom/interface/Attic/lonchart.pm	2002/06/03 19:28:17	1.41
@@ -1,4 +1,30 @@
 # The LearningOnline Network with CAPA
+# (Publication Handler
+#
+# $Id: lonchart.pm,v 1.41 2002/06/03 19:28:17 albertel 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/
+#
 # Homework Performance Chart
 #
 # (Navigate Maps Handler
@@ -6,111 +32,159 @@
 # (Page Handler
 #
 # (TeX Content Handler
-#
+# YEAR=2000
 # 05/29/00,05/30 Gerd Kortemeyer)
 # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
 # 10/02,10/10,10/14,10/16,10/18,10/19,10/31,11/6,11/14,11/16 Gerd Kortemeyer)
-#
-# 3/1/1,6/1,17/1,29/1,30/1 Gerd Kortemeyer)
-#
-# 1/31 Gerd Kortemeyer
-#
+# YEAR=2001
+# 3/1/1,6/1,17/1,29/1,30/1,31/1 Gerd Kortemeyer)
 # 7/10/01 Behrouz Minaei
 # 9/8 Gerd Kortemeyer
-# 10/18/01, 10/19/01 Behrouz Minaei
+# 10/1, 10/19, 11/17, 11/22, 11/24, 11/28 12/18 Behrouz Minaei
+# YEAR=2002
+# 2/1, 2/6, 2/19, 2/28 Behrouz Minaei
+#
+###
 
 package Apache::lonchart;
 
 use strict;
 use Apache::Constants qw(:common :http);
 use Apache::lonnet();
+use Apache::loncommon();
 use HTML::TokeParser;
 use GDBM_File;
 
 # -------------------------------------------------------------- Module Globals
 my %hash;
+my %CachData;
 my @cols;
 my @rowlabels;
 my @students;
-
+my @PreCol;
+my $r;
+ 
 # ------------------------------------------------------------- Find out status
 
 sub ExtractStudentData {
     my ($index,$coid)=@_;
     my ($sname,$sdom) = split( /\:/, $students[$index] );
-    my $shome=&Apache::lonnet::homeserver( $sname,$sdom );          
-    my $reply=&Apache::lonnet::reply('dump:'.$sdom.':'.$sname.':'.$coid,$shome );
-    my %result=();
+    my %result=&Apache::lonnet::dump($coid,$sdom,$sname);
     my $ResId;
     my $Code;
     my $Tries;
     my $Wrongs;
     my %TempHash;
     my $Version;
-    my $LatestVersion;            
-                
+    my $ProbNo;
+    my $ProbSolved;
+    my $ProbTotal;
+    my $LatestVersion;                     
     my $Str=substr($students[$index].
             '                                                        ',0,14).' ! '.
             substr($rowlabels[$index].
             '                                                        ',0,45).' ! ';
 
-    unless ($reply=~/^error\:/) {
-        map {
-            my ($name,$value)=split(/\=/,&Apache::lonnet::unescape($_));
-            $result{$name}=$value;
-        } split(/\&/,$reply);
-        foreach $ResId (@cols) {
-	    if ( !$ResId ) { $Str .= ' ! '; next; }
-            $ResId=~/(\d+)\.(\d+)/;
-            my $Prob = &Apache::lonnet::declutter( $hash{'map_id_'.$1} ).
+    my($checkForError)=keys (%result);
+    if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
+	my $PrTot = sprintf( "%5d", $ProbTotal );
+	my $PrSvd = sprintf( "%5d", $ProbSolved );
+	$Str .= ' '.'<font color="#000088">'.$PrSvd.'  /'.$PrTot.'</font> ';
+	return $Str;
+    }
+
+    $ProbNo = 0;
+    $ProbTotal = 0;
+    $ProbSolved = 0;
+    my $IterationNo = 0;
+    foreach $ResId (@cols) {
+	if ($IterationNo == 0) {$IterationNo++; next;}
+	if (!$ResId) { 
+	    my $PrNo = sprintf( "%3d", $ProbNo );
+	    $Str .= ' '.'<font color="#007700">'.$PrNo.'</font> ';
+	    $ProbSolved += $ProbNo;
+	    $ProbNo=0;
+	    next; 
+	}
+	$ResId=~/(\d+)\.(\d+)/;
+	my $meta=$hash{'src_'.$ResId};
+	my $PartNo = 0;
+	undef %TempHash;
+	foreach (split(/\,/,&Apache::lonnet::metadata($meta,'keys'))) {
+	    if ($_=~/^stores\_(\d+)\_tries$/) {
+		my $Part=&Apache::lonnet::metadata($meta,$_.'.part');
+		if ( $TempHash{"$Part"} eq '' ) { 
+		    $TempHash{"$Part"} = $Part;
+		    $TempHash{$PartNo}=$Part;
+		    $TempHash{"$Part.Code"} = ' ';  
+		    $PartNo++;
+		}
+	    }
+	}
+
+	my $Prob = &Apache::lonnet::symbclean(
+		       &Apache::lonnet::declutter($hash{'map_id_'.$1} ).
                        '___'.$2.'___'.
-                       &Apache::lonnet::declutter( $hash{'src_'.$ResId} );
-            $Code=' ';
-            $Tries = 0;
-  	    $LatestVersion = $result{"version:$Prob"};
-
-	    undef %TempHash;
-	    my $PartNo = 0;
-            
-            if ( $LatestVersion ) {
-
-		for ( my $Version=1; $Version<=$LatestVersion; $Version++ ) {
-		    my $vkeys = $result{"$Version:keys:$Prob"};
-		    my @keys = split(/\:/,$vkeys);		  
-		    foreach my $Key (@keys) {		  
-			if (($Key=~/\.(\w+)\.solved$/) && ($Key!~/^\d+\:/)) {
-			    my $Part = $1;
-			    if ( $TempHash{"$Part"} eq '' ) { 
-				$TempHash{"$Part"} = $Part;
-				$TempHash{$PartNo}=$Part;  
-				$PartNo++;
-			    }
-			    $TempHash{"$Part.Tries"} = $result{"$Version:$Prob:resource.$Part.tries"};
-			    $Tries = $result{"$Version:$Prob:resource.$Part.tries"};
-			    my $Val = $result{"$Version:$Prob:$Key"};
-			    if ($Val eq 'correct_by_student'){$Code='*';} 
-			    elsif ($Val eq 'correct_by_override'){$Code = '+';}                        
-			    elsif ($Val eq 'incorrect_attempted'){$Code = '.';} 
-			    elsif ($Val eq 'incorrect_by_override'){$Code = '-';}
-			    elsif ($Val eq 'excused'){$Code = 'x';}
-			    $TempHash{"$Part.Code"} = $Code;
-			}
-      		    }
-                } 
-
-		for ( my $n = 0; $n < $PartNo; $n++ ) {		  
-		    my $part = $TempHash{$n};
-                    if (($TempHash{$part.'.Code'} eq '*')&&
-                        ($TempHash{$part.'.Tries'}<10)) {
-                        $TempHash{$part.'.Code'}=$Tries;
-                    }
-		    $Str .= $TempHash{$part.'.Code'}; 
+                       &Apache::lonnet::declutter( $hash{'src_'.$ResId} ));
+	$Code=' ';
+	$Tries = 0;
+	$LatestVersion = $result{"version:$Prob"};
+
+	if ( $LatestVersion ) {
+	    for ( my $Version=1; $Version<=$LatestVersion; $Version++ ) {
+		my $vkeys = $result{"$Version:keys:$Prob"};
+		my @keys = split(/\:/,$vkeys);		  
+
+		foreach my $Key (@keys) {		  
+		    if (($Key=~/\.(\w+)\.solved$/) && ($Key!~/^\d+\:/)) {
+			my $Part = $1;
+			$Tries = $result{"$Version:$Prob:resource.$Part.tries"};
+			$TempHash{"$Part.Tries"}=($Tries) ? $Tries : 0;
+			my $Val = $result{"$Version:$Prob:resource.$Part.solved"};
+			if ($Val eq 'correct_by_student'){$Code='*';} 
+			elsif ($Val eq 'correct_by_override'){$Code = '+';}
+			elsif ($Val eq 'incorrect_attempted'){$Code = '.';} 
+			elsif ($Val eq 'incorrect_by_override'){$Code = '-';}
+			elsif ($Val eq 'excused'){$Code = 'x';}
+			elsif ($Val eq 'ungraded_attempted'){$Code = '#';}
+			else {$Code = ' ';}
+
+			$TempHash{"$Part.Code"} = $Code;
+		    }
+		}
+	    }
+# Actually append problem to output (all parts)
+	    $Str.='<a href="/adm/grades?symb='.
+                &Apache::lonnet::escape($Prob).
+                '&student='.$sname.'&domain='.$sdom.'&command=submission">'; 
+	    for ( my $n = 0; $n < $PartNo; $n++ ) {		  
+		my $part = $TempHash{$n};
+		my $Code = $TempHash{"$part.Code"};
+		if ( $Code eq '*') {
+		    $ProbNo++;
+		    if (($TempHash{"$part.Tries"}<10) ||
+			($TempHash{"$part.Tries"} eq '')) {
+			$TempHash{"$part.Code"}=$TempHash{"$part.Tries"};
+		    }
 		}
-            }   
-	    else { $Str .= ' '; }
-        } 
+		elsif ( $Code eq '+' ) {$ProbNo++;}
+		$Str .= $TempHash{"$part.Code"};
+		if ( $Code ne 'x' ) {$ProbTotal++;}
+	    }
+	    $Str.='</a>';
+	} else {
+	    for(my $n=0; $n<$PartNo; $n++) {
+		$Str.=' ';
+		$ProbTotal++;
+	    }
+	}
     }
-    return $Str;
+
+    my $PrTot = sprintf( "%5d", $ProbTotal );
+    my $PrSvd = sprintf( "%5d", $ProbSolved );
+    $Str .= ' '.'<font color="#000088">'.$PrSvd.'  /'.$PrTot.'</font> ';
+
+    return $Str ;
 }
 
 
@@ -150,189 +224,298 @@ sub tracetable {
           }
        }
        if (defined($hash{'to_'.$rid})) {
-          map {
+          foreach (split(/\,/,$hash{'to_'.$rid})){
               &tracetable($hash{'goesto_'.$_},$beenhere);
-          } split(/\,/,$hash{'to_'.$rid});
+          }
        }
     }
 }
 
-# ================================================================ Main Handler
-
-sub handler {
-  my $r=shift;
-
-  if (&Apache::lonnet::allowed('vgr',$ENV{'request.course.id'})) {
-# ------------------------------------------- Set document type for header only
-
-  if ($r->header_only) {
-       if ($ENV{'browser.mathml'}) {
-           $r->content_type('text/xml');
-       } else {
-           $r->content_type('text/html');
-       }
-       $r->send_http_header;
-       return OK;
-   }
-
-  my $requrl=$r->uri;
-# ----------------------------------------------------------------- Tie db file
-  if ($ENV{'request.course.fn'}) {
-      my $fn=$ENV{'request.course.fn'};
-      if (-e "$fn.db") {
-          if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
-# ------------------------------------------------------------------- Hash tied
-
-
-# ------------------------------------------------------------------ Build page
-
-# ---------------------------------------------------------------- Send headers
-
-             $r->content_type('text/html');
-             $r->send_http_header;
-             $r->print(
-  '<html><head><title>LON-CAPA Assessment Chart</title></head>');
-
-	     $r->print('<body bgcolor="#FFFFFF">'.
-                                    '<script>window.focus();</script>'.
-                           '<img align=right src=/adm/lonIcons/lonlogos.gif>'.
-                                    '<h1>Assessment Chart</h1>');
-
-# ---------------------------------------------------------------- Course title
-
-    $r->print('<h1>'.
-    $ENV{'course.'.$ENV{'request.course.id'}.'.description'}.'</h1><h3>'.
-    localtime()."</h3><p><pre>1..9: correct by student in 1..9 tries\n".
-                            "   *: correct by student in more than 9 tries\n".
-	                    "   +: correct by override\n".
-                            "   -: incorrect by override\n".
-	                    "   .: incorrect attempted\n".
-                            "    : not attempted\n".
-	                    "   x: excused</pre><p>");
-  
-# ------------------------------- This is going to take a while, produce output
-
-             $r->rflush();
+sub usection {
+    my ($udom,$unam,$courseid,$ActiveFlag)=@_;
+    $courseid=~s/\_/\//g;
+    $courseid=~s/^(\w)/\/$1/;
+
+    my %result=&Apache::lonnet::dump('roles',$udom,$unam);
+
+    my($checkForError)=keys (%result);
+    if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
+	return -1;
+    }
+    my $cursection='-1';
+    my $oldsection='-1';
+    my $status='Expired';
+    foreach my $key (keys (%result)) {
+	my $value = $result{$key};
+        if ($key=~/^$courseid(?:\/)*(\w+)*\_st$/) {
+            my $section=$1;
+            if ($key eq $courseid.'_st') { $section=''; }
+	    my ($dummy,$end,$start)=split(/\_/,$value);
+	    my $now=time;
+	    my $notactive=0;
+	    if ($start) { if ($now<$start) { $notactive=1; } }
+	    if ($end) { if ($now>$end) { $notactive=1; } }
+	    if ($notactive == 0) { $status='Active';$cursection=$section;}
+	    if ($notactive == 1) { $oldsection=$section;}
+        }
+    }
+    if ($status eq $ActiveFlag) {
+      if ($cursection eq '-1') { return $oldsection; }
+      return $cursection;
+    }
+    if ($ActiveFlag eq 'Any') { 
+      if ($cursection eq '-1') { return $oldsection; }
+      return $cursection;
+    }
+    return '-1';
+}
 
+sub BuildChart {
 # ----------------------- Get first and last resource, see if there is anything
-
-
-              my $firstres=$hash{'map_start_/res/'.$ENV{'request.course.uri'}};
-              my $lastres=$hash{'map_finish_/res/'.$ENV{'request.course.uri'}};
-              if (($firstres) && ($lastres)) {
+    my $firstres=$hash{'map_start_/res/'.$ENV{'request.course.uri'}};
+    my $lastres=$hash{'map_finish_/res/'.$ENV{'request.course.uri'}};
+    if (($firstres) && ($lastres)) {
 # ----------------------------------------------------------------- Render page
-
-                 my $cid=$ENV{'request.course.id'};
-                 my $chome=$ENV{'course.'.$cid.'.home'};
-                 my ($cdom,$cnum)=split(/\_/,$cid);
-
+	my $cid=$ENV{'request.course.id'};
+        my $chome=$ENV{'course.'.$cid.'.home'};
+        my ($cdom,$cnum)=split(/\_/,$cid);
 # ---------------------------------------------- Read class list and row labels
+	my %classlist=&Apache::lonnet::dump('classlist',$cdom,$cnum);
 
-    undef @rowlabels;
-    undef @students;
+	my($checkForError)=keys (%classlist);
+	if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
+	    $r->print('<h1>Could not access course data</h1>');
+	} else {
+	    my $now=time;
+	    foreach my $name (sort(keys(%classlist))) {
+		my $value=$classlist{$name};
+		my ($end,$start)=split(/\:/,$value);
+		my $active=1;
+		my $Status=$ENV{'form.status'};
+		$Status = ($Status) ? $Status : 'Active';
+		if ( ( ($end) && $now > $end ) && 
+		     ( ($Status eq 'Active') ) ) { $active=0; }
+		if ( ($Status eq 'Expired') && 
+		     ($end == 0 || $now < $end) ) { $active=0; }
+		if ($active) {
+		    my $thisindex=$#students+1;
+		    $students[$thisindex]=$name;
+		    my ($sname,$sdom)=split(/\:/,$name);
+		    $PreCol[$thisindex]=$sname.':';
+		    my $ssec=&usection($sdom,$sname,$cid,$Status);
+		    if ($ssec==-1) {
+			$rowlabels[$thisindex]=
+			    'Data not available: '.$name;
+		    } else {
+			my %reply=&Apache::lonnet::idrget($sdom,$sname);
+			my %name=&Apache::lonnet::get('environment',
+						       ['lastname','generation'
+						       ,'firstname'
+						       ,'middlename'],
+						       $sdom,$sname);
+			my $name=$name{lastname};
+			if ($name{generation}) {$name.=" $name{generation}";}
+			$name.=',';
+			if ($name{firstname}) {$name.=" $name{firstname}";}
+			if ($name{middlename}) {$name.=" $name{middlename}";}
+			if ($name eq ',') {$name='';}
+			#$ssec=(int($ssec)) ? int($ssec) : $ssec;
+			my $sec=sprintf('%3s',$ssec);
+			$rowlabels[$thisindex]=$sec.' '.$reply{$sname}.' ';
+			$PreCol[$thisindex] .= $name.':'.$sec;
+			$rowlabels[$thisindex].=$name.' ';
+		    }
+		}
+	    }
+	}
+
+	my $allstudents=$#students+1;
+	$r->print('<h3>'.$allstudents.' students</h3>');
+	&CreateForm();
+	$r->rflush();
 
-    my $classlst=&Apache::lonnet::reply
-                                 ('dump:'.$cdom.':'.$cnum.':classlist',$chome);
-    my $now=time;
-    unless ($classlst=~/^error\:/) {
-        map {
-            my ($name,$value)=split(/\=/,$_);
-            my ($end,$start)=split(/\:/,&Apache::lonnet::unescape($value));
-            my $active=1;
-            if (($end) && ($now>$end)) { $active=0; }
-            if ($active) {
-                my $thisindex=$#students+1;
-                $name=&Apache::lonnet::unescape($name);
-                $students[$thisindex]=$name;
-                my ($sname,$sdom)=split(/\:/,$name);
-                my $ssec=&Apache::lonnet::usection($sdom,$sname,$cid);
-                if ($ssec==-1) {
-                    $rowlabels[$thisindex]=
-                      'Data not available: '.$name;
-                } else {
-                    my %reply=&Apache::lonnet::idrget($sdom,$sname);
-		    my $reply=&Apache::lonnet::reply('get:'.$sdom.':'.$sname.
-                                                     ':environment:lastname&generation&firstname&middlename',
-                                                     &Apache::lonnet::homeserver($sname,$sdom));
-                    $rowlabels[$thisindex]=
-                      sprintf('%3s',$ssec).' '.$reply{$sname}.' ';
-                    my $i=0;
-                    map {
-                      $i++;
-                      if ( $_ ne '') {
-                        $rowlabels[$thisindex].=&Apache::lonnet::unescape($_).' ';
-                      }
-                      if ($i == 2) {
-                        chop($rowlabels[$thisindex]);
-                        $rowlabels[$thisindex].=', ';
-                      }
-                    } split(/\&/,$reply);
-
-                }
-            }
-        } sort split(/\&/,$classlst);
+# --------------- Find all assessments and put them into some linear-like order
+	&tracetable($firstres,'&'.$lastres.'&');
+# ----------------------------------------------------------------- Start table
 
+        $r->print('<p><pre>');
+ 	my $index;
+        for ($index=0;$index<=$#students;$index++) {
+	    my $Str=&ExtractStudentData($index,$cid);
+	    $r->print($Str.'<br>');
+            $r->rflush();
+	    $CachData{$PreCol[$index]}=$Str;
+        }
+        $r->print('</pre>');
     } else {
-        $r->print('<h1>Could not access course data</h1>');
+	$r->print('<h3>Undefined course sequence</h3>');
     }
+}
 
-    my $allstudents=$#students+1;
-    $r->print('<h3>'.$allstudents.' students</h3>');
+sub CreateForm {
+    my $OpSel1='';
+    my $OpSel2='';
+    my $OpSel3='';
+    my $Status = $ENV{'form.status'};
+    if ( $Status eq 'Any' ) { $OpSel3='selected'; }
+    elsif ($Status eq 'Expired' ) { $OpSel2 = 'selected'; }
+    else { $OpSel1 = 'selected'; }
+
+    my $Ptr = '<form name=stat method=post action="/adm/chart" >'."\n";
+    $Ptr .= '<b> Sort by: &nbsp; </b>'."\n";
+    $Ptr .= '&nbsp;&nbsp;&nbsp;';
+    $Ptr .= '<input type=submit name=sort value="User Name" />'."\n";
+    $Ptr .= '&nbsp;&nbsp;&nbsp;';
+    $Ptr .= '<input type=submit name=sort value="Last Name" />'."\n";
+    $Ptr .= '&nbsp;&nbsp;&nbsp;';
+    $Ptr .= '<input type=submit name=sort value="Section"/>'."\n";
+    $Ptr .= '<br><br>';
+    $Ptr .= '<b> Student Status: &nbsp; </b>'."\n".
+            '<select name="status">'. 
+            '<option '.$OpSel1.' >Active</option>'."\n".
+            '<option '.$OpSel2.' >Expired</option>'."\n".
+	    '<option '.$OpSel3.' >Any</option> </select> '."\n";
+    $Ptr .= '&nbsp;&nbsp;&nbsp;';
+    $Ptr .= '<input type=submit name=sort value="Recalculate Chart"/>'."\n";
+    $Ptr .= '</form>'."\n";
+    $r->print( $Ptr );
+}
+
+sub CacheChart {
+    my %list = ();
+    my $count=0;
+
+    my $Pos = $ENV{'form.sort'};
+    if ( $Pos eq 'Last Name' ) {$Pos=1;}
+    elsif ( $Pos eq 'Section' ) {$Pos=2;}
+    else {$Pos=0;}
+
+    foreach my $key( keys %CachData) { 
+	my @Temp=split(/\:/,$key);
+	my $Use = $Temp[$Pos];
+	$list{$Use.$key}=$key;
+	$count++;
+    }
+
+    my @order = sort(keys(%list));
+
+    $r->print('<h3>'.$count.' students</h3>');
+    &CreateForm();
     $r->rflush();
+    
+    $r->print('<p><pre>');
+    for ( my $n; $n < $count; $n++) {
+	$r->print($CachData{$list{$order[$n]}}.'<br>');
+    }	
+    $r->print('</pre>');
+}
 
-# --------------- Find all assessments and put them into some linear-like order
+sub Start {
+    undef %hash;
+    undef %CachData;
+    undef @students;
+    undef @cols;
+    undef @rowlabels;
+    undef @PreCol;
 
-   &tracetable($firstres,'&'.$lastres.'&');
+    $r->print('<html><head><title>'.
+              'LON-CAPA Assessment Chart</title></head>');
+    $r->print('<body bgcolor="#FFFFFF">'.
+              '<script>window.focus();</script>'.
+              '<img align=right src=/adm/lonIcons/lonlogos.gif>'.
+              '<h1>Assessment Chart</h1>');
+# ---------------------------------------------------------------- Course title
+    $r->print('<h1>'.$ENV{'course.'.$ENV{'request.course.id'}.
+              '.description'}.'</h1><h3>'.localtime().
+              "</h3><p><pre>1..9: correct by student in 1..9 tries\n".
+              "   *: correct by student in more than 9 tries\n".
+	      "   +: correct by override\n".
+              "   -: incorrect by override\n".
+	      "   .: incorrect attempted\n".
+	      "   #: ungraded attempted\n".
+              "    : not attempted\n".
+	      "   x: excused</pre><p>"); 
+# ------------------------------- This is going to take a while, produce output
+    $r->rflush();
 
-# ----------------------------------------------------------------- Start table
+    my $cid=$ENV{'request.course.id'};
+    my $ChartDB = "/home/httpd/perl/tmp/$ENV{'user.name'}".
+                  "_$ENV{'user.domain'}_$cid\_chart.db";
+
+    if ((-e "$ChartDB") && ($ENV{'form.sort'} ne 'Recalculate Chart')) {
+	if (tie(%CachData,'GDBM_File',"$ChartDB",&GDBM_READER,0640)) {
+	    &CacheChart();
+	}
+	else {
+	    $r->print("Unable to tie hash to db file");
+	}
+    }
+    else {
+	if (tie(%CachData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
+	    foreach (keys %CachData) {delete $CachData{$_};}
+	    &BuildChart();
+	}
+	else {
+	    $r->print("Unable to tie hash to db file");
+	}
+    }
+    untie(%CachData);
+}
 
-                          $r->print('<p><pre>');
- 			  my $index;
-                           for ($index=0;$index<=$#students;$index++) {
-                              $r->print(&ExtractStudentData($index,$cid).'<br>');
-                              $r->rflush();
-                          }
-                          $r->print('</pre>');
+# ================================================================ Main Handler
 
-	     } else {
-                 $r->print('<h3>Undefined course sequence</h3>');
-             }
+sub handler {
+    $r=shift;
+    if (&Apache::lonnet::allowed('vgr',$ENV{'request.course.id'})) {
+# ------------------------------------------- Set document type for header only
+	if ($r->header_only) {
+	    if ($ENV{'browser.mathml'}) {
+		$r->content_type('text/xml');
+	    } else {
+		$r->content_type('text/html');
+	    }
+	    &Apache::loncommon::no_cache($r);
+	    $r->send_http_header;
+	    return OK;
+	}
 
-                      $r->print('</body></html>');
-                                     
+	my $requrl=$r->uri;
+# ----------------------------------------------------------------- Tie db file
+	if ($ENV{'request.course.fn'}) {
+	    my $fn=$ENV{'request.course.fn'};
+	    if (-e "$fn.db") {
+		if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
+# ------------------------------------------------------------------- Hash tied
+# ---------------------------------------------------------------- Send headers
+		    $r->content_type('text/html');
+		    $r->send_http_header;
+		    &Start();
+		    $r->print('</body></html>');                 
 # ------------------------------------------------------------- End render page
-              } else {
-                  $r->content_type('text/html');
-                  $r->send_http_header;
-		  $r->print('<html><body>Coursemap undefined.</body></html>');
-              }
+		} else {
+		    $r->content_type('text/html');
+		    $r->send_http_header;
+		    $r->print('<html><body>Coursemap undefined.</body></html>');
+		}
 # ------------------------------------------------------------------ Untie hash
-              unless (untie(%hash)) {
-                   &Apache::lonnet::logthis("<font color=blue>WARNING: ".
-                       "Could not untie coursemap $fn (browse).</font>"); 
-              }
+		unless (untie(%hash)) {
+		    &Apache::lonnet::logthis("<font color=blue>WARNING: ".
+			     "Could not untie coursemap $fn (browse).</font>"); 
+		}
 
 # -------------------------------------------------------------------- All done
-	      return OK;
+		return OK;
 # ----------------------------------------------- Errors, hash could no be tied
-      }
-  } else {
-  $ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized";
-  return HTTP_NOT_ACCEPTABLE; 
-}
-} else {
-      $ENV{'user.error.msg'}=
+	    }
+	} else {
+	    $ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized";
+	    return HTTP_NOT_ACCEPTABLE; 
+	}
+    } else {
+	$ENV{'user.error.msg'}=
         $r->uri.":vgr:0:0:Cannot view grades for complete course";
-      return HTTP_NOT_ACCEPTABLE; 
-
-}
+	return HTTP_NOT_ACCEPTABLE; 
+    }
 }
 1;
 __END__
-
-
-
-
-
-
-