--- loncom/interface/Attic/lonchart.pm	2002/07/02 21:48:36	1.52
+++ loncom/interface/Attic/lonchart.pm	2002/07/17 12:36:17	1.60
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # (Publication Handler
 #
-# $Id: lonchart.pm,v 1.52 2002/07/02 21:48:36 stredwic Exp $
+# $Id: lonchart.pm,v 1.60 2002/07/17 12:36:17 stredwic Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -48,6 +48,54 @@
 
 =pod
 
+=head1 NAME
+
+lonchart
+
+=head1 SYNOPSIS
+
+Quick display of students grades for a course in a compressed table format.
+
+=head1 DESCRIPTION
+
+This module process all student grades for a course and turns them into a 
+table like structure.
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org
+
+lonchart presents the user with a condensed view all a course's data.  The
+class title, the number of students, and the date for the last update of the
+displayed data.  There is also a legend that describes the chart values.  
+
+For each valid grade for a student is linked with a submission record for that
+problem.  The ability to add and remove columns of data from the chart was
+added for reducing the burden of having to scroll through large quantities
+of data.  The interface also allows for sorting of students by username,
+last name, and section number of class.  Active and expired students are
+also available.
+
+The interface is controlled by three primary buttons: Recalculate Chart, 
+Refresh Chart, and Reset Selections.  Recalculate Chart will update 
+the chart to the most recent data and keep the display settings for the chart
+the same.  Refresh Chart is used to redisplay the chart after selecting
+different output formatting.  Reset Selections is used to set the chart
+display options back to default values.
+
+=head1 CODE LAYOUT DESCRIPTION
+
+The code is broken down into three components: formatting data for printing,
+helper functions, and the central processing functions.  The module is broken 
+into chunks for each component.
+
+=head1 PACKAGES USED
+
+ Apache::Constants qw(:common :http)
+ Apache::lonnet()
+ Apache::loncommon()
+ HTML::TokeParser
+ GDBM_File
+
 =cut
 
 package Apache::lonchart;
@@ -56,21 +104,59 @@ use strict;
 use Apache::Constants qw(:common :http);
 use Apache::lonnet();
 use Apache::loncommon();
+use Apache::loncoursedata();
 use HTML::TokeParser;
 use GDBM_File;
 
 #my $jr; 
+
+=pod
+
+=head1 FORMAT DATA FOR PRINTING
+
+=cut
+
 # ----- FORMAT PRINT DATA ----------------------------------------------
 
+=pod
+
+=item &FormatStudentInformation()
+
+This function produces a formatted string of the student's information:
+username, domain, section, full name, and PID.
+
+=over 4
+
+Input: $cache, $name, $studentInformation, $spacePadding
+
+$cache: This is a pointer to a hash that is tied to the cached data
+
+$name:  The name and domain of the current student in name:domain format
+
+$studentInformation: A pointer to an array holding the names used to
+
+remove data from the hash.  They represent the name of the data to be removed.
+
+$spacePadding: Extra spaces that represent the space between columns
+
+Output: $Str
+
+$Str: Formatted string.
+
+=back
+
+=cut
+
 sub FormatStudentInformation {
     my ($cache,$name,$studentInformation,$spacePadding)=@_;
     my $Str='';
+    my $data;
 
     for(my $index=0; $index<(scalar @$studentInformation); $index++) {
-        if(!&ShouldShowColumn($cache, 'heading'.$index)) {
+        if(!&ShouldShowColumn($cache, 'ChartHeading'.$index)) {
             next;
         }
-	my $data=$cache->{$name.':'.$studentInformation->[$index]};
+        $data=$cache->{$name.':'.$studentInformation->[$index]};
 	$Str .= $data;
 
 	my @dataLength=split(//,$data);
@@ -83,8 +169,42 @@ sub FormatStudentInformation {
     return $Str;
 }
 
+=pod
+
+=item &FormatStudentData()
+
+First, FormatStudentInformation is called and prefixes the course information.
+This function produces a formatted string of the student's course information.
+Each column of data represents all the problems for a given sequence.  For
+valid grade data, a link is created for that problem to a submission record
+for that problem.
+
+=over 4
+
+Input: $name, $studentInformation, $spacePadding, $ChartDB
+
+$name: The name and domain of the current student in name:domain format
+
+$studentInformation: A pointer to an array holding the names used to 
+remove data from the hash.  They represent 
+the name of the data to be removed.
+
+$spacePadding: Extra spaces that represent the space between columns
+
+$ChartDB: The name of the cached data database which will be tied to that 
+database.
+
+Output: $Str
+
+$Str: Formatted string that is an entire row of the chart.  It is a 
+concatenation of student information and student course information.
+
+=back
+
+=cut
+
 sub FormatStudentData {
-    my ($name,$coid,$studentInformation,$spacePadding,$ChartDB)=@_;
+    my ($name,$studentInformation,$spacePadding,$ChartDB)=@_;
     my ($sname,$sdom) = split(/\:/,$name);
     my $Str;
     my %CacheData;
@@ -92,6 +212,14 @@ sub FormatStudentData {
     unless(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_READER,0640)) {
         return '';
     }
+
+#    my $section = &Apache::loncoursedata::CheckStatus($name, \%CacheData, 
+#                                               $CacheData{'form.Status'});
+#    if($section eq 'not found') {
+#        untie(%CacheData);
+#        return;
+#    }
+
     # Handle Student information ------------------------------------------
     # Handle user data
     $Str=&FormatStudentInformation(\%CacheData, $name, $studentInformation, 
@@ -117,7 +245,7 @@ sub FormatStudentData {
     my $problemsSolved  = 0;
     my $numberOfParts   = 0;
     foreach my $sequence (split(/\:/,$CacheData{'orderedSequences'})) {
-        if(!&ShouldShowColumn(\%CacheData, 'sequence'.$sequence)) {
+        if(!&ShouldShowColumn(\%CacheData, 'ChartSequence'.$sequence)) {
             next;
         }
 
@@ -126,6 +254,8 @@ sub FormatStudentData {
 	    my $problem = $CacheData{$problemID.':problem'};
 	    my $LatestVersion = $CacheData{$name.":version:$problem"};
 
+            # Output blanks for all the parts of this problem if there
+            # is no version information about the current problem.
             if(!$LatestVersion) {
                 foreach my $part (split(/\:/,$CacheData{$sequence.':'.
                                                         $problemID.
@@ -138,13 +268,19 @@ sub FormatStudentData {
             }
 
             my %partData=undef;
-            #initialize data, displays skips correctly
+            # Initialize part data, display skips correctly
+            # Skip refers to when a student made no submissions on that
+            # part/problem.
             foreach my $part (split(/\:/,$CacheData{$sequence.':'.
                                                     $problemID.
                                                     ':parts'})) {
                 $partData{$part.':tries'}=0;
                 $partData{$part.':code'}=' ';
             }
+
+            # Looping through all the versions of each part, starting with the
+            # oldest version.  Basically, it gets the most recent 
+            # set of grade data for each part.
 	    for(my $Version=1; $Version<=$LatestVersion; $Version++) {
                 foreach my $part (split(/\:/,$CacheData{$sequence.':'.
                                                         $problemID.
@@ -152,6 +288,7 @@ sub FormatStudentData {
 
                     if(!defined($CacheData{$name.":$Version:$problem".
                                                ":resource.$part.solved"})) {
+                        # No grade for this submission, so skip
                         next;
                     }
 
@@ -175,6 +312,9 @@ sub FormatStudentData {
                 }
             }
 
+            # All grades (except for versionless parts) are displayed as links
+            # to their submission record.  Loop through all the parts for the
+            # current problem in the correct order and prepare the output links
             $Str.='<a href="/adm/grades?symb='.
                 &Apache::lonnet::escape($problem).
                 '&student='.$sname.'&domain='.$sdom.'&command=submission">'; 
@@ -200,6 +340,9 @@ sub FormatStudentData {
             $Str.='</a>';
         }
 
+        # Output the number of correct answers for the current sequence.
+        # This part takes up 6 character slots, but is formated right 
+        # justified.
         my $spacesNeeded=$CacheData{$sequence.':columnWidth'}-$characterCount;
         $spacesNeeded -= 3;
         $Str .= (' 'x$spacesNeeded);
@@ -212,6 +355,9 @@ sub FormatStudentData {
         $Str .= $spacePadding;
     }
 
+    # Output the total correct problems over the total number of problems.
+    # I don't like this type of formatting, but it is a solution.  Need
+    # a way to dynamically determine the space requirements.
     my $outputProblemsSolved = sprintf( "%4d", $problemsSolved );
     my $outputTotalProblems  = sprintf( "%4d", $totalProblems );
     $Str .= '<font color="#000088">'.$outputProblemsSolved.
@@ -221,15 +367,43 @@ sub FormatStudentData {
     return $Str;
 }
 
+=pod
+
+=item &CreateTableHeadings()
+
+This function generates the column headings for the chart.
+
+=over 4
+
+Inputs: $CacheData, $studentInformation, $headings, $spacePadding
+
+$CacheData: pointer to a hash tied to the cached data database
+
+$studentInformation: a pointer to an array containing the names of the data 
+held in a column and is used as part of a key into $CacheData
+
+$headings: The names of the headings for the student information
+
+$spacePadding: The spaces to go between columns
+
+Output: $Str
+
+$Str: A formatted string of the table column headings.
+
+=back
+
+=cut
+
 sub CreateTableHeadings {
     my ($CacheData,$studentInformation,$headings,$spacePadding)=@_;
-    my $Str='<pre>';
+    my $Str='<tr>';
 
     for(my $index=0; $index<(scalar @$headings); $index++) {
-        if(!&ShouldShowColumn($CacheData, 'heading'.$index)) {
+        if(!&ShouldShowColumn($CacheData, 'ChartHeading'.$index)) {
             next;
         }
 
+        $Str .= '<td align="left"><pre>';
 	my $data=$$headings[$index];
 	$Str .= $data;
 
@@ -238,13 +412,15 @@ sub CreateTableHeadings {
 	$Str .= (' 'x($CacheData->{$$studentInformation[$index].'Length'}-
                       $length));
 	$Str .= $spacePadding;
+        $Str .= '</pre></td>';
     }
 
     foreach my $sequence (split(/\:/,$CacheData->{'orderedSequences'})) {
-        if(!&ShouldShowColumn($CacheData, 'sequence'.$sequence)) {
+        if(!&ShouldShowColumn($CacheData, 'ChartSequence'.$sequence)) {
             next;
         }
 
+        $Str .= '<td align="left"><pre>';
         my $name = $CacheData->{$sequence.':title'};
 	$Str .= $name;
 	my @titleLength=split(//,$CacheData->{$sequence.':title'});
@@ -252,39 +428,69 @@ sub CreateTableHeadings {
                      (scalar @titleLength);
 	$Str .= (' 'x$leftover);
 	$Str .= $spacePadding;
+        $Str .= '</pre></td>';
     }
 
-    $Str .= 'Total Solved/Total Problems';
-    $Str .= '</pre>';
+    $Str .= '<td><pre>Total Solved/Total Problems</pre></td>';
+    $Str .= '</tr>';
 
     return $Str;
 }
 
+=pod
+
+=item &CreateColumnSelectionBox()
+
+If there are columns not being displayed then this selection box is created
+with a list of those columns.  When selections are made and the page 
+refreshed, the columns will be removed from this box and the column is
+put back in the chart.  If there is no columns to select, no row is added
+to the interface table.
+
+=over 4
+Input: $CacheData, $headings
+
+
+$CacheData: A pointer to a hash tied to the cached data
+
+$headings:  An array of the names of the columns for the student information.  
+They are used for displaying which columns are missing.
+
+Output: $notThere
+
+$notThere: The string contains one row of a table.  The first column has the 
+name of the selection box.  The second contains the selection box 
+which has a size of four.
+
+=back
+
+=cut
+
 sub CreateColumnSelectionBox {
-    my ($CacheData,$studentInformation,$headings,$spacePadding)=@_;
+    my ($CacheData,$headings)=@_;
 
     my $missing=0;
     my $notThere='<tr><td align="right"><b>Select column to view:</b>';
     my $name;
     $notThere .= '<td align="left">';
-    $notThere .= '<select name="reselect" size="4" multiple="true">'."\n";
+    $notThere .= '<select name="ChartReselect" size="4" multiple="true">'."\n";
 
     for(my $index=0; $index<(scalar @$headings); $index++) {
-        if(&ShouldShowColumn($CacheData, 'heading'.$index)) {
+        if(&ShouldShowColumn($CacheData, 'ChartHeading'.$index)) {
             next;
         }
         $name = $headings->[$index];
-        $notThere .= '<option value="heading'.$index.'">';
+        $notThere .= '<option value="ChartHeading'.$index.'">';
         $notThere .= $name.'</option>'."\n";
         $missing++;
     }
 
     foreach my $sequence (split(/\:/,$CacheData->{'orderedSequences'})) {
-        if(&ShouldShowColumn($CacheData, 'sequence'.$sequence)) {
+        if(&ShouldShowColumn($CacheData, 'ChartSequence'.$sequence)) {
             next;
         }
         $name = $CacheData->{$sequence.':title'};
-        $notThere .= '<option value="sequence'.$sequence.'">';
+        $notThere .= '<option value="ChartSequence'.$sequence.'">';
         $notThere .= $name.'</option>'."\n";
         $missing++;
     }
@@ -295,91 +501,129 @@ sub CreateColumnSelectionBox {
         $notThere='<tr><td>';
     }
 
-    return $notThere.'</td></tr></tbody></table>';
+    return $notThere.'</td></tr>';
 }
 
+=pod
+
+=item &CreateColumnSelectors()
+
+This function generates the checkboxes above the column headings.  The 
+column will be removed if the checkbox is unchecked.
+
+=over 4
+
+Input: $CacheData, $headings
+
+$CacheData: A pointer to a hash tied to the cached data
+
+$headings:  An array of the names of the columns for the student 
+information.  They are used to know what are the student information columns
+
+Output: $present
+
+$present: The string contains the first row of a table.  Each column contains
+a checkbox which is left justified.  Currently left justification is used
+for consistency of location over the column in which it presides.
+
+=back
+
+=cut
+
 sub CreateColumnSelectors {
-    my ($CacheData,$studentInformation,$headings,$spacePadding)=@_;
+    my ($CacheData,$headings)=@_;
 
     my $found=0;
     my ($name, $length, $position);
-    my $present='<pre>';
+
+    my $present = '<tr>';
     for(my $index=0; $index<(scalar @$headings); $index++) {
-        if(!&ShouldShowColumn($CacheData, 'heading'.$index)) {
+        if(!&ShouldShowColumn($CacheData, 'ChartHeading'.$index)) {
             next;
         }
-        $name = $headings->[$index];
-        $length=$CacheData->{$$studentInformation[$index].'Length'};
-        $position=int($length/2);
-	$present .= (' 'x($position));
+        $present .= '<td align="left">';
         $present .= '<input type="checkbox" checked="on" ';
-        $present .= 'name="heading'.$index.'">';
-        $position+=2;
-	$present .= (' 'x($length-$position));
-	$present .= $spacePadding;
+        $present .= 'name="ChartHeading'.$index.'" />';
+        $present .= '</td>';
         $found++;
     }
 
     foreach my $sequence (split(/\:/,$CacheData->{'orderedSequences'})) {
-        if(!&ShouldShowColumn($CacheData, 'sequence'.$sequence)) {
+        if(!&ShouldShowColumn($CacheData, 'ChartSequence'.$sequence)) {
             next;
         }
-        $name = $CacheData->{$sequence.':title'};
-        $length=$CacheData->{$sequence.':columnWidth'};
-        $position=int($length/2);
-	$present .= (' 'x($position));
+        $present .= '<td align="left">';
         $present .= '<input type="checkbox" checked="on" ';
-        $present .= 'name="sequence'.$sequence.'">';
-        $position+=2;
-	$present .= (' 'x($length-$position));
-	$present .= $spacePadding;
+        $present .= 'name="ChartSequence'.$sequence.'" />';
+        $present .= '</td>';
         $found++;
     }
 
-    if($found) {
-        $present .= '</pre>';
-        $present  = $present;
-    } else {
+    if(!$found) {
         $present = '';
     }
 
-    return $present.'</form>'."\n";;
+    return $present.'<td></td></tr></form>'."\n";;
 }
 
+=pod
+
+=item &CreateForm()
+
+The interface for this module consists primarily of the controls in this
+function.  The student status selection (active, expired, any) is set here.
+The sort buttons: username, last name, and section are set here.  The
+other buttons are Recalculate Chart, Refresh Chart, and Reset Selections.
+These controls are in a table to clean up the interface.
+
+=over 4
+
+Input: $CacheData
+
+$CacheData is a hash pointer to tied database for cached data.
+
+Output: $Ptr
+
+$Ptr is a string containing all the html for the above mentioned buttons.
+
+=back
+
+=cut
+
 sub CreateForm {
     my ($CacheData)=@_;
     my $OpSel1='';
     my $OpSel2='';
     my $OpSel3='';
-    my $Status = $CacheData->{'form.status'};
+    my $Status = $CacheData->{'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 .= '<table border="0"><tbody>';
+    my $Ptr .= '<form name="ChartStat" method="post" action="/adm/chart" >';
+    $Ptr .= "\n";
     $Ptr .= '<tr><td align="right">';
     $Ptr .= '</td><td align="left">';
-    $Ptr .= '<input type="submit" name="recalculate" ';
+    $Ptr .= '<input type="submit" name="ChartRecalculate" ';
     $Ptr .= 'value="Recalculate Chart"/>'."\n";
     $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="refresh" ';
+    $Ptr .= '<input type="submit" name="ChartRefresh" ';
     $Ptr .= 'value="Refresh Chart"/>'."\n";
     $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="reset" ';
+    $Ptr .= '<input type="submit" name="ChartReset" ';
     $Ptr .= 'value="Reset Selections"/></td>'."\n";
     $Ptr .= '</tr><tr><td align="right">';
     $Ptr .= '<b> Sort by: </b>'."\n";
     $Ptr .= '</td><td align="left">';
-    $Ptr .= '<input type="submit" name="sort" value="User Name" />'."\n";
+    $Ptr .= '<input type="submit" name="ChartSort" value="User Name" />'."\n";
     $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="sort" value="Last Name" />'."\n";
+    $Ptr .= '<input type="submit" name="ChartSort" value="Last Name" />'."\n";
     $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="sort" value="Section"/>'."\n";
+    $Ptr .= '<input type="submit" name="ChartSort" value="Section"/>'."\n";
     $Ptr .= '</td></tr><tr><td align="right">';
     $Ptr .= '<b> Student Status: &nbsp; </b>'."\n".
             '</td><td align="left">'.
-            '<select name="status">'. 
+            '<select name="Status">'. 
             '<option '.$OpSel1.' >Active</option>'."\n".
             '<option '.$OpSel2.' >Expired</option>'."\n".
 	    '<option '.$OpSel3.' >Any</option> </select> '."\n";
@@ -388,6 +632,16 @@ sub CreateForm {
     return $Ptr;
 }
 
+=pod
+
+=item &CreateLegend()
+
+This function returns a formatted string containing the legend for the
+chart.  The legend describes the symbols used to represent grades for
+problems.
+
+=cut
+
 sub CreateLegend {
     my $Str = "<p><pre>".
               "1..9: correct by student in 1..9 tries\n".
@@ -402,16 +656,25 @@ sub CreateLegend {
     return $Str;
 }
 
+=pod
+
+=item &StartDocument()
+
+Returns a string containing the header information for the chart: title,
+logo, and course title.
+
+=cut
+
 sub StartDocument {
+    my ($title, $header)=@_;
     my $Str = '';
     $Str .= '<html>';
     $Str .= '<head><title>';
-    $Str .= 'LON-CAPA Assessment Chart</title></head>';
+    $Str .= $title.'</title></head>';
     $Str .= '<body bgcolor="#FFFFFF">';
     $Str .= '<script>window.focus();</script>';
     $Str .= '<img align=right src=/adm/lonIcons/lonlogos.gif>';
-    $Str .= '<h1>Assessment Chart</h1>';
-    $Str .= '<h3>'.localtime().'</h3>';
+    $Str .= '<h1>'.$header.'</h1>';
     $Str .= '<h1>'.$ENV{'course.'.$ENV{'request.course.id'}.'.description'};
     $Str .= '</h1>';
 
@@ -420,435 +683,187 @@ sub StartDocument {
 
 # ----- END FORMAT PRINT DATA ------------------------------------------
 
-# ----- DOWNLOAD INFORMATION -------------------------------------------
+=pod
 
-sub DownloadPrerequisiteData {
-    my ($courseID, $c)=@_;
-    my ($courseDomain,$courseNumber)=split(/\_/,$courseID);
+=head1 HELPER FUNCTIONS
 
-    my %classlist=&Apache::lonnet::dump('classlist',$courseDomain,
-                                        $courseNumber);
-    my ($checkForError)=keys (%classlist);
-    if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
-        return \%classlist;
-    }
+These are just a couple of functions do various odd and end 
+jobs.
 
-    foreach my $name (keys(%classlist)) {
-        if($c->aborted()) {
-            $classlist{'error'}='aborted';
-            return \%classlist;
-        }
+=cut
 
-        my ($studentName,$studentDomain) = split(/\:/,$name);
-        # Download student environment data, specifically the full name and id.
-        my %studentInformation=&Apache::lonnet::get('environment',
-                                                    ['lastname','generation',
-                                                     'firstname','middlename',
-                                                     'id'],
-                                                    $studentDomain,
-                                                    $studentName);
-        $classlist{$name.':studentInformation'}=\%studentInformation;
+# ----- HELPER FUNCTIONS -----------------------------------------------
 
-        if($c->aborted()) {
-            $classlist{'error'}='aborted';
-            return \%classlist;
-        }
+=pod
 
-        #Section
-        my %section=&Apache::lonnet::dump('roles',$studentDomain,$studentName);
-        $classlist{$name.':section'}=\%section;
-    }
+=item &ProcessFormData()
 
-    return \%classlist;
-}
+Cache form data and set default form data (sort, status, heading.$number,
+sequence.$number, reselect, reset, recalculate, and refresh)
 
-sub DownloadStudentCourseInformation {
-    my ($name,$courseID)=@_;
-    my ($studentName,$studentDomain) = split(/\:/,$name);
-
-    # Download student course data
-    my %courseData=&Apache::lonnet::dump($courseID,$studentDomain,
-					 $studentName);
-    return \%courseData;
-}
+=over 4
 
-# ----- END DOWNLOAD INFORMATION ---------------------------------------
+Input: $ChartDB, $isCached
 
-# ----- END PROCESSING FUNCTIONS ---------------------------------------
+$ChartDB: The name of the database for cached data
 
-sub ProcessTopResourceMap {
-    my ($ChartDB,$c)=@_;
-    my %hash;
-    my $fn=$ENV{'request.course.fn'};
-    if(-e "$fn.db") {
-	my $tieTries=0;
-	while($tieTries < 3) {
-	    if(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
-		last;
-	    }
-	    $tieTries++;
-	    sleep 1;
-	}
-	if($tieTries >= 3) {
-            return 'Coursemap undefined.';
-        }
-    } else {
-        return 'Can not open Coursemap.';
-    }
+$isCached: Is there already data for this course cached.  This is used in 
+conjunction with the absence of all form data to know to display all selection 
+types.
+
+Output: None
+
+=back
 
+=cut
+
+# For all data, if ENV data doesn't exist for it, default values is used.
+sub ProcessFormData {
+    my ($ChartDB, $isCached)=@_;
     my %CacheData;
-    unless(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
-        untie(%hash);
-	return 'Could not tie cache hash.';
-    }
 
-    my (@sequences, @currentResource, @finishResource);
-    my ($currentSequence, $currentResourceID, $lastResourceID);
+    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
+        # Ignore $ENV{'form.ChartRefresh'}
+        # Ignore $ENV{'form.ChartRecalculate'}
 
-    $currentResourceID=$hash{'ids_/res/'.$ENV{'request.course.uri'}};
-    push(@currentResource, $currentResourceID);
-    $lastResourceID=-1;
-    $currentSequence=-1;
-    my $topLevelSequenceNumber = $currentSequence;
+        if(defined($ENV{'form.ChartSort'})) {
+            $CacheData{'form.ChartSort'}=$ENV{'form.ChartSort'};
+        } elsif(!defined($CacheData{'form.ChartSort'})) {
+            $CacheData{'form.ChartSort'}='username';
+        }
 
-    while(1) {
-        if($c->aborted()) {
-            last;
+        if(defined($ENV{'form.Status'})) {
+            $CacheData{'form.Status'}=$ENV{'form.Status'};
+        } elsif(!defined($CacheData{'form.Status'})) {
+            $CacheData{'form.Status'}='Active';
         }
-	# HANDLE NEW SEQUENCE!
-	#if page || sequence
-	if(defined($hash{'map_pc_'.$hash{'src_'.$currentResourceID}})) {
-	    push(@sequences, $currentSequence);
-	    push(@currentResource, $currentResourceID);
-	    push(@finishResource, $lastResourceID);
-
-	    $currentSequence=$hash{'map_pc_'.$hash{'src_'.$currentResourceID}};
-
-            # Mark sequence as containing problems.  If it doesn't, then
-            # it will be removed when processing for this sequence is
-            # complete.  This allows the problems in a sequence
-            # to be outputed before problems in the subsequences
-            if(!defined($CacheData{'orderedSequences'})) {
-                $CacheData{'orderedSequences'}=$currentSequence;
-            } else {
-                $CacheData{'orderedSequences'}.=':'.$currentSequence;
-            }
 
-	    $lastResourceID=$hash{'map_finish_'.
-				  $hash{'src_'.$currentResourceID}};
-	    $currentResourceID=$hash{'map_start_'.
-				     $hash{'src_'.$currentResourceID}};
-
-	    if(!($currentResourceID) || !($lastResourceID)) {
-		$currentSequence=pop(@sequences);
-		$currentResourceID=pop(@currentResource);
-		$lastResourceID=pop(@finishResource);
-		if($currentSequence eq $topLevelSequenceNumber) {
-		    last;
-		}
-	    }
-	}
+        # $found checks for any instances of form data in the ENV.  If it is
+        # missing I assume the chrt button on the remote has been pressed.
+        my @headings=();
+        my @sequences=();
+        my $found=0;
+        foreach (keys(%ENV)) {
+            if(/form\.ChartHeading/) {
+                $found++;
+                push(@headings, $_);
+            } elsif(/form\.ChartSequence/) {
+                $found++;
+                push(@sequences, $_);
+            } elsif(/form\./) {
+                $found++;
+            }
+        }
 
-	# Handle gradable resources: exams, problems, etc
-	$currentResourceID=~/(\d+)\.(\d+)/;
-        my $partA=$1;
-        my $partB=$2;
-	if($hash{'src_'.$currentResourceID}=~
-	   /\.(problem|exam|quiz|assess|survey|form)$/ &&
-	   $partA eq $currentSequence) {
-	    my $Problem = &Apache::lonnet::symbclean(
-			  &Apache::lonnet::declutter($hash{'map_id_'.$partA}).
-			  '___'.$partB.'___'.
-			  &Apache::lonnet::declutter($hash{'src_'.
-							 $currentResourceID}));
-
-	    $CacheData{$currentResourceID.':problem'}=$Problem;
-	    if(!defined($CacheData{$currentSequence.':problems'})) {
-		$CacheData{$currentSequence.':problems'}=$currentResourceID;
-	    } else {
-		$CacheData{$currentSequence.':problems'}.=
-		    ':'.$currentResourceID;
-	    }
-
-            #Get Parts for problem
-	    my $meta=$hash{'src_'.$currentResourceID};
-	    foreach (split(/\,/,&Apache::lonnet::metadata($meta,'keys'))) {
-		if($_=~/^stores\_(\d+)\_tries$/) {
-		    my $Part=&Apache::lonnet::metadata($meta,$_.'.part');
-                    if(!defined($CacheData{$currentSequence.':'.
-                                          $currentResourceID.':parts'})) {
-                        $CacheData{$currentSequence.':'.$currentResourceID.
-                                   ':parts'}=$Part;
-                    } else {
-                        $CacheData{$currentSequence.':'.$currentResourceID.
-                                   ':parts'}.=':'.$Part;
-                    }
-		}
-	    }
-	}
+        if($found) {
+            $CacheData{'form.ChartHeadings'}=join(":::",@headings);
+            $CacheData{'form.ChartSequences'}=join(":::",@sequences);
+        }
 
-	#if resource == finish resource
-	if($currentResourceID eq $lastResourceID) {
-	    #pop off last resource of sequence
-	    $currentResourceID=pop(@currentResource);
-	    $lastResourceID=pop(@finishResource);
-
-	    if(defined($CacheData{$currentSequence.':problems'})) {
-		# Capture sequence information here
-		$CacheData{$currentSequence.':title'}=
-		    $hash{'title_'.$currentResourceID};
-
-                my $totalProblems=0;
-                foreach my $currentProblem (split(/\:/,
-                                               $CacheData{$currentSequence.
-                                               ':problems'})) {
-                    foreach (split(/\:/,$CacheData{$currentSequence.':'.
-                                                   $currentProblem.
-                                                   ':parts'})) {
-                        $totalProblems++;
-                    }
+        if(defined($ENV{'form.ChartReselect'})) {
+            my @reselected = (ref($ENV{'form.ChartReselect'}) ? 
+                              @{$ENV{'form.ChartReselect'}}
+                              : ($ENV{'form.ChartReselect'}));
+            foreach (@reselected) {
+                if(/ChartHeading/) {
+                    $CacheData{'form.ChartHeadings'}.=":::".$_;
+                } elsif(/ChartSequence/) {
+                    $CacheData{'form.ChartSequences'}.=":::".$_;
                 }
-		my @titleLength=split(//,$CacheData{$currentSequence.
-                                                    ':title'});
-                # $extra is 3 for problems correct and 3 for space
-                # between problems correct and problem output
-                my $extra = 6;
-		if(($totalProblems + $extra) > (scalar @titleLength)) {
-		    $CacheData{$currentSequence.':columnWidth'}=
-                        $totalProblems + $extra;
-		} else {
-		    $CacheData{$currentSequence.':columnWidth'}=
-                        (scalar @titleLength);
-		}
-	    } else {
-                $CacheData{'orderedSequences'}=~s/$currentSequence//;
-                $CacheData{'orderedSequences'}=~s/::/:/g;
-                $CacheData{'orderedSequences'}=~s/^:|:$//g;
             }
+        }
 
-	    $currentSequence=pop(@sequences);
-	    if($currentSequence eq $topLevelSequenceNumber) {
-		last;
-	    }
-	}
+        # !$found and !$isCached are how I determine if the chrt button
+        # on the remote was pressed and needs to reset all the selections
+        if(defined($ENV{'form.ChartReset'}) || (!$found && !$isCached)) {
+            $CacheData{'form.ChartReset'}='true';
+            $CacheData{'form.Status'}='Active';
+            $CacheData{'form.ChartSort'}='username';
+            $CacheData{'form.ChartHeadings'}='ALLHEADINGS';
+            $CacheData{'form.ChartSequences'}='ALLSEQUENCES';
+        } else {
+            $CacheData{'form.ChartReset'}='false';
+        }
 
-	# MOVE!!!
-	#move to next resource
-	unless(defined($hash{'to_'.$currentResourceID})) {
-	    # big problem, need to handle.  Next is probably wrong
-	    last;
-	}
-	my @nextResources=();
-	foreach (split(/\,/,$hash{'to_'.$currentResourceID})) {
-	    push(@nextResources, $hash{'goesto_'.$_});
-	}
-	push(@currentResource, @nextResources);
-	# Set the next resource to be processed
-	$currentResourceID=pop(@currentResource);
+        untie(%CacheData);
     }
 
-    unless (untie(%hash)) {
-        &Apache::lonnet::logthis("<font color=blue>WARNING: ".
-                                 "Could not untie coursemap $fn (browse)".
-                                 ".</font>"); 
-    }
+    return;
+}
 
-    unless (untie(%CacheData)) {
-        &Apache::lonnet::logthis("<font color=blue>WARNING: ".
-                                 "Could not untie Cache Hash (browse)".
-                                 ".</font>"); 
-    }
+=pod
 
-    return 'OK';
-}
+=item &SpaceColumns()
 
-sub ProcessSection {
-    my ($sectionData, $courseid,$ActiveFlag)=@_;
-    $courseid=~s/\_/\//g;
-    $courseid=~s/^(\w)/\/$1/;
-
-    my $cursection='-1';
-    my $oldsection='-1';
-    my $status='Expired';
-    my $section='';
-    foreach my $key (keys (%$sectionData)) {
-	my $value = $sectionData->{$key};
-        if ($key=~/^$courseid(?:\/)*(\w+)*\_st$/) {
-	    $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;
-		last;
-	    }
-	    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';
-}
+Determines the width of all the columns in the chart.  It is based on
+the max of the data for that column and its header.
 
-sub ProcessStudentInformation {
-    my ($CacheData,$studentInformation,$section,$date,$name,$courseID,$c)=@_;
-    my ($studentName,$studentDomain) = split(/\:/,$name);
-
-    $CacheData->{$name.':username'}=$studentName;
-    $CacheData->{$name.':domain'}=$studentDomain;
-    $CacheData->{$name.':date'}=$date;
-
-    my ($checkForError)=keys(%$studentInformation);
-    if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
-	$CacheData->{$name.':error'}=
-	    'Could not download student environment data.';
-	$CacheData->{$name.':fullname'}='';
-	$CacheData->{$name.':id'}='';
-    } else {
-	$CacheData->{$name.':fullname'}=&ProcessFullName(
-                                          $studentInformation->{'lastname'},
-				          $studentInformation->{'generation'},
-				          $studentInformation->{'firstname'},
-                                          $studentInformation->{'middlename'});
-	$CacheData->{$name.':id'}=$studentInformation->{'id'};
-    }
+=over 4
 
-    # Get student's section number
-    my $sec=&ProcessSection($section, $courseID, $CacheData->{'form.status'});
-    if($sec != -1) {
-	$CacheData->{$name.':section'}=$sec;
-    } else {
-	$CacheData->{$name.':section'}='';
-    }
+Input: $students, $studentInformation, $headings, $ChartDB
 
-    return 0;
-}
+$students: An array pointer to a list of students (username:domain)
 
-sub ProcessClassList {
-    my ($classlist,$courseID,$ChartDB,$c)=@_;
-    my @names=();
+$studentInformatin: The type of data for the student information.  It is
+used as part of the key in $CacheData.
 
-    my %CacheData;
-    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
-        foreach my $name (keys(%$classlist)) {
-            if($name =~ /\:section/ || $name =~ /\:studentInformation/ ||
-               $name eq '') {
-                next;
-            }
-            if($c->aborted()) {
-                last;
-            }
-            push(@names,$name);
-            &ProcessStudentInformation(
-                                    \%CacheData,
-                                    $classlist->{$name.':studentInformation'},
-                                    $classlist->{$name.':section'},
-                                    $classlist->{$name},
-                                    $name,$courseID,$c);
-        }
+$headings: The name of the student information columns.
 
-	untie(%CacheData);
-    }
+$ChartDB: The name of the cache database which is opened for read/write.
 
-    return @names;
-}
+Output: None - All data stored in cache.
 
-# ----- END PROCESSING FUNCTIONS ---------------------------------------
+=back
 
-# ----- HELPER FUNCTIONS -----------------------------------------------
+=cut
 
 sub SpaceColumns {
-    my ($students,$studentInformation,$headings,$ChartDB)=@_;
+    my ($students,$studentInformation,$headings,$cache)=@_;
 
-    my %CacheData;
-    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
-        # Initialize Lengths
-        for(my $index=0; $index<(scalar @$headings); $index++) {
-	    my @titleLength=split(//,$$headings[$index]);
-	    $CacheData{$$studentInformation[$index].'Length'}=
-                scalar @titleLength;
-	}
+    # Initialize Lengths
+    for(my $index=0; $index<(scalar @$headings); $index++) {
+        my @titleLength=split(//,$$headings[$index]);
+        $cache->{$$studentInformation[$index].'Length'}=
+            scalar @titleLength;
+    }
 
-        foreach my $name (@$students) {
-            foreach (@$studentInformation) {
-		my @dataLength=split(//,$CacheData{$name.':'.$_});
-		my $length=scalar @dataLength;
-		if($length > $CacheData{$_.'Length'}) {
-		    $CacheData{$_.'Length'}=$length;
-		}
+    foreach my $name (@$students) {
+        foreach (@$studentInformation) {
+            my @dataLength=split(//,$cache->{$name.':'.$_});
+            my $length=scalar @dataLength;
+            if($length > $cache->{$_.'Length'}) {
+                $cache->{$_.'Length'}=$length;
             }
         }
-        untie(%CacheData);
     }
 
     return;
 }
 
-sub ProcessFullName {
-    my ($lastname, $generation, $firstname, $middlename)=@_;
-    my $Str = '';
+=pod
 
-    if($lastname ne '') {
-	$Str .= $lastname.' ';
-	if($generation ne '') {
-	    $Str .= $generation;
-	} else {
-	    chop($Str);
-	}
-	$Str .= ', ';
-	if($firstname ne '') {
-	    $Str .= $firstname.' ';
-	}
-	if($middlename ne '') {
-	    $Str .= $middlename;
-	} else {
-	    chop($Str);
-	    if($firstname eq '') {
-		chop($Str);
-	    }
-	}
-    } else {
-	if($firstname ne '') {
-	    $Str .= $firstname.' ';
-	}
-	if($middlename ne '') {
-	    $Str .= $middlename.' ';
-	}
-	if($generation ne '') {
-	    $Str .= $generation;
-	} else {
-	    chop($Str);
-	}
-    }
+=item &SortStudents()
 
-    return $Str;
-}
+Determines which students to display and in which order.  Which are 
+displayed are determined by their status(active/expired).  The order
+is determined by the sort button pressed (default to username).  The
+type of sorting is username, lastname, or section.
+
+=over 4
+
+Input: $students, $CacheData
+
+$students: A array pointer to a list of students (username:domain)
+
+$CacheData: A pointer to the hash tied to the cached data
+
+Output: @order
+
+@order: An ordered list of students (username:domain)
+
+=back
+
+=cut
 
 sub SortStudents {
     my ($students,$CacheData)=@_;
@@ -858,7 +873,7 @@ sub SortStudents {
         my ($end,$start)=split(/\:/,$CacheData->{$_.':date'});
         my $active=1;
         my $now=time;
-        my $Status=$CacheData->{'form.status'};
+        my $Status=$CacheData->{'form.Status'};
         $Status = ($Status) ? $Status : 'Active';
         if((($end) && $now > $end) && (($Status eq 'Active'))) { 
             $active=0; 
@@ -871,7 +886,7 @@ sub SortStudents {
         }
     }
 
-    my $Pos = $CacheData->{'form.sort'};
+    my $Pos = $CacheData->{'form.ChartSort'};
     my %sortData;
     if($Pos eq 'Last Name') {
 	for(my $index=0; $index<scalar @sorted1Students; $index++) {
@@ -898,156 +913,84 @@ sub SortStudents {
     return @order;
 }
 
-sub TestCacheData {
-    my ($ChartDB)=@_;
-    my $isCached=-1;
-    my %testData;
-    my $tieTries=0;
+=pod
 
-    if ((-e "$ChartDB") && (!defined($ENV{'form.recalculate'}))) {
-	$isCached = 1;
-    } else {
-	$isCached = 0;
-    }
+=item &ShouldShowColumn()
 
-    while($tieTries < 10) {
-        my $result=0;
-        if($isCached) {
-            $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_READER,0640);
-        } else {
-            $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_NEWDB,0640);
-        }
-        if($result) {
-            last;
-        }
-        $tieTries++;
-        sleep 1;
-    }
-    if($tieTries >= 10) {
-        return -1;
-    }
+Determine if a specified column should be shown on the chart.
 
-    untie(%testData);
+=over 4
 
-    return $isCached;
-}
+Input: $cache, $test
 
-sub ExtractStudentData {
-    my ($courseData, $name, $ChartDB)=@_;
+$cache: A pointer to the hash tied to the cached data
 
-    my %CacheData;
-    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
-        my ($checkForError) = keys(%$courseData);
-        if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
-            $CacheData{$name.':error'}='Could not download course data.';
-        } else {
-            foreach my $key (keys (%$courseData)) {
-                $CacheData{$name.':'.$key}=$courseData->{$key};
-            }
-            if(defined($CacheData{'NamesOfStudents'})) {
-                $CacheData{'NamesOfStudents'}.=':::'.$name;
-            } else {
-                $CacheData{'NamesOfStudents'}=$name;
-            }
-        }
-        untie(%CacheData);
-    }
+$test: The form name of the column (heading.$headingIndex) or 
+(sequence.$sequenceIndex)
 
-    return;
-}
+Output: 0 (false), 1 (true)
+
+=back
+
+=cut
 
 sub ShouldShowColumn {
     my ($cache,$test)=@_;
 
-    if($cache->{'form.reset'} eq 'true') {
+    if($cache->{'form.ChartReset'} eq 'true') {
         return 1;
     }
 
-    my $headings=$cache->{'form.headings'};
-    my $sequences=$cache->{'form.sequences'};
+    my $headings=$cache->{'form.ChartHeadings'};
+    my $sequences=$cache->{'form.ChartSequences'};
     if($headings eq 'ALLHEADINGS' || $sequences eq 'ALLSEQUENCES' ||
        $headings=~/$test/ || $sequences=~/$test/) {
         return 1;
     }
 
-#    my $reselected=$cache->{'form.reselect'};
-#    if($reselected=~/$test/) {
-#        return 1;
-#    }
-
     return 0;
 }
 
-sub ProcessFormData {
-    my ($ChartDB)=@_;
-    my %CacheData;
+# ----- END HELPER FUNCTIONS --------------------------------------------
 
-    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
-        if(defined($ENV{'form.sort'})) {
-            $CacheData{'form.sort'}=$ENV{'form.sort'};
-        } elsif(!defined($CacheData{'form.sort'})) {
-            $CacheData{'form.sort'}='username';
-        }
+=pod
 
-        # Ignore $ENV{'form.refresh'}
-        # Ignore $ENV{'form.recalculate'}
-
-        if(defined($ENV{'form.status'})) {
-            $CacheData{'form.status'}=$ENV{'form.status'};
-        } elsif(!defined($CacheData{'form.status'})) {
-            $CacheData{'form.status'}='Active';
-        }
+=head1 Handler and main function(BuildChart)
 
-        my @headings=();
-        my @sequences=();
-        my $found=0;
-        foreach (keys(%ENV)) {
-            if(/form\.heading/) {
-                $found++;
-                push(@headings, $_);
-            } elsif(/form\.sequence/) {
-                $found++;
-                push(@sequences, $_);
-            } elsif(/form\./) {
-                $found++;
-            }
-        }
+The handler does some initial error checking and then passes the torch to
+BuildChart.  BuildChart calls all the appropriate functions to get the
+job done.  These are the only two functions that use print ($r).  All other
+functions return strings to BuildChart to be printed.
 
-        if($found) {
-            $CacheData{'form.headings'}=join(":::",@headings);
-            $CacheData{'form.sequences'}=join(":::",@sequences);
-        }
+=cut
 
-        if(defined($ENV{'form.reselect'})) {
-            my @reselected = (ref($ENV{'form.reselect'}) ? 
-                              @{$ENV{'form.reselect'}}
-                              : ($ENV{'form.reselect'}));
-            foreach (@reselected) {
-                if(/heading/) {
-                    $CacheData{'form.headings'}.=":::".$_;
-                } elsif(/sequence/) {
-                    $CacheData{'form.sequences'}.=":::".$_;
-                }
-            }
-        }
+=pod
 
-        if(defined($ENV{'form.reset'})) {
-            $CacheData{'form.reset'}='true';
-            $CacheData{'form.status'}='Active';
-            $CacheData{'form.sort'}='username';
-            $CacheData{'form.headings'}='ALLHEADINGS';
-            $CacheData{'form.sequences'}='ALLSEQUENCES';
-        } else {
-            $CacheData{'form.reset'}='false';
-        }
+=item &BuildChart()
 
-        untie(%CacheData);
-    }
+ The following is the process that BuildChart goes through to 
+  create the html document.
 
-    return;
-}
+ -Start the lonchart document
+ -Test for access to the CacheData
+ -Download class list information if not using cached data 
+ -Sort students and print out table desciptive data
+ -Output student data
+ -If recalculating, store a list of students, but only if all 
+  their data was downloaded.  Leave off the others.
+ -End document
 
-# ----- END HELPER FUNCTIONS --------------------------------------------
+=over 4
+
+Input: $r
+
+$r:  Used to print html
+
+Output: None
+
+=back
+
+=cut
 
 sub BuildChart {
     my ($r)=@_;
@@ -1056,7 +999,7 @@ sub BuildChart {
     # Start the lonchart document
     $r->content_type('text/html');
     $r->send_http_header;
-    $r->print(&StartDocument());
+    $r->print(&StartDocument('LON-CAPA Assessment Chart', 'Assessment Chart'));
     $r->rflush();
 
     # Test for access to the CacheData
@@ -1064,14 +1007,17 @@ sub BuildChart {
     my $cid=$ENV{'request.course.id'};
     my $ChartDB = "/home/httpd/perl/tmp/$ENV{'user.name'}".
                   "_$ENV{'user.domain'}_$cid\_chart.db";
-
-    $isCached=&TestCacheData($ChartDB);
+    my $isRecalculate=0;
+    if(defined($ENV{'form.ChartRecalculate'})) {
+        $isRecalculate=1;
+    }
+    $isCached=&Apache::loncoursedata::TestCacheData($ChartDB, $isRecalculate);
     if($isCached < 0) {
-        $r->print("Unable to tie hash to db file");
+        $r->print("Unable to tie hash to db file</body></html>");
         $r->rflush();
         return;
     }
-    &ProcessFormData($ChartDB);
+    &ProcessFormData($ChartDB, $isCached);
 
     # Download class list information if not using cached data
     my %CacheData;
@@ -1080,24 +1026,65 @@ sub BuildChart {
     my @headings=('User Name','Domain','Section','PID','Full Name');
     my $spacePadding='   ';
     if(!$isCached) {
-        my $processTopResourceMapReturn=&ProcessTopResourceMap($ChartDB,$c);
+        unless(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
+            $r->print("Unable to tie hash to db file</body></html>");
+            $r->rflush();
+            return;
+        }
+
+        my $processTopResourceMapReturn=
+            &Apache::loncoursedata::ProcessTopResourceMap(\%CacheData,$c);
         if($processTopResourceMapReturn ne 'OK') {
-            $r->print($processTopResourceMapReturn);
+            $r->print($processTopResourceMapReturn.'</body></html>');
+            untie(%CacheData);
             return;
         }
-        if($c->aborted()) { return; }
-        my $classlist=&DownloadPrerequisiteData($cid, $c);
+
+        if($c->aborted()) {
+            untie(%CacheData);
+            $r->print('</body></html>'); 
+            return;
+        }
+
+        my $classlist=&Apache::loncoursedata::DownloadStudentNamePIDSection(
+                                                                   $cid, $c);
         my ($checkForError)=keys(%$classlist);
         if($checkForError =~ /^(con_lost|error|no_such_host)/i ||
            defined($classlist->{'error'})) {
+            $r->print("Error getting student data.</body></html>");
+            $r->rflush();
+            untie(%CacheData);
             return;
         }
-        if($c->aborted()) { return; }
-        @students=&ProcessClassList($classlist,$cid,$ChartDB,$c);
-        if($c->aborted()) { return; }
+
+        if($c->aborted()) {
+            untie(%CacheData);
+            $r->print('</body></html>'); 
+            return;
+        }
+
+
+        @students=&Apache::loncoursedata::ProcessClassList(\%CacheData, 
+                                                     $classlist, $cid, 
+                                                     $CacheData{'form.Status'},
+                                                     $c);
+
+        if($c->aborted()) {
+            untie(%CacheData);
+            $r->print('</body></html>'); 
+            return;
+        }
+
         &SpaceColumns(\@students,\@studentInformation,\@headings,
-                      $ChartDB);
-        if($c->aborted()) { return; }
+                      \%CacheData);
+
+        if($c->aborted()) {
+            untie(%CacheData);
+            $r->print('</body></html>'); 
+            return;
+        }
+
+        untie(%CacheData);
     } else {
         if(!$c->aborted() && tie(%CacheData,'GDBM_File',$ChartDB,
                                  &GDBM_READER,0640)) {
@@ -1106,28 +1093,36 @@ sub BuildChart {
     }
 
     # Sort students and print out table desciptive data
+    my $downloadTime=0;
     if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_READER,0640)) {
         if(!$c->aborted()) { @students=&SortStudents(\@students,\%CacheData); }
+        if(defined($CacheData{'time'})) { $downloadTime=$CacheData{'time'}; }
+        else { $downloadTime=localtime(); }
+        if(!$c->aborted()) { $r->print('<h3>'.$downloadTime.'</h3>'); }
         if(!$c->aborted()) { $r->print('<h1>'.(scalar @students).
                                        ' students</h1>'); }
 	if(!$c->aborted()) { $r->rflush(); }
 	if(!$c->aborted()) { $r->print(&CreateLegend()); }
+        if(!$c->aborted()) { $r->print('<table border="0"><tbody>'); }
 	if(!$c->aborted()) { $r->print(&CreateForm(\%CacheData)); }
 	if(!$c->aborted()) { $r->print(&CreateColumnSelectionBox(
                                                        \%CacheData,
-                                                       \@studentInformation, 
-						       \@headings, 
-                                                       $spacePadding)); }
+                                                       \@headings)); }
+        if(!$c->aborted()) { $r->print('</tbody></table>'); }
+        if(!$c->aborted()) { $r->print('<b>Note: Uncheck the boxes above a'); }
+        if(!$c->aborted()) { $r->print(' column to remove that column from'); }
+        if(!$c->aborted()) { $r->print(' the display.</b></pre>'); }
+        if(!$c->aborted()) { $r->print('<table border="0" cellpadding="0" '); }
+        if(!$c->aborted()) { $r->print('cellspacing="0"><tbody>'); }
 	if(!$c->aborted()) { $r->print(&CreateColumnSelectors(
                                                        \%CacheData,
-                                                       \@studentInformation, 
-						       \@headings, 
-                                                       $spacePadding)); }
+                                                       \@headings)); }
 	if(!$c->aborted()) { $r->print(&CreateTableHeadings(
                                                          \%CacheData,
                                                          \@studentInformation, 
 							 \@headings, 
 							 $spacePadding)); }
+        if(!$c->aborted()) { $r->print('</tbody></table>'); }
 	if(!$c->aborted()) { $r->rflush(); }
 	untie(%CacheData);
     } else {
@@ -1135,6 +1130,7 @@ sub BuildChart {
 	return;
     }
 
+    # Output student data
     my @updateStudentList = ();
     my $courseData;
     $r->print('<pre>');
@@ -1144,16 +1140,26 @@ sub BuildChart {
         }
 
         if(!$isCached) {
-            $courseData=&DownloadStudentCourseInformation($_, $cid);
+            $courseData=
+                &Apache::loncoursedata::DownloadStudentCourseInformation($_, 
+                                                                         $cid);
             if($c->aborted()) { last; }
-            push(@updateStudentList, $_);
-            &ExtractStudentData($courseData, $_, $ChartDB);
+            if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
+                &Apache::loncoursedata::ProcessStudentData(\%CacheData, 
+                                                           $courseData, $_);
+                push(@updateStudentList, $_);
+                untie(%CacheData);
+            } else {
+                next;
+            }
         }
-        $r->print(&FormatStudentData($_, $cid, \@studentInformation,
+        $r->print(&FormatStudentData($_, \@studentInformation,
                                      $spacePadding, $ChartDB));
         $r->rflush();
     }
 
+    # If recalculating, store a list of students, but only if all their 
+    # data was downloaded.  Leave off the others.
     if(!$isCached && tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
         $CacheData{'NamesOfStudents'}=join(":::", @updateStudentList);
 #		    $CacheData{'NamesOfStudents'}=
@@ -1161,6 +1167,7 @@ sub BuildChart {
         untie(%CacheData);
     }
 
+    # End document
     $r->print('</pre></body></html>');
     $r->rflush();
 
@@ -1169,6 +1176,26 @@ sub BuildChart {
 
 # ================================================================ Main Handler
 
+=pod
+
+=item &handler()
+
+The handler checks for permission to access the course data and for 
+initial header problem.  Then it passes the torch to the work horse
+function BuildChart.
+
+=over 4
+
+Input: $r
+
+$r: This is the object that is used to print.
+
+Output: A Value (OK or HTTP_NOT_ACCEPTABLE)
+
+=back
+
+=cut
+
 sub handler {
     my $r=shift;
 #    $jr=$r;
@@ -1189,7 +1216,7 @@ sub handler {
         $r->send_http_header;
         return OK;
     }
-    
+
     unless($ENV{'request.course.fn'}) {
         my $requrl=$r->uri;
         $ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized";