--- loncom/interface/spreadsheet/assesscalc.pm	2003/10/03 15:39:46	1.17.2.2
+++ loncom/interface/spreadsheet/assesscalc.pm	2005/05/17 18:04:40	1.49
@@ -1,5 +1,5 @@
 #
-# $Id: assesscalc.pm,v 1.17.2.2 2003/10/03 15:39:46 albertel Exp $
+# $Id: assesscalc.pm,v 1.49 2005/05/17 18:04:40 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -44,6 +44,8 @@ assesscalc
 package Apache::assesscalc;
 
 use strict;
+use warnings FATAL=>'all';
+no warnings 'uninitialized';
 use Apache::Constants qw(:common :http);
 use Apache::lonnet;
 use Apache::loncommon;
@@ -53,6 +55,7 @@ use HTML::Entities();
 use Spreadsheet::WriteExcel;
 use GDBM_File;
 use Time::HiRes;
+use Apache::lonlocal;
 
 @Apache::assesscalc::ISA = ('Apache::Spreadsheet');
 
@@ -89,6 +92,7 @@ use Time::HiRes;
 ########################################################
 
 my %Exportrows;
+my %newExportrows;
 
 my $current_name;
 my $current_domain;
@@ -98,7 +102,9 @@ my %parmhash;
 my %nice_parameter_name;
 
 my %useropt;
+my %userdata;
 my %courseopt;
+my $navmap;
 
 ########################################################
 ########################################################
@@ -109,23 +115,50 @@ my %courseopt;
 
 =item &clear_package()
 
-Reset all package variables.  
+Reset all package variables and clean up caches.
 
 =cut
 
 ########################################################
 ########################################################
 sub clear_package {
+    if (defined($current_name) &&
+        defined($current_domain) &&
+        defined($current_course) &&
+        $current_course eq $env{'request.course.id'} &&
+        %newExportrows) {
+        &save_cached_export_rows($current_name,$current_domain);
+    }
     undef(%Exportrows);
+    undef(%newExportrows);
     undef($current_name);
     undef($current_domain);
     undef($current_course);
     undef(%useropt);
+    undef(%userdata);
     undef(%courseopt);
+    undef($navmap);
+}
+
+sub save_cached_export_rows {
+    my ($sname,$sdomain) = @_;
+    my $result = &Apache::lonnet::put
+        ('nohist_calculatedsheets_'.$env{'request.course.id'},
+         $newExportrows{$sname.':'.$sdomain},
+         $sdomain,$sname);
+    delete($newExportrows{$sname.':'.$sdomain});
 }
 
 sub initialize {
+    my ($in_navmap) = @_;
     &clear_package();
+    $navmap = $in_navmap;
+    if (! defined($navmap)) {
+        $navmap = Apache::lonnavmaps::navmap->new();
+    }
+    if (!defined($navmap)) {
+        &Apache::lonnet::logthis('assesscalc:Can not open Coursemap');
+    }
     &Apache::loncoursedata::clear_internal_caches();
 }
 
@@ -141,11 +174,14 @@ sub initialize {
 ########################################################
 ########################################################
 sub initialize_package {
-    my ($sname,$sdomain) = @_;
+    my ($sname,$sdomain,$in_navmap) = @_;
     $current_name   = $sname;
     $current_domain = $sdomain;
-    if ($current_course ne $ENV{'request.course.id'}) {
-        $current_course = $ENV{'request.course.id'};
+    $navmap = $in_navmap;
+    undef(%useropt);
+    undef(%userdata);
+    if ($current_course ne $env{'request.course.id'}) {
+        $current_course = $env{'request.course.id'};
         undef(%courseopt);
     }
     &load_cached_export_rows();
@@ -153,6 +189,7 @@ sub initialize_package {
     &Apache::loncoursedata::clear_internal_caches();
 }
 
+
 ########################################################
 ########################################################
 
@@ -170,15 +207,13 @@ sub load_parameter_caches {
     #
     # Course Parameters Cache
     if (! %courseopt) {
-        &Apache::lonnet::logthis("loading course options");
-        $current_course = $ENV{'request.course.id'};
+        $current_course = $env{'request.course.id'};
         undef(%courseopt);
         if (! defined($current_name) || ! defined($current_domain)) {
-            &Apache::lonnet::logthis('bad call to setup_parameter_caches');
             return;
         }
-        my $dom = $ENV{'course.'.$ENV{'request.course.id'}.'.domain'};
-        my $id  = $ENV{'course.'.$ENV{'request.course.id'}.'.num'};
+        my $dom = $env{'course.'.$env{'request.course.id'}.'.domain'};
+        my $id  = $env{'course.'.$env{'request.course.id'}.'.num'};
         my %Tmp = &Apache::lonnet::dump('resourcedata',$dom,$id);
         while (my ($name,$value) = each(%Tmp)) {
             $courseopt{$name}=$value;
@@ -194,7 +229,14 @@ sub load_parameter_caches {
             }
             $useropt{$userprefix.$name}=$value;
         }
+        $useropt{'loadtime'} = time;
     }
+    if (! %userdata) {
+        %userdata = &Apache::loncoursedata::get_current_state($current_name,
+                                                              $current_domain);
+        $userdata{'loadtime'} = time;
+    }
+    return;
 }
 
 ########################################################
@@ -208,18 +250,27 @@ sub load_parameter_caches {
 
 ########################################################
 ########################################################
-sub ensure_current_parameter_caches {
+sub ensure_current_caches {
     my $self = shift;
+    ##
+    ## Check for a modified parameters
+    ##
     if (! defined($current_course) || 
-        $current_course ne $ENV{'request.course.id'} ) {
-        $current_course = $ENV{'request.course.id'};
+        $current_course ne $env{'request.course.id'} ) {
+        $current_course = $env{'request.course.id'};
         undef(%courseopt); 
+        undef(%useropt);
+        undef(%userdata);
     }
+    ##
+    ## Check for new user
+    ##
     if (! defined($current_name)   || $current_name ne $self->{'name'} ||
         ! defined($current_domain) || $current_domain ne $self->{'domain'}) {
         $current_domain = $self->{'domain'};
         $current_name   = $self->{'name'};
         undef(%useropt);
+        undef(%userdata);
     }
     &load_parameter_caches();
 }
@@ -250,7 +301,7 @@ this user and course.
 ##################################################
 sub parmval {
     my $self = shift;
-    my ($what,$symb,$uname,$udom,$csec,$recurse)=@_;
+    my ($what,$symb,$uname,$udom,$csec,$recurse,$mapname,$id,$fn)=@_;
     $uname = $self->{'name'}    if (! defined($uname));
     $udom  = $self->{'domain'}  if (! defined($udom));
     $csec  = $self->{'section'} if (! defined($csec));
@@ -259,7 +310,9 @@ sub parmval {
     my $result='';
     #
     # This should be a 
-    my ($mapname,$id,$fn)=split(/___/,$symb);
+    if (!defined($mapname) || !defined($id) || !defined($fn)) {
+	($mapname,$id,$fn)=&Apache::lonnet::decode_symb($symb);
+    }
     # Cascading lookup scheme
     my $rwhat=$what;
     $what =~ s/^parameter\_//;
@@ -296,18 +349,19 @@ sub parmval {
     #
     # check course
     return $courseopt{$courselevelr} if (defined($courseopt{$courselevelr}));
-    return $courseopt{$courselevelm} if (defined($courseopt{$courselevelm}));
-    return $courseopt{$courselevel}  if (defined($courseopt{$courselevel}));
     # check map parms
     my $thisparm = $parmhash{$symbparm};
     return $thisparm if (defined($thisparm));
     # check default
     $thisparm = &Apache::lonnet::metadata($fn,$rwhat.'.default');
     return $thisparm if (defined($thisparm));
-    #
+    # check more course
+    return $courseopt{$courselevelm} if (defined($courseopt{$courselevelm}));
+    return $courseopt{$courselevel}  if (defined($courseopt{$courselevel}));
+
     # Cascade Up
     my $space=$what;
-    $space=~s/\.\w+$//;
+    $space=~s/\.[^._]+$//;
     if ($space ne '0') {
 	my @parts=split(/_/,$space);
 	my $id=pop(@parts);
@@ -315,7 +369,8 @@ sub parmval {
 	if ($part eq '') { $part='0'; }
 	my $newwhat=$rwhat;
 	$newwhat=~s/\Q$space\E/$part/;
-	my $partgeneral=$self->parmval($newwhat,$symb,$uname,$udom,$csec,1);
+	my $partgeneral=$self->parmval($newwhat,$symb,$uname,$udom,$csec,1,
+				       $mapname,$id,$fn);
 	if (defined($partgeneral)) { return $partgeneral; }
     }
     if ($recurse) { return undef; }
@@ -327,7 +382,7 @@ sub parmval {
 
 sub get_html_title {
     my $self = shift;
-    my ($assess_title,$name,$time) = $self->get_title();
+    my ($assess_title,$name,$time) = $self->get_full_title();
     my $title = '<h1>'.$assess_title.'</h1>'.
         '<h2>'.$name.', '.
         &Apache::loncommon::aboutmewrapper
@@ -339,26 +394,27 @@ sub get_html_title {
 
 sub get_title {
     my $self = shift;
-    my @title = ();
     if (($self->{'symb'} eq '_feedback') ||
         ($self->{'symb'} eq '_evaluation') ||
         ($self->{'symb'} eq '_discussion') ||
         ($self->{'symb'} eq '_tutoring')) {
         my $assess_title = ucfirst($self->{'symb'});
         $assess_title =~ s/^_//;
-        push(@title,$assess_title);
+        return $assess_title;
     } else {
-        push(@title,&Apache::lonnet::gettitle($self->{'symb'}));
+        return &Apache::lonnet::gettitle($self->{'symb'});
     }
+}
+
+sub get_full_title {
+    my $self = shift;
+    my @title = ($self->get_title());
     # Look up the users identifying information
     # Get the users information
-    my %userenv = &Apache::loncoursedata::GetUserName($self->{'name'},
-                                                      $self->{'domain'});
-    my $name = 
-        join(' ',@userenv{'firstname','middlename','lastname','generation'});
-    $name =~ s/\s+$//;
+    my $name = &Apache::loncommon::plainname($self->{'name'},
+					     $self->{'domain'});
     push (@title,$name);
-    push (@title,scalar(localtime(time)));
+    push (@title,&Apache::lonlocal::locallocaltime(time));
     return @title;
 }
 
@@ -367,13 +423,17 @@ sub parent_link {
     my $link .= '<p><a href="/adm/studentcalc?'.
         'sname='.$self->{'name'}.
             '&sdomain='.$self->{'domain'}.'">'.
-                'Student level sheet</a></p>'."\n";
+                &mt('Student level sheet').'</a></p>'."\n";
     return $link;
 }
 
 sub outsheet_html {
     my $self = shift;
     my ($r) = @_;
+    ####################################
+    # Report any calculation errors    #
+    ####################################
+    $r->print($self->html_report_error());
     ###################################
     # Determine table structure
     ###################################
@@ -381,13 +441,17 @@ sub outsheet_html {
     my $exportcolor = '#FFFFAA';
     my $num_uneditable = 1;
     my $num_left = 52-$num_uneditable;
+    my %lt=&Apache::lonlocal::texthash(
+				       'as' => 'Assessment',
+				       'ca' => 'Calculations',
+				       );
     my $tableheader =<<"END";
 <table border="2">
 <tr>
-  <th colspan="2" rowspan="2"><font size="+2">Assessment</font></th>
+  <th colspan="2" rowspan="2"><font size="+2">$lt{'as'}</font></th>
   <td bgcolor="$importcolor" colspan="$num_uneditable">&nbsp;</td>
   <td colspan="$num_left">
-      <b><font size="+1">Calculations</font></b></td>
+      <b><font size="+1">$lt{'ca'}</font></b></td>
 </tr><tr>
 END
     my $label_num = 0;
@@ -429,6 +493,11 @@ END
     #
     my $num_output = 0;
     foreach my $rownum (sort {$a <=> $b} ($self->rows())) {
+        if (! $self->parameter_part_is_valid(
+                                             $self->{'formulas'}->{'A'.$rownum}
+                                             )) {
+            next;
+        }
 	if ($num_output++ % 50 == 0) {
 	    $r->print("</table>\n".$tableheader);
 	}
@@ -446,8 +515,8 @@ sub assess_html_row {
     my @rowdata = $self->get_row($row);
     my $num_cols_output = 0;
     my $row_html;
-    if (exists($nice_parameter_name{$parameter_name})) {
-        my $name = $nice_parameter_name{$parameter_name};
+    my $name=$self->get_parm_name($parameter_name);
+    if ($name ne '') {
         $name =~ s/ /\&nbsp;/g;
         $row_html .= '<td>'.$name.'<br />'.$parameter_name.'</td>';
     } else {
@@ -473,19 +542,16 @@ sub csv_rows {
     # writes the meat of the spreadsheet to an excel worksheet.  Called
     # by Spreadsheet::outsheet_excel;
     my $self = shift;
-    my ($filehandle) = @_;
+    my ($connection,$filehandle) = @_;
     #
     # Write a header row
     $self->csv_output_row($filehandle,undef,
-                          ('Parameter','Description','Value'));
+                          (&mt('Parameter'),&mt('Description'),&mt('Value')));
     #
     # Write each row
     foreach my $rownum (sort {$a <=> $b} ($self->rows())) {
         my $parameter_name = $self->{'formulas'}->{'A'.$rownum};
-        my $description = '';
-        if (exists($nice_parameter_name{$parameter_name})) {
-            $description = $nice_parameter_name{$parameter_name};
-        }
+        my $description = $self->get_parm_name($parameter_name);
         $self->csv_output_row($filehandle,$rownum,
                               $parameter_name,$description);
     }
@@ -496,31 +562,161 @@ sub excel_rows {
     # writes the meat of the spreadsheet to an excel worksheet.  Called
     # by Spreadsheet::outsheet_excel;
     my $self = shift;
-    my ($worksheet,$cols_output,$rows_output) = @_;
+    my ($connection,$worksheet,$cols_output,$rows_output,$format) = @_;
+    return if (! ref($worksheet));
     #
     # Write a header row
     $cols_output = 0;
     foreach my $value ('Parameter','Description','Value') {
-        $worksheet->write($rows_output,$cols_output++,$value);
+        $worksheet->write($rows_output,$cols_output++,$value,$format->{'h4'});
     }
-    $rows_output++;    
+    $rows_output++;
     #
     # Write each row
     foreach my $rownum (sort {$a <=> $b} ($self->rows())) {
         my $parameter_name = $self->{'formulas'}->{'A'.$rownum};
-        my $description = '';
-        if (exists($nice_parameter_name{$parameter_name})) {
-            $description = $nice_parameter_name{$parameter_name};
-        }
+        my $description = $self->get_parm_name($parameter_name);
         $self->excel_output_row($worksheet,$rownum,$rows_output++,
                                 $parameter_name,$description);
     }
     return;
 }
 
+##
+## Routines to support assesscalc::compute
+##
+sub get_parm {
+    my $self = shift;
+    my @Mandatory_parameters = @_;
+    my %parameters;
+    #
+    my ($symap,$syid,$srcf) = &Apache::lonnet::decode_symb($self->{'symb'});
+    my @Metadata = split(/\,/,&Apache::lonnet::metadata($srcf,'keys'));
+    foreach my $parm (@Mandatory_parameters,@Metadata) {
+        next if ($parm !~ /^(resource\.|stores|parameter)_/);
+        my $cleaned_name = $parm;
+        $cleaned_name =~ s/^resource\./stores_/;
+        $cleaned_name =~ s/\./_/g;
+        $parameters{$cleaned_name}=1;
+    }
+    return (keys(%parameters));
+}
+
+sub get_parm_name {
+    my $self = shift;
+    my $parm = shift;
+    my ($symap,$syid,$srcf) = &Apache::lonnet::decode_symb($self->{'symb'});
+    my $display = &Apache::lonnet::metadata($srcf,$parm.'.display');
+    if (! $display) {
+	$display .= &Apache::lonnet::metadata($srcf,$parm.'.name');
+    }
+    return $display;
+}
+
+sub get_parameter_values {
+    my $self = shift();
+    my @Parameters;
+    my ($parameters) = @_;
+    if (!ref($parameters)) {
+        @Parameters = @_;
+    } elsif (ref($parameters) eq 'ARRAY') {
+        @Parameters = @$parameters;
+    } elsif (ref($parameters) eq 'HASH') {
+        @Parameters = keys(%$parameters);
+    }
+    #
+    my %parameters;
+    #
+    my $filename = $self->{'coursefilename'}.'_parms.db';
+    if (tie(%parmhash,'GDBM_File',
+            $self->{'coursefilename'}.'_parms.db',&GDBM_READER(),0640)) {
+	my ($mapname,$id,$fn)=&Apache::lonnet::decode_symb($self->{'symb'});
+        foreach my $parmname (@Parameters) {
+            my $value = $self->parmval($parmname,$self->{'symb'},
+				       $self->{'name'},$self->{'domain'},
+				       $self->{'section'},undef,
+				       $mapname,$id,$fn);
+            $parameters{$parmname} =$value;
+        }
+        untie(%parmhash);
+    } else {
+        $self->logthis('unable to tie '.$filename);
+    }
+    return %parameters;
+}
+
+sub deal_with_export_row {
+    my $self = shift();
+    my @exportarray = @_;
+    $Exportrows{$self->{'symb'}}->{'time'} = time;
+    $Exportrows{$self->{'symb'}}->{$self->{'filename'}} = \@exportarray;
+    #
+    # Save the export data
+    $self->save_export_data();
+    return;
+}
+
+sub get_problem_state {
+    my $self = shift;
+    my %student_parameters;
+    if (exists($userdata{$self->{'symb'}}) && 
+        ref($userdata{$self->{'symb'}}) eq 'HASH') {
+        %student_parameters = %{$userdata{$self->{'symb'}}};
+    }
+    return %student_parameters;
+}
+
+sub determine_parts {
+    my $self = shift;
+    my $check_hidden = shift;
+    if (exists($self->{'Parts'}) && ref($self->{'Parts'}) eq 'HASH') {
+        return;
+    }
+    my (undef,undef,$url) = &Apache::lonnet::decode_symb($self->{'symb'});
+    my $src = &Apache::lonnet::clutter($url);
+    return if (! defined($src));
+    my %Parts;
+    my $metadata = &Apache::lonnet::metadata($src,'packages');
+    foreach (split(',',$metadata)) {
+        my ($part) = (/^part_(.*)$/);
+        if (!defined($part)) { next; }
+        if (!$check_hidden) { $Parts{$part}++; next; }
+        if (!&Apache::loncommon::check_if_partid_hidden
+	    ($part,$self->{'symb'},$self->{'name'},$self->{'domain'})
+            ) {
+            $Parts{$part}++;
+        }
+    }
+    # Make sure part 0 is defined.
+    $Parts{'0'}++;
+    $self->{'Parts'} = \%Parts;
+    return;
+}
+
+sub parameter_part_is_valid {
+    my $self = shift;
+    my ($parameter) = @_;
+    return 1 if ($parameter eq 'timestamp');
+    if (! defined($self->{'Parts'}) || 
+        ! ref ($self->{'Parts'})    ||
+        ref($self->{'Parts'}) ne 'HASH') {
+        return 1;
+    }
+    #
+    my (undef,$part) = 
+        ($parameter =~ m/^(resource|stores|parameter)_([^_]+)_.*/);
+    if (exists($self->{'Parts'})          && 
+        exists($self->{'Parts'}->{$part}) &&
+        $self->{'Parts'}->{$part} ) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
 sub compute {
     my $self = shift;
-#    $self->logthis('computing');
+    my ($r) = @_;
     $self->initialize_safe_space();
     #########################################
     #########################################
@@ -541,35 +737,11 @@ sub compute {
     my %parameters;   # holds underscored parameters by name
     #
     # Get the metadata fields and determine their proper names
-    my ($symap,$syid,$srcf)=split(/___/,$self->{'symb'});
-    my @Metadata = split(/\,/,&Apache::lonnet::metadata($srcf,'keys'));
-    foreach my $parm (@Mandatory_parameters,@Metadata) {
-        next if ($parm !~ /^(resource\.|stores|parameter)_/);
-        my $cleaned_name = $parm;
-        $cleaned_name =~ s/^resource\./stores_/;
-        $cleaned_name =~ s/\./_/g;
-        my $display = &Apache::lonnet::metadata($srcf,
-                                                $cleaned_name.'.display');
-        if (! $display) {
-            $display .= &Apache::lonnet::metadata($srcf,$cleaned_name.'.name');
-        }
-        $parameters{$cleaned_name}++;
-        $nice_parameter_name{$cleaned_name} = $display;
-    }
+    my @parameters=$self->get_parm(@Mandatory_parameters);
     #
     # Get the values of the metadata fields
-    $self->ensure_current_parameter_caches();
-    my $filename = $self->{'coursefilename'}.'_parms.db';
-    if (tie(%parmhash,'GDBM_File',
-            $self->{'coursefilename'}.'_parms.db',&GDBM_READER(),0640)) {
-        foreach my $parmname (keys(%parameters)) {
-            my $value = $self->parmval($parmname);
-            $parameters{$parmname} =$value;
-        }
-        untie(%parmhash);
-    } else {
-        $self->logthis('unable to tie '.$filename);
-    }
+    $self->ensure_current_caches();
+    %parameters = $self->get_parameter_values(@parameters);
     #
     # Clean out unnecessary parameters
     foreach (keys(%parameters)) {
@@ -577,15 +749,14 @@ sub compute {
     }
     #
     # Get the students performance data
-    my %student_parameters = 
-        &Apache::loncoursedata::get_current_state($self->{'name'},
-                                                  $self->{'domain'},
-                                                  $self->{'symb'},
-                                                  $self->{'cid'});
+    $self->determine_parts(($parameters{'parameter_0_hiddenparts'} ne ''));
+    my %student_parameters = $self->get_problem_state();
     while (my ($parm,$value) = each(%student_parameters)) {
         $parm =~ s/^resource\./stores_/;
         $parm =~ s/\./_/g;
-        $parameters{$parm} = $value;
+	# Clean out any bad parameters
+	next if (! $self->parameter_part_is_valid($parm));
+	$parameters{$parm} = $value;
     }
     #
     # Set up the formulas and parameter values
@@ -593,14 +764,14 @@ sub compute {
     my %c;
     #
     # Check for blackout requirements
-    if ((!exists($ENV{'request.role.adv'}) || !$ENV{'request.role.adv'})) {
+    if ((!exists($env{'request.role.adv'}) || !$env{'request.role.adv'})) {
         while (my ($parm,$value) = each(%parameters)) {
             last if ($self->blackout());
             next if ($parm !~ /^(parameter_.*)_problemstatus$/);
-	    if ($parameters{$1.'_answerdate'} ne '' &&
-		$parameters{$1.'_answerdate'} < time) {
-		next;
-	    }
+            if ($parameters{$1.'_answerdate'} ne '' &&
+                $parameters{$1.'_answerdate'} < time) {
+                next;
+            }
             if (lc($value) eq 'no') {
                 # We must blackout this sheet
                 $self->blackout(1);
@@ -612,7 +783,10 @@ sub compute {
     while (my ($parm,$value) = each(%parameters)) {
         my $cell = 'A'.$self->get_row_number_from_key($parm);
         $f{$cell} = $parm;
-        $value = '"'.$value.'"' if ($value =~/[^0-9.]/);
+        if ($parm =~ /_submission$/ && $value =~ /(\{|\})/) {
+            $value = 'witheld';
+        }
+        $value = 'q{'.$value.'}' if ($value =~/([^\d\.]|\.\.)/);
         $c{$parm} = $value;
     }
     $self->formulas(\%f);
@@ -621,11 +795,7 @@ sub compute {
     #
     # Store export row in cache
     my @exportarray = $self->exportrow();
-    $Exportrows{$self->{'symb'}}->{'time'} = time;
-    $Exportrows{$self->{'symb'}}->{$self->{'filename'}} = \@exportarray;
-    #
-    # Save the export data
-    $self->save_export_data();
+    $self->deal_with_export_row(@exportarray);
     $self->save() if ($self->need_to_save());
     return;
 }
@@ -636,6 +806,7 @@ sub compute {
 sub sett {
     my $self = shift;
     my %t=();
+    undef(%Apache::Spreadsheet::sheet_values);
     #
     # Deal with the template row by copying the template formulas into each
     # row.
@@ -661,8 +832,12 @@ sub sett {
     while (my ($cell,$formula) = each(%{$self->{'formulas'}})) {
 	next if ($cell =~ /template_/);
         if ($cell =~ /^A/ && $cell ne 'A0') {
-            if ($formula !~ /^\!/) {
-                $t{$cell}=$self->{'constants'}->{$formula};
+	    if ($formula !~ /^\!/ 
+		&& exists($self->{'constants'}->{$formula}) 
+		&& $self->{'constants'}->{$formula} ne ''
+		) {
+		$Apache::Spreadsheet::sheet_values{$cell}=
+		    eval($self->{'constants'}->{$formula});
             }
         } else {
             $t{$cell}=$formula;
@@ -695,17 +870,21 @@ These rows are saved in the students dir
 ########################################################
 ########################################################
 sub load_cached_export_rows {
-    %Exportrows = undef;
+    undef(%Exportrows);
     my @tmp = &Apache::lonnet::dump('nohist_calculatedsheets_'.
-                                    $ENV{'request.course.id'},
+                                    $env{'request.course.id'},
                                     $current_domain,$current_name,undef);
     if ($tmp[0]!~/^error/) {
         my %tmp = @tmp;
-        my $default_filename =  $ENV{'course.'.$ENV{'request.course.id'}.
+        my $default_filename =  $env{'course.'.$env{'request.course.id'}.
                                          '.spreadsheet_default_assesscalc'};
         # We only got one key, so we will access it directly.
         while (my ($key,$sheetdata) = each(%tmp)) {
             my ($sname,$sdom,$sheettype,$symb) = split(':',$key);
+            if (! defined($sname) || $sname eq '' ||
+                ! defined($sdom)  || $sdom eq '' ) {
+                next;
+            }
             if ($symb =~ /\.time$/) {
                 $symb =~ s/\.time$//;
                 $Exportrows{$symb}->{'time'} = $sheetdata;
@@ -736,21 +915,31 @@ spreadsheet only if necessary.
 #############################################
 sub export_data {
     my $self = shift;
+    my ($r) = @_;
     my $symb = $self->{'symb'};
-    if (! exists($ENV{'request.role.adv'}) || ! $ENV{'request.role.adv'} ||
+    if (! exists($env{'request.role.adv'}) || ! $env{'request.role.adv'} ||
         ! exists($Exportrows{$symb}) || ! defined($Exportrows{$symb})  ||
         ! $self->check_expiration_time($Exportrows{$symb}->{'time'}) ||
         ! exists($Exportrows{$symb}->{$self->{'filename'}}) ||
-        ! defined($Exportrows{$symb}->{$self->{'filename'}})) {
-        $self->compute();
-    }
-    my @Data = @{$Exportrows{$symb}->{$self->{'filename'}}};
-    if ($Data[0] =~ /^(.*)___=___/) {
-        $self->{'sheetname'} = $1;
-        $Data[0] =~ s/^(.*)___=___//;
-    }
-    for (my $i=0;$i<$#Data;$i++) {
-        $Data[$i]="'".$Data[$i]."'" if ($Data[$i]=~/\D/ && defined($Data[$i]));
+        ! defined($Exportrows{$symb}->{$self->{'filename'}}) ||
+        ! ref($Exportrows{$symb}->{$self->{'filename'}}) 
+        ) {
+        $self->compute($r);
+    }
+    my @Data;
+    if ($self->badcalc()) {
+        @Data = ();
+    } else {
+        @Data = @{$Exportrows{$symb}->{$self->{'filename'}}};
+        if ($Data[0] =~ /^(.*)___=___/) {
+            $self->{'sheetname'} = $1;
+            $Data[0] =~ s/^(.*)___=___//;
+        }
+        for (my $i=0;$i<$#Data;$i++) {
+            if ($Data[$i]=~/\D/ && defined($Data[$i])) {
+                $Data[$i]="'".$Data[$i]."'";
+            }
+        }
     }
     return @Data;
 }
@@ -773,21 +962,23 @@ sub save_export_data {
     return if ($self->temporary());
     my $student = $self->{'name'}.':'.$self->{'domain'};
     my $symb    = $self->{'symb'};
+    if ($self->badcalc()){
+        # do not save data away when calculations have not been done properly.
+        delete($Exportrows{$symb});
+        return;
+    }
     if (! exists($Exportrows{$symb}) || 
         ! exists($Exportrows{$symb}->{$self->{'filename'}})) {
         return;
     }
     my $key = join(':',($self->{'name'},$self->{'domain'},'assesscalc',$symb));
     my $timekey = $key.'.time';
-    my $newstore= join('___;___',@{$Exportrows{$symb}->{$self->{'filename'}}});
+    my $newstore= join('___;___',
+                       map {s/[^[:print:]]//g;$_;} # strip out unprintable
+                                @{$Exportrows{$symb}->{$self->{'filename'}}});
     $newstore = $self->{'filename'}.'___=___'.$newstore;
-    my $result = &Apache::lonnet::put
-        ('nohist_calculatedsheets_'.$ENV{'request.course.id'},
-         { $key     => $newstore,
-           $timekey => $Exportrows{$symb}->{'time'} },
-         $self->{'domain'},
-         $self->{'name'});
-
+    $newExportrows{$student}->{$key} = $newstore;
+    $newExportrows{$student}->{$timekey} = $Exportrows{$symb}->{'time'};
     return;
 }