[LON-CAPA-cvs] cvs: loncom /interface lonspreadsheet.pm

matthew lon-capa-cvs@mail.lon-capa.org
Wed, 29 Jan 2003 16:26:08 -0000


This is a MIME encoded message

--matthew1043857568
Content-Type: text/plain

matthew		Wed Jan 29 11:26:08 2003 EDT

  Modified files:              
    /loncom/interface	lonspreadsheet.pm 
  Log:
  BIG CHANGES (this commit is 3000 lines longer than the code is :) )
  This code has been tested and I believe it produces identical results to
  the lonspreadsheet.pm in 0.6.1.
  The spreadsheet is now an object, accessed via methods and all that nifty
  stuff.
  &mask, being a pure function, now memoizes its results.
  The HASH and related subroutines have temporarily been removed from the
  safe space.  I would like to remove them permenantly but this is unlikely
  to be feasable.
  &expandnamed and &sett have been moved outside the safe space.
  logging and accessor/setter functions have been added.  In
  more than a few cases the previous code did 
  foreach my $cell (keys(%formulas)) {
      next if ($cell !~ /^A(\d+)/);
  ..
  methods have been written to return just the needed cells for the 'A' column 
  and the template row.
  A few debugging routines have been added ($sheet->dump_formulas_to_log() and 
  $sheet->dump_values_to_log() );
  The code has been re-arranged and will be re-arranged further.
  
  
--matthew1043857568
Content-Type: text/plain
Content-Disposition: attachment; filename="matthew-20030129112608.txt"

Index: loncom/interface/lonspreadsheet.pm
diff -u loncom/interface/lonspreadsheet.pm:1.163 loncom/interface/lonspreadsheet.pm:1.164
--- loncom/interface/lonspreadsheet.pm:1.163	Wed Jan 15 14:34:03 2003
+++ loncom/interface/lonspreadsheet.pm	Wed Jan 29 11:26:08 2003
@@ -1,5 +1,5 @@
 #
-# $Id: lonspreadsheet.pm,v 1.163 2003/01/15 19:34:03 matthew Exp $
+# $Id: lonspreadsheet.pm,v 1.164 2003/01/29 16:26:08 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -50,3272 +50,3484 @@
 
 =cut
 
+
 package Apache::lonspreadsheet;
             
 use strict;
 use Apache::Constants qw(:common :http);
 use Apache::lonnet;
 use Apache::lonhtmlcommon;
-use Apache::loncoursedata;
-use Apache::File();
-use Safe;
-use Safe::Hole;
-use Opcode;
-use GDBM_File;
 use HTML::Entities();
-use HTML::TokeParser;
-use Spreadsheet::WriteExcel;
 
-#
-# Caches for coursewide information 
-#
-my %Section;
+# --------------------------------------------------------- Various form fields
 
-#
-# Caches for previously calculated spreadsheets
-#
+sub textfield {
+    my ($title,$name,$value)=@_;
+    return "\n<p><b>$title:</b><br>".
+        '<input type=text name="'.$name.'" size=80 value="'.$value.'">';
+}
+
+sub hiddenfield {
+    my ($name,$value)=@_;
+    return "\n".'<input type=hidden name="'.$name.'" value="'.$value.'">';
+}
+
+sub selectbox {
+    my ($title,$name,$value,%options)=@_;
+    my $selout="\n<p><b>$title:</b><br>".'<select name="'.$name.'">';
+    foreach (sort keys(%options)) {
+        $selout.='<option value="'.$_.'"';
+        if ($_ eq $value) { $selout.=' selected'; }
+        $selout.='>'.$options{$_}.'</option>';
+    }
+    return $selout.'</select>';
+}
 
 my %oldsheets;
 my %loadedcaches;
-my %expiredates;
 
+# ================================================================ Main handler
 #
-# Cache for stores of an individual user
+# Interactive call to screen
 #
+#
+sub handler {
+    my $r=shift;
 
-my $cachedassess;
-my %cachedstores;
+    my ($sheettype) = ($r->uri=~/\/(\w+)$/);
 
-#
-# These cache hashes need to be independent of user, resource and course
-# (user and course can/should be in the keys)
-#
+    if (! exists($ENV{'form.Status'})) {
+        $ENV{'form.Status'} = 'Active';
+    }
+    if ( ! exists($ENV{'form.output'}) || 
+             ($sheettype ne 'classcalc' && 
+              lc($ENV{'form.output'}) eq 'recursive excel')) {
+        $ENV{'form.output'} = 'HTML';
+    }
+    #
+    # Overload checking
+    #
+    # Check this server
+    my $loaderror=&Apache::lonnet::overloaderror($r);
+    if ($loaderror) { return $loaderror; }
+    # Check the course homeserver
+    $loaderror= &Apache::lonnet::overloaderror($r,
+                      $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
+    if ($loaderror) { return $loaderror; } 
+    #
+    # HTML Header
+    #
+    if ($r->header_only) {
+        $r->content_type('text/html');
+        $r->send_http_header;
+        return OK;
+    }
+    #
+    # Roles Checking
+    #
+    # Needs to be in a course
+    if (! $ENV{'request.course.fn'}) { 
+        # Not in a course, or not allowed to modify parms
+        $ENV{'user.error.msg'}=
+            $r->uri.":opa:0:0:Cannot modify spreadsheet";
+        return HTTP_NOT_ACCEPTABLE; 
+    }
+    #
+    # Get query string for limited number of parameters
+    #
+    &Apache::loncommon::get_unprocessed_cgi
+        ($ENV{'QUERY_STRING'},['uname','udom','usymb','ufn','mapid','resid']);
+    #
+    # Deal with restricted student permissions 
+    #
+    if ($ENV{'request.role'} =~ /^st\./) {
+        delete $ENV{'form.unewfield'}   if (exists($ENV{'form.unewfield'}));
+        delete $ENV{'form.unewformula'} if (exists($ENV{'form.unewformula'}));
+    }
+    #
+    # Look for special assessment spreadsheets - '_feedback', etc.
+    #
+    if (($ENV{'form.usymb'}=~/^\_(\w+)/) && (!$ENV{'form.ufn'} || 
+                                             $ENV{'form.ufn'} eq '' || 
+                                             $ENV{'form.ufn'} eq 'default')) {
+        $ENV{'form.ufn'}='default_'.$1;
+    }
+    if (!$ENV{'form.ufn'} || $ENV{'form.ufn'} eq 'default') {
+        $ENV{'form.ufn'}='course_default_'.$sheettype;
+    }
+    #
+    # Interactive loading of specific sheet?
+    #
+    if (($ENV{'form.load'}) && ($ENV{'form.loadthissheet'} ne 'Default')) {
+        $ENV{'form.ufn'}=$ENV{'form.loadthissheet'};
+    }
+    #
+    # Determine the user name and domain for the sheet.
+    my $aname;
+    my $adom;
+    unless ($ENV{'form.uname'}) {
+        $aname=$ENV{'user.name'};
+        $adom=$ENV{'user.domain'};
+    } else {
+        $aname=$ENV{'form.uname'};
+        $adom=$ENV{'form.udom'};
+    }
+    #
+    # Open page, try to prevent browser cache.
+    #
+    $r->content_type('text/html');
+    $r->header_out('Cache-control','no-cache');
+    $r->header_out('Pragma','no-cache');
+    $r->send_http_header;
+    #
+    # Header....
+    #
+    $r->print('<html><head><title>LON-CAPA Spreadsheet</title>');
+    my $nothing = "''";
+    if ($ENV{'browser.type'} eq 'explorer') {
+        $nothing = "'javascript:void(0);'";
+    }
 
-my %spreadsheets;
-my %courserdatas;
-my %userrdatas;
-my %defaultsheets;
-my %rowlabel_cache;
+    if ($ENV{'request.role'} !~ /^st\./) {
+        $r->print(<<ENDSCRIPT);
+<script language="JavaScript">
 
-#
-# These global hashes are dependent on user, course and resource, 
-# and need to be initialized every time when a sheet is calculated
-#
-my %courseopt;
-my %useropt;
-my %parmhash;
+    var editwin;
 
-#
-# Some hashes for stats on timing and performance
-#
+    function celledit(cellname,cellformula) {
+        var edit_text = '';
+        // cellformula may contain less-than and greater-than symbols, so
+        // we need to escape them?  
+        edit_text +='<html><head><title>Cell Edit Window</title></head><body>';
+        edit_text += '<form name="editwinform">';
+        edit_text += '<center><h3>Cell '+cellname+'</h3>';
+        edit_text += '<textarea name="newformula" cols="40" rows="6"';
+        edit_text += ' wrap="off" >'+cellformula+'</textarea>';
+        edit_text += '</br>';
+        edit_text += '<input type="button" name="accept" value="Accept"';
+        edit_text += ' onClick=\\\'javascript:';
+        edit_text += 'opener.document.sheet.unewfield.value=';
+        edit_text +=     '"'+cellname+'";';
+        edit_text += 'opener.document.sheet.unewformula.value=';
+        edit_text +=     'document.editwinform.newformula.value;';
+        edit_text += 'opener.document.sheet.submit();';
+        edit_text += 'self.close()\\\' />';
+        edit_text += '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
+        edit_text += '<input type="button" name="abort" ';
+        edit_text +=     'value="Discard Changes"';
+        edit_text += ' onClick="javascript:self.close()" />';
+        edit_text += '</center></body></html>';
 
-my %starttimes;
-my %usedtimes;
-my %numbertimes;
+        if (editwin != null && !(editwin.closed) ) {
+            editwin.close();
+        }
 
-# Stuff that only the screen handler can know
+        editwin = window.open($nothing,'CellEditWin','height=200,width=350,scrollbars=no,resizeable=yes,alwaysRaised=yes,dependent=yes',true);
+        editwin.document.write(edit_text);
+    }
 
-my $includedir;
-my $tmpdir;
+    function changesheet(cn) {
+	document.sheet.unewfield.value=cn;
+        document.sheet.unewformula.value='changesheet';
+        document.sheet.submit();
+    }
 
-# =============================================================================
-# ===================================== Implements an instance of a spreadsheet
+    function insertrow(cn) {
+	document.sheet.unewfield.value='insertrow';
+        document.sheet.unewformula.value=cn;
+        document.sheet.submit();
+    }
 
-##
-## mask - used to reside in the safe space.  
-##
-sub mask {
-    my ($lower,$upper)=@_;
-    $upper = $lower if (! defined($upper));
+</script>
+ENDSCRIPT
+    }
+    $r->print('</head>'.&Apache::loncommon::bodytag('Grades Spreadsheet').
+              '<form action="'.$r->uri.'" name="sheet" method="post">');
+    $r->print(&hiddenfield('uname',$ENV{'form.uname'}).
+              &hiddenfield('udom',$ENV{'form.udom'}).
+              &hiddenfield('usymb',$ENV{'form.usymb'}).
+              &hiddenfield('unewfield','').
+              &hiddenfield('unewformula',''));
+    $r->rflush();
     #
-    my ($la,$ld) = ($lower=~/([A-Za-z]|\*)(\d+|\*)/);
-    my ($ua,$ud) = ($upper=~/([A-Za-z]|\*)(\d+|\*)/);
+    # Full recalc?
     #
-    my $alpha='';
-    my $num='';
+    # Read new sheet or modified worksheet
+    my $sheet=Apache::lonspreadsheet::Spreadsheet->new($aname,$adom,$sheettype,$ENV{'form.usymb'});
+    if ($ENV{'form.forcerecalc'}) {
+        $r->print('<h4>Completely Recalculating Sheet ...</h4>');
+        $sheet->complete_recalc();
+    }
     #
-    if (($la eq '*') || ($ua eq '*')) {
-        $alpha='[A-Za-z]';
-    } else {
-       if (($la=~/[A-Z]/) && ($ua=~/[A-Z]/) ||
-           ($la=~/[a-z]/) && ($ua=~/[a-z]/)) {
-          $alpha='['.$la.'-'.$ua.']';
-       } else {
-          $alpha='['.$la.'-Za-'.$ua.']';
-       }
-    }   
-    if (($ld eq '*') || ($ud eq '*')) {
-	$num='\d+';
-    } else {
-        if (length($ld)!=length($ud)) {
-           $num.='(';
-	   foreach ($ld=~m/\d/g) {
-              $num.='['.$_.'-9]';
-	   }
-           if (length($ud)-length($ld)>1) {
-              $num.='|\d{'.(length($ld)+1).','.(length($ud)-1).'}';
-	   }
-           $num.='|';
-           foreach ($ud=~m/\d/g) {
-               $num.='[0-'.$_.']';
-           }
-           $num.=')';
-       } else {
-           my @lda=($ld=~m/\d/g);
-           my @uda=($ud=~m/\d/g);
-           my $i; 
-           my $j=0; 
-           my $notdone=1;
-           for ($i=0;($i<=$#lda)&&($notdone);$i++) {
-               if ($lda[$i]==$uda[$i]) {
-		   $num.=$lda[$i];
-                   $j=$i;
-               } else {
-                   $notdone=0;
-               }
-           }
-           if ($j<$#lda-1) {
-	       $num.='('.$lda[$j+1];
-               for ($i=$j+2;$i<=$#lda;$i++) {
-                   $num.='['.$lda[$i].'-9]';
-               }
-               if ($uda[$j+1]-$lda[$j+1]>1) {
-		   $num.='|['.($lda[$j+1]+1).'-'.($uda[$j+1]-1).']\d{'.
-                   ($#lda-$j-1).'}';
-               }
-	       $num.='|'.$uda[$j+1];
-               for ($i=$j+2;$i<=$#uda;$i++) {
-                   $num.='[0-'.$uda[$i].']';
-               }
-               $num.=')';
-           } else {
-               if ($lda[-1]!=$uda[-1]) {
-                  $num.='['.$lda[-1].'-'.$uda[-1].']';
-	       }
-           }
-       }
-    }
-    return '^'.$alpha.$num."\$";
-}
-
-sub initsheet {
-    my $safeeval = new Safe(shift);
-    my $safehole = new Safe::Hole;
-    $safeeval->permit("entereval");
-    $safeeval->permit(":base_math");
-    $safeeval->permit("sort");
-    $safeeval->deny(":base_io");
-    $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
-    $safehole->wrap(\&Apache::lonspreadsheet::mask,$safeeval,'&mask');
-    $safeeval->share('$@');
-    my $code=<<'ENDDEFS';
-# ---------------------------------------------------- Inside of the safe space
-
-#
-# f: formulas
-# t: intermediate format (variable references expanded)
-# v: output values
-# c: preloaded constants (A-column)
-# rl: row label
-# os: other spreadsheets (for student spreadsheet only)
-
-undef %sheet_values;   # Holds the (computed, final) values for the sheet
-    # This is only written to by &calc, the spreadsheet computation routine.
-    # It is read by many functions
-undef %t; # Holds the values of the spreadsheet temporarily. Set in &sett, 
-    # which does the translation of strings like C5 into the value in C5.
-    # Used in &calc - %t holds the values that are actually eval'd.
-undef %f;    # Holds the formulas for each cell.  This is the users
-    # (spreadsheet authors) data for each cell.
-    # set by &setformulas and returned by &getformulas
-    # &setformulas is called by &readsheet, &tmpread, &updateclasssheet,
-    # &updatestudentassesssheet, &loadstudent, &loadcourse
-    # &getformulas is called by &writesheet, &tmpwrite, &updateclasssheet,
-    # &updatestudentassesssheet, &loadstudent, &loadcourse, &loadassessment, 
-undef %c; # Holds the constants for a sheet.  In the assessment
-    # sheets, this is the A column.  Used in &MINPARM, &MAXPARM, &expandnamed,
-    # &sett, and &setconstants.  There is no &getconstants.
-    # &setconstants is called by &loadstudent, &loadcourse, &load assessment,
-undef @os;  # Holds the names of other spreadsheets - this is used to specify
-    # the spreadsheets that are available for the assessment sheet.
-    # Set by &setothersheets.  &setothersheets is called by &handler.  A
-    # related subroutine is &othersheets.
-#$errorlog = '';
-
-$maxrow = 0;
-$sheettype = '';
-
-# filename/reference of the sheet
-$filename = '';
-
-# user data
-$uname = '';
-$uhome = '';
-$udom  = '';
-
-# course data
-
-$csec = '';
-$chome= '';
-$cnum = '';
-$cdom = '';
-$cid  = '';
-$coursefilename  = '';
-
-# symb
-
-$usymb = '';
-
-# error messages
-$errormsg = '';
-
-
-#-------------------------------------------------------
-
-=item UWCALC(hashname,modules,units,date) 
-
-returns the proportion of the module 
-weights not previously completed by the student.
-
-=over 4
-
-=item hashname 
-
-name of the hash the module dates have been inserted into
-
-=item modules 
-
-reference to a cell which contains a comma deliminated list of modules 
-covered by the assignment.
-
-=item units 
-
-reference to a cell which contains a comma deliminated list of module 
-weights with respect to the assignment
-
-=item date 
-
-reference to a cell which contains the date the assignment was completed.
-
-=back 
-
-=cut
-
-#-------------------------------------------------------
-sub UWCALC {
-    my ($hashname,$modules,$units,$date) = @_;
-    my @Modules = split(/,/,$modules);
-    my @Units   = split(/,/,$units);
-    my $total_weight;
-    foreach (@Units) {
-	$total_weight += $_;
+    # Global directory configs
+    #
+    $sheet->includedir($r->dir_config('lonIncludes'));
+    $sheet->tmpdir($r->dir_config('lonDaemons').'/tmp/');
+    #
+    # Check user permissions
+    if (($sheet->{'type'}  eq 'classcalc'       ) || 
+        ($sheet->{'uname'} ne $ENV{'user.name'} ) ||
+        ($sheet->{'udom'}  ne $ENV{'user.domain'})) {
+        unless (&Apache::lonnet::allowed('vgr',$sheet->{'cid'})) {
+            $r->print('<h1>Access Permission Denied</h1>'.
+                      '</form></body></html>');
+            return OK;
+        }
     }
-    my $usum=0;
-    for (my $i=0; $i<=$#Modules; $i++) {
-	if (&HASH($hashname,$Modules[$i]) eq $date) {
-	    $usum += $Units[$i];
-	}
+    # Print out user information
+    $r->print('<h2>'.$sheet->{'coursedesc'}.'</h2>');
+    if ($sheet->{'type'} ne 'classcalc') {
+        $r->print('<h2>'.$sheet->gettitle().'</h2><p>');
     }
-    return $usum/$total_weight;
-}
-
-#-------------------------------------------------------
-
-=item CDLSUM(list) 
-
-returns the sum of the elements in a cell which contains
-a Comma Deliminate List of numerical values.
-'list' is a reference to a cell which contains a comma deliminated list.
-
-=cut
-
-#-------------------------------------------------------
-sub CDLSUM {
-    my ($list)=@_;
-    my $sum;
-    foreach (split/,/,$list) {
-	$sum += $_;
+    if ($sheet->{'type'} eq 'assesscalc') {
+        $r->print('<b>User:</b> '.$sheet->{'uname'}.
+                  '<br /><b>Domain:</b> '.$sheet->{'udom'}.'<br />');
     }
-    return $sum;
-}
-
-#-------------------------------------------------------
-
-=item CDLITEM(list,index) 
-
-returns the item at 'index' in a Comma Deliminated List.
-
-=over 4
-
-=item list
-
-reference to a cell which contains a comma deliminated list.
-
-=item index 
-
-the Perl index of the item requested (first element in list has
-an index of 0) 
-
-=back
-
-=cut
-
-#-------------------------------------------------------
-sub CDLITEM {
-    my ($list,$index)=@_;
-    my @Temp = split/,/,$list;
-    return $Temp[$index];
-}
-
-#-------------------------------------------------------
-
-=item CDLHASH(name,key,value) 
-
-loads a comma deliminated list of keys into
-the hash 'name', all with a value of 'value'.
-
-=over 4
-
-=item name  
-
-name of the hash.
-
-=item key
-
-(a pointer to) a comma deliminated list of keys.
-
-=item value
-
-a single value to be entered for each key.
-
-=back
-
-=cut
-
-#-------------------------------------------------------
-sub CDLHASH {
-    my ($name,$key,$value)=@_;
-    my @Keys;
-    my @Values;
-    # Check to see if we have multiple $key values
-    if ($key =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
-	my $keymask = &mask($key);
-	# Assume the keys are addresses
-	my @Temp = grep /$keymask/,keys(%sheet_values);
-	@Keys = $sheet_values{@Temp};
+    if ($sheet->{'type'} eq 'studentcalc' || 
+        $sheet->{'type'} eq 'assesscalc') {
+        $r->print('<b>Section/Group:</b>'.$sheet->{'csec'}.'</p>');
+    } 
+    #
+    # If a new formula had been entered, go from work copy
+    if ($ENV{'form.unewfield'}) {
+        $r->print('<h2>Modified Workcopy</h2>');
+        #$ENV{'form.unewformula'}=~s/\'/\"/g;
+        $r->print('<p>Cell '.$ENV{'form.unewfield'}.' = <pre>');
+        $r->print(&HTML::Entities::encode($ENV{'form.unewformula'}).
+                  '</pre></p>');
+        $sheet->{'filename'} = $ENV{'form.ufn'};
+        $sheet->tmpread($ENV{'form.unewfield'},$ENV{'form.unewformula'});
+    } elsif ($ENV{'form.saveas'}) {
+        $sheet->{'filename'} = $ENV{'form.ufn'};
+        $sheet->tmpread();
     } else {
-	$Keys[0]= $key;
+        $sheet->readsheet($ENV{'form.ufn'});
     }
-    my @Temp;
-    foreach $key (@Keys) {
-	@Temp = (@Temp, split/,/,$key);
-    }
-    @Keys = @Temp;
-    if ($value =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
-	my $valmask = &mask($value);
-	my @Temp = grep /$valmask/,keys(%sheet_values);
-	@Values =$sheet_values{@Temp};
-    } else {
-	$Values[0]= $value;
+    # Additional options
+    if ($sheet->{'type'} eq 'assesscalc') {
+        $r->print('<p><font size=+2>'.
+                  '<a href="/adm/studentcalc?'.
+                  'uname='.$sheet->{'uname'}.
+                  '&udom='.$sheet->{'udom'}.'">'.
+                  'Level up: Student Sheet</a></font></p>');
     }
-    $value = $Values[0];
-    # Add values to hash
-    for (my $i = 0; $i<=$#Keys; $i++) {
-	my $key   = $Keys[$i];
-	if (! exists ($hashes{$name}->{$key})) {
-	    $hashes{$name}->{$key}->[0]=$value;
-	} else {
-	    my @Temp = sort(@{$hashes{$name}->{$key}},$value);
-	    $hashes{$name}->{$key} = \@Temp;
-	}
+    if (($sheet->{'type'} eq 'studentcalc') && 
+        (&Apache::lonnet::allowed('vgr',$sheet->{'cid'}))) {
+        $r->print ('<p><font size=+2><a href="/adm/classcalc">'.
+                   'Level up: Course Sheet</a></font></p>');
     }
-    return "hash '$name' updated";
-}
-
-#-------------------------------------------------------
-
-=item GETHASH(name,key,index) 
-
-returns the element in hash 'name' 
-reference by the key 'key', at index 'index' in the values list.
-
-=cut
-
-#-------------------------------------------------------
-sub GETHASH {
-    my ($name,$key,$index)=@_;
-    if (! defined($index)) {
-	$index = 0;
+    # Recalc button
+    $r->print('<br />'.
+              '<input type="submit" name="forcerecalc" '.
+              'value="Completely Recalculate Sheet"></p>');
+    # Save dialog
+    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
+        my $fname=$ENV{'form.ufn'};
+        $fname=~s/\_[^\_]+$//;
+        if ($fname eq 'default') { $fname='course_default'; }
+        $r->print('<input type=submit name=saveas value="Save as ...">'.
+                  '<input type=text size=20 name=newfn value="'.$fname.'">'.
+                  'make default: <input type=checkbox name="makedefufn"><p>');
     }
-    if ($key =~ /^[A-z]\d+$/) {
-	$key = $sheet_values{$key};
+    $r->print(&hiddenfield('ufn',$sheet->{'filename'}));
+    # Load dialog
+    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
+        $r->print('<p><input type=submit name=load value="Load ...">'.
+                  '<select name="loadthissheet">'.
+                  '<option name="default">Default</option>');
+        foreach ($sheet->othersheets()) {
+            $r->print('<option name="'.$_.'"');
+            if ($ENV{'form.ufn'} eq $_) {
+                $r->print(' selected');
+            }
+            $r->print('>'.$_.'</option>');
+        } 
+        $r->print('</select><p>');
+        if ($sheet->{'type'} eq 'studentcalc') {
+            $sheet->setothersheets($sheet->othersheets('assesscalc'));
+        }
     }
-    return $hashes{$name}->{$key}->[$index];
-}
-
-#-------------------------------------------------------
-
-=item CLEARHASH(name) 
-
-clears all the values from the hash 'name'
-
-=item CLEARHASH(name,key) 
-
-clears all the values from the hash 'name' associated with the given key.
-
-=cut
-
-#-------------------------------------------------------
-sub CLEARHASH {
-    my ($name,$key)=@_;
-    if (defined($key)) {
-	if (exists($hashes{$name}->{$key})) {
-	    $hashes{$name}->{$key}=undef;
-	    return "hash '$name' key '$key' cleared";
-	}
-    } else {
-	if (exists($hashes{$name})) {
-	    $hashes{$name}=undef;
-	    return "hash '$name' cleared";
-	}
+    #
+    # Set up caching mechanisms
+    #
+    &Apache::lonspreadsheet::Spreadsheet::load_spreadsheet_expirationdates();
+    # Clear out old caches if we have not seen this class before.
+    if (exists($oldsheets{'course'}) &&
+        $oldsheets{'course'} ne $sheet->{'cid'}) {
+        undef %oldsheets;
+        undef %loadedcaches;
     }
-    return "Error in clearing hash";
-}
-
-#-------------------------------------------------------
-
-=item HASH(name,key,value) 
-
-loads values into an internal hash.  If a key 
-already has a value associated with it, the values are sorted numerically.  
-
-=item HASH(name,key) 
-
-returns the 0th value in the hash 'name' associated with 'key'.
-
-=cut
-
-#-------------------------------------------------------
-sub HASH {
-    my ($name,$key,$value)=@_;
-    my @Keys;
-    undef @Keys;
-    my @Values;
-    # Check to see if we have multiple $key values
-    if ($key =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
-	my $keymask = &mask($key);
-	# Assume the keys are addresses
-	my @Temp = grep /$keymask/,keys(%sheet_values);
-	@Keys = $sheet_values{@Temp};
-    } else {
-	$Keys[0]= $key;
+    $oldsheets{'course'} = $sheet->{'cid'};
+    #
+    if ($sheet->{'type'} eq 'classcalc') {
+        $r->print("Loading previously calculated student sheets ...\n");
+        $r->rflush();
+        &Apache::lonspreadsheet::Spreadsheet::cachedcsheets();
+    } elsif ($sheet->{'type'} eq 'studentcalc') {
+        $r->print("Loading previously calculated assessment sheets ...\n");
+        $r->rflush();
+        $sheet->cachedssheets();
     }
-    # If $value is empty, return the first value associated 
-    # with the first key.
-    if (! $value) {
-	return $hashes{$name}->{$Keys[0]}->[0];
+    # Update sheet, load rows
+    $r->print("Loaded sheet(s), updating rows ...<br>\n");
+    $r->rflush();
+    #
+    $sheet->updatesheet();
+    $r->print("Updated rows, loading row data ...\n");
+    $r->rflush();
+    #
+    $sheet->loadrows($r);
+    $r->print("Loaded row data, calculating sheet ...<br>\n");
+    $r->rflush();
+    #
+    my $calcoutput=$sheet->calcsheet();
+    $r->print('<h3><font color=red>'.$calcoutput.'</h3></font>');
+    # See if something to save
+    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
+        my $fname='';
+        if ($ENV{'form.saveas'} && ($fname=$ENV{'form.newfn'})) {
+            $fname=~s/\W/\_/g;
+            if ($fname eq 'default') { $fname='course_default'; }
+            $fname.='_'.$sheet->{'type'};
+            $sheet->{'filename'} = $fname;
+            $ENV{'form.ufn'}=$fname;
+            $r->print('<p>Saving spreadsheet: '.
+                      $sheet->writesheet($ENV{'form.makedefufn'}).
+                      '<p>');
+        }
     }
-    # Check to see if we have multiple $value(s) 
-    if ($value =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
-	my $valmask = &mask($value);
-	my @Temp = grep /$valmask/,keys(%sheet_values);
-	@Values =$sheet_values{@Temp};
+    #
+    # Write the modified worksheet
+    $r->print('<b>Current sheet:</b> '.$sheet->{'filename'}.'</p>');
+    $sheet->tmpwrite();
+    if ($sheet->{'type'} eq 'assesscalc') {
+        $r->print('<p>Show rows with empty A column: ');
     } else {
-	$Values[0]= $value;
+        $r->print('<p>Show empty rows: ');
     }
-    # Add values to hash
-    for (my $i = 0; $i<=$#Keys; $i++) {
-	my $key   = $Keys[$i];
-	my $value = ($i<=$#Values ? $Values[$i] : $Values[0]);
-	if (! exists ($hashes{$name}->{$key})) {
-	    $hashes{$name}->{$key}->[0]=$value;
-	} else {
-	    my @Temp = sort(@{$hashes{$name}->{$key}},$value);
-	    $hashes{$name}->{$key} = \@Temp;
-	}
+    #
+    $r->print(&hiddenfield('userselhidden','true').
+              '<input type="checkbox" name="showall" onClick="submit()"');
+    #
+    if ($ENV{'form.showall'}) { 
+        $r->print(' checked'); 
+    } else {
+        unless ($ENV{'form.userselhidden'}) {
+            unless 
+                ($ENV{'course.'.$sheet->{'cid'}.'.hideemptyrows'} eq 'yes') {
+                    $r->print(' checked');
+                    $ENV{'form.showall'}=1;
+                }
+        }
     }
-    return $Values[-1];
+    $r->print('>');
+    #
+    # output format select box 
+    $r->print(' Output as <select name="output" size="1" onChange="submit()">'.
+              "\n");
+    foreach my $mode (qw/HTML CSV Excel/) {
+        $r->print('<option value="'.$mode.'"');
+        if ($ENV{'form.output'} eq $mode) {
+            $r->print(' selected ');
+        } 
+        $r->print('>'.$mode.'</option>'."\n");
+    }
+#
+#    Mulit-sheet excel takes too long and does not work at all for large
+#    classes.  Future inclusion of this option may be possible with the
+#    Spreadsheet::WriteExcel::Big and speed improvements.
+#
+#    if ($sheet->{'type'} eq 'classcalc') {
+#        $r->print('<option value="recursive excel"');
+#        if ($ENV{'form.output'} eq 'recursive excel') {
+#            $r->print(' selected ');
+#        } 
+#        $r->print(">Multi-Sheet Excel</option>\n");
+#    }
+    $r->print("</select>\n");
+    #
+    if ($sheet->{'type'} eq 'classcalc') {
+        $r->print('&nbsp;Student Status: '.
+                  &Apache::lonhtmlcommon::StatusOptions
+                  ($ENV{'form.Status'},'sheet'));
+    }
+    #
+    # Buttons to insert rows
+#    $r->print(<<ENDINSERTBUTTONS);
+#<br>
+#<input type='button' onClick='insertrow("top");' 
+#value='Insert Row Top'>
+#<input type='button' onClick='insertrow("bottom");' 
+#value='Insert Row Bottom'><br>
+#ENDINSERTBUTTONS
+    # Print out sheet
+    $sheet->outsheet($r);
+    $r->print('</form></body></html>');
+    #  Done
+    return OK;
 }
 
-#-------------------------------------------------------
+1;
 
-=item NUM(range)
+#############################################################
+#############################################################
+#############################################################
 
-returns the number of items in the range.
+package Apache::lonspreadsheet::Spreadsheet;
+            
+use strict;
+use Apache::Constants qw(:common :http);
+use Apache::lonnet;
+use Apache::loncoursedata;
+use Apache::File();
+use Safe;
+use Safe::Hole;
+use Opcode;
+use GDBM_File;
+use HTML::Entities();
+use HTML::TokeParser;
+use Spreadsheet::WriteExcel;
+#
+# These global hashes are dependent on user, course and resource, 
+# and need to be initialized every time when a sheet is calculated
+#
+my %courseopt;
+my %useropt;
+my %parmhash;
 
-=cut
+#
+# Caches for coursewide information 
+#
+my %Section;
 
-#-------------------------------------------------------
-sub NUM {
-    my $mask=mask(@_);
-    my $num= $#{@{grep(/$mask/,keys(%sheet_values))}}+1;
-    return $num;   
-}
+#
+# Caches for previously calculated spreadsheets
+#
+my %expiredates;
 
-sub BIN {
-    my ($low,$high,$lower,$upper)=@_;
-    my $mask=mask($lower,$upper);
-    my $num=0;
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        if (($sheet_values{$_}>=$low) && ($sheet_values{$_}<=$high)) {
-            $num++;
-        }
-    }
-    return $num;   
-}
+#
+# Cache for stores of an individual user
+#
+my $cachedassess;
+my %cachedstores;
 
+#
+# Some hashes for stats on timing and performance
+#
+my %starttimes;
+my %usedtimes;
+my %numbertimes;
 
-#-------------------------------------------------------
+#
+# Directories
+#
+my $includedir;
+my $tmpdir;
 
-=item SUM(range)
+sub includedir {
+    my $self = shift;
+    $includedir = shift;
+}
 
-returns the sum of items in the range.
+sub tmpdir {
+    my $self = shift;
+    $tmpdir = shift;
+}
 
-=cut
+my %spreadsheets;
+my %loadedcaches;
+my %courserdatas;
+my %userrdatas;
+my %defaultsheets;
+my %rowlabel_cache;
+my %oldsheets;
 
-#-------------------------------------------------------
-sub SUM {
-    my $mask=mask(@_);
-    my $sum=0;
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        $sum+=$sheet_values{$_};
+sub complete_recalc {
+    my $self = shift;
+    undef %spreadsheets;
+    undef %courserdatas;
+    undef %userrdatas;
+    undef %defaultsheets;
+    undef %rowlabel_cache;
+}
+
+sub get_sheet {
+    my $self = shift;
+    my $sheet_id = shift;
+    my $formulas;
+    # if we already have the file loaded and parsed, return the formulas
+    if (exists($self->{'sheets'}->{$sheet_id})) {
+        $formulas = $self->{'sheets'}->{$sheet_id};
+        $self->debug('retrieved '.$sheet_id);
+    } else {
+        # load the file
+        #     set $error and return undef if there is an error loading
+        # parse it
+        #     set $error and return undef if there is an error parsing
     }
-    return $sum;   
+    return $formulas;
 }
 
-#-------------------------------------------------------
-
-=item MEAN(range)
-
-compute the average of the items in the range.
-
-=cut
-
-#-------------------------------------------------------
-sub MEAN {
-    my $mask=mask(@_);
-    my $sum=0; 
-    my $num=0;
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        $sum+=$sheet_values{$_};
-        $num++;
+#
+# Load previously cached student spreadsheets for this course
+#
+sub load_spreadsheet_expirationdates {
+    undef %expiredates;
+    my $cid=$ENV{'request.course.id'};
+    my @tmp = &Apache::lonnet::dump('nohist_expirationdates',
+                                    $ENV{'course.'.$cid.'.domain'},
+                                    $ENV{'course.'.$cid.'.num'});
+    if (lc($tmp[0]) !~ /^error/){
+        %expiredates = @tmp;
     }
-    if ($num) {
-       return $sum/$num;
-    } else {
-       return undef;
-    }   
 }
 
-#-------------------------------------------------------
-
-=item STDDEV(range)
-
-compute the standard deviation of the items in the range.
-
-=cut
-
-#-------------------------------------------------------
-sub STDDEV {
-    my $mask=mask(@_);
-    my $sum=0; my $num=0;
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        $sum+=$sheet_values{$_};
-        $num++;
-    }
-    unless ($num>1) { return undef; }
-    my $mean=$sum/$num;
-    $sum=0;
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        $sum+=($sheet_values{$_}-$mean)**2;
+# ===================================================== Calculated sheets cache
+#
+# Load previously cached student spreadsheets for this course
+#
+sub cachedcsheets {
+    my $cid=$ENV{'request.course.id'};
+    my @tmp = &Apache::lonnet::dump('nohist_calculatedsheets',
+                                    $ENV{'course.'.$cid.'.domain'},
+                                    $ENV{'course.'.$cid.'.num'});
+    if ($tmp[0] !~ /^error/) {
+        my %StupidTempHash = @tmp;
+        while (my ($key,$value) = each %StupidTempHash) {
+            $Apache::lonspreadsheet::oldsheets{$key} = $value;
+        }
     }
-    return sqrt($sum/($num-1));    
 }
 
-#-------------------------------------------------------
-
-=item PROD(range)
-
-compute the product of the items in the range.
-
-=cut
+#
+# Load previously cached assessment spreadsheets for this student
+#
+sub cachedssheets {
+    my $self = shift;
+    my ($uname,$udom) = @_;
+    $uname = $uname || $self->{'uname'};
+    $udom  = $udom  || $self->{'udom'};
+    if (! $Apache::lonspreadsheet::loadedcaches{$uname.'_'.$udom}) {
+        my @tmp = &Apache::lonnet::dump('nohist_calculatedsheets_'.
+                                        $ENV{'request.course.id'},
+                                        $self->{'udom'},
+                                        $self->{'uname'});
+        if ($tmp[0] !~ /^error/) {
+            my %TempHash = @tmp;
+            my $count = 0;
+            while (my ($key,$value) = each %TempHash) {
+                $Apache::lonspreadsheet::oldsheets{$key} = $value;
+                $count++;
+            }
+            $Apache::lonspreadsheet::loadedcaches{$self->{'uname'}.'_'.$self->{'udom'}}=1;
+        }
+    }    
+}
 
-#-------------------------------------------------------
-sub PROD {
-    my $mask=mask(@_);
-    my $prod=1;
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        $prod*=$sheet_values{$_};
+# ======================================================= Forced recalculation?
+sub checkthis {
+    my ($keyname,$time)=@_;
+    if (! exists($expiredates{$keyname})) {
+        return 0;
+    } else {
+        return ($time<$expiredates{$keyname});
     }
-    return $prod;   
 }
 
-#-------------------------------------------------------
-
-=item MAX(range)
-
-compute the maximum of the items in the range.
-
-=cut
-
-#-------------------------------------------------------
-sub MAX {
-    my $mask=mask(@_);
-    my $max='-';
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        unless ($max) { $max=$sheet_values{$_}; }
-        if (($sheet_values{$_}>$max) || ($max eq '-')) { $max=$sheet_values{$_}; }
-    } 
-    return $max;   
+sub forcedrecalc {
+    my ($uname,$udom,$stype,$usymb)=@_;
+    my $key=$uname.':'.$udom.':'.$stype.':'.$usymb;
+    my $time=$Apache::lonspreadsheet::oldsheets{$key.'.time'};
+    if ($ENV{'form.forcerecalc'}) { return 1; }
+    unless ($time) { return 1; }
+    if ($stype eq 'assesscalc') {
+        my $map=(split(/___/,$usymb))[0];
+        if (&checkthis('::assesscalc:',$time) ||
+            &checkthis('::assesscalc:'.$map,$time) ||
+            &checkthis('::assesscalc:'.$usymb,$time) ||
+            &checkthis($uname.':'.$udom.':assesscalc:',$time) ||
+            &checkthis($uname.':'.$udom.':assesscalc:'.$map,$time) ||
+            &checkthis($uname.':'.$udom.':assesscalc:'.$usymb,$time)) {
+            return 1;
+        }
+    } else {
+        if (&checkthis('::studentcalc:',$time) || 
+            &checkthis($uname.':'.$udom.':studentcalc:',$time)) {
+	    return 1;
+        }
+    }
+    return 0; 
 }
 
-#-------------------------------------------------------
 
-=item MIN(range)
+##################################################
+##################################################
 
-compute the minimum of the items in the range.
+=pod
 
-=cut
+=item &parmval()
 
-#-------------------------------------------------------
-sub MIN {
-    my $mask=mask(@_);
-    my $min='-';
-    foreach (grep /$mask/,keys(%sheet_values)) {
-        unless ($max) { $max=$sheet_values{$_}; }
-        if (($sheet_values{$_}<$min) || ($min eq '-')) { 
-            $min=$sheet_values{$_}; 
-        }
-    }
-    return $min;   
-}
+Determine the value of a parameter.
 
-#-------------------------------------------------------
+Inputs: $what, the parameter needed, $symb, $uname, $udom, $csec 
 
-=item SUMMAX(num,lower,upper)
+Returns: The value of a parameter, or '' if none.
 
-compute the sum of the largest 'num' items in the range from
-'lower' to 'upper'
+This function cascades through the possible levels searching for a value for
+a parameter.  The levels are checked in the following order:
+user, course (at section level and course level), map, and lonnet::metadata.
+This function uses %parmhash, which must be tied prior to calling it.
+This function also requires %courseopt and %useropt to be initialized for
+this user and course.
 
 =cut
 
-#-------------------------------------------------------
-sub SUMMAX {
-    my ($num,$lower,$upper)=@_;
-    my $mask=mask($lower,$upper);
-    my @inside=();
-    foreach (grep /$mask/,keys(%sheet_values)) {
-	push (@inside,$sheet_values{$_});
+##################################################
+##################################################
+sub parmval {
+    my ($what,$symb,$uname,$udom,$csec)=@_;
+    return '' if (!$symb);
+    #
+    my $cid   = $ENV{'request.course.id'};
+    my $result='';
+    #
+    my ($mapname,$id,$fn)=split(/\_\_\_/,$symb);
+    # Cascading lookup scheme
+    my $rwhat=$what;
+    $what =~ s/^parameter\_//;
+    $what =~ s/\_([^\_]+)$/\.$1/;
+    #
+    my $symbparm = $symb.'.'.$what;
+    my $mapparm  = $mapname.'___(all).'.$what;
+    my $usercourseprefix = $uname.'_'.$udom.'_'.$cid;
+    #
+    my $seclevel  = $usercourseprefix.'.['.$csec.'].'.$what;
+    my $seclevelr = $usercourseprefix.'.['.$csec.'].'.$symbparm;
+    my $seclevelm = $usercourseprefix.'.['.$csec.'].'.$mapparm;
+    #
+    my $courselevel  = $usercourseprefix.'.'.$what;
+    my $courselevelr = $usercourseprefix.'.'.$symbparm;
+    my $courselevelm = $usercourseprefix.'.'.$mapparm;
+    # fourth, check user
+    if (defined($uname)) {
+        return $useropt{$courselevelr} if (defined($useropt{$courselevelr}));
+        return $useropt{$courselevelm} if (defined($useropt{$courselevelm}));
+        return $useropt{$courselevel}  if (defined($useropt{$courselevel}));
     }
-    @inside=sort(@inside);
-    my $sum=0; my $i;
-    for ($i=$#inside;(($i>$#inside-$num) && ($i>=0));$i--) { 
-        $sum+=$inside[$i];
+    # third, check course
+    if (defined($csec)) {
+        return $courseopt{$seclevelr} if (defined($courseopt{$seclevelr}));
+        return $courseopt{$seclevelm} if (defined($courseopt{$seclevelm}));
+        return $courseopt{$seclevel}  if (defined($courseopt{$seclevel}));
     }
-    return $sum;   
+    #
+    return $courseopt{$courselevelr} if (defined($courseopt{$courselevelr}));
+    return $courseopt{$courselevelm} if (defined($courseopt{$courselevelm}));
+    return $courseopt{$courselevel}  if (defined($courseopt{$courselevel}));
+    # second, check map parms
+    my $thisparm = $parmhash{$symbparm};
+    return $thisparm if (defined($thisparm));
+    # first, check default
+    return &Apache::lonnet::metadata($fn,$rwhat.'.default');
 }
 
-#-------------------------------------------------------
-
-=item SUMMIN(num,lower,upper)
+#
+# new: Make a new spreadsheet
+#
+sub new {
+    my $this = shift;
+    my $class = ref($this) || $this;
+    #
+    my ($uname,$udom,$stype,$usymb)=@_;
+    #
+    my $self = {
+        uname => $uname,
+        udom  => $udom,
+        type  => $stype,
+        usymb => $usymb,
+        errorlog => '',
+        maxrow   => '',
+        mapid => $ENV{'form.mapid'},
+        resid => $ENV{'form.resid'},
+        cid   => $ENV{'request.course.id'},
+        csec  => $Section{$uname.':'.$udom},
+        cnum  => $ENV{'course.'.$ENV{'request.course.id'}.'.num'},
+        cdom  => $ENV{'course.'.$ENV{'request.course.id'}.'.domain'},
+        chome => $ENV{'course.'.$ENV{'request.course.id'}.'.home'},
+        coursefilename => $ENV{'request.course.fn'},
+        coursedesc => $ENV{'course.'.$ENV{'request.course.id'}.'.description'},
+        A_column       => [],
+        template_cells => [],
+        };
+    $self->{'uhome'} = &Apache::lonnet::homeserver($uname,$udom);
+    #
+    #
+    $self->{'formulas'} = {};
+    $self->{'constants'} = {};
+    $self->{'othersheets'} = [];
+    $self->{'rowlabel'} = {};
+    #
+    #
+    $self->{'safe'} = &initsheet($self->{'type'});
+    $self->{'root'} = $self->{'safe'}->root();
+    #
+    # Place some of the %$self  items into the safe space except the safe space
+    # itself
+    my $initstring = '';
+    foreach (qw/uname udom type usymb cid csec coursefilename
+             cnum cdom chome uhome/) {
+        $initstring.= qq{\$$_="$self->{$_}";};
+    }
+    $self->{'safe'}->reval($initstring);
+    bless($self,$class);
+    return $self;
+}
 
-compute the sum of the smallest 'num' items in the range from
-'lower' to 'upper'
+##
+## mask - used to reside in the safe space.  
+##
+{
 
-=cut
+my %memoizer;
 
-#-------------------------------------------------------
-sub SUMMIN {
-    my ($num,$lower,$upper)=@_;
-    my $mask=mask($lower,$upper);
-    my @inside=();
-    foreach (grep /$mask/,keys(%sheet_values)) {
-	$inside[$#inside+1]=$sheet_values{$_};
+sub mask {
+    my ($lower,$upper)=@_;
+    my $key = $lower.'_'.$upper;
+    if (exists($memoizer{$key})) {
+        return $memoizer{$key};
     }
-    @inside=sort(@inside);
-    my $sum=0; my $i;
-    for ($i=0;(($i<$num) && ($i<=$#inside));$i++) { 
-        $sum+=$inside[$i];
+    $upper = $lower if (! defined($upper));
+    #
+    my ($la,$ld) = ($lower=~/([A-Za-z]|\*)(\d+|\*)/);
+    my ($ua,$ud) = ($upper=~/([A-Za-z]|\*)(\d+|\*)/);
+    #
+    my $alpha='';
+    my $num='';
+    #
+    if (($la eq '*') || ($ua eq '*')) {
+        $alpha='[A-Za-z]';
+    } else {
+       if (($la=~/[A-Z]/) && ($ua=~/[A-Z]/) ||
+           ($la=~/[a-z]/) && ($ua=~/[a-z]/)) {
+          $alpha='['.$la.'-'.$ua.']';
+       } else {
+          $alpha='['.$la.'-Za-'.$ua.']';
+       }
+    }   
+    if (($ld eq '*') || ($ud eq '*')) {
+	$num='\d+';
+    } else {
+        if (length($ld)!=length($ud)) {
+           $num.='(';
+	   foreach ($ld=~m/\d/g) {
+              $num.='['.$_.'-9]';
+	   }
+           if (length($ud)-length($ld)>1) {
+              $num.='|\d{'.(length($ld)+1).','.(length($ud)-1).'}';
+	   }
+           $num.='|';
+           foreach ($ud=~m/\d/g) {
+               $num.='[0-'.$_.']';
+           }
+           $num.=')';
+       } else {
+           my @lda=($ld=~m/\d/g);
+           my @uda=($ud=~m/\d/g);
+           my $i; 
+           my $j=0; 
+           my $notdone=1;
+           for ($i=0;($i<=$#lda)&&($notdone);$i++) {
+               if ($lda[$i]==$uda[$i]) {
+		   $num.=$lda[$i];
+                   $j=$i;
+               } else {
+                   $notdone=0;
+               }
+           }
+           if ($j<$#lda-1) {
+	       $num.='('.$lda[$j+1];
+               for ($i=$j+2;$i<=$#lda;$i++) {
+                   $num.='['.$lda[$i].'-9]';
+               }
+               if ($uda[$j+1]-$lda[$j+1]>1) {
+		   $num.='|['.($lda[$j+1]+1).'-'.($uda[$j+1]-1).']\d{'.
+                   ($#lda-$j-1).'}';
+               }
+	       $num.='|'.$uda[$j+1];
+               for ($i=$j+2;$i<=$#uda;$i++) {
+                   $num.='[0-'.$uda[$i].']';
+               }
+               $num.=')';
+           } else {
+               if ($lda[-1]!=$uda[-1]) {
+                  $num.='['.$lda[-1].'-'.$uda[-1].']';
+	       }
+           }
+       }
     }
-    return $sum;   
+    my $expression ='^'.$alpha.$num."\$";
+    $memoizer{$key} = $expression;
+    return $expression;
 }
 
+}
+
+sub add_hash_to_safe {
+    my $self = shift;
+    my $code = <<'END';
 #-------------------------------------------------------
 
-=item MINPARM(parametername)
+=item UWCALC(hashname,modules,units,date) 
 
-Returns the minimum value of the parameters matching the parametername.
-parametername should be a string such as 'duedate'.
+returns the proportion of the module 
+weights not previously completed by the student.
 
-=cut
+=over 4
 
-#-------------------------------------------------------
-sub MINPARM {
-    my ($expression) = @_;
-    my $min = undef;
-    study($expression);
-    foreach $parameter (keys(%c)) {
-        next if ($parameter !~ /$expression/);
-        if ((! defined($min)) || ($min > $c{$parameter})) {
-            $min = $c{$parameter} 
-        }
-    }
-    return $min;
-}
+=item hashname 
 
-#-------------------------------------------------------
+name of the hash the module dates have been inserted into
 
-=item MAXPARM(parametername)
+=item modules 
 
-Returns the maximum value of the parameters matching the input parameter name.
-parametername should be a string such as 'duedate'.
+reference to a cell which contains a comma deliminated list of modules 
+covered by the assignment.
 
-=cut
+=item units 
 
-#-------------------------------------------------------
-sub MAXPARM {
-    my ($expression) = @_;
-    my $max = undef;
-    study($expression);
-    foreach $parameter (keys(%c)) {
-        next if ($parameter !~ /$expression/);
-        if ((! defined($min)) || ($max < $c{$parameter})) {
-            $max = $c{$parameter} 
-        }
-    }
-    return $max;
-}
+reference to a cell which contains a comma deliminated list of module 
+weights with respect to the assignment
 
-#--------------------------------------------------------
-sub expandnamed {
-    my $expression=shift;
-    if ($expression=~/^\&/) {
-	my ($func,$var,$formula)=($expression=~/^\&(\w+)\(([^\;]+)\;(.*)\)/);
-	my @vars=split(/\W+/,$formula);
-        my %values=();
-        undef %values;
-	foreach ( @vars ) {
-            my $varname=$_;
-            if ($varname=~/\D/) {
-               $formula=~s/$varname/'$c{\''.$varname.'\'}'/ge;
-               $varname=~s/$var/\(\\w\+\)/g;
-	       foreach (keys(%c)) {
-		  if ($_=~/$varname/) {
-		      $values{$1}=1;
-                  }
-               }
-	    }
-        }
-        if ($func eq 'EXPANDSUM') {
-            my $result='';
-	    foreach (keys(%values)) {
-                my $thissum=$formula;
-                $thissum=~s/$var/$_/g;
-                $result.=$thissum.'+';
-            } 
-            $result=~s/\+$//;
-            return $result;
-        } else {
-	    return 0;
-        }
-    } else {
-        # it is not a function, so it is a parameter name
-        # We should do the following:
-        #    1. Take the list of parameter names
-        #    2. look through the list for ones that match the parameter we want
-        #    3. If there are no collisions, return the one that matches
-        #    4. If there is a collision, return 'bad parameter name error'
-        my $returnvalue = '';
-        my @matches = ();
-        $#matches = -1;
-        study $expression;
-        foreach $parameter (keys(%c)) {
-            push @matches,$parameter if ($parameter =~ /$expression/);
-        }
-        if (scalar(@matches) == 0) {
-            $returnvalue = 'unmatched parameter: '.$parameter;
-        } elsif (scalar(@matches) == 1) {
-            $returnvalue = '$c{\''.$matches[0].'\'}';
-        } elsif (scalar(@matches) > 0) {
-            # more than one match.  Look for a concise one
-            $returnvalue =  "'non-unique parameter name : $expression'";
-            foreach (@matches) {
-                if (/^$expression$/) {
-                    $returnvalue = '$c{\''.$_.'\'}';
-                }
-            }
-        } else {
-            # There was a negative number of matches, which indicates 
-            # something is wrong with reality.  Better warn the user.
-            $returnvalue = 'bizzare parameter: '.$parameter;
-        }
-        return $returnvalue;
-    }
-}
+=item date 
 
-sub sett {
-    %t=();
-    my $pattern='';
-    if ($sheettype eq 'assesscalc') {
-	$pattern='A';
-    } else {
-        $pattern='[A-Z]';
-    }
-    # Deal with the template row
-    foreach (keys(%f)) {
-	next if ($_!~/template\_(\w)/);
-        my $col=$1;
-        next if ($col=~/^$pattern/);
-        foreach (keys(%f)) {
-            next if ($_!~/A(\d+)/);
-            my $trow=$1;
-            next if (! $trow);
-            # Get the name of this cell
-            my $lb=$col.$trow;
-            # Grab the template declaration
-            $t{$lb}=$f{'template_'.$col};
-            # Replace '#' with the row number
-            $t{$lb}=~s/\#/$trow/g;
-            # Replace '....' with ','
-            $t{$lb}=~s/\.\.+/\,/g;
-            # Replace 'A0' with the value from 'A0'
-            $t{$lb}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
-            # Replace parameters
-            $t{$lb}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.&expandnamed($2)/ge;
-        }
-    }
-    # Deal with the normal cells
-    foreach (keys(%f)) {
-	if (exists($f{$_}) && ($_!~/template\_/)) {
-            my $matches=($_=~/^$pattern(\d+)/);
-            if  (($matches) && ($1)) {
-	        unless ($f{$_}=~/^\!/) {
-		    $t{$_}=$c{$_};
-                }
-            } else {
-	       $t{$_}=$f{$_};
-               $t{$_}=~s/\.\.+/\,/g;
-               $t{$_}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
-               $t{$_}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.&expandnamed($2)/ge;
-            }
-        }
+reference to a cell which contains the date the assignment was completed.
+
+=back 
+
+=cut
+
+#-------------------------------------------------------
+sub UWCALC {
+    my ($hashname,$modules,$units,$date) = @_;
+    my @Modules = split(/,/,$modules);
+    my @Units   = split(/,/,$units);
+    my $total_weight;
+    foreach (@Units) {
+	$total_weight += $_;
     }
-    # For inserted lines, [B-Z] is also valid
-    unless ($sheettype eq 'assesscalc') {
-       foreach (keys(%f)) {
-	   if ($_=~/[B-Z](\d+)/) {
-	       if ($f{'A'.$1}=~/^[\~\-]/) {
-  	          $t{$_}=$f{$_};
-                  $t{$_}=~s/\.\.+/\,/g;
-                  $t{$_}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
-                  $t{$_}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.&expandnamed($2)/ge;
-               }
-           }
-       }
+    my $usum=0;
+    for (my $i=0; $i<=$#Modules; $i++) {
+	if (&HASH($hashname,$Modules[$i]) eq $date) {
+	    $usum += $Units[$i];
+	}
     }
-    # For some reason 'A0' gets special treatment...  This seems superfluous
-    # but I imagine it is here for a reason.
-    $t{'A0'}=$f{'A0'};
-    $t{'A0'}=~s/\.\.+/\,/g;
-    $t{'A0'}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
-    $t{'A0'}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.&expandnamed($2)/ge;
+    return $usum/$total_weight;
 }
 
-sub calc {
-    undef %sheet_values;
-    &sett();
-    my $notfinished=1;
-    my $lastcalc='';
-    my $depth=0;
-    while ($notfinished) {
-	$notfinished=0;
-        foreach (keys(%t)) {
-            #$errorlog .= "$_:".$t{$_};
-            my $old=$sheet_values{$_};
-            $sheet_values{$_}=eval $t{$_};
-	    if ($@) {
-		undef %sheet_values;
-                return $_.': '.$@;
-            }
-	    if ($sheet_values{$_} ne $old) { $notfinished=1; $lastcalc=$_; }
-            #$errorlog .= ":".$sheet_values{$_}."\n";
-        }
-        $depth++;
-        if ($depth>100) {
-	    undef %sheet_values;
-            return $lastcalc.': Maximum calculation depth exceeded';
-        }
-    }
-    return '';
-}
+#-------------------------------------------------------
 
-# ------------------------------------------- End of "Inside of the safe space"
-ENDDEFS
-    $safeeval->reval($code);
-    return $safeeval;
-}
+=item CDLSUM(list) 
 
-#
-# 
-#
-sub templaterow {
-    my $sheet = shift;
-    my @cols=();
-    my $rowlabel = 'Template</td><td>&nbsp;';
-    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
-	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
-	     'a','b','c','d','e','f','g','h','i','j','k','l','m',
-	     'n','o','p','q','r','s','t','u','v','w','x','y','z') {
-        push(@cols,{ name    => 'template_'.$_,
-                     formula => $sheet->{'f'}->{'template_'.$_},
-                     value   => $sheet->{'f'}->{'template_'.$_} });
-    }
-    return ($rowlabel,@cols);
-}
+returns the sum of the elements in a cell which contains
+a Comma Deliminate List of numerical values.
+'list' is a reference to a cell which contains a comma deliminated list.
 
-sub outrowassess {
-    # $n is the current row number
-    my ($sheet,$n) = @_;
-    my @cols=();
-    my $rowlabel='';
-    if ($n) {
-        my ($usy,$ufn)=split(/__&&&\__/,$sheet->{'f'}->{'A'.$n});
-        if (exists($sheet->{'rowlabel'}->{$usy})) {
-            # This is dumb, but we need the information when we output
-            # the html version of the studentcalc spreadsheet for the
-            # links to the assesscalc sheets.
-            $rowlabel = $sheet->{'rowlabel'}->{$usy}.':'.
-                &Apache::lonnet::escape($ufn);
-        } else { 
-            $rowlabel = '';
-        }
-    } elsif ($ENV{'request.role'} =~ /^st\./) {
-        $rowlabel = 'Summary</td><td>0';
-    } else {
-        $rowlabel = 'Export</td><td>0';
-    }
-    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
-	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
-	     'a','b','c','d','e','f','g','h','i','j','k','l','m',
-	     'n','o','p','q','r','s','t','u','v','w','x','y','z') {
-        push(@cols,{ name    => $_.$n,
-                     formula => $sheet->{'f'}->{$_.$n},
-                     value   => $sheet->{'values'}->{$_.$n}});
-    }
-    return ($rowlabel,@cols);
-}
+=cut
 
-sub outrow {
-    my ($sheet,$n)=@_;
-    my @cols=();
-    my $rowlabel;
-    if ($n) {
-        $rowlabel = $sheet->{'rowlabel'}->{$sheet->{'f'}->{'A'.$n}};
-    } else {
-        if ($sheet->{'sheettype'} eq 'classcalc') {
-            $rowlabel = 'Summary</td><td>0';
-        } else {
-            $rowlabel = 'Export</td><td>0';
-        }
-    }
-    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
-	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
-	     'a','b','c','d','e','f','g','h','i','j','k','l','m',
-	     'n','o','p','q','r','s','t','u','v','w','x','y','z') {
-        push(@cols,{ name    => $_.$n,
-                     formula => $sheet->{'f'}->{$_.$n},
-                     value   => $sheet->{'values'}->{$_.$n}});
+#-------------------------------------------------------
+sub CDLSUM {
+    my ($list)=@_;
+    my $sum;
+    foreach (split/,/,$list) {
+	$sum += $_;
     }
-    return ($rowlabel,@cols);
+    return $sum;
 }
 
-# ------------------------------------------------ Add or change formula values
-sub setformulas {
-    my ($sheet)=shift;
-    %{$sheet->{'safe'}->varglob('f')}=%{$sheet->{'f'}};
-}
+#-------------------------------------------------------
 
-# ------------------------------------------------ Add or change formula values
-sub setconstants {
-    my ($sheet)=shift;
-    my ($constants) = @_;
-    if (! ref($constants)) {
-        my %tmp = @_;
-        $constants = \%tmp;
-    }
-    $sheet->{'constants'} = $constants;
-    return %{$sheet->{'safe'}->varglob('c')}=%{$sheet->{'constants'}};
-}
+=item CDLITEM(list,index) 
 
-# --------------------------------------------- Set names of other spreadsheets
-sub setothersheets {
-    my $sheet = shift;
-    my @othersheets = @_;
-    $sheet->{'othersheets'} = \@othersheets;
-    @{$sheet->{'safe'}->varglob('os')}=@othersheets;
-    return;
-}
+returns the item at 'index' in a Comma Deliminated List.
 
-# ------------------------------------------------ Add or change formula values
-sub setrowlabels {
-    my $sheet=shift;
-    my ($rowlabel) = @_;
-    if (! ref($rowlabel)) {
-        my %tmp = @_;
-        $rowlabel = \%tmp;
-    }
-    $sheet->{'rowlabel'}=$rowlabel;
-}
+=over 4
 
-# ------------------------------------------------------- Calculate spreadsheet
-sub calcsheet {
-    my $sheet=shift;
-    my $result =  $sheet->{'safe'}->reval('&calc();');
-    %{$sheet->{'values'}} = %{$sheet->{'safe'}->varglob('sheet_values')};
-    return $result;
-}
+=item list
 
-# ---------------------------------------------------------------- Get formulas
-# Return a copy of the formulas
-sub getformulas {
-    my $sheet = shift;
-    return %{$sheet->{'safe'}->varglob('f')};
-}
+reference to a cell which contains a comma deliminated list.
 
-sub geterrorlog {
-    my $sheet = shift;
-    return ${$sheet->{'safe'}->varglob('errorlog')};    
-}
+=item index 
 
-sub gettitle {
-    my $sheet = shift;
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-        return $sheet->{'coursedesc'};
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-        return 'Grades for '.$sheet->{'uname'}.'@'.$sheet->{'udom'};
-    } elsif ($sheet->{'sheettype'} eq 'assesscalc') {
-        if (($sheet->{'usymb'} eq '_feedback') ||
-            ($sheet->{'usymb'} eq '_evaluation') ||
-            ($sheet->{'usymb'} eq '_discussion') ||
-            ($sheet->{'usymb'} eq '_tutoring')) {
-            my $title = $sheet->{'usymb'};
-            $title =~ s/^_//;
-            $title = ucfirst($title);
-            return $title;
-        }
-        return if (! defined($sheet->{'mapid'}) || 
-                   $sheet->{'mapid'} !~ /^\d+$/);
-        my $mapid = $sheet->{'mapid'};
-        return if (! defined($sheet->{'resid'}) || 
-                   $sheet->{'resid'} !~ /^\d+$/);
-        my $resid = $sheet->{'resid'};
-        my %course_db;
-        tie(%course_db,'GDBM_File',$sheet->{'coursefilename'}.'.db',
-            &GDBM_READER(),0640);
-        return if (! tied(%course_db));
-        my $key = 'title_'.$mapid.'.'.$resid;
-        my $title = '';
-        if (exists($course_db{$key})) {
-            $title = $course_db{$key};
-        } else {
-            $title = $sheet->{'usymb'};
-        }
-        untie (%course_db);
-        return $title;
-    }
-}
+the Perl index of the item requested (first element in list has
+an index of 0) 
 
-# ----------------------------------------------------- Get value of $f{'A'.$n}
-sub getfa {
-    my $sheet = shift;
-    my ($n)=@_;
-    return $sheet->{'safe'}->reval('$f{"A'.$n.'"}');
-}
+=back
 
-# ------------------------------------------------------------- Export of A-row
-sub exportdata {
-    my $sheet=shift;
-    my @exportarray=();
-    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
-	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
-        if (exists($sheet->{'values'}->{$_.'0'})) {
-            push(@exportarray,$sheet->{'values'}->{$_.'0'});
-        } else {
-            push(@exportarray,'');
-        }
-    } 
-    return @exportarray;
+=cut
+
+#-------------------------------------------------------
+sub CDLITEM {
+    my ($list,$index)=@_;
+    my @Temp = split/,/,$list;
+    return $Temp[$index];
 }
 
+#-------------------------------------------------------
 
+=item CDLHASH(name,key,value) 
 
-sub update_student_sheet{
-    my ($sheet,$r,$c) = @_;
-    # Load in the studentcalc sheet
-    &readsheet($sheet,'default_studentcalc');
-    # Determine the structure (contained assessments, etc) of the sheet
-    &updatesheet($sheet);
-    # Load in the cached sheets for this student
-    &cachedssheets($sheet);
-    # Load in the (possibly cached) data from the assessment sheets        
-    &loadstudent($sheet,$r,$c);
-    # Compute the sheet
-    &calcsheet($sheet);
-}
+loads a comma deliminated list of keys into
+the hash 'name', all with a value of 'value'.
 
-# ========================================================== End of Spreadsheet
-# =============================================================================
-#
-# Procedures for spreadsheet output
-#
-# --------------------------------------------- Produce output row n from sheet
+=over 4
 
-sub get_row {
-    my ($sheet,$n) = @_;
-    my ($rowlabel,@rowdata);
-    if ($n eq '-') { 
-        ($rowlabel,@rowdata) = &templaterow($sheet);
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-        ($rowlabel,@rowdata) = &outrowassess($sheet,$n);
+=item name  
+
+name of the hash.
+
+=item key
+
+(a pointer to) a comma deliminated list of keys.
+
+=item value
+
+a single value to be entered for each key.
+
+=back
+
+=cut
+
+#-------------------------------------------------------
+sub CDLHASH {
+    my ($name,$key,$value)=@_;
+    my @Keys;
+    my @Values;
+    # Check to see if we have multiple $key values
+    if ($key =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
+	my $keymask = &mask($key);
+	# Assume the keys are addresses
+	my @Temp = grep /$keymask/,keys(%sheet_values);
+	@Keys = $sheet_values{@Temp};
     } else {
-        ($rowlabel,@rowdata) = &outrow($sheet,$n);
+	$Keys[0]= $key;
     }
-    return ($rowlabel,@rowdata);
-}
-
-########################################################################
-########################################################################
-sub sort_indicies {
-    my $sheet = shift;
-    my @sortidx=();
-    #
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-        my @sortby=(undef);
-        # Skip row 0
-        for (my $row=1;$row<=$sheet->{'maxrow'};$row++) {
-            my (undef,$sname,$sdom,$fullname,$section,$id) = 
-                split(':',$sheet->{'rowlabel'}->{$sheet->{'f'}->{'A'.$row}});
-            push (@sortby, lc($fullname));
-            push (@sortidx, $row);
-        }
-        @sortidx = sort { $sortby[$a] cmp $sortby[$b]; } @sortidx;
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-        my @sortby1=(undef);
-        my @sortby2=(undef);
-        # Skip row 0
-        for (my $row=1;$row<=$sheet->{'maxrow'};$row++) {
-            my ($key,undef) = split(/__&&&\__/,$sheet->{'f'}->{'A'.$row});
-            my $rowlabel = $sheet->{'rowlabel'}->{$key};
-            my (undef,$symb,$mapid,$resid,$title,$ufn) = 
-                split(':',$rowlabel);
-            $ufn   = &Apache::lonnet::unescape($ufn);
-            $symb  = &Apache::lonnet::unescape($symb);
-            $title = &Apache::lonnet::unescape($title);
-            my ($sequence) = ($symb =~ /\/([^\/]*\.sequence)/);
-            if ($sequence eq '') {
-                $sequence = $symb;
-            }
-            push (@sortby1, $sequence);
-            push (@sortby2, $title);
-            push (@sortidx, $row);
-        }
-        @sortidx = sort { $sortby1[$a] cmp $sortby1[$b] || 
-                              $sortby2[$a] cmp $sortby2[$b] } @sortidx;
+    my @Temp;
+    foreach $key (@Keys) {
+	@Temp = (@Temp, split/,/,$key);
+    }
+    @Keys = @Temp;
+    if ($value =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
+	my $valmask = &mask($value);
+	my @Temp = grep /$valmask/,keys(%sheet_values);
+	@Values =$sheet_values{@Temp};
     } else {
-        my @sortby=(undef);
-        # Skip row 0
-        for (my $row=1;$row<=$sheet->{'maxrow'};$row++) {
-            push (@sortby, $sheet->{'safe'}->reval('$f{"A'.$row.'"}'));
-            push (@sortidx, $row);
-        }
-        @sortidx = sort { $sortby[$a] cmp $sortby[$b]; } @sortidx;
+	$Values[0]= $value;
     }
-    return @sortidx;
+    $value = $Values[0];
+    # Add values to hash
+    for (my $i = 0; $i<=$#Keys; $i++) {
+	my $key   = $Keys[$i];
+	if (! exists ($hashes{$name}->{$key})) {
+	    $hashes{$name}->{$key}->[0]=$value;
+	} else {
+	    my @Temp = sort(@{$hashes{$name}->{$key}},$value);
+	    $hashes{$name}->{$key} = \@Temp;
+	}
+    }
+    return "hash '$name' updated";
 }
 
-#############################################################
-###                                                       ###
-###              Spreadsheet Output Routines              ###
-###                                                       ###
-#############################################################
+#-------------------------------------------------------
 
-############################################
-##         HTML output routines           ##
-############################################
-sub html_editable_cell {
-    my ($cell,$bgcolor) = @_;
-    my $result;
-    my ($name,$formula,$value);
-    if (defined($cell)) {
-        $name    = $cell->{'name'};
-        $formula = $cell->{'formula'};
-        $value   = $cell->{'value'};
+=item GETHASH(name,key,index) 
+
+returns the element in hash 'name' 
+reference by the key 'key', at index 'index' in the values list.
+
+=cut
+
+#-------------------------------------------------------
+sub GETHASH {
+    my ($name,$key,$index)=@_;
+    if (! defined($index)) {
+	$index = 0;
     }
-    $name    = '' if (! defined($name));
-    $formula = '' if (! defined($formula));
-    if (! defined($value)) {
-        $value = '<font color="'.$bgcolor.'">#</font>';
-        if ($formula ne '') {
-            $value = '<i>undefined value</i>';
-        }
-    } elsif ($value =~ /^\s*$/ ) {
-        $value = '<font color="'.$bgcolor.'">#</font>';
+    if ($key =~ /^[A-z]\d+$/) {
+	$key = $sheet_values{$key};
+    }
+    return $hashes{$name}->{$key}->[$index];
+}
+
+#-------------------------------------------------------
+
+=item CLEARHASH(name) 
+
+clears all the values from the hash 'name'
+
+=item CLEARHASH(name,key) 
+
+clears all the values from the hash 'name' associated with the given key.
+
+=cut
+
+#-------------------------------------------------------
+sub CLEARHASH {
+    my ($name,$key)=@_;
+    if (defined($key)) {
+	if (exists($hashes{$name}->{$key})) {
+	    $hashes{$name}->{$key}=undef;
+	    return "hash '$name' key '$key' cleared";
+	}
     } else {
-        $value = &HTML::Entities::encode($value) if ($value !~/&nbsp;/);
+	if (exists($hashes{$name})) {
+	    $hashes{$name}=undef;
+	    return "hash '$name' cleared";
+	}
     }
-    # Make the formula safe for outputting
-    $formula =~ s/\'/\"/g;
-    # The formula will be parsed by the browser *twice* before being 
-    # displayed to the user for editing.
-    $formula = &HTML::Entities::encode(&HTML::Entities::encode($formula));
-    # Escape newlines so they make it into the edit window
-    $formula =~ s/\n/\\n/gs;
-    # Glue everything together
-    $result .= "<a href=\"javascript:celledit(\'".
-        $name."','".$formula."');\">".$value."</a>";
-    return $result;
+    return "Error in clearing hash";
 }
 
-sub html_uneditable_cell {
-    my ($cell,$bgcolor) = @_;
-    my $value = (defined($cell) ? $cell->{'value'} : '');
-    $value = &HTML::Entities::encode($value) if ($value !~/&nbsp;/);
-    return '&nbsp;'.$value.'&nbsp;';
-}
+#-------------------------------------------------------
+
+=item HASH(name,key,value) 
+
+loads values into an internal hash.  If a key 
+already has a value associated with it, the values are sorted numerically.  
+
+=item HASH(name,key) 
 
-sub outsheet_html  {
-    my ($sheet,$r) = @_;
-    my ($num_uneditable,$realm,$row_type);
-    my $requester_is_student = ($ENV{'request.role'} =~ /^st\./);
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
-        $num_uneditable = 1;
-        $realm = 'Assessment';
-        $row_type = 'Item';
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-        $num_uneditable = 26;
-        $realm = 'User';
-        $row_type = 'Assessment';
-    } elsif ($sheet->{'sheettype'} eq 'classcalc') {
-        $num_uneditable = 26;
-        $realm = 'Course';
-        $row_type = 'Student';
+returns the 0th value in the hash 'name' associated with 'key'.
+
+=cut
+
+#-------------------------------------------------------
+sub HASH {
+    my ($name,$key,$value)=@_;
+    my @Keys;
+    undef @Keys;
+    my @Values;
+    # Check to see if we have multiple $key values
+    if ($key =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
+	my $keymask = &mask($key);
+	# Assume the keys are addresses
+	my @Temp = grep /$keymask/,keys(%sheet_values);
+	@Keys = $sheet_values{@Temp};
     } else {
-        return;  # error
+	$Keys[0]= $key;
     }
-    ####################################
-    # Print out header table
-    ####################################
-    my $num_left = 52-$num_uneditable;
-    my $tabledata =<<"END";
-<table border="2">
-<tr>
-  <th colspan="2" rowspan="2"><font size="+2">$realm</font></th>
-  <td bgcolor="#FFDDDD" colspan="$num_uneditable">
-      <b><font size="+1">Import</font></b></td>
-  <td colspan="$num_left">
-      <b><font size="+1">Calculations</font></b></td>
-</tr><tr>
-END
-    my $label_num = 0;
-    foreach (split(//,'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz')){
-        if ($label_num<$num_uneditable) { 
-            $tabledata.='<td bgcolor="#FFDDDD">';
-        } else {
-            $tabledata.='<td>';
-        }
-        $tabledata.="<b><font size=+1>$_</font></b></td>";
-        $label_num++;
+    # If $value is empty, return the first value associated 
+    # with the first key.
+    if (! $value) {
+	return $hashes{$name}->{$Keys[0]}->[0];
     }
-    $tabledata.="</tr>\n";
-    $r->print($tabledata);
-    ####################################
-    # Print out template row
-    ####################################
-    my ($num_cols_output,$row_html,$rowlabel,@rowdata);
-    
-    if (! $requester_is_student) {
-        ($rowlabel,@rowdata) = &get_row($sheet,'-');
-        $row_html = '<tr><td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
-        $num_cols_output = 0;
-        foreach my $cell (@rowdata) {
-            if ($requester_is_student || 
-                $num_cols_output++ < $num_uneditable) {
-                $row_html .= '<td bgcolor="#FFDDDD">';
-                $row_html .= &html_uneditable_cell($cell,'#FFDDDD');
-            } else {
-                $row_html .= '<td bgcolor="#EOFFDD">';
-                $row_html .= &html_editable_cell($cell,'#E0FFDD');
-            }
-            $row_html .= '</td>';
-        }
-        $row_html.= "</tr>\n";
-        $r->print($row_html);
+    # Check to see if we have multiple $value(s) 
+    if ($value =~ /[A-z](\-[A-z])?\d+(\-\d+)?/) {
+	my $valmask = &mask($value);
+	my @Temp = grep /$valmask/,keys(%sheet_values);
+	@Values =$sheet_values{@Temp};
+    } else {
+	$Values[0]= $value;
     }
-    ####################################
-    # Print out summary/export row
-    ####################################
-    ($rowlabel,@rowdata) = &get_row($sheet,'0');
-    $row_html = '<tr><td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
-    $num_cols_output = 0;
-    foreach my $cell (@rowdata) {
-        if ($num_cols_output++ < 26 && ! $requester_is_student) {
-            $row_html .= '<td bgcolor="#CCCCFF">';
-            $row_html .= &html_editable_cell($cell,'#CCCCFF');
-        } else {
-            $row_html .= '<td bgcolor="#DDCCFF">';
-            $row_html .= &html_uneditable_cell($cell,'#CCCCFF');
-        }
-        $row_html .= '</td>';
+    # Add values to hash
+    for (my $i = 0; $i<=$#Keys; $i++) {
+	my $key   = $Keys[$i];
+	my $value = ($i<=$#Values ? $Values[$i] : $Values[0]);
+	if (! exists ($hashes{$name}->{$key})) {
+	    $hashes{$name}->{$key}->[0]=$value;
+	} else {
+	    my @Temp = sort(@{$hashes{$name}->{$key}},$value);
+	    $hashes{$name}->{$key} = \@Temp;
+	}
     }
-    $row_html.= "</tr>\n";
-    $r->print($row_html);
-    $r->print('</table>');
-    ####################################
-    # Prepare to output rows
-    ####################################
-    my @Rows = &sort_indicies($sheet);
-    #
-    # Loop through the rows and output them one at a time
-    my $rows_output=0;
-    foreach my $rownum (@Rows) {
-        my ($rowlabel,@rowdata) = &get_row($sheet,$rownum);
-        next if ($rowlabel =~ /^\s*$/);
-        next if (($sheet->{'sheettype'} eq 'assesscalc') && 
-                 (! $ENV{'form.showall'})                &&
-                 ($rowdata[0]->{'value'} =~ /^\s*$/));
-        if (! $ENV{'form.showall'} &&
-            $sheet->{'sheettype'} =~ /^(studentcalc|classcalc)$/) {
-            my $row_is_empty = 1;
-            foreach my $cell (@rowdata) {
-                if ($cell->{'value'} !~  /^\s*$/) {
-                    $row_is_empty = 0;
-                    last;
-                }
-            }
-            next if ($row_is_empty);
-        }
-        #
-        my $defaultbg='#E0FF';
-        #
-        my $row_html ="\n".'<tr><td><b><font size=+1>'.$rownum.
-            '</font></b></td>';
-        #
-        if ($sheet->{'sheettype'} eq 'classcalc') {
-            $row_html.='<td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
-            # Output links for each student?
-            # Nope, that is already done for us in format_html_rowlabel 
-            # (for now)
-        } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-            my $ufn = (split(/:/,$rowlabel))[5];
-            $row_html.='<td>'.&format_html_rowlabel($sheet,$rowlabel);
-            $row_html.= '<br>'.
-                '<select name="sel_'.$rownum.'" '.
-                    'onChange="changesheet('.$rownum.')">'.
-                        '<option name="default">Default</option>';
+    return $Values[-1];
+}
+END
+    $self->{'safe'}->reval($code);
+    return;
+}
 
-            foreach (@{$sheet->{'othersheets'}}) {
-                $row_html.='<option name="'.$_.'"';
-                if ($ufn eq $_) {
-                    $row_html.=' selected';
-                }
-                $row_html.='>'.$_.'</option>';
-            }
-            $row_html.='</select></td>';
-        } elsif ($sheet->{'sheettype'} eq 'assesscalc') {
-            $row_html.='<td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
-        }
-        #
-        my $shown_cells = 0;
-        foreach my $cell (@rowdata) {
-            my $value    = $cell->{'value'};
-            my $formula  = $cell->{'formula'};
-            my $cellname = $cell->{'name'};
-            #
-            my $bgcolor;
-            if ($shown_cells && ($shown_cells/5 == int($shown_cells/5))) {
-                $bgcolor = $defaultbg.'99';
-            } else {
-                $bgcolor = $defaultbg.'DD';
-            }
-            $bgcolor='#FFDDDD' if ($shown_cells < $num_uneditable);
-            #
-            $row_html.='<td bgcolor='.$bgcolor.'>';
-            if ($requester_is_student || $shown_cells < $num_uneditable) {
-                $row_html .= &html_uneditable_cell($cell,$bgcolor);
-            } else {
-                $row_html .= &html_editable_cell($cell,$bgcolor);
-            }
-            $row_html.='</td>';
-            $shown_cells++;
-        }
-        if ($row_html) {
-            if ($rows_output % 25 == 0) {
-                $r->print("</table>\n<br>\n");
-                $r->rflush();
-                $r->print('<table border=2>'.
-                          '<tr><td>&nbsp;<td>'.$row_type.'</td>'.
-                          '<td>'.
-                          join('</td><td>',
-                               (split(//,'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.
-                                      'abcdefghijklmnopqrstuvwxyz'))).
-                          "</td></tr>\n");
-            }
-            $rows_output++;
-            $r->print($row_html);
+sub initsheet {
+    my $safeeval = new Safe(shift);
+    my $safehole = new Safe::Hole;
+    $safeeval->permit("entereval");
+    $safeeval->permit(":base_math");
+    $safeeval->permit("sort");
+    $safeeval->deny(":base_io");
+    $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
+    $safehole->wrap(\&mask,$safeeval,'&mask');
+    $safeeval->share('$@');
+    my $code=<<'ENDDEFS';
+# ---------------------------------------------------- Inside of the safe space
+#
+# f: formulas
+# t: intermediate format (variable references expanded)
+# v: output values
+# c: preloaded constants (A-column)
+# rl: row label
+# os: other spreadsheets (for student spreadsheet only)
+
+undef %sheet_values;   # Holds the (computed, final) values for the sheet
+    # This is only written to by &calc, the spreadsheet computation routine.
+    # It is read by many functions
+undef %t; # Holds the values of the spreadsheet temporarily. Set in &sett, 
+    # which does the translation of strings like C5 into the value in C5.
+    # Used in &calc - %t holds the values that are actually eval'd.
+undef %f;    # Holds the formulas for each cell.  This is the users
+    # (spreadsheet authors) data for each cell.
+undef %c; # Holds the constants for a sheet.  In the assessment
+    # sheets, this is the A column.  Used in &MINPARM, &MAXPARM, &expandnamed,
+    # &sett, and &constants.  There is no &getconstants.
+    # &constants is called by &loadstudent, &loadcourse, &load assessment,
+undef @os;  # Holds the names of other spreadsheets - this is used to specify
+    # the spreadsheets that are available for the assessment sheet.
+    # Set by &setothersheets.  &setothersheets is called by &handler.  A
+    # related subroutine is &othersheets.
+$errorlog = '';
+
+$maxrow = 0;
+$type = '';
+
+# filename/reference of the sheet
+$filename = '';
+
+# user data
+$uname = '';
+$uhome = '';
+$udom  = '';
+
+# course data
+
+$csec = '';
+$chome= '';
+$cnum = '';
+$cdom = '';
+$cid  = '';
+$coursefilename  = '';
+
+# symb
+
+$usymb = '';
+
+# error messages
+$errormsg = '';
+
+#-------------------------------------------------------
+
+=item NUM(range)
+
+returns the number of items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub NUM {
+    my $mask=&mask(@_);
+    my $num= $#{@{grep(/$mask/,keys(%sheet_values))}}+1;
+    return $num;   
+}
+
+sub BIN {
+    my ($low,$high,$lower,$upper)=@_;
+    my $mask=&mask($lower,$upper);
+    my $num=0;
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        if (($sheet_values{$_}>=$low) && ($sheet_values{$_}<=$high)) {
+            $num++;
         }
     }
-    #
-    $r->print('</table>');
-    #
-    # Debugging code (be sure to uncomment errorlog code in safe space):
-    #
-    # $r->print("\n<pre>");
-    # $r->print(&geterrorlog($sheet));
-    # $r->print("\n</pre>");
-    return 1;
+    return $num;   
 }
 
-############################################
-##         csv output routines            ##
-############################################
-sub outsheet_csv   {
-    my ($sheet,$r) = @_;
-    my $csvdata = '';
-    my @Values;
-    ####################################
-    # Prepare to output rows
-    ####################################
-    my @Rows = &sort_indicies($sheet);
-    #
-    # Loop through the rows and output them one at a time
-    my $rows_output=0;
-    foreach my $rownum (@Rows) {
-        my ($rowlabel,@rowdata) = &get_row($sheet,$rownum);
-        next if ($rowlabel =~ /^\s*$/);
-        push (@Values,&format_csv_rowlabel($sheet,$rowlabel));
-        foreach my $cell (@rowdata) {
-            push (@Values,'"'.$cell->{'value'}.'"');
-        }
-        $csvdata.= join(',',@Values)."\n";
-        @Values = ();
+
+#-------------------------------------------------------
+
+=item SUM(range)
+
+returns the sum of items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub SUM {
+    my $mask=&mask(@_);
+    my $sum=0;
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        $sum+=$sheet_values{$_};
     }
-    #
-    # Write the CSV data to a file and serve up a link
-    #
-    my $filename = '/prtspool/'.
-        $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
-        time.'_'.rand(1000000000).'.csv';
-    my $file;
-    unless ($file = Apache::File->new('>'.'/home/httpd'.$filename)) {
-        $r->log_error("Couldn't open $filename for output $!");
-        $r->print("Problems occured in writing the csv file.  ".
-                  "This error has been logged.  ".
-                  "Please alert your LON-CAPA administrator.");
-        $r->print("<pre>\n".$csvdata."</pre>\n");
-        return 0;
+    return $sum;   
+}
+
+#-------------------------------------------------------
+
+=item MEAN(range)
+
+compute the average of the items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub MEAN {
+    my $mask=&mask(@_);
+#    $errorlog.='(mask = '.$mask.' )';
+    my $sum=0; 
+    my $num=0;
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        $sum+=$sheet_values{$_};
+        $num++;
     }
-    print $file $csvdata;
-    close($file);
-    $r->print('<br /><br />'.
-              '<a href="'.$filename.'">Your CSV spreadsheet.</a>'."\n");
-    #
-    return 1;
+    if ($num) {
+       return $sum/$num;
+    } else {
+       return undef;
+    }   
 }
 
-############################################
-##        Excel output routines           ##
-############################################
-sub outsheet_recursive_excel {
-    my ($sheet,$r) = @_;
-    my $c = $r->connection;
-    return undef if ($sheet->{'sheettype'} ne 'classcalc');
-    my ($workbook,$filename) = &create_excel_spreadsheet($sheet,$r);
-    return undef if (! defined($workbook));
-    #
-    # Create main worksheet
-    my $main_worksheet = $workbook->addworksheet('main');
-    #
-    # Figure out who the students are
-    my %f=&getformulas($sheet);
-    my $count = 0;
-    $r->print(<<END);
-<p>
-Compiling Excel Workbook with a worksheet for each student.
-</p><p>
-This operation may take longer than a complete recalculation of the
-spreadsheet. 
-</p><p>
-To abort this operation, hit the stop button on your browser.
-</p><p>
-A link to the spreadsheet will be available at the end of this process.
-</p>
-<p>
-END
-    $r->rflush();
-    my $starttime = time;
-    foreach my $rownum (&sort_indicies($sheet)) {
-        $count++;
-        my ($sname,$sdom) = split(':',$f{'A'.$rownum});
-        my $student_excel_worksheet=$workbook->addworksheet($sname.'@'.$sdom);
-        # Create a new spreadsheet
-        my $studentsheet = &makenewsheet($sname,$sdom,'studentcalc',undef);
-        # Read in the spreadsheet definition
-        &update_student_sheet($studentsheet,$r,$c);
-        # Stuff the sheet into excel
-        &export_sheet_as_excel($studentsheet,$student_excel_worksheet);
-        my $totaltime = int((time - $starttime) / $count * $sheet->{'maxrow'});
-        my $timeleft = int((time - $starttime) / $count * ($sheet->{'maxrow'} - $count));
-        if ($count % 5 == 0) {
-            $r->print($count.' students completed.'.
-                      '  Time remaining: '.$timeleft.' sec. '.
-                      '  Estimated total time: '.$totaltime." sec <br />\n");
-            $r->rflush();
-        }
-        if(defined($c) && ($c->aborted())) {
-            last;
+#-------------------------------------------------------
+
+=item STDDEV(range)
+
+compute the standard deviation of the items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub STDDEV {
+    my $mask=&mask(@_);
+#    $errorlog.='(mask = '.$mask.' )';
+    my $sum=0; my $num=0;
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        $sum+=$sheet_values{$_};
+        $num++;
+    }
+    unless ($num>1) { return undef; }
+    my $mean=$sum/$num;
+    $sum=0;
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        $sum+=($sheet_values{$_}-$mean)**2;
+    }
+    return sqrt($sum/($num-1));    
+}
+
+#-------------------------------------------------------
+
+=item PROD(range)
+
+compute the product of the items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub PROD {
+    my $mask=&mask(@_);
+    my $prod=1;
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        $prod*=$sheet_values{$_};
+    }
+    return $prod;   
+}
+
+#-------------------------------------------------------
+
+=item MAX(range)
+
+compute the maximum of the items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub MAX {
+    my $mask=&mask(@_);
+    my $max='-';
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        unless ($max) { $max=$sheet_values{$_}; }
+        if (($sheet_values{$_}>$max) || ($max eq '-')) { $max=$sheet_values{$_}; }
+    } 
+    return $max;   
+}
+
+#-------------------------------------------------------
+
+=item MIN(range)
+
+compute the minimum of the items in the range.
+
+=cut
+
+#-------------------------------------------------------
+sub MIN {
+    my $mask=&mask(@_);
+    my $min='-';
+    foreach (grep /$mask/,keys(%sheet_values)) {
+        unless ($max) { $max=$sheet_values{$_}; }
+        if (($sheet_values{$_}<$min) || ($min eq '-')) { 
+            $min=$sheet_values{$_}; 
         }
     }
-    #
-    if(! $c->aborted() ) {
-        $r->print('All students spreadsheets completed!<br />');
-        $r->rflush();
-        #
-        # &export_sheet_as_excel fills $worksheet with the data from $sheet
-        &export_sheet_as_excel($sheet,$main_worksheet);
-        #
-        $workbook->close();
-        # Okay, the spreadsheet is taken care of, so give the user a link.
-        $r->print('<br /><br />'.
-                  '<a href="'.$filename.'">Your Excel spreadsheet.</a>'."\n");
-    } else {
-        $workbook->close();  # Not sure how necessary this is.
-        #unlink('/home/httpd'.$filename); # No need to keep this around?
+    return $min;   
+}
+
+#-------------------------------------------------------
+
+=item SUMMAX(num,lower,upper)
+
+compute the sum of the largest 'num' items in the range from
+'lower' to 'upper'
+
+=cut
+
+#-------------------------------------------------------
+sub SUMMAX {
+    my ($num,$lower,$upper)=@_;
+    my $mask=&mask($lower,$upper);
+    my @inside=();
+    foreach (grep /$mask/,keys(%sheet_values)) {
+	push (@inside,$sheet_values{$_});
     }
-    return 1;
+    @inside=sort(@inside);
+    my $sum=0; my $i;
+    for ($i=$#inside;(($i>$#inside-$num) && ($i>=0));$i--) { 
+        $sum+=$inside[$i];
+    }
+    return $sum;   
 }
 
-sub outsheet_excel {
-    my ($sheet,$r) = @_;
-    my ($workbook,$filename) = &create_excel_spreadsheet($sheet,$r);
-    return undef if (! defined($workbook));
-    my $sheetname;
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-        $sheetname = 'Main';
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-        $sheetname = $sheet->{'uname'}.'@'.$sheet->{'udom'};
-    } elsif ($sheet->{'sheettype'} eq 'assesscalc') {
-        $sheetname = $sheet->{'uname'}.'@'.$sheet->{'udom'}.' assessment';
+#-------------------------------------------------------
+
+=item SUMMIN(num,lower,upper)
+
+compute the sum of the smallest 'num' items in the range from
+'lower' to 'upper'
+
+=cut
+
+#-------------------------------------------------------
+sub SUMMIN {
+    my ($num,$lower,$upper)=@_;
+    my $mask=&mask($lower,$upper);
+    my @inside=();
+    foreach (grep /$mask/,keys(%sheet_values)) {
+	$inside[$#inside+1]=$sheet_values{$_};
     }
-    my $worksheet = $workbook->addworksheet($sheetname);
-    #
-    # &export_sheet_as_excel fills $worksheet with the data from $sheet
-    &export_sheet_as_excel($sheet,$worksheet);
-    #
-    $workbook->close();
-    # Okay, the spreadsheet is taken care of, so give the user a link.
-    $r->print('<br /><br />'.
-              '<a href="'.$filename.'">Your Excel spreadsheet.</a>'."\n");
-    return 1;
+    @inside=sort(@inside);
+    my $sum=0; my $i;
+    for ($i=0;(($i<$num) && ($i<=$#inside));$i++) { 
+        $sum+=$inside[$i];
+    }
+    return $sum;   
 }
 
-sub create_excel_spreadsheet {
-    my ($sheet,$r) = @_;
-    my $filename = '/prtspool/'.
-        $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
-        time.'_'.rand(1000000000).'.xls';
-    my $workbook  = Spreadsheet::WriteExcel->new('/home/httpd'.$filename);
-    if (! defined($workbook)) {
-        $r->log_error("Error creating excel spreadsheet $filename: $!");
-        $r->print("Problems creating new Excel file.  ".
-                  "This error has been logged.  ".
-                  "Please alert your LON-CAPA administrator");
-        return undef;
+#-------------------------------------------------------
+
+=item MINPARM(parametername)
+
+Returns the minimum value of the parameters matching the parametername.
+parametername should be a string such as 'duedate'.
+
+=cut
+
+#-------------------------------------------------------
+sub MINPARM {
+    my ($expression) = @_;
+    my $min = undef;
+    study($expression);
+    foreach $parameter (keys(%c)) {
+        next if ($parameter !~ /$expression/);
+        if ((! defined($min)) || ($min > $c{$parameter})) {
+            $min = $c{$parameter} 
+        }
     }
-    #
-    # The spreadsheet stores temporary data in files, then put them
-    # together.  If needed we should be able to disable this (memory only).
-    # The temporary directory must be specified before calling 'addworksheet'.
-    # File::Temp is used to determine the temporary directory.
-    $workbook->set_tempdir('/home/httpd/perl/tmp');
-    #
-    # Determine the name to give the worksheet
-    return ($workbook,$filename);
+    return $min;
 }
 
-sub export_sheet_as_excel {
-    my $sheet = shift;
-    my $worksheet = shift;
-    #
-    my $rows_output = 0;
-    my $cols_output = 0;
-    ####################################
-    #    Write an identifying row      #
-    ####################################
-    my @Headerinfo = ($sheet->{'coursedesc'});
-    my $title = &gettitle($sheet);
-    $cols_output = 0;    
-    if (defined($title)) {
-        $worksheet->write($rows_output++,$cols_output++,$title);
-    }
-    ####################################
-    #   Write the summary/export row   #
-    ####################################
-    my ($rowlabel,@rowdata) = &get_row($sheet,'0');
-    my $label = &format_excel_rowlabel($sheet,$rowlabel);
-    $cols_output = 0;
-    $worksheet->write($rows_output,$cols_output++,$label);
-    foreach my $cell (@rowdata) {
-        $worksheet->write($rows_output,$cols_output++,$cell->{'value'});
+#-------------------------------------------------------
+
+=item MAXPARM(parametername)
+
+Returns the maximum value of the parameters matching the input parameter name.
+parametername should be a string such as 'duedate'.
+
+=cut
+
+#-------------------------------------------------------
+sub MAXPARM {
+    my ($expression) = @_;
+    my $max = undef;
+    study($expression);
+    foreach $parameter (keys(%c)) {
+        next if ($parameter !~ /$expression/);
+        if ((! defined($min)) || ($max < $c{$parameter})) {
+            $max = $c{$parameter} 
+        }
     }
-    $rows_output+= 2;   # Skip a row, just for fun
-    ####################################
-    # Prepare to output rows
-    ####################################
-    my @Rows = &sort_indicies($sheet);
-    #
-    # Loop through the rows and output them one at a time
-    foreach my $rownum (@Rows) {
-        my ($rowlabel,@rowdata) = &get_row($sheet,$rownum);
-        next if ($rowlabel =~ /^[\s]*$/);
-        $cols_output = 0;
-        my $label = &format_excel_rowlabel($sheet,$rowlabel);
-        if ( ! $ENV{'form.showall'} &&
-             $sheet->{'sheettype'} =~ /^(studentcalc|classcalc)$/) {
-            my $row_is_empty = 1;
-            foreach my $cell (@rowdata) {
-                if ($cell->{'value'} !~  /^\s*$/) {
-                    $row_is_empty = 0;
-                    last;
-                }
+    return $max;
+}
+
+sub calc {
+#    $errorlog .= "\%t has ".(keys(%t))." keys\n";
+    %sheet_values = %t; # copy %t into %sheet_values.
+#    $errorlog .= "\%sheet_values has ".(keys(%sheet_values))." keys\n";
+    my $notfinished=1;
+    my $lastcalc='';
+    my $depth=0;
+    while ($notfinished) {
+	$notfinished=0;
+        while (my ($cell,$value) = each(%t)) {
+            my $old=$sheet_values{$cell};
+            $sheet_values{$cell}=eval $value;
+	    if ($@) {
+		undef %sheet_values;
+                return $cell.': '.$@;
+            }
+	    if ($sheet_values{$cell} ne $old) { 
+                $notfinished=1; 
+                $lastcalc=$cell; 
             }
-            next if ($row_is_empty);
-        }
-        $worksheet->write($rows_output,$cols_output++,$label);
-        if (ref($label)) {
-            $cols_output = (scalar(@$label));
         }
-        foreach my $cell (@rowdata) {
-            $worksheet->write($rows_output,$cols_output++,$cell->{'value'});
+        $depth++;
+        if ($depth>100) {
+	    undef %sheet_values;
+            return $lastcalc.': Maximum calculation depth exceeded';
         }
-        $rows_output++;
     }
-    return;
+    return '';
 }
 
-############################################
-##          XML output routines           ##
-############################################
-sub outsheet_xml   {
-    my ($sheet,$r) = @_;
-    ## Someday XML
-    ## Will be rendered for the user
-    ## But not on this day
+# ------------------------------------------- End of "Inside of the safe space"
+ENDDEFS
+    $safeeval->reval($code);
+    return $safeeval;
 }
 
-##
-## Outsheet - calls other outsheet_* functions
-##
-sub outsheet {
-    my ($sheet,$r)=@_;
-    if (! exists($ENV{'form.output'})) {
-        $ENV{'form.output'} = 'HTML';
-    }
-    if (lc($ENV{'form.output'}) eq 'csv') {
-        &outsheet_csv($sheet,$r);
-    } elsif (lc($ENV{'form.output'}) eq 'excel') {
-        &outsheet_excel($sheet,$r);
-    } elsif (lc($ENV{'form.output'}) eq 'recursive excel') {
-        &outsheet_recursive_excel($sheet,$r);
-#    } elsif (lc($ENV{'form.output'}) eq 'xml' ) {
-#        &outsheet_xml($sheet,$r);
-    } else {
-        &outsheet_html($sheet,$r);
-    }
-}
 
-########################################################################
-########################################################################
-sub othersheets {
-    my ($sheet,$stype)=@_;
-    $stype = $sheet->{'sheettype'} if (! defined($stype));
-    #
-    my $cnum  = $sheet->{'cnum'};
-    my $cdom  = $sheet->{'cdom'};
-    my $chome = $sheet->{'chome'};
-    #
-    my @alternatives=();
-    my %results=&Apache::lonnet::dump($stype.'_spreadsheets',$cdom,$cnum);
-    my ($tmp) = keys(%results);
-    unless ($tmp =~ /^(con_lost|error|no_such_host)/i) {
-        @alternatives = sort (keys(%results));
+#
+# expandnamed used to reside in the safe space
+#
+sub expandnamed {
+    my $self = shift;
+    my $expression=shift;
+    if ($expression=~/^\&/) {
+	my ($func,$var,$formula)=($expression=~/^\&(\w+)\(([^\;]+)\;(.*)\)/);
+	my @vars=split(/\W+/,$formula);
+        my %values=();
+	foreach my $varname ( @vars ) {
+            if ($varname=~/\D/) {
+               $formula=~s/$varname/'$c{\''.$varname.'\'}'/ge;
+               $varname=~s/$var/\(\\w\+\)/g;
+	       foreach (keys(%{$self->{'constants'}})) {
+		  if ($_=~/$varname/) {
+		      $values{$1}=1;
+                  }
+               }
+	    }
+        }
+        if ($func eq 'EXPANDSUM') {
+            my $result='';
+	    foreach (keys(%values)) {
+                my $thissum=$formula;
+                $thissum=~s/$var/$_/g;
+                $result.=$thissum.'+';
+            } 
+            $result=~s/\+$//;
+            return $result;
+        } else {
+	    return 0;
+        }
+    } else {
+        # it is not a function, so it is a parameter name
+        # We should do the following:
+        #    1. Take the list of parameter names
+        #    2. look through the list for ones that match the parameter we want
+        #    3. If there are no collisions, return the one that matches
+        #    4. If there is a collision, return 'bad parameter name error'
+        my $returnvalue = '';
+        my @matches = ();
+        $#matches = -1;
+        study $expression;
+        my $parameter;
+        foreach $parameter (keys(%{$self->{'constants'}})) {
+            push @matches,$parameter if ($parameter =~ /$expression/);
+        }
+        if (scalar(@matches) == 0) {
+            $returnvalue = 'unmatched parameter: '.$parameter;
+        } elsif (scalar(@matches) == 1) {
+            # why do we not do this lookup here, instead of delaying it?
+            $returnvalue = '$c{\''.$matches[0].'\'}';
+        } elsif (scalar(@matches) > 0) {
+            # more than one match.  Look for a concise one
+            $returnvalue =  "'non-unique parameter name : $expression'";
+            foreach (@matches) {
+                if (/^$expression$/) {
+                    # why do we not do this lookup here?
+                    $returnvalue = '$c{\''.$_.'\'}';
+                }
+            }
+        } else {
+            # There was a negative number of matches, which indicates 
+            # something is wrong with reality.  Better warn the user.
+            $returnvalue = 'bizzare parameter: '.$parameter;
+        }
+        return $returnvalue;
     }
-    return @alternatives; 
 }
 
 #
-# -------------------------------------- Parse a spreadsheet
-# 
-sub parse_sheet {
-    # $sheetxml is a scalar reference or a scalar
-    my ($sheetxml) = @_;
-    if (! ref($sheetxml)) {
-        my $tmp = $sheetxml;
-        $sheetxml = \$tmp;
+# sett used to reside in the safe space
+#
+sub sett {
+    my $self = shift;
+    my %t=();
+    my $pattern='';
+    if ($self->{'type'} eq 'assesscalc') {
+	$pattern='A';
+    } else {
+        $pattern='[A-Z]';
     }
-    my %f;
-    my $parser=HTML::TokeParser->new($sheetxml);
-    my $token;
-    while ($token=$parser->get_token) {
-        if ($token->[0] eq 'S') {
-            if ($token->[1] eq 'field') {
-                $f{$token->[2]->{'col'}.$token->[2]->{'row'}}=
-                    $parser->get_text('/field');
-            }
-            if ($token->[1] eq 'template') {
-                $f{'template_'.$token->[2]->{'col'}}=
-                    $parser->get_text('/template');
+    # Deal with the template row
+    foreach ($self->template_cells()) {
+        my ($col) = ($_=~/template\_(\w)/);
+        next if ($col=~/^$pattern/);
+        foreach ($self->A_column()) {
+            my ($trow)=($_!~/A(\d+)/);
+            next if (! $trow);
+            # Get the name of this cell
+            my $lb=$col.$trow;
+            # Grab the template declaration
+            $t{$lb}=$self->formula('template_'.$col);
+            # Replace '#' with the row number
+            $t{$lb}=~s/\#/$trow/g;
+            # Replace '....' with ','
+            $t{$lb}=~s/\.\.+/\,/g;
+            # Replace 'A0' with the value from 'A0'
+            $t{$lb}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
+            # Replace parameters
+            $t{$lb}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.$self->expandnamed($2)/ge;
+        }
+    }
+    # Deal with the normal cells
+    foreach ($self->formulas_keys()) {
+	next if ($_=~/template\_/);
+        if  (($_=~/^$pattern(\d+)/) && ($1)) {
+            if ($self->formula($_) !~ /^\!/) {
+                $t{$_}=$self->{'constants'}->{$_};
             }
+        } else {
+            $t{$_}=$self->formula($_);
+            $t{$_}=~s/\.\.+/\,/g;
+            $t{$_}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
+            $t{$_}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.$self->expandnamed($2)/ge;
         }
     }
-    return \%f;
+    # For inserted lines, [B-Z] is also valid
+    if ($self->{'type'} ne 'assesscalc') {
+        foreach ($self->formulas_keys()) {
+            next if ($_ !~ /[B-Z](\d+)/);
+            next if ($self->formula('A'.$1) !~ /^[\~\-]/);
+            $t{$_}=$self->formula($_);
+            $t{$_}=~s/\.\.+/\,/g;
+            $t{$_}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
+            $t{$_}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.$self->expandnamed($2)/ge;
+        }
+    }
+    # For some reason 'A0' gets special treatment...  This seems superfluous
+    # but I imagine it is here for a reason.
+    $t{'A0'}=$self->formula('A0');
+    $t{'A0'}=~s/\.\.+/\,/g;
+    $t{'A0'}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
+    $t{'A0'}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.$self->expandnamed($2)/ge;
+    # Put %t into the safe space
+    %{$self->{'safe'}->varglob('t')}=%t;
 }
 
+
+###########################################
+###          Row output routines        ###
+###########################################
 #
-# -------------------------------------- Read spreadsheet formulas for a course
+# get_row: Produce output row n from sheet by calling the appropriate routine
 #
-sub readsheet {
-    my ($sheet,$fn)=@_;
-    #
-    my $stype = $sheet->{'sheettype'};
-    my $cnum  = $sheet->{'cnum'};
-    my $cdom  = $sheet->{'cdom'};
-    my $chome = $sheet->{'chome'};
-    #
-    if (! defined($fn)) {
-        # There is no filename. Look for defaults in course and global, cache
-        unless ($fn=$defaultsheets{$cnum.'_'.$cdom.'_'.$stype}) {
-            my %tmphash = &Apache::lonnet::get('environment',
-                                               ['spreadsheet_default_'.$stype],
-                                               $cdom,$cnum);
-            my ($tmp) = keys(%tmphash);
-            if ($tmp =~ /^(con_lost|error|no_such_host)/i) {
-                $fn = 'default_'.$stype;
-            } else {
-                $fn = $tmphash{'spreadsheet_default_'.$stype};
-            } 
-            unless (($fn) && ($fn!~/^error\:/)) {
-                $fn='default_'.$stype;
-            }
-            $defaultsheets{$cnum.'_'.$cdom.'_'.$stype}=$fn; 
-        }
-    }
-    # $fn now has a value
-    $sheet->{'filename'} = $fn;
-    # see if sheet is cached
-    my $fstring='';
-    if ($fstring=$spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}) {
-        my %tmp = split(/___;___/,$fstring);
-        $sheet->{'f'} = \%tmp;
-        &setformulas($sheet);
+sub get_row {
+    my $self = shift;
+    my ($n) = @_;
+    my ($rowlabel,@rowdata);
+    if ($n eq '-') { 
+        ($rowlabel,@rowdata) = $self->templaterow();
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        ($rowlabel,@rowdata) = $self->outrowassess($n);
     } else {
-        # Not cached, need to read
-        my %f=();
-        if ($fn=~/^default\_/) {
-            my $sheetxml='';
-            my $fh;
-            my $dfn=$fn;
-            $dfn=~s/\_/\./g;
-            if ($fh=Apache::File->new($includedir.'/'.$dfn)) {
-                $sheetxml=join('',<$fh>);
-            } else {
-                # $sheetxml='<field row="0" col="A">"Error"</field>';
-                $sheetxml='<field row="0" col="A"></field>';
-            }
-            %f=%{&parse_sheet(\$sheetxml)};
-        } elsif($fn=~/\/*\.spreadsheet$/) {
-            my $sheetxml=&Apache::lonnet::getfile
-                (&Apache::lonnet::filelocation('',$fn));
-            if ($sheetxml == -1) {
-                $sheetxml='<field row="0" col="A">"Error loading spreadsheet '
-                    .$fn.'"</field>';
-            }
-            %f=%{&parse_sheet(\$sheetxml)};
-        } else {
-            my %tmphash = &Apache::lonnet::dump($fn,$cdom,$cnum);
-            my ($tmp) = keys(%tmphash);
-            if ($tmp !~ /^(con_lost|error|no_such_host)/i) {
-                foreach (keys(%tmphash)) {
-                    $f{$_}=$tmphash{$_};
-                }
-            } else {
-                # Unable to grab the specified spreadsheet,
-                # so we get the default ones instead.
-                $fn = 'default_'.$stype;
-                $sheet->{'filename'} = $fn;
-                my $dfn = $fn;
-                $dfn =~ s/\_/\./g;
-                my $sheetxml;
-                if (my $fh=Apache::File->new($includedir.'/'.$dfn)) {
-                    $sheetxml = join('',<$fh>);
-                } else {
-                    $sheetxml='<field row="0" col="A">'.
-                        '"Unable to load spreadsheet"</field>';
-                }
-                %f=%{&parse_sheet(\$sheetxml)};
-            }
-        }
-        # Cache and set
-        $spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}=join('___;___',%f);  
-        $sheet->{'f'}=\%f;
-        &setformulas($sheet);
+        ($rowlabel,@rowdata) = $self->outrow($n);
     }
+    return ($rowlabel,@rowdata);
 }
 
-# -------------------------------------------------------- Make new spreadsheet
-sub makenewsheet {
-    my ($uname,$udom,$stype,$usymb)=@_;
-    my $sheet={};
-    $sheet->{'uname'} = $uname;
-    $sheet->{'udom'}  = $udom;
-    $sheet->{'sheettype'} = $stype;
-    $sheet->{'usymb'} = $usymb;
-    $sheet->{'mapid'} = $ENV{'form.mapid'};
-    $sheet->{'resid'} = $ENV{'form.resid'};
-    $sheet->{'cid'}   = $ENV{'request.course.id'};
-    $sheet->{'csec'}  = $Section{$uname.':'.$udom};
-    $sheet->{'coursefilename'}   = $ENV{'request.course.fn'};
-    $sheet->{'cnum'}  = $ENV{'course.'.$ENV{'request.course.id'}.'.num'};
-    $sheet->{'cdom'}  = $ENV{'course.'.$ENV{'request.course.id'}.'.domain'};
-    $sheet->{'chome'} = $ENV{'course.'.$ENV{'request.course.id'}.'.home'};
-    $sheet->{'coursedesc'} = $ENV{'course.'.$ENV{'request.course.id'}.
-                                      '.description'};
-    $sheet->{'uhome'} = &Apache::lonnet::homeserver($uname,$udom);
-    #
-    #
-    $sheet->{'f'} = {};
-    $sheet->{'constants'} = {};
-    $sheet->{'othersheets'} = [];
-    $sheet->{'rowlabel'} = {};
-    #
-    #
-    $sheet->{'safe'}=&initsheet($sheet->{'sheettype'});
-    #
-    # Place all the %$sheet items into the safe space except the safe space
-    # itself
-    my $initstring = '';
-    foreach (qw/uname udom sheettype usymb cid csec coursefilename
-             cnum cdom chome uhome/) {
-        $initstring.= qq{\$$_="$sheet->{$_}";};
+sub templaterow {
+    my $self = shift;
+    my @cols=();
+    my $rowlabel = 'Template</td><td>&nbsp;';
+    foreach my $n ('A','B','C','D','E','F','G','H','I','J','K','L','M',
+                   'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
+                   'a','b','c','d','e','f','g','h','i','j','k','l','m',
+                   'n','o','p','q','r','s','t','u','v','w','x','y','z') {
+        push(@cols,{ name    => 'template_'.$_,
+                     formula => $self->formula('template_'.$n),
+                     value   => $self->value('template_'.$n) });
     }
-    $sheet->{'safe'}->reval($initstring);
-    return $sheet;
+    return ($rowlabel,@cols);
 }
 
-# ------------------------------------------------------------ Save spreadsheet
-sub writesheet {
-    my ($sheet,$makedef)=@_;
-    my $cid=$sheet->{'cid'};
-    if (&Apache::lonnet::allowed('opa',$cid)) {
-        my %f=&getformulas($sheet);
-        my $stype= $sheet->{'sheettype'};
-        my $cnum = $sheet->{'cnum'};
-        my $cdom = $sheet->{'cdom'};
-        my $chome= $sheet->{'chome'};
-        my $fn   = $sheet->{'filename'};
-        # Cache new sheet
-        $spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}=join('___;___',%f);
-        # Write sheet
-        foreach (keys(%f)) {
-            delete($f{$_}) if ($f{$_} eq 'import');
+sub outrowassess {
+    my $self = shift;
+    # $n is the current row number
+    my ($n) = @_;
+    my @cols=();
+    my $rowlabel='';
+    if ($n) {
+        my ($usy,$ufn)=split(/__&&&\__/,$self->formula('A'.$n));
+        if (exists($self->{'rowlabel'}->{$usy})) {
+            # This is dumb, but we need the information when we output
+            # the html version of the studentcalc spreadsheet for the
+            # links to the assesscalc sheets.
+            $rowlabel = $self->{'rowlabel'}->{$usy}.':'.
+                &Apache::lonnet::escape($ufn);
+        } else { 
+            $rowlabel = '';
         }
-        my $reply = &Apache::lonnet::put($fn,\%f,$cdom,$cnum);
-        if ($reply eq 'ok') {
-            $reply = &Apache::lonnet::put($stype.'_spreadsheets',
-                            {$fn => $ENV{'user.name'}.'@'.$ENV{'user.domain'}},
-                                          $cdom,$cnum);
-            if ($reply eq 'ok') {
-                if ($makedef) { 
-                    $reply = &Apache::lonnet::put('environment',
-                                    {'spreadsheet_default_'.$stype => $fn },
-                                                  $cdom,$cnum);
-                    if ($reply eq 'ok' && 
-                        ($sheet->{'sheettype'} eq 'studentcalc' ||
-                         $sheet->{'sheettype'} eq 'assesscalc')) {
-                        # Expire the spreadsheets of the other students.
-                        &Apache::lonnet::expirespread('','','studentcalc','');
-                    }
-                    return $reply;
-                } 
-                return $reply;
-            } 
-            return $reply;
-        } 
-        return $reply;
+    } elsif ($ENV{'request.role'} =~ /^st\./) {
+        $rowlabel = 'Summary</td><td>0';
+    } else {
+        $rowlabel = 'Export</td><td>0';
     }
-    return 'unauthorized';
+    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
+	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
+	     'a','b','c','d','e','f','g','h','i','j','k','l','m',
+	     'n','o','p','q','r','s','t','u','v','w','x','y','z') {
+        push(@cols,{ name    => $_.$n,
+                     formula => $self->formula($_.$n),
+                     value   => $self->value($_.$n)});
+    }
+    return ($rowlabel,@cols);
 }
 
-# ----------------------------------------------- Make a temp copy of the sheet
-# "Modified workcopy" - interactive only
-#
-sub tmpwrite {
-    my ($sheet) = @_;
-    my $fn=$ENV{'user.name'}.'_'.
-        $ENV{'user.domain'}.'_spreadsheet_'.$sheet->{'usymb'}.'_'.
-           $sheet->{'filename'};
-    $fn=~s/\W/\_/g;
-    $fn=$tmpdir.$fn.'.tmp';
-    my $fh;
-    if ($fh=Apache::File->new('>'.$fn)) {
-        my %f = &getformulas($sheet);
-        while( my ($cell,$formula) = each(%f)) {
-            print $fh &Apache::lonnet::escape($cell)."=".&Apache::lonnet::escape($formula)."\n";
+sub outrow {
+    my $self = shift;
+    my ($n)=@_;
+    my @cols=();
+    my $rowlabel;
+    if ($n) {
+        $rowlabel = $self->{'rowlabel'}->{$self->formula('A'.$n)};
+    } else {
+        if ($self->{'type'} eq 'classcalc') {
+            $rowlabel = 'Summary</td><td>0';
+        } else {
+            $rowlabel = 'Export</td><td>0';
         }
     }
+    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
+	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
+	     'a','b','c','d','e','f','g','h','i','j','k','l','m',
+	     'n','o','p','q','r','s','t','u','v','w','x','y','z') {
+        push(@cols,{ name    => $_.$n,
+                     formula => $self->formula($_.$n),
+                     value   => $self->value($_.$n)});
+    }
+    return ($rowlabel,@cols);
 }
 
-# ---------------------------------------------------------- Read the temp copy
-sub tmpread {
-    my ($sheet,$nfield,$nform)=@_;
-    my $fn=$ENV{'user.name'}.'_'.
-           $ENV{'user.domain'}.'_spreadsheet_'.$sheet->{'usymb'}.'_'.
-           $sheet->{'filename'};
-    $fn=~s/\W/\_/g;
-    $fn=$tmpdir.$fn.'.tmp';
-    my $fh;
-    my %fo=();
-    my $countrows=0;
-    if ($fh=Apache::File->new($fn)) {
-        while (<$fh>) {
-	    chomp;
-            my ($cell,$formula) = split(/=/);
-            $cell    = &Apache::lonnet::unescape($cell);
-            $formula = &Apache::lonnet::unescape($formula);
-            $fo{$cell} = $formula;
+########################################################
+####         Spreadsheet calculation methods       #####
+########################################################
+#
+# calcsheet: makes all the calls to compute the spreadsheet.
+#
+sub calcsheet {
+    my $self = shift;
+    $self->sync_safe_space();
+    $self->clear_errorlog();
+    $self->sett();
+    my $result =  $self->{'safe'}->reval('&calc();');
+    %{$self->{'values'}} = %{$self->{'safe'}->varglob('sheet_values')};
+#    $self->logthis($self->get_errorlog());
+#    $self->logthis('number of values = '.(keys(%{$self->{'values'}})));
+    return $result;
+}
+
+##
+## sync_safe_space:  Called by calcsheet to make sure all the data we 
+#  need to calculate is placed into the safe space
+##
+sub sync_safe_space {
+    my $self = shift;
+    # Inside the safe space 'formulas' has a diabolical alter-ego named 'f'.
+    %{$self->{'safe'}->varglob('f')}=%{$self->{'formulas'}};
+    # 'constants' leads a peaceful hidden life of 'c'.
+    %{$self->{'safe'}->varglob('c')}=%{$self->{'constants'}};
+    # 'othersheets' hides as 'os', a disguise few can penetrate.
+    @{$self->{'safe'}->varglob('os')}=@{$self->{'othersheets'}};
+}
+
+##
+## Retrieve the error log from the safe space (used for debugging)
+##
+sub get_errorlog {
+    my $self = shift;
+    $self->{'errorlog'} = ${$self->{'safe'}->varglob('errorlog')};
+    return $self->{'errorlog'};
+}
+
+##
+## Clear the error log inside the safe space
+##
+sub clear_errorlog {
+    my $self = shift;
+    ${$self->{'safe'}->varglob('errorlog')} = '';
+    $self->{'errorlog'} = '';
+}
+
+
+########################################################
+#### Spreadsheet content retrieval/setting methods #####
+########################################################
+##
+## contents:  either set or get the constants.  Cannot do both.  It is just too
+## clunky to swing around big hashes when we may not need to.
+##
+sub constants {
+    my $self=shift;
+    my ($constants) = @_;
+    if (defined($constants)) {
+        if (! ref($constants)) {
+            my %tmp = @_;
+            $constants = \%tmp;
         }
+        $self->{'constants'} = $constants;
+        return;
+    } else {
+        return %{$self->{'constants'}};
     }
-#            chomp($value);
-#            $fo{$name}=$value;
-#            if ($name=~/^A(\d+)$/) {
-#		if ($1>$countrows) {
-#		    $countrows=$1;
-#                }
-#            }
-#        }
-#    }
-    if ($nform eq 'changesheet') {
-        $fo{'A'.$nfield}=(split(/__&&&\__/,$fo{'A'.$nfield}))[0];
-        unless ($ENV{'form.sel_'.$nfield} eq 'Default') {
-	    $fo{'A'.$nfield}.='__&&&__'.$ENV{'form.sel_'.$nfield};
-        }
-#    } elsif ($nfield eq 'insertrow') {
-#        $countrows++;
-#        my $newrow=substr('000000'.$countrows,-7);
-#        if ($nform eq 'top') {
-#	    $fo{'A'.$countrows}='--- '.$newrow;
-#        } else {
-#            $fo{'A'.$countrows}='~~~ '.$newrow;
-#        }
+}
+    
+##
+## formulas: either set or get the formulas.  Cannot do both.  It is just too
+## clunky to swing around big hashes when we may not need to.
+sub formulas {
+    my $self=shift;
+    my ($formulas) = @_;
+    if (defined($formulas)) {
+        if (! ref($formulas)) {
+            my %tmp = @_;
+            $formulas = \%tmp;
+        }
+        $self->{'formulas'} = $formulas;
+        $self->{'A_column'} = [];
+        $self->{'template_cells'} = [];
+        return;
     } else {
-       if ($nfield) { $fo{$nfield}=$nform; }
+        return %{$self->{'formulas'}};
     }
-    $sheet->{'f'}=\%fo;
-    &setformulas($sheet);
 }
 
-##################################################
-##################################################
+##
+## formulas_keys:  Return the keys to the formulas hash.
+##
+sub formulas_keys {
+    my $self = shift;
+    my @keys = keys(%{$self->{'formulas'}});
+#    $self->logthis('formulas keys has '.@keys.' elements');
+    return keys(%{$self->{'formulas'}});
+}
 
-=pod
+##
+## formula:  Return the formula for a given cell in the spreadsheet
+## returns '' if the cell does not have a formula or does not exist
+##
+sub formula {
+    my $self = shift;
+    my $cell = shift;
+    if (defined($cell) && exists($self->{'formulas'}->{$cell})) {
+        return $self->{'formulas'}->{$cell};
+    }
+    return '';
+}
 
-=item &parmval()
+##
+## logthis: write the input to lonnet.log
+##
+sub logthis {
+    my $self = shift;
+    my $message = shift;
+    &Apache::lonnet::logthis($self->{'type'}.':'.
+                             $self->{'uname'}.':'.$self->{'udom'}.':'.
+                             $message);
+}
 
-Determine the value of a parameter.
+##
+## dump_formulas_to_log: makes lonnet.log huge...
+##
+sub dump_formulas_to_log {
+    my $self =shift;
+    $self->logthis("Spreadsheet formulas");
+    $self->logthis("--------------------------------------------------------");
+    while (my ($cell, $formula) = each(%{$self->{'formulas'}})) {
+        $self->logthis('    '.$cell.' = '.$formula);
+    }
+    $self->logthis("--------------------------------------------------------");}
 
-Inputs: $what, the parameter needed, $sheet, the safe space
+##
+## value: returns the computed value of a particular cell
+##
+sub value {
+    my $self = shift;
+    my $cell = shift;
+    if (defined($cell) && exists($self->{'values'}->{$cell})) {
+        return $self->{'values'}->{$cell};
+    }
+    return '';
+}
 
-Returns: The value of a parameter, or '' if none.
+##
+## dump_values_to_log: makes lonnet.log huge...
+##
+sub dump_values_to_log {
+    my $self =shift;
+    $self->logthis("Spreadsheet Values");
+    $self->logthis("--------------------------------------------------------");
+    while (my ($cell, $value) = each(%{$self->{'values'}})) {
+        $self->logthis('    '.$cell.' = '.$value);
+    }
+    $self->logthis("--------------------------------------------------------");}
+
+################################
+##      Helper functions      ##
+################################
+##
+## rebuild_stats: rebuilds the A_column and template_cells arrays
+##
+sub rebuild_stats {
+    my $self = shift;
+    $self->{'A_column'}=[];
+    $self->{'template_cells'}=[];
+    foreach my $cell($self->formulas_keys()) {
+        push(@{$self->{'A_column'}},$cell) if $cell =~ /^A\d+/;
+        push(@{$self->{'template_cells'}},$cell) if ($cell =~ /^template_/);
+    }
+    # $self->logthis('rebuilt A_column '.@{$self->{'A_column'}});
+    # $self->logthis('rebuilt tempate_cells '.@{$self->{'template_cells'}});
+    return;
+}
 
-This function cascades through the possible levels searching for a value for
-a parameter.  The levels are checked in the following order:
-user, course (at section level and course level), map, and lonnet::metadata.
-This function uses %parmhash, which must be tied prior to calling it.
-This function also requires %courseopt and %useropt to be initialized for
-this user and course.
+##
+## template_cells returns a list of the cells defined in the template row
+##
+sub template_cells {
+    my $self = shift;
+    $self->rebuild_stats() if (!@{$self->{'template_cells'}});
+    return @{$self->{'template_cells'}};
+}
 
-=cut
+##
+## A_column returns a list of the names of cells defined in the A column
+##
+sub A_column {
+    my $self = shift;
+    $self->rebuild_stats() if (!@{$self->{'A_column'}});
+    return @{$self->{'A_column'}};
+}
 
-##################################################
-##################################################
-sub parmval {
-    my ($what,$sheet)=@_;
-    my $symb  = $sheet->{'usymb'};
-    unless ($symb) { return ''; }
-    #
-    my $cid   = $sheet->{'cid'};
-    my $csec  = $sheet->{'csec'};
-    my $uname = $sheet->{'uname'};
-    my $udom  = $sheet->{'udom'};
-    my $result='';
-    #
-    my ($mapname,$id,$fn)=split(/\_\_\_/,$symb);
-    # Cascading lookup scheme
-    my $rwhat=$what;
-    $what =~ s/^parameter\_//;
-    $what =~ s/\_([^\_]+)$/\.$1/;
-    #
-    my $symbparm = $symb.'.'.$what;
-    my $mapparm  = $mapname.'___(all).'.$what;
-    my $usercourseprefix = $uname.'_'.$udom.'_'.$cid;
-    #
-    my $seclevel  = $usercourseprefix.'.['.$csec.'].'.$what;
-    my $seclevelr = $usercourseprefix.'.['.$csec.'].'.$symbparm;
-    my $seclevelm = $usercourseprefix.'.['.$csec.'].'.$mapparm;
-    #
-    my $courselevel  = $usercourseprefix.'.'.$what;
-    my $courselevelr = $usercourseprefix.'.'.$symbparm;
-    my $courselevelm = $usercourseprefix.'.'.$mapparm;
-    # fourth, check user
-    if (defined($uname)) {
-        return $useropt{$courselevelr} if (defined($useropt{$courselevelr}));
-        return $useropt{$courselevelm} if (defined($useropt{$courselevelm}));
-        return $useropt{$courselevel}  if (defined($useropt{$courselevel}));
+##
+## Sigh.... 
+##
+sub setothersheets {
+    my $self = shift;
+    my @othersheets = @_;
+    $self->{'othersheets'} = \@othersheets;
+}
+
+##
+## rowlabels: get or set the rowlabels hash from the spreadsheet.
+##
+sub rowlabels {
+    my $self = shift;
+    my ($rowlabel) = @_;
+    if (defined($rowlabel)) {
+        if (! ref($rowlabel)) {
+            my %tmp = @_;
+            $rowlabel = \%tmp;
+        }
+        $self->{'rowlabel'}=$rowlabel;
+        return;
+    } else {
+        return %{$self->{'rowlabel'}} if (defined($self->{'rowlabels'}));
     }
-    # third, check course
-    if (defined($csec)) {
-        return $courseopt{$seclevelr} if (defined($courseopt{$seclevelr}));
-        return $courseopt{$seclevelm} if (defined($courseopt{$seclevelm}));
-        return $courseopt{$seclevel}  if (defined($courseopt{$seclevel}));
+}
+
+##
+## gettitle: returns a title for the spreadsheet.
+##
+sub gettitle {
+    my $self = shift;
+    if ($self->{'type'} eq 'classcalc') {
+        return $self->{'coursedesc'};
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        return 'Grades for '.$self->{'uname'}.'@'.$self->{'udom'};
+    } elsif ($self->{'type'} eq 'assesscalc') {
+        if (($self->{'usymb'} eq '_feedback') ||
+            ($self->{'usymb'} eq '_evaluation') ||
+            ($self->{'usymb'} eq '_discussion') ||
+            ($self->{'usymb'} eq '_tutoring')) {
+            my $title = $self->{'usymb'};
+            $title =~ s/^_//;
+            $title = ucfirst($title);
+            return $title;
+        }
+        return if (! defined($self->{'mapid'}) || 
+                   $self->{'mapid'} !~ /^\d+$/);
+        my $mapid = $self->{'mapid'};
+        return if (! defined($self->{'resid'}) || 
+                   $self->{'resid'} !~ /^\d+$/);
+        my $resid = $self->{'resid'};
+        my %course_db;
+        tie(%course_db,'GDBM_File',$self->{'coursefilename'}.'.db',
+            &GDBM_READER(),0640);
+        return if (! tied(%course_db));
+        my $key = 'title_'.$mapid.'.'.$resid;
+        my $title = '';
+        if (exists($course_db{$key})) {
+            $title = $course_db{$key};
+        } else {
+            $title = $self->{'usymb'};
+        }
+        untie (%course_db);
+        return $title;
     }
-    #
-    return $courseopt{$courselevelr} if (defined($courseopt{$courselevelr}));
-    return $courseopt{$courselevelm} if (defined($courseopt{$courselevelm}));
-    return $courseopt{$courselevel}  if (defined($courseopt{$courselevel}));
-    # second, check map parms
-    my $thisparm = $parmhash{$symbparm};
-    return $thisparm if (defined($thisparm));
-    # first, check default
-    return &Apache::lonnet::metadata($fn,$rwhat.'.default');
 }
 
+#
+# Export of A-row
+#
+sub exportdata {
+    my $self=shift;
+    my @exportarray=();
+    foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
+	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
+        push(@exportarray,$self->value($_.'0'));
+    } 
+    return @exportarray;
+}
 
-##################################################################
-##                  Row label formatting routines               ##
-##################################################################
-sub format_html_rowlabel {
-    my $sheet = shift;
-    my $rowlabel = shift;
-    return '' if ($rowlabel eq '');
-    my ($type,$labeldata) = split(':',$rowlabel,2);
-    my $result = '';
-    if ($type eq 'symb') {
-        my ($symb,$mapid,$resid,$title,$ufn) = split(':',$labeldata);
-        $ufn   = 'default' if (!defined($ufn) || $ufn eq '');
-        $ufn   = &Apache::lonnet::unescape($ufn);
-        $symb  = &Apache::lonnet::unescape($symb);
-        $title = &Apache::lonnet::unescape($title);
-        $result = '<a href="/adm/assesscalc?usymb='.$symb.
-            '&uname='.$sheet->{'uname'}.'&udom='.$sheet->{'udom'}.
-                '&ufn='.$ufn.
-                    '&mapid='.$mapid.'&resid='.$resid.'">'.$title.'</a>';
-    } elsif ($type eq 'student') {
-        my ($sname,$sdom,$fullname,$section,$id) = split(':',$labeldata);
-        if ($fullname =~ /^\s*$/) {
-            $fullname = $sname.'@'.$sdom;
+##
+## update_student_sheet: experimental function
+##
+sub update_student_sheet{
+    my $self = shift;
+    my ($r,$c) = @_;
+    # Load in the studentcalc sheet
+    $self->readsheet('default_studentcalc');
+    # Determine the structure (contained assessments, etc) of the sheet
+    $self->updatesheet();
+    # Load in the cached sheets for this student
+    $self->cachedssheets();
+    # Load in the (possibly cached) data from the assessment sheets        
+    $self->loadstudent($r,$c);
+    # Compute the sheet
+    $self->calcsheet();
+}
+
+#
+# sort_indicies: returns an ordered list of the rows of the spreadsheet
+#
+sub sort_indicies {
+    my $self = shift;
+    my @sortidx=();
+    #
+    if ($self->{'type'} eq 'classcalc') {
+        my @sortby=(undef);
+        # Skip row 0
+        for (my $row=1;$row<=$self->{'maxrow'};$row++) {
+            my (undef,$sname,$sdom,$fullname,$section,$id) = 
+                split(':',$self->{'rowlabel'}->{$self->formula('A'.$row)});
+            push (@sortby, lc($fullname));
+            push (@sortidx, $row);
         }
-        $result ='<a href="/adm/studentcalc?uname='.$sname.
-            '&udom='.$sdom.'">';
-        $result.=$section.'&nbsp;'.$id."&nbsp;".$fullname.'</a>';
-    } elsif ($type eq 'parameter') {
-        $result = $labeldata;
+        @sortidx = sort { $sortby[$a] cmp $sortby[$b]; } @sortidx;
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        my @sortby1=(undef);
+        my @sortby2=(undef);
+        # Skip row 0
+        for (my $row=1;$row<=$self->{'maxrow'};$row++) {
+            my ($key,undef) = split(/__&&&\__/,$self->formula('A'.$row));
+            my $rowlabel = $self->{'rowlabel'}->{$key};
+            my (undef,$symb,$mapid,$resid,$title,$ufn) = 
+                split(':',$rowlabel);
+            $ufn   = &Apache::lonnet::unescape($ufn);
+            $symb  = &Apache::lonnet::unescape($symb);
+            $title = &Apache::lonnet::unescape($title);
+            my ($sequence) = ($symb =~ /\/([^\/]*\.sequence)/);
+            if ($sequence eq '') {
+                $sequence = $symb;
+            }
+            push (@sortby1, $sequence);
+            push (@sortby2, $title);
+            push (@sortidx, $row);
+        }
+        @sortidx = sort { $sortby1[$a] cmp $sortby1[$b] || 
+                              $sortby2[$a] cmp $sortby2[$b] } @sortidx;
     } else {
-        $result = '<b><font size=+1>'.$rowlabel.'</font></b>';
+        my @sortby=(undef);
+        # Skip row 0
+        $self->sync_safe_space();
+        for (my $row=1;$row<=$self->{'maxrow'};$row++) {
+            push (@sortby, $self->{'safe'}->reval('$f{"A'.$row.'"}'));
+            push (@sortidx, $row);
+        }
+        @sortidx = sort { $sortby[$a] cmp $sortby[$b]; } @sortidx;
     }
-    return $result;
+    return @sortidx;
 }
 
-sub format_csv_rowlabel {
-    my $sheet = shift;
-    my $rowlabel = shift;
-    return '' if ($rowlabel eq '');
-    my ($type,$labeldata) = split(':',$rowlabel,2);
-    my $result = '';
-    if ($type eq 'symb') {
-        my ($symb,$mapid,$resid,$title,$ufn) = split(':',$labeldata);
-        $ufn   = &Apache::lonnet::unescape($ufn);
-        $symb  = &Apache::lonnet::unescape($symb);
-        $title = &Apache::lonnet::unescape($title);
-        $result = $title;
-    } elsif ($type eq 'student') {
-        my ($sname,$sdom,$fullname,$section,$id) = split(':',$labeldata);
-        $result = join('","',($sname,$sdom,$fullname,$section,$id));
-    } elsif ($type eq 'parameter') {
-        $labeldata =~ s/<br>/ /g;
-        $result = $labeldata;
+#############################################################
+###                                                       ###
+###              Spreadsheet Output Routines              ###
+###                                                       ###
+#############################################################
+
+############################################
+##         HTML output routines           ##
+############################################
+sub html_editable_cell {
+    my ($cell,$bgcolor) = @_;
+    my $result;
+    my ($name,$formula,$value);
+    if (defined($cell)) {
+        $name    = $cell->{'name'};
+        $formula = $cell->{'formula'};
+        $value   = $cell->{'value'};
+    }
+    $name    = '' if (! defined($name));
+    $formula = '' if (! defined($formula));
+    if (! defined($value)) {
+        $value = '<font color="'.$bgcolor.'">#</font>';
+        if ($formula ne '') {
+            $value = '<i>undefined value</i>';
+        }
+    } elsif ($value =~ /^\s*$/ ) {
+        $value = '<font color="'.$bgcolor.'">#</font>';
     } else {
-        $result = $rowlabel;
+        $value = &HTML::Entities::encode($value) if ($value !~/&nbsp;/);
     }
-    return '"'.$result.'"';
+    # Make the formula safe for outputting
+    $formula =~ s/\'/\"/g;
+    # The formula will be parsed by the browser *twice* before being 
+    # displayed to the user for editing.
+    $formula = &HTML::Entities::encode(&HTML::Entities::encode($formula));
+    # Escape newlines so they make it into the edit window
+    $formula =~ s/\n/\\n/gs;
+    # Glue everything together
+    $result .= "<a href=\"javascript:celledit(\'".
+        $name."','".$formula."');\">".$value."</a>";
+    return $result;
 }
 
-sub format_excel_rowlabel {
-    my $sheet = shift;
-    my $rowlabel = shift;
-    return '' if ($rowlabel eq '');
-    my ($type,$labeldata) = split(':',$rowlabel,2);
-    my $result = '';
-    if ($type eq 'symb') {
-        my ($symb,$mapid,$resid,$title,$ufn) = split(':',$labeldata);
-        $ufn   = &Apache::lonnet::unescape($ufn);
-        $symb  = &Apache::lonnet::unescape($symb);
-        $title = &Apache::lonnet::unescape($title);
-        $result = $title;
-    } elsif ($type eq 'student') {
-        my ($sname,$sdom,$fullname,$section,$id) = split(':',$labeldata);
-        $section = '' if (! defined($section));
-        $id      = '' if (! defined($id));
-        my @Data = ($sname,$sdom,$fullname,$section,$id);
-        $result = \@Data;
-    } elsif ($type eq 'parameter') {
-        $labeldata =~ s/<br>/ /g;
-        $result = $labeldata;
-    } else {
-        $result = $rowlabel;
-    }
-    return $result;
+sub html_uneditable_cell {
+    my ($cell,$bgcolor) = @_;
+    my $value = (defined($cell) ? $cell->{'value'} : '');
+    $value = &HTML::Entities::encode($value) if ($value !~/&nbsp;/);
+    return '&nbsp;'.$value.'&nbsp;';
 }
 
-# ---------------------------------------------- Update rows for course listing
-sub updateclasssheet {
-    my ($sheet) = @_;
-    my $cnum  =$sheet->{'cnum'};
-    my $cdom  =$sheet->{'cdom'};
-    my $cid   =$sheet->{'cid'};
-    my $chome =$sheet->{'chome'};
-    #
-    %Section = ();
-    #
-    # Read class list and row labels
-    my $classlist = &Apache::loncoursedata::get_classlist();
-    if (! defined($classlist)) {
-        return 'Could not access course classlist';
-    } 
-    #
-    my %currentlist=();
-    foreach my $student (keys(%$classlist)) {
-        my ($studentDomain,$studentName,$end,$start,$id,$studentSection,
-            $fullname,$status)   =   @{$classlist->{$student}};
-        $Section{$studentName.':'.$studentDomain} = $studentSection;
-        if ($ENV{'form.Status'} eq $status || $ENV{'form.Status'} eq 'Any') {
-            $currentlist{$student}=join(':',('student',$studentName,
-                                             $studentDomain,$fullname,
-                                             $studentSection,$id));
+sub outsheet_html  {
+    my $self = shift;
+    my ($r) = @_;
+    my ($num_uneditable,$realm,$row_type);
+    my $requester_is_student = ($ENV{'request.role'} =~ /^st\./);
+    if ($self->{'type'} eq 'assesscalc') {
+        $num_uneditable = 1;
+        $realm = 'Assessment';
+        $row_type = 'Item';
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        $num_uneditable = 26;
+        $realm = 'User';
+        $row_type = 'Assessment';
+    } elsif ($self->{'type'} eq 'classcalc') {
+        $num_uneditable = 26;
+        $realm = 'Course';
+        $row_type = 'Student';
+    } else {
+        return;  # error
+    }
+    ####################################
+    # Print out header table
+    ####################################
+    my $num_left = 52-$num_uneditable;
+    my $tabledata =<<"END";
+<table border="2">
+<tr>
+  <th colspan="2" rowspan="2"><font size="+2">$realm</font></th>
+  <td bgcolor="#FFDDDD" colspan="$num_uneditable">
+      <b><font size="+1">Import</font></b></td>
+  <td colspan="$num_left">
+      <b><font size="+1">Calculations</font></b></td>
+</tr><tr>
+END
+    my $label_num = 0;
+    foreach (split(//,'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz')){
+        if ($label_num<$num_uneditable) { 
+            $tabledata.='<td bgcolor="#FFDDDD">';
+        } else {
+            $tabledata.='<td>';
         }
+        $tabledata.="<b><font size=+1>$_</font></b></td>";
+        $label_num++;
     }
-    #
-    # Find discrepancies between the course row table and this
-    #
-    my %f=&getformulas($sheet);
-    my $changed=0;
-    #
-    $sheet->{'maxrow'}=0;
-    my %existing=();
-    #
-    # Now obsolete rows
-    foreach (keys(%f)) {
-        if ($_=~/^A(\d+)/) {
-            if ($1 > $sheet->{'maxrow'}) {
-                $sheet->{'maxrow'}= $1;
-            }
-            $existing{$f{$_}}=1;
-            unless ((defined($currentlist{$f{$_}})) || (!$1) ||
-                    ($f{$_}=~/^(~~~|---)/)) {
-                $f{$_}='!!! Obsolete';
-                $changed=1;
+    $tabledata.="</tr>\n";
+    $r->print($tabledata);
+    ####################################
+    # Print out template row
+    ####################################
+    my ($num_cols_output,$row_html,$rowlabel,@rowdata);
+    
+    if (! $requester_is_student) {
+        ($rowlabel,@rowdata) = $self->get_row('-');
+        $row_html = '<tr><td>'.$self->format_html_rowlabel($rowlabel).'</td>';
+        $num_cols_output = 0;
+        foreach my $cell (@rowdata) {
+            if ($requester_is_student || 
+                $num_cols_output++ < $num_uneditable) {
+                $row_html .= '<td bgcolor="#FFDDDD">';
+                $row_html .= &html_uneditable_cell($cell,'#FFDDDD');
+            } else {
+                $row_html .= '<td bgcolor="#EOFFDD">';
+                $row_html .= &html_editable_cell($cell,'#E0FFDD');
             }
+            $row_html .= '</td>';
         }
+        $row_html.= "</tr>\n";
+        $r->print($row_html);
     }
-    #
-    # New and unknown keys
-    foreach my $student (sort keys(%currentlist)) {
-        unless ($existing{$student}) {
-            $changed=1;
-            $sheet->{'maxrow'}++;
-            $f{'A'.$sheet->{'maxrow'}}=$student;
+    ####################################
+    # Print out summary/export row
+    ####################################
+    ($rowlabel,@rowdata) = $self->get_row('0');
+    $row_html = '<tr><td>'.$self->format_html_rowlabel($rowlabel).'</td>';
+    $num_cols_output = 0;
+    foreach my $cell (@rowdata) {
+        if ($num_cols_output++ < 26 && ! $requester_is_student) {
+            $row_html .= '<td bgcolor="#CCCCFF">';
+            $row_html .= &html_editable_cell($cell,'#CCCCFF');
+        } else {
+            $row_html .= '<td bgcolor="#DDCCFF">';
+            $row_html .= &html_uneditable_cell($cell,'#CCCCFF');
         }
+        $row_html .= '</td>';
     }
-    if ($changed) { 
-        $sheet->{'f'} = \%f;
-        &setformulas($sheet,%f); 
-    }
-    #
-    &setrowlabels($sheet,\%currentlist);
-}
-
-# ----------------------------------- Update rows for student and assess sheets
-sub get_student_rowlabels {
-    my ($sheet) = @_;
-    #
-    my %course_db;
-    #
-    my $stype = $sheet->{'sheettype'};
-    my $uname = $sheet->{'uname'};
-    my $udom  = $sheet->{'udom'};
-    #
-    $sheet->{'rowlabel'} = {};
+    $row_html.= "</tr>\n";
+    $r->print($row_html);
+    $r->print('</table>');
+    ####################################
+    # Prepare to output rows
+    ####################################
+    my @Rows = $self->sort_indicies();
     #
-    my $identifier =$sheet->{'coursefilename'}.'_'.$stype;
-    if  ($rowlabel_cache{$identifier}) {
-        %{$sheet->{'rowlabel'}}=split(/___;___/,$rowlabel_cache{$identifier});
-    } else {
-        # Get the data and store it in the cache
-        # Tie hash
-        tie(%course_db,'GDBM_File',$sheet->{'coursefilename'}.'.db',
-            &GDBM_READER(),0640);
-        if (! tied(%course_db)) {
-            return 'Could not access course data';
+    # Loop through the rows and output them one at a time
+    my $rows_output=0;
+    foreach my $rownum (@Rows) {
+        my ($rowlabel,@rowdata) = $self->get_row($rownum);
+        next if ($rowlabel =~ /^\s*$/);
+        next if (($self->{'type'} eq 'assesscalc') && 
+                 (! $ENV{'form.showall'})                &&
+                 ($rowdata[0]->{'value'} =~ /^\s*$/));
+        if (! $ENV{'form.showall'} &&
+            $self->{'type'} =~ /^(studentcalc|classcalc)$/) {
+            my $row_is_empty = 1;
+            foreach my $cell (@rowdata) {
+                if ($cell->{'value'} !~  /^\s*$/) {
+                    $row_is_empty = 0;
+                    last;
+                }
+            }
+            next if ($row_is_empty);
         }
         #
-        my %assesslist = ();
-        foreach ('Feedback','Evaluation','Tutoring','Discussion') {
-            my $symb = '_'.lc($_);
-            $assesslist{$symb} = join(':',('symb',$symb,0,0,
-                                           &Apache::lonnet::escape($_)));
+        my $defaultbg='#E0FF';
+        #
+        my $row_html ="\n".'<tr><td><b><font size=+1>'.$rownum.
+            '</font></b></td>';
+        #
+        if ($self->{'type'} eq 'classcalc') {
+            $row_html.='<td>'.$self->format_html_rowlabel($rowlabel).'</td>';
+            # Output links for each student?
+            # Nope, that is already done for us in format_html_rowlabel 
+            # (for now)
+        } elsif ($self->{'type'} eq 'studentcalc') {
+            my $ufn = (split(/:/,$rowlabel))[5];
+            $row_html.='<td>'.$self->format_html_rowlabel($rowlabel);
+            $row_html.= '<br>'.
+                '<select name="sel_'.$rownum.'" '.
+                    'onChange="changesheet('.$rownum.')">'.
+                        '<option name="default">Default</option>';
+            foreach (@{$self->{'othersheets'}}) {
+                $row_html.='<option name="'.$_.'"';
+                if ($ufn eq $_) {
+                    $row_html.=' selected';
+                }
+                $row_html.='>'.$_.'</option>';
+            }
+            $row_html.='</select></td>';
+        } elsif ($self->{'type'} eq 'assesscalc') {
+            $row_html.='<td>'.$self->format_html_rowlabel($rowlabel).'</td>';
         }
         #
-        while (my ($key,$srcf) = each(%course_db)) {
-            next if ($key !~ /^src_(\d+)\.(\d+)$/);
-            my $mapid = $1;
-            my $resid = $2;
-            my $id   = $mapid.'.'.$resid;
-            if ($srcf=~/\.(problem|exam|quiz|assess|survey|form)$/) {
-                my $symb=
-                    &Apache::lonnet::declutter($course_db{'map_id_'.$mapid}).
-                        '___'.$resid.'___'.&Apache::lonnet::declutter($srcf);
-                $assesslist{$symb} ='symb:'.&Apache::lonnet::escape($symb).':'
-                    .$mapid.':'.$resid.':'.
-                        &Apache::lonnet::escape($course_db{'title_'.$id});
+        my $shown_cells = 0;
+        foreach my $cell (@rowdata) {
+            my $value    = $cell->{'value'};
+            my $formula  = $cell->{'formula'};
+            my $cellname = $cell->{'name'};
+            #
+            my $bgcolor;
+            if ($shown_cells && ($shown_cells/5 == int($shown_cells/5))) {
+                $bgcolor = $defaultbg.'99';
+            } else {
+                $bgcolor = $defaultbg.'DD';
+            }
+            $bgcolor='#FFDDDD' if ($shown_cells < $num_uneditable);
+            #
+            $row_html.='<td bgcolor='.$bgcolor.'>';
+            if ($requester_is_student || $shown_cells < $num_uneditable) {
+                $row_html .= &html_uneditable_cell($cell,$bgcolor);
+            } else {
+                $row_html .= &html_editable_cell($cell,$bgcolor);
+            }
+            $row_html.='</td>';
+            $shown_cells++;
+        }
+        if ($row_html) {
+            if ($rows_output % 25 == 0) {
+                $r->print("</table>\n<br>\n");
+                $r->rflush();
+                $r->print('<table border=2>'.
+                          '<tr><td>&nbsp;<td>'.$row_type.'</td>'.
+                          '<td>'.
+                          join('</td><td>',
+                               (split(//,'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.
+                                      'abcdefghijklmnopqrstuvwxyz'))).
+                          "</td></tr>\n");
             }
+            $rows_output++;
+            $r->print($row_html);
         }
-        untie(%course_db);
-        # Store away the data
-        $sheet->{'rowlabel'} = \%assesslist;
-        $rowlabel_cache{$identifier}=join('___;___',%{$sheet->{'rowlabel'}});
     }
-
-}
-
-sub get_assess_rowlabels {
-    my ($sheet) = @_;
-    #
-    my %course_db;
     #
-    my $stype = $sheet->{'sheettype'};
-    my $uname = $sheet->{'uname'};
-    my $udom  = $sheet->{'udom'};
-    my $usymb = $sheet->{'usymb'};
+    $r->print('</table>');
     #
-    $sheet->{'rowlabel'} = {};
-    my $identifier =$sheet->{'coursefilename'}.'_'.$stype.'_'.$usymb;
+    # Debugging code (be sure to uncomment errorlog code in safe space):
     #
-    if  ($rowlabel_cache{$identifier}) {
-        %{$sheet->{'rowlabel'}}=split(/___;___/,$rowlabel_cache{$identifier});
-    } else {
-        # Get the data and store it in the cache
-        # Tie hash
-        tie(%course_db,'GDBM_File',$sheet->{'coursefilename'}.'.db',
-            &GDBM_READER(),0640);
-        if (! tied(%course_db)) {
-            return 'Could not access course data';
-        }
-        #
-        my %parameter_labels=
-            ('timestamp' => 
-                 'parameter:Timestamp of Last Transaction<br>timestamp',
-             'subnumber' =>
-                 'parameter:Number of Submissions<br>subnumber',
-             'tutornumber' =>
-                 'parameter:Number of Tutor Responses<br>tutornumber',
-             'totalpoints' =>
-                 'parameter:Total Points Granted<br>totalpoints');
-        while (my ($key,$srcf) = each(%course_db)) {
-            next if ($key !~ /^src_(\d+)\.(\d+)$/);
-            my $mapid = $1;
-            my $resid = $2;
-            my $id   = $mapid.'.'.$resid;
-            if ($srcf=~/\.(problem|exam|quiz|assess|survey|form)$/) {
-                # Loop through the metadata for this key
-                my @Metadata = split(/,/,
-                                     &Apache::lonnet::metadata($srcf,'keys'));
-                foreach my $key (@Metadata) {
-                    next if ($key !~ /^(stores|parameter)_/);
-                    my $display=
-                        &Apache::lonnet::metadata($srcf,$key.'.display');
-                    unless ($display) {
-                        $display.=
-                            &Apache::lonnet::metadata($srcf,$key.'.name');
-                    }
-                    $display.='<br>'.$key;
-                    $parameter_labels{$key}='parameter:'.$display;
-                } # end of foreach
-            }
-        }
-        untie(%course_db);
-        # Store away the results
-        $sheet->{'rowlabel'} = \%parameter_labels;
-        $rowlabel_cache{$identifier}=join('___;___',%{$sheet->{'rowlabel'}});
-    }
-        
+    # $r->print("\n<pre>");
+    # $r->print(&geterrorlog($self));
+    # $r->print("\n</pre>");
+    return 1;
 }
 
-sub updatestudentassesssheet {
-    my $sheet = shift;
-    if ($sheet->{'sheettype'} eq 'studentcalc') {
-        &get_student_rowlabels($sheet);
-    } else {
-        &get_assess_rowlabels($sheet);
-    }
-    # Determine if any of the information has changed
-    my %f=&getformulas($sheet);
-    my $changed=0;
-    
-    $sheet->{'maxrow'} = 0;
-    my %existing=();
-    # Now obsolete rows
-    foreach my $cell (keys(%f)) {
-        my $formula = $f{$cell};
-        next if ($cell !~ /^A(\d+)/);
-        $sheet->{'maxrow'} = $1 if ($1 > $sheet->{'maxrow'});
-        my ($usy,$ufn)=split(/__&&&\__/,$formula);
-        $existing{$usy}=1;
-        unless ((exists($sheet->{'rowlabel'}->{$usy}) && 
-                 (defined($sheet->{'rowlabel'}->{$usy})) || (!$1) ||
-                 ($formula =~ /^(~~~|---)/) )) {
-            $f{$cell}='!!! Obsolete';
-            $changed=1;
-        }
-    }
-    # New and unknown keys
-    foreach (keys(%{$sheet->{'rowlabel'}})) {
-        unless ($existing{$_}) {
-            $changed=1;
-            $sheet->{'maxrow'}++;
-            $f{'A'.$sheet->{'maxrow'}}=$_;
+############################################
+##         csv output routines            ##
+############################################
+sub outsheet_csv   {
+    my $self = shift;
+    my ($r) = @_;
+    my $csvdata = '';
+    my @Values;
+    ####################################
+    # Prepare to output rows
+    ####################################
+    my @Rows = $self->sort_indicies();
+    #
+    # Loop through the rows and output them one at a time
+    my $rows_output=0;
+    foreach my $rownum (@Rows) {
+        my ($rowlabel,@rowdata) = $self->get_row($rownum);
+        next if ($rowlabel =~ /^\s*$/);
+        push (@Values,$self->format_csv_rowlabel($rowlabel));
+        foreach my $cell (@rowdata) {
+            push (@Values,'"'.$cell->{'value'}.'"');
         }
+        $csvdata.= join(',',@Values)."\n";
+        @Values = ();
     }
-    if ($changed) { 
-        $sheet->{'f'} = \%f;
-        &setformulas($sheet); 
-    }
-}
-
-# ------------------------------------------------ Load data for one assessment
-
-sub loadstudent{
-    my ($sheet,$r,$c)=@_;
-    my %constants=();
-    my %formulas=&getformulas($sheet);
-    $cachedassess=$sheet->{'uname'}.':'.$sheet->{'udom'};
-    # Get ALL the student preformance data
-    my @tmp = &Apache::lonnet::currentdump($sheet->{'cid'},
-                                           $sheet->{'udom'},
-                                           $sheet->{'uname'});
-    if ((scalar @tmp > 0) && ($tmp[0] !~ /^error:/)) {
-        %cachedstores = @tmp;
-    }
-    undef @tmp;
-    # 
-    my @assessdata=();
-    foreach my $cell (keys(%formulas)) {
-        my $value = $formulas{$cell};
-        if(defined($c) && ($c->aborted())) {
-            last;
-        }
-	next if ($cell !~ /^A(\d+)/);
-        my $row=$1;
-        next if (($value =~ /^[!~-]/) || ($row==0));
-        my ($usy,$ufn)=split(/__&&&\__/,$value);
-        @assessdata=&exportsheet($sheet,$sheet->{'uname'},
-                                 $sheet->{'udom'},
-                                 'assesscalc',$usy,$ufn,$r);
-        my $index=0;
-        foreach my $col ('A','B','C','D','E','F','G','H','I','J','K','L','M',
-                         'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
-            if (defined($assessdata[$index])) {
-                if ($assessdata[$index]=~/\D/) {
-                    $constants{$col.$row}="'".$assessdata[$index]."'";
-                } else {
-                    $constants{$col.$row}=$assessdata[$index];
-                }
-                $formulas{$col.$row}='import' if ($col ne 'A');
-            }
-            $index++;
-        }
+    #
+    # Write the CSV data to a file and serve up a link
+    #
+    my $filename = '/prtspool/'.
+        $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
+        time.'_'.rand(1000000000).'.csv';
+    my $file;
+    unless ($file = Apache::File->new('>'.'/home/httpd'.$filename)) {
+        $r->log_error("Couldn't open $filename for output $!");
+        $r->print("Problems occured in writing the csv file.  ".
+                  "This error has been logged.  ".
+                  "Please alert your LON-CAPA administrator.");
+        $r->print("<pre>\n".$csvdata."</pre>\n");
+        return 0;
     }
-    $cachedassess='';
-    undef %cachedstores;
-    $sheet->{'f'} = \%formulas;
-    &setformulas($sheet);
-    &setconstants($sheet,\%constants);
+    print $file $csvdata;
+    close($file);
+    $r->print('<br /><br />'.
+              '<a href="'.$filename.'">Your CSV spreadsheet.</a>'."\n");
+    #
+    return 1;
 }
 
-# --------------------------------------------------- Load data for one student
-#
-sub loadcourse {
-    my ($sheet,$r,$c)=@_;
+############################################
+##        Excel output routines           ##
+############################################
+sub outsheet_recursive_excel {
+    my $self = shift;
+    my ($r) = @_;
+    my $c = $r->connection;
+    return undef if ($self->{'type'} ne 'classcalc');
+    my ($workbook,$filename) = $self->create_excel_spreadsheet($r);
+    return undef if (! defined($workbook));
     #
-    my %constants=();
-    my %formulas=&getformulas($sheet);
+    # Create main worksheet
+    my $main_worksheet = $workbook->addworksheet('main');
     #
-    my $total=0;
-    foreach (keys(%formulas)) {
-	if ($_=~/^A(\d+)/) {
-	    unless ($formulas{$_}=~/^[\!\~\-]/) { $total++; }
-        }
-    }
-    my $now=0;
-    my $since=time;
-    $r->print(<<ENDPOP);
-<script>
-    popwin=open('','popwin','width=400,height=100');
-    popwin.document.writeln('<html><body bgcolor="#FFFFFF">'+
-      '<h3>Spreadsheet Calculation Progress</h3>'+
-      '<form name=popremain>'+
-      '<input type=text size=35 name=remaining value=Starting></form>'+
-      '</body></html>');
-    popwin.document.close();
-</script>
-ENDPOP
+    # Figure out who the students are
+    my %f=$self->formulas();
+    my $count = 0;
+    $r->print(<<END);
+<p>
+Compiling Excel Workbook with a worksheet for each student.
+</p><p>
+This operation may take longer than a complete recalculation of the
+spreadsheet. 
+</p><p>
+To abort this operation, hit the stop button on your browser.
+</p><p>
+A link to the spreadsheet will be available at the end of this process.
+</p>
+<p>
+END
     $r->rflush();
-    foreach (keys(%formulas)) {
+    my $starttime = time;
+    foreach my $rownum ($self->sort_indicies()) {
+        $count++;
+        my ($sname,$sdom) = split(':',$f{'A'.$rownum});
+        my $student_excel_worksheet=$workbook->addworksheet($sname.'@'.$sdom);
+        # Create a new spreadsheet
+        my $studentsheet = &Apache::lonspreadsheet::Spreadsheet->new
+                                   ($sname,$sdom,'studentcalc',undef);
+        # Read in the spreadsheet definition
+        $studentsheet->update_student_sheet($r,$c);
+        # Stuff the sheet into excel
+        $studentsheet->export_sheet_as_excel($student_excel_worksheet);
+        my $totaltime = int((time - $starttime) / $count * $self->{'maxrow'});
+        my $timeleft = int((time - $starttime) / $count * ($self->{'maxrow'} - $count));
+        if ($count % 5 == 0) {
+            $r->print($count.' students completed.'.
+                      '  Time remaining: '.$timeleft.' sec. '.
+                      '  Estimated total time: '.$totaltime." sec <br />\n");
+            $r->rflush();
+        }
         if(defined($c) && ($c->aborted())) {
             last;
         }
-	next if ($_!~/^A(\d+)/);
-        my $row=$1;
-        next if (($formulas{$_}=~/^[\!\~\-]/)  || ($row==0));
-        my ($sname,$sdom) = split(':',$formulas{$_});
-        my @studentdata=&exportsheet($sheet,$sname,$sdom,'studentcalc',
-                                     undef,undef,$r);
-        undef %userrdatas;
-        $now++;
-        $r->print('<script>popwin.document.popremain.remaining.value="'.
-                  $now.'/'.$total.': '.int((time-$since)/$now*($total-$now)).
-                  ' secs remaining";</script>');
-        $r->rflush(); 
-        #
-        my $index=0;
-        foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
-                 'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
-            if (defined($studentdata[$index])) {
-                my $col=$_;
-                if ($studentdata[$index]=~/\D/) {
-                    $constants{$col.$row}="'".$studentdata[$index]."'";
-                } else {
-                    $constants{$col.$row}=$studentdata[$index];
-                }
-                unless ($col eq 'A') { 
-                    $formulas{$col.$row}='import';
-                }
-            } 
-            $index++;
-        }
     }
-    $sheet->{'f'}=\%formulas;
-    &setformulas($sheet);
-    &setconstants($sheet,\%constants);
-    $r->print('<script>popwin.close()</script>');
-    $r->rflush(); 
-}
-
-# ------------------------------------------------ Load data for one assessment
-#
-sub loadassessment {
-    my ($sheet,$r,$c)=@_;
-
-    my $uhome = $sheet->{'uhome'};
-    my $uname = $sheet->{'uname'};
-    my $udom  = $sheet->{'udom'};
-    my $symb  = $sheet->{'usymb'};
-    my $cid   = $sheet->{'cid'};
-    my $cnum  = $sheet->{'cnum'};
-    my $cdom  = $sheet->{'cdom'};
-    my $chome = $sheet->{'chome'};
-
-    my $namespace;
-    unless ($namespace=$cid) { return ''; }
-    # Get stored values
-    my %returnhash=();
-    if ($cachedassess eq $uname.':'.$udom) {
-        #
-        # get data out of the dumped stores
-        # 
-        if (exists($cachedstores{$symb})) {
-            %returnhash = %{$cachedstores{$symb}};
-        } else {
-            %returnhash = ();
-        }
-    } else {
+    #
+    if(! $c->aborted() ) {
+        $r->print('All students spreadsheets completed!<br />');
+        $r->rflush();
         #
-        # restore individual
+        # &export_sheet_as_excel fills $worksheet with the data from $sheet
+        $self->export_sheet_as_excel($main_worksheet);
         #
-        %returnhash = &Apache::lonnet::restore($symb,$namespace,$udom,$uname);
+        $workbook->close();
+        # Okay, the spreadsheet is taken care of, so give the user a link.
+        $r->print('<br /><br />'.
+                  '<a href="'.$filename.'">Your Excel spreadsheet.</a>'."\n");
+    } else {
+        $workbook->close();  # Not sure how necessary this is.
+        #unlink('/home/httpd'.$filename); # No need to keep this around?
     }
+    return 1;
+}
+
+sub outsheet_excel {
+    my $self = shift;
+    my ($r) = @_;
+    my ($workbook,$filename) = $self->create_excel_spreadsheet($r);
+    return undef if (! defined($workbook));
+    my $sheetname;
+    if ($self->{'type'} eq 'classcalc') {
+        $sheetname = 'Main';
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        $sheetname = $self->{'uname'}.'@'.$self->{'udom'};
+    } elsif ($self->{'type'} eq 'assesscalc') {
+        $sheetname = $self->{'uname'}.'@'.$self->{'udom'}.' assessment';
+    }
+    my $worksheet = $workbook->addworksheet($sheetname);
     #
-    # returnhash now has all stores for this resource
-    # convert all "_" to "." to be able to use libraries, multiparts, etc
-    #
-    # This is dumb.  It is also necessary :(
-    my @oldkeys=keys %returnhash;
+    # &export_sheet_as_excel fills $worksheet with the data from $sheet
+    $self->export_sheet_as_excel($worksheet);
     #
-    foreach my $name (@oldkeys) {
-        my $value=$returnhash{$name};
-        delete $returnhash{$name};
-        $name=~s/\_/\./g;
-        $returnhash{$name}=$value;
-    }
-    # initialize coursedata and userdata for this user
-    undef %courseopt;
-    undef %useropt;
-
-    my $userprefix=$uname.'_'.$udom.'_';
+    $workbook->close();
+    # Okay, the spreadsheet is taken care of, so give the user a link.
+    $r->print('<br /><br />'.
+              '<a href="'.$filename.'">Your Excel spreadsheet.</a>'."\n");
+    return 1;
+}
 
-    unless ($uhome eq 'no_host') { 
-        # Get coursedata
-        unless ((time-$courserdatas{$cid.'.last_cache'})<240) {
-            my %Tmp = &Apache::lonnet::dump('resourcedata',$cdom,$cnum);
-            $courserdatas{$cid}=\%Tmp;
-            $courserdatas{$cid.'.last_cache'}=time;
-        }
-        while (my ($name,$value) = each(%{$courserdatas{$cid}})) {
-            $courseopt{$userprefix.$name}=$value;
-        }
-        # Get userdata (if present)
-        unless ((time-$userrdatas{$uname.'@'.$udom.'.last_cache'})<240) {
-            my %Tmp = &Apache::lonnet::dump('resourcedata',$udom,$uname);
-            $userrdatas{$cid} = \%Tmp;
-            # Most of the time the user does not have a 'resourcedata.db' 
-            # file.  We need to cache that we got nothing instead of bothering
-            # with requesting it every time.
-            $userrdatas{$uname.'@'.$udom.'.last_cache'}=time;
-        }
-        while (my ($name,$value) = each(%{$userrdatas{$cid}})) {
-            $useropt{$userprefix.$name}=$value;
-        }
+sub create_excel_spreadsheet {
+    my $self = shift;
+    my ($r) = @_;
+    my $filename = '/prtspool/'.
+        $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
+        time.'_'.rand(1000000000).'.xls';
+    my $workbook  = Spreadsheet::WriteExcel->new('/home/httpd'.$filename);
+    if (! defined($workbook)) {
+        $r->log_error("Error creating excel spreadsheet $filename: $!");
+        $r->print("Problems creating new Excel file.  ".
+                  "This error has been logged.  ".
+                  "Please alert your LON-CAPA administrator");
+        return undef;
     }
-    # now courseopt, useropt initialized for this user and course
-    # (used by parmval)
     #
-    # Load keys for this assessment only
+    # The excel spreadsheet stores temporary data in files, then put them
+    # together.  If needed we should be able to disable this (memory only).
+    # The temporary directory must be specified before calling 'addworksheet'.
+    # File::Temp is used to determine the temporary directory.
+    $workbook->set_tempdir('/home/httpd/perl/tmp');
     #
-    my %thisassess=();
-    my ($symap,$syid,$srcf)=split(/\_\_\_/,$symb);
-    foreach (split(/\,/,&Apache::lonnet::metadata($srcf,'keys'))) {
-        $thisassess{$_}=1;
-    } 
+    # Determine the name to give the worksheet
+    return ($workbook,$filename);
+}
+
+sub export_sheet_as_excel {
+    my $self = shift;
+    my $worksheet = shift;
     #
-    # Load parameters
+    my $rows_output = 0;
+    my $cols_output = 0;
+    ####################################
+    #    Write an identifying row      #
+    ####################################
+    my @Headerinfo = ($self->{'coursedesc'});
+    my $title = $self->gettitle();
+    $cols_output = 0;    
+    if (defined($title)) {
+        $worksheet->write($rows_output++,$cols_output++,$title);
+    }
+    ####################################
+    #   Write the summary/export row   #
+    ####################################
+    my ($rowlabel,@rowdata) = &get_row($self,'0');
+    my $label = &format_excel_rowlabel($self,$rowlabel);
+    $cols_output = 0;
+    $worksheet->write($rows_output,$cols_output++,$label);
+    foreach my $cell (@rowdata) {
+        $worksheet->write($rows_output,$cols_output++,$cell->{'value'});
+    }
+    $rows_output+= 2;   # Skip a row, just for fun
+    ####################################
+    # Prepare to output rows
+    ####################################
+    my @Rows = &sort_indicies($self);
     #
-    my %c=();
-    if (tie(%parmhash,'GDBM_File',
-            $sheet->{'coursefilename'}.'_parms.db',&GDBM_READER(),0640)) {
-        my %f=&getformulas($sheet);
-        foreach my $cell (keys(%f))  {
-            next if ($cell !~ /^A/);
-            next if  ($f{$cell} =~/^[\!\~\-]/);
-            if ($f{$cell}=~/^parameter/) {
-                if (defined($thisassess{$f{$cell}})) {
-                    my $val       = &parmval($f{$cell},$sheet);
-                    $c{$cell}     = $val;
-                    $c{$f{$cell}} = $val;
+    # Loop through the rows and output them one at a time
+    foreach my $rownum (@Rows) {
+        my ($rowlabel,@rowdata) = &get_row($self,$rownum);
+        next if ($rowlabel =~ /^[\s]*$/);
+        $cols_output = 0;
+        my $label = &format_excel_rowlabel($self,$rowlabel);
+        if ( ! $ENV{'form.showall'} &&
+             $self->{'type'} =~ /^(studentcalc|classcalc)$/) {
+            my $row_is_empty = 1;
+            foreach my $cell (@rowdata) {
+                if ($cell->{'value'} !~  /^\s*$/) {
+                    $row_is_empty = 0;
+                    last;
                 }
-            } else {
-                my $key=$f{$cell};
-                my $ckey=$key;
-                $key=~s/^stores\_/resource\./;
-                $key=~s/\_/\./g;
-                $c{$cell}=$returnhash{$key};
-                $c{$ckey}=$returnhash{$key};
             }
+            next if ($row_is_empty);
         }
-        untie(%parmhash);
+        $worksheet->write($rows_output,$cols_output++,$label);
+        if (ref($label)) {
+            $cols_output = (scalar(@$label));
+        }
+        foreach my $cell (@rowdata) {
+            $worksheet->write($rows_output,$cols_output++,$cell->{'value'});
+        }
+        $rows_output++;
     }
-    &setconstants($sheet,\%c);
-}
-
-# --------------------------------------------------------- Various form fields
-
-sub textfield {
-    my ($title,$name,$value)=@_;
-    return "\n<p><b>$title:</b><br>".
-        '<input type=text name="'.$name.'" size=80 value="'.$value.'">';
+    return;
 }
 
-sub hiddenfield {
-    my ($name,$value)=@_;
-    return "\n".'<input type=hidden name="'.$name.'" value="'.$value.'">';
+############################################
+##          XML output routines           ##
+############################################
+sub outsheet_xml   {
+    my $self = shift;
+    my ($r) = @_;
+    ## Someday XML
+    ## Will be rendered for the user
+    ## But not on this day
 }
 
-sub selectbox {
-    my ($title,$name,$value,%options)=@_;
-    my $selout="\n<p><b>$title:</b><br>".'<select name="'.$name.'">';
-    foreach (sort keys(%options)) {
-        $selout.='<option value="'.$_.'"';
-        if ($_ eq $value) { $selout.=' selected'; }
-        $selout.='>'.$options{$_}.'</option>';
+##
+## Outsheet - calls other outsheet_* functions
+##
+sub outsheet {
+    my $self = shift;
+    my ($r)=@_;
+    if (! exists($ENV{'form.output'})) {
+        $ENV{'form.output'} = 'HTML';
     }
-    return $selout.'</select>';
-}
-
-# =============================================== Update information in a sheet
-#
-# Add new users or assessments, etc.
-#
-
-sub updatesheet {
-    my ($sheet)=@_;
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-	return &updateclasssheet($sheet);
+    if (lc($ENV{'form.output'}) eq 'csv') {
+        $self->outsheet_csv($r);
+    } elsif (lc($ENV{'form.output'}) eq 'excel') {
+        $self->outsheet_excel($r);
+    } elsif (lc($ENV{'form.output'}) eq 'recursive excel') {
+        $self->outsheet_recursive_excel($r);
+#    } elsif (lc($ENV{'form.output'}) eq 'xml' ) {
+#        $self->outsheet_xml($r);
     } else {
-        return &updatestudentassesssheet($sheet);
+        $self->outsheet_html($r);
     }
 }
 
-# =================================================== Load the rows for a sheet
 #
-# Import the data for rows
+# othersheets: Returns the list of other spreadsheets available 
 #
-
-sub loadrows {
-    my ($sheet,$r)=@_;
-    my $c = $r->connection;
-    my $stype=$sheet->{'sheettype'};
-    if ($stype eq 'classcalc') {
-	&loadcourse($sheet,$r,$c);
-    } elsif ($stype eq 'studentcalc') {
-        &loadstudent($sheet,$r,$c);
-    } else {
-        &loadassessment($sheet,$r,$c);
-    }
-}
-
-# ======================================================= Forced recalculation?
-
-sub checkthis {
-    my ($keyname,$time)=@_;
-    if (! exists($expiredates{$keyname})) {
-        return 0;
-    } else {
-        return ($time<$expiredates{$keyname});
-    }
-}
-
-sub forcedrecalc {
-    my ($uname,$udom,$stype,$usymb)=@_;
-    my $key=$uname.':'.$udom.':'.$stype.':'.$usymb;
-    my $time=$oldsheets{$key.'.time'};
-    if ($ENV{'form.forcerecalc'}) { return 1; }
-    unless ($time) { return 1; }
-    if ($stype eq 'assesscalc') {
-        my $map=(split(/___/,$usymb))[0];
-        if (&checkthis('::assesscalc:',$time) ||
-            &checkthis('::assesscalc:'.$map,$time) ||
-            &checkthis('::assesscalc:'.$usymb,$time) ||
-            &checkthis($uname.':'.$udom.':assesscalc:',$time) ||
-            &checkthis($uname.':'.$udom.':assesscalc:'.$map,$time) ||
-            &checkthis($uname.':'.$udom.':assesscalc:'.$usymb,$time)) {
-            return 1;
-        }
-    } else {
-        if (&checkthis('::studentcalc:',$time) || 
-            &checkthis($uname.':'.$udom.':studentcalc:',$time)) {
-	    return 1;
-        }
+sub othersheets {
+    my $self = shift;
+    my ($stype)=@_;
+    $stype = $self->{'type'} if (! defined($stype));
+    #
+    my $cnum  = $self->{'cnum'};
+    my $cdom  = $self->{'cdom'};
+    my $chome = $self->{'chome'};
+    #
+    my @alternatives=();
+    my %results=&Apache::lonnet::dump($stype.'_spreadsheets',$cdom,$cnum);
+    my ($tmp) = keys(%results);
+    unless ($tmp =~ /^(con_lost|error|no_such_host)/i) {
+        @alternatives = sort (keys(%results));
     }
-    return 0; 
+    return @alternatives; 
 }
 
-# ============================================================== Export handler
-# exportsheet
-# returns the export row for a spreadsheet.
 #
-sub exportsheet {
-    my ($sheet,$uname,$udom,$stype,$usymb,$fn,$r)=@_;
-    my $flag = 0;
-    $uname = $uname || $sheet->{'uname'};
-    $udom  = $udom  || $sheet->{'udom'};
-    $stype = $stype || $sheet->{'sheettype'};
-    my @exportarr=();
-    # This handles the assessment sheets for '_feedback', etc
-    if (defined($usymb) && ($usymb=~/^\_(\w+)/) && 
-        (!defined($fn) || $fn eq '')) {
-        $fn='default_'.$1;
+# Parse a spreadsheet
+# 
+sub parse_sheet {
+    # $sheetxml is a scalar reference or a scalar
+    my ($sheetxml) = @_;
+    if (! ref($sheetxml)) {
+        my $tmp = $sheetxml;
+        $sheetxml = \$tmp;
+    }
+    my %f;
+    my $parser=HTML::TokeParser->new($sheetxml);
+    my $token;
+    while ($token=$parser->get_token) {
+        if ($token->[0] eq 'S') {
+            if ($token->[1] eq 'field') {
+                $f{$token->[2]->{'col'}.$token->[2]->{'row'}}=
+                    $parser->get_text('/field');
+            }
+            if ($token->[1] eq 'template') {
+                $f{'template_'.$token->[2]->{'col'}}=
+                    $parser->get_text('/template');
+            }
+        }
     }
+    return \%f;
+}
+
+sub readsheet {
+    my $self = shift;
+    my ($fn)=@_;
     #
-    # Check if cached
+    my $stype = $self->{'type'};
+    my $cnum  = $self->{'cnum'};
+    my $cdom  = $self->{'cdom'};
+    my $chome = $self->{'chome'};
     #
-    my $key=$uname.':'.$udom.':'.$stype.':'.$usymb;
-    my $found='';
-    if ($oldsheets{$key}) {
-        foreach (split(/___&\___/,$oldsheets{$key})) {
-            my ($name,$value)=split(/___=___/,$_);
-            if ($name eq $fn) {
-                $found=$value;
+    if (! defined($fn)) {
+        # There is no filename. Look for defaults in course and global, cache
+        unless ($fn=$defaultsheets{$cnum.'_'.$cdom.'_'.$stype}) {
+            my %tmphash = &Apache::lonnet::get('environment',
+                                               ['spreadsheet_default_'.$stype],
+                                               $cdom,$cnum);
+            my ($tmp) = keys(%tmphash);
+            if ($tmp =~ /^(con_lost|error|no_such_host)/i) {
+                $fn = 'default_'.$stype;
+            } else {
+                $fn = $tmphash{'spreadsheet_default_'.$stype};
+            } 
+            unless (($fn) && ($fn!~/^error\:/)) {
+                $fn='default_'.$stype;
             }
+            $defaultsheets{$cnum.'_'.$cdom.'_'.$stype}=$fn; 
         }
     }
-    unless ($found) {
-        &cachedssheets($sheet,$uname,$udom);
-        if ($oldsheets{$key}) {
-            foreach (split(/___&\___/,$oldsheets{$key})) {
-                my ($name,$value)=split(/___=___/,$_);
-                if ($name eq $fn) {
-                    $found=$value;
+    # $fn now has a value
+    $self->{'filename'} = $fn;
+    # see if sheet is cached
+    my $fstring='';
+    if ($fstring=$spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}) {
+        my %tmp = split(/___;___/,$fstring);
+        $self->formulas(\%tmp);
+#        $self->logthis('readsheet found cached ');
+#        $self->dump_formulas_to_log();
+    } else {
+        # Not cached, need to read
+        my %f=();
+        if ($fn=~/^default\_/) {
+            my $sheetxml='';
+            my $fh;
+            my $dfn=$fn;
+            $dfn=~s/\_/\./g;
+            if ($fh=Apache::File->new($includedir.'/'.$dfn)) {
+                $sheetxml=join('',<$fh>);
+            } else {
+                # $sheetxml='<field row="0" col="A">"Error"</field>';
+                $sheetxml='<field row="0" col="A"></field>';
+            }
+            %f=%{&parse_sheet(\$sheetxml)};
+        } elsif($fn=~/\/*\.spreadsheet$/) {
+            my $sheetxml=&Apache::lonnet::getfile
+                (&Apache::lonnet::filelocation('',$fn));
+            if ($sheetxml == -1) {
+                $sheetxml='<field row="0" col="A">"Error loading spreadsheet '
+                    .$fn.'"</field>';
+            }
+            %f=%{&parse_sheet(\$sheetxml)};
+        } else {
+            my %tmphash = &Apache::lonnet::dump($fn,$cdom,$cnum);
+            my ($tmp) = keys(%tmphash);
+            if ($tmp !~ /^(con_lost|error|no_such_host)/i) {
+                foreach (keys(%tmphash)) {
+                    $f{$_}=$tmphash{$_};
                 }
-            } 
+            } else {
+                # Unable to grab the specified spreadsheet,
+                # so we get the default ones instead.
+                $fn = 'default_'.$stype;
+                $self->{'filename'} = $fn;
+                my $dfn = $fn;
+                $dfn =~ s/\_/\./g;
+                my $sheetxml;
+                if (my $fh=Apache::File->new($includedir.'/'.$dfn)) {
+                    $sheetxml = join('',<$fh>);
+                } else {
+                    $sheetxml='<field row="0" col="A">'.
+                        '"Unable to load spreadsheet"</field>';
+                }
+                %f=%{&parse_sheet(\$sheetxml)};
+            }
         }
+        # Cache and set
+        $spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}=join('___;___',%f);  
+        $self->formulas(\%f);
+#        $self->logthis('readsheet loaded ');
+#        $self->dump_formulas_to_log();
     }
-    #
-    # Check if still valid
-    #
-    if ($found) {
-        if (&forcedrecalc($uname,$udom,$stype,$usymb)) {
-            $found='';
+}
+
+# ------------------------------------------------------------ Save spreadsheet
+sub writesheet {
+    my $self = shift;
+    my ($makedef)=@_;
+    my $cid=$self->{'cid'};
+    if (&Apache::lonnet::allowed('opa',$cid)) {
+        my %f=$self->formulas();
+        my $stype= $self->{'type'};
+        my $cnum = $self->{'cnum'};
+        my $cdom = $self->{'cdom'};
+        my $chome= $self->{'chome'};
+        my $fn   = $self->{'filename'};
+        # Cache new sheet
+        $spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}=join('___;___',%f);
+        # Write sheet
+        foreach (keys(%f)) {
+            delete($f{$_}) if ($f{$_} eq 'import');
         }
+        my $reply = &Apache::lonnet::put($fn,\%f,$cdom,$cnum);
+        if ($reply eq 'ok') {
+            $reply = &Apache::lonnet::put($stype.'_spreadsheets',
+                            {$fn => $ENV{'user.name'}.'@'.$ENV{'user.domain'}},
+                                          $cdom,$cnum);
+            if ($reply eq 'ok') {
+                if ($makedef) { 
+                    $reply = &Apache::lonnet::put('environment',
+                                    {'spreadsheet_default_'.$stype => $fn },
+                                                  $cdom,$cnum);
+                    if ($reply eq 'ok' && 
+                        ($self->{'type'} eq 'studentcalc' ||
+                         $self->{'type'} eq 'assesscalc')) {
+                        # Expire the spreadsheets of the other students.
+                        &Apache::lonnet::expirespread('','','studentcalc','');
+                    }
+                    return $reply;
+                } 
+                return $reply;
+            } 
+            return $reply;
+        } 
+        return $reply;
     }
-    if ($found) {
-        #
-        # Return what was cached
-        #
-        @exportarr=split(/___;___/,$found);
-        return @exportarr;
-    }
-    #
-    # Not cached
-    #
-    my ($newsheet)=&makenewsheet($uname,$udom,$stype,$usymb);
-    &readsheet($newsheet,$fn);
-    &updatesheet($newsheet);
-    &loadrows($newsheet,$r);
-    &calcsheet($newsheet); 
-    @exportarr=&exportdata($newsheet);
-    ##
-    ## Store now
-    ##
-    #
-    # load in the old value
-    #
-    my %currentlystored=();
-    if ($stype eq 'studentcalc') {
-        my @tmp = &Apache::lonnet::get('nohist_calculatedsheets',
-                                       [$key],
-                                       $sheet->{'cdom'},$sheet->{'cnum'});
-        if ($tmp[0]!~/^error/) {
-            # We only got one key, so we will access it directly.
-            foreach (split('___&___',$tmp[1])) {
-                my ($key,$value) = split('___=___',$_);
-                $key = '' if (! defined($key));
-                $currentlystored{$key} = $value;
-            }
-        }
-    } else {
-        my @tmp = &Apache::lonnet::get('nohist_calculatedsheets_'.
-                                       $sheet->{'cid'},[$key],
-                                       $sheet->{'udom'},$sheet->{'uname'});
-        if ($tmp[0]!~/^error/) {
-            # We only got one key, so we will access it directly.
-            foreach (split('___&___',$tmp[1])) {
-                my ($key,$value) = split('___=___',$_);
-                $key = '' if (! defined($key));
-                $currentlystored{$key} = $value;
-            }
+    return 'unauthorized';
+}
+
+# ----------------------------------------------- Make a temp copy of the sheet
+# "Modified workcopy" - interactive only
+#
+sub tmpwrite {
+    my $self = shift;
+    my $fn=$ENV{'user.name'}.'_'.
+        $ENV{'user.domain'}.'_spreadsheet_'.$self->{'usymb'}.'_'.
+           $self->{'filename'};
+    $fn=~s/\W/\_/g;
+    $fn=$tmpdir.$fn.'.tmp';
+    my $fh;
+    if ($fh=Apache::File->new('>'.$fn)) {
+        my %f = $self->formulas();
+        while( my ($cell,$formula) = each(%f)) {
+            print $fh &Apache::lonnet::escape($cell)."=".&Apache::lonnet::escape($formula)."\n";
         }
     }
-    #
-    # Add the new line
-    #
-    $currentlystored{$fn}=join('___;___',@exportarr);
-    #
-    # Stick everything back together
-    #
-    my $newstore='';
-    foreach (keys(%currentlystored)) {
-        if ($newstore) { $newstore.='___&___'; }
-        $newstore.=$_.'___=___'.$currentlystored{$_};
+}
+
+
+# ---------------------------------------------------------- Read the temp copy
+sub tmpread {
+    my $self = shift;
+    my ($nfield,$nform)=@_;
+    my $fn=$ENV{'user.name'}.'_'.
+           $ENV{'user.domain'}.'_spreadsheet_'.$self->{'usymb'}.'_'.
+           $self->{'filename'};
+    $fn=~s/\W/\_/g;
+    $fn=$tmpdir.$fn.'.tmp';
+    my $fh;
+    my %fo=();
+    my $countrows=0;
+    if ($fh=Apache::File->new($fn)) {
+        while (<$fh>) {
+	    chomp;
+            my ($cell,$formula) = split(/=/);
+            $cell    = &Apache::lonnet::unescape($cell);
+            $formula = &Apache::lonnet::unescape($formula);
+            $fo{$cell} = $formula;
+        }
     }
-    my $now=time;
-    #
-    # Store away the new value
-    #
-    my $timekey = $key.'.time';
-    if ($stype eq 'studentcalc') {
-        my $result = &Apache::lonnet::put('nohist_calculatedsheets',
-                                          { $key     => $newstore,
-                                            $timekey => $now },
-                                          $sheet->{'cdom'},
-                                          $sheet->{'cnum'});
+    if ($nform eq 'changesheet') {
+        $fo{'A'.$nfield}=(split(/__&&&\__/,$fo{'A'.$nfield}))[0];
+        unless ($ENV{'form.sel_'.$nfield} eq 'Default') {
+	    $fo{'A'.$nfield}.='__&&&__'.$ENV{'form.sel_'.$nfield};
+        }
     } else {
-        my $result = &Apache::lonnet::put('nohist_calculatedsheets_'.$sheet->{'cid'},
-                                          { $key     => $newstore,
-                                            $timekey => $now },
-                                          $sheet->{'udom'},
-                                          $sheet->{'uname'});
+       if ($nfield) { $fo{$nfield}=$nform; }
     }
-    return @exportarr;
+    $self->formulas(\%fo);
 }
 
-# ============================================================ Expiration Dates
-#
-# Load previously cached student spreadsheets for this course
-#
-sub load_spreadsheet_expirationdates {
-    undef %expiredates;
-    my $cid=$ENV{'request.course.id'};
-    my @tmp = &Apache::lonnet::dump('nohist_expirationdates',
-                                    $ENV{'course.'.$cid.'.domain'},
-                                    $ENV{'course.'.$cid.'.num'});
-    if (lc($tmp[0]) !~ /^error/){
-        %expiredates = @tmp;
+##################################################################
+##                  Row label formatting routines               ##
+##################################################################
+sub format_html_rowlabel {
+    my $self = shift;
+    my $rowlabel = shift;
+    return '' if ($rowlabel eq '');
+    my ($type,$labeldata) = split(':',$rowlabel,2);
+    my $result = '';
+    if ($type eq 'symb') {
+        my ($symb,$mapid,$resid,$title,$ufn) = split(':',$labeldata);
+        $ufn   = 'default' if (!defined($ufn) || $ufn eq '');
+        $ufn   = &Apache::lonnet::unescape($ufn);
+        $symb  = &Apache::lonnet::unescape($symb);
+        $title = &Apache::lonnet::unescape($title);
+        $result = '<a href="/adm/assesscalc?usymb='.$symb.
+            '&uname='.$self->{'uname'}.'&udom='.$self->{'udom'}.
+                '&ufn='.$ufn.
+                    '&mapid='.$mapid.'&resid='.$resid.'">'.$title.'</a>';
+    } elsif ($type eq 'student') {
+        my ($sname,$sdom,$fullname,$section,$id) = split(':',$labeldata);
+        if ($fullname =~ /^\s*$/) {
+            $fullname = $sname.'@'.$sdom;
+        }
+        $result ='<a href="/adm/studentcalc?uname='.$sname.
+            '&udom='.$sdom.'">';
+        $result.=$section.'&nbsp;'.$id."&nbsp;".$fullname.'</a>';
+    } elsif ($type eq 'parameter') {
+        $result = $labeldata;
+    } else {
+        $result = '<b><font size=+1>'.$rowlabel.'</font></b>';
     }
+    return $result;
 }
 
-# ===================================================== Calculated sheets cache
-#
-# Load previously cached student spreadsheets for this course
-#
-
-sub cachedcsheets {
-    my $cid=$ENV{'request.course.id'};
-    my @tmp = &Apache::lonnet::dump('nohist_calculatedsheets',
-                                    $ENV{'course.'.$cid.'.domain'},
-                                    $ENV{'course.'.$cid.'.num'});
-    if ($tmp[0] !~ /^error/) {
-        my %StupidTempHash = @tmp;
-        while (my ($key,$value) = each %StupidTempHash) {
-            $oldsheets{$key} = $value;
-        }
+sub format_csv_rowlabel {
+    my $self = shift;
+    my $rowlabel = shift;
+    return '' if ($rowlabel eq '');
+    my ($type,$labeldata) = split(':',$rowlabel,2);
+    my $result = '';
+    if ($type eq 'symb') {
+        my ($symb,$mapid,$resid,$title,$ufn) = split(':',$labeldata);
+        $ufn   = &Apache::lonnet::unescape($ufn);
+        $symb  = &Apache::lonnet::unescape($symb);
+        $title = &Apache::lonnet::unescape($title);
+        $result = $title;
+    } elsif ($type eq 'student') {
+        my ($sname,$sdom,$fullname,$section,$id) = split(':',$labeldata);
+        $result = join('","',($sname,$sdom,$fullname,$section,$id));
+    } elsif ($type eq 'parameter') {
+        $labeldata =~ s/<br>/ /g;
+        $result = $labeldata;
+    } else {
+        $result = $rowlabel;
     }
+    return '"'.$result.'"';
 }
 
-# ===================================================== Calculated sheets cache
-#
-# Load previously cached assessment spreadsheets for this student
-#
-
-sub cachedssheets {
-    my ($sheet,$uname,$udom) = @_;
-    $uname = $uname || $sheet->{'uname'};
-    $udom  = $udom  || $sheet->{'udom'};
-    if (! $loadedcaches{$uname.'_'.$udom}) {
-        my @tmp = &Apache::lonnet::dump('nohist_calculatedsheets_'.
-                                        $ENV{'request.course.id'},
-                                        $sheet->{'udom'},
-                                        $sheet->{'uname'});
-        if ($tmp[0] !~ /^error/) {
-            my %TempHash = @tmp;
-            my $count = 0;
-            while (my ($key,$value) = each %TempHash) {
-                $oldsheets{$key} = $value;
-                $count++;
-            }
-            $loadedcaches{$sheet->{'uname'}.'_'.$sheet->{'udom'}}=1;
-        }
+sub format_excel_rowlabel {
+    my $self = shift;
+    my $rowlabel = shift;
+    return '' if ($rowlabel eq '');
+    my ($type,$labeldata) = split(':',$rowlabel,2);
+    my $result = '';
+    if ($type eq 'symb') {
+        my ($symb,$mapid,$resid,$title,$ufn) = split(':',$labeldata);
+        $ufn   = &Apache::lonnet::unescape($ufn);
+        $symb  = &Apache::lonnet::unescape($symb);
+        $title = &Apache::lonnet::unescape($title);
+        $result = $title;
+    } elsif ($type eq 'student') {
+        my ($sname,$sdom,$fullname,$section,$id) = split(':',$labeldata);
+        $section = '' if (! defined($section));
+        $id      = '' if (! defined($id));
+        my @Data = ($sname,$sdom,$fullname,$section,$id);
+        $result = \@Data;
+    } elsif ($type eq 'parameter') {
+        $labeldata =~ s/<br>/ /g;
+        $result = $labeldata;
+    } else {
+        $result = $rowlabel;
     }
-    
+    return $result;
 }
 
-# ===================================================== Calculated sheets cache
-#
-# Load previously cached assessment spreadsheets for this student
-#
-
-# ================================================================ Main handler
-#
-# Interactive call to screen
-#
-#
-sub handler {
-    my $r=shift;
-
-    my ($sheettype) = ($r->uri=~/\/(\w+)$/);
-
-    if (! exists($ENV{'form.Status'})) {
-        $ENV{'form.Status'} = 'Active';
-    }
-    if ( ! exists($ENV{'form.output'}) || 
-             ($sheettype ne 'classcalc' && 
-              lc($ENV{'form.output'}) eq 'recursive excel')) {
-        $ENV{'form.output'} = 'HTML';
-    }
-    #
-    # Overload checking
+# ---------------------------------------------- Update rows for course listing
+sub updateclasssheet {
+    my $self = shift;
+    my $cnum  =$self->{'cnum'};
+    my $cdom  =$self->{'cdom'};
+    my $cid   =$self->{'cid'};
+    my $chome =$self->{'chome'};
     #
-    # Check this server
-    my $loaderror=&Apache::lonnet::overloaderror($r);
-    if ($loaderror) { return $loaderror; }
-    # Check the course homeserver
-    $loaderror= &Apache::lonnet::overloaderror($r,
-                      $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
-    if ($loaderror) { return $loaderror; } 
+    %Section = ();
     #
-    # HTML Header
+    # Read class list and row labels
+    my $classlist = &Apache::loncoursedata::get_classlist();
+    if (! defined($classlist)) {
+        return 'Could not access course classlist';
+    } 
     #
-    if ($r->header_only) {
-        $r->content_type('text/html');
-        $r->send_http_header;
-        return OK;
+    my %currentlist=();
+    foreach my $student (keys(%$classlist)) {
+        my ($studentDomain,$studentName,$end,$start,$id,$studentSection,
+            $fullname,$status)   =   @{$classlist->{$student}};
+        $Section{$studentName.':'.$studentDomain} = $studentSection;
+        if ($ENV{'form.Status'} eq $status || $ENV{'form.Status'} eq 'Any') {
+            $currentlist{$student}=join(':',('student',$studentName,
+                                             $studentDomain,$fullname,
+                                             $studentSection,$id));
+        }
     }
     #
-    # Global directory configs
+    # Find discrepancies between the course row table and this
     #
-    $includedir = $r->dir_config('lonIncludes');
-    $tmpdir = $r->dir_config('lonDaemons').'/tmp/';
+    my %f=$self->formulas();
+    my $changed=0;
     #
-    # Roles Checking
+    $self->{'maxrow'}=0;
+    my %existing=();
     #
-    # Needs to be in a course
-    if (! $ENV{'request.course.fn'}) { 
-        # Not in a course, or not allowed to modify parms
-        $ENV{'user.error.msg'}=
-            $r->uri.":opa:0:0:Cannot modify spreadsheet";
-        return HTTP_NOT_ACCEPTABLE; 
+    # Now obsolete rows
+    foreach my $cell ($self->A_column()) {
+        $cell =~ /^A(\d+)/;
+        if ($1 > $self->{'maxrow'}) {
+            $self->{'maxrow'}= $1;
+        }
+        $existing{$f{$cell}}=1;
+        unless ((defined($currentlist{$f{$cell}})) || (!$1) ||
+                ($f{$cell}=~/^(~~~|---)/)) {
+            $f{$cell}='!!! Obsolete';
+            $changed=1;
+        }
     }
     #
-    # Get query string for limited number of parameters
+    # New and unknown keys
+    foreach my $student (sort keys(%currentlist)) {
+        next if ($existing{$student});
+        $changed=1;
+        $self->{'maxrow'}++;
+        $f{'A'.$self->{'maxrow'}}=$student;
+    }
+    $self->formulas(\%f) if ($changed);
     #
-    &Apache::loncommon::get_unprocessed_cgi
-        ($ENV{'QUERY_STRING'},['uname','udom','usymb','ufn','mapid','resid']);
+    $self->rowlabels(\%currentlist);
+}
+
+# ----------------------------------- Update rows for student and assess sheets
+sub get_student_rowlabels {
+    my $self = shift;
     #
-    # Deal with restricted student permissions 
+    my %course_db;
     #
-    if ($ENV{'request.role'} =~ /^st\./) {
-        delete $ENV{'form.unewfield'}   if (exists($ENV{'form.unewfield'}));
-        delete $ENV{'form.unewformula'} if (exists($ENV{'form.unewformula'}));
-    }
+    my $stype = $self->{'type'};
+    my $uname = $self->{'uname'};
+    my $udom  = $self->{'udom'};
     #
-    # Look for special assessment spreadsheets - '_feedback', etc.
+    $self->{'rowlabel'} = {};
     #
-    if (($ENV{'form.usymb'}=~/^\_(\w+)/) && (!$ENV{'form.ufn'} || 
-                                             $ENV{'form.ufn'} eq '' || 
-                                             $ENV{'form.ufn'} eq 'default')) {
-        $ENV{'form.ufn'}='default_'.$1;
-    }
-    if (!$ENV{'form.ufn'} || $ENV{'form.ufn'} eq 'default') {
-        $ENV{'form.ufn'}='course_default_'.$sheettype;
+    my $identifier =$self->{'coursefilename'}.'_'.$stype;
+    if  ($rowlabel_cache{$identifier}) {
+        %{$self->{'rowlabel'}}=split(/___;___/,$rowlabel_cache{$identifier});
+    } else {
+        # Get the data and store it in the cache
+        # Tie hash
+        tie(%course_db,'GDBM_File',$self->{'coursefilename'}.'.db',
+            &GDBM_READER(),0640);
+        if (! tied(%course_db)) {
+            return 'Could not access course data';
+        }
+        #
+        my %assesslist = ();
+        foreach ('Feedback','Evaluation','Tutoring','Discussion') {
+            my $symb = '_'.lc($_);
+            $assesslist{$symb} = join(':',('symb',$symb,0,0,
+                                           &Apache::lonnet::escape($_)));
+        }
+        #
+        while (my ($key,$srcf) = each(%course_db)) {
+            next if ($key !~ /^src_(\d+)\.(\d+)$/);
+            my $mapid = $1;
+            my $resid = $2;
+            my $id   = $mapid.'.'.$resid;
+            if ($srcf=~/\.(problem|exam|quiz|assess|survey|form)$/) {
+                my $symb=
+                    &Apache::lonnet::declutter($course_db{'map_id_'.$mapid}).
+                        '___'.$resid.'___'.&Apache::lonnet::declutter($srcf);
+                $assesslist{$symb} ='symb:'.&Apache::lonnet::escape($symb).':'
+                    .$mapid.':'.$resid.':'.
+                        &Apache::lonnet::escape($course_db{'title_'.$id});
+            }
+        }
+        untie(%course_db);
+        # Store away the data
+        $self->{'rowlabel'} = \%assesslist;
+        $rowlabel_cache{$identifier}=join('___;___',%{$self->{'rowlabel'}});
     }
+    
+}
+
+sub get_assess_rowlabels {
+    my $self = shift;
     #
-    # Interactive loading of specific sheet?
+    my %course_db;
     #
-    if (($ENV{'form.load'}) && ($ENV{'form.loadthissheet'} ne 'Default')) {
-        $ENV{'form.ufn'}=$ENV{'form.loadthissheet'};
+    my $stype = $self->{'type'};
+    my $uname = $self->{'uname'};
+    my $udom  = $self->{'udom'};
+    my $usymb = $self->{'usymb'};
+    #
+    $self->rowlabels({});
+    my $identifier =$self->{'coursefilename'}.'_'.$stype.'_'.$usymb;
+    #
+    if  ($rowlabel_cache{$identifier}) {
+        $self->rowlabels(split(/___;___/,$rowlabel_cache{$identifier}));
+    } else {
+        # Get the data and store it in the cache
+        # Tie hash
+        tie(%course_db,'GDBM_File',$self->{'coursefilename'}.'.db',
+            &GDBM_READER(),0640);
+        if (! tied(%course_db)) {
+            return 'Could not access course data';
+        }
+        #
+        my %parameter_labels=
+            ('timestamp' => 
+                 'parameter:Timestamp of Last Transaction<br>timestamp',
+             'subnumber' =>
+                 'parameter:Number of Submissions<br>subnumber',
+             'tutornumber' =>
+                 'parameter:Number of Tutor Responses<br>tutornumber',
+             'totalpoints' =>
+                 'parameter:Total Points Granted<br>totalpoints');
+        while (my ($key,$srcf) = each(%course_db)) {
+            next if ($key !~ /^src_(\d+)\.(\d+)$/);
+            my $mapid = $1;
+            my $resid = $2;
+            my $id   = $mapid.'.'.$resid;
+            if ($srcf=~/\.(problem|exam|quiz|assess|survey|form)$/) {
+                # Loop through the metadata for this key
+                my @Metadata = split(/,/,
+                                     &Apache::lonnet::metadata($srcf,'keys'));
+                foreach my $key (@Metadata) {
+                    next if ($key !~ /^(stores|parameter)_/);
+                    my $display=
+                        &Apache::lonnet::metadata($srcf,$key.'.display');
+                    unless ($display) {
+                        $display.=
+                            &Apache::lonnet::metadata($srcf,$key.'.name');
+                    }
+                    $display.='<br>'.$key;
+                    $parameter_labels{$key}='parameter:'.$display;
+                } # end of foreach
+            }
+        }
+        untie(%course_db);
+        # Store away the results
+        $self->rowlabels(\%parameter_labels);
+        $rowlabel_cache{$identifier}=join('___;___',$self->rowlabels());
     }
-    #
-    # Determine the user name and domain for the sheet.
-    my $aname;
-    my $adom;
-    unless ($ENV{'form.uname'}) {
-        $aname=$ENV{'user.name'};
-        $adom=$ENV{'user.domain'};
+        
+}
+
+sub updatestudentassesssheet {
+    my $self = shift;
+    if ($self->{'type'} eq 'studentcalc') {
+        $self->get_student_rowlabels();
     } else {
-        $aname=$ENV{'form.uname'};
-        $adom=$ENV{'form.udom'};
+        $self->get_assess_rowlabels();
     }
-    #
-    # Open page, try to prevent browser cache.
-    #
-    $r->content_type('text/html');
-    $r->header_out('Cache-control','no-cache');
-    $r->header_out('Pragma','no-cache');
-    $r->send_http_header;
-    #
-    # Header....
-    #
-    $r->print('<html><head><title>LON-CAPA Spreadsheet</title>');
-    my $nothing = "''";
-    if ($ENV{'browser.type'} eq 'explorer') {
-        $nothing = "'javascript:void(0);'";
+    # Determine if any of the information has changed
+    my %f=$self->formulas();
+    my $changed=0;
+    $self->{'maxrow'} = 0;
+    my %existing=();
+    # Now obsolete rows
+    foreach my $cell ($self->A_column()) {
+        my $formula = $f{$cell};
+        my ($n)= ($cell =~ /A(\d+)/);
+        next if ($n eq '0');
+        $self->{'maxrow'} = $n if ($n > $self->{'maxrow'});
+        my ($usy,$ufn)=split(/__&&&\__/,$formula);
+        $existing{$usy}=1;
+        if ( ! exists($self->{'rowlabel'}->{$usy})  ||
+             ! defined($self->{'rowlabel'}->{$usy}) ||
+             ($formula =~ /^(~~~|---)/) ||
+             ($formula =~ /^\s*$/)) {
+            $f{$cell}='!!! Obsolete';
+#            $self->logthis('obsoleted row '.$n);
+            $changed=1;
+        }
     }
-
-    if ($ENV{'request.role'} !~ /^st\./) {
-        $r->print(<<ENDSCRIPT);
-<script language="JavaScript">
-
-    var editwin;
-
-    function celledit(cellname,cellformula) {
-        var edit_text = '';
-        // cellformula may contain less-than and greater-than symbols, so
-        // we need to escape them?  
-        edit_text +='<html><head><title>Cell Edit Window</title></head><body>';
-        edit_text += '<form name="editwinform">';
-        edit_text += '<center><h3>Cell '+cellname+'</h3>';
-        edit_text += '<textarea name="newformula" cols="40" rows="6"';
-        edit_text += ' wrap="off" >'+cellformula+'</textarea>';
-        edit_text += '</br>';
-        edit_text += '<input type="button" name="accept" value="Accept"';
-        edit_text += ' onClick=\\\'javascript:';
-        edit_text += 'opener.document.sheet.unewfield.value=';
-        edit_text +=     '"'+cellname+'";';
-        edit_text += 'opener.document.sheet.unewformula.value=';
-        edit_text +=     'document.editwinform.newformula.value;';
-        edit_text += 'opener.document.sheet.submit();';
-        edit_text += 'self.close()\\\' />';
-        edit_text += '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
-        edit_text += '<input type="button" name="abort" ';
-        edit_text +=     'value="Discard Changes"';
-        edit_text += ' onClick="javascript:self.close()" />';
-        edit_text += '</center></body></html>';
-
-        if (editwin != null && !(editwin.closed) ) {
-            editwin.close();
+    # New and unknown keys
+    my %keys_hates_me = $self->rowlabels();
+    foreach (keys(%keys_hates_me)) {
+        unless ($existing{$_}) {
+            $changed=1;
+            $self->{'maxrow'}++;
+            $f{'A'.$self->{'maxrow'}}=$_;
         }
-
-        editwin = window.open($nothing,'CellEditWin','height=200,width=350,scrollbars=no,resizeable=yes,alwaysRaised=yes,dependent=yes',true);
-        editwin.document.write(edit_text);
     }
+    $self->formulas(\%f) if ($changed);
+#    $self->dump_formulas_to_log();    
+}
 
-    function changesheet(cn) {
-	document.sheet.unewfield.value=cn;
-        document.sheet.unewformula.value='changesheet';
-        document.sheet.submit();
+# ------------------------------------------------ Load data for one assessment
+sub loadstudent{
+    my $self = shift;
+    my ($r,$c)=@_;
+    my %constants = ();
+    my %formulas  = $self->formulas();
+    $cachedassess = $self->{'uname'}.':'.$self->{'udom'};
+    # Get ALL the student preformance data
+    my @tmp = &Apache::lonnet::currentdump($self->{'cid'},
+                                           $self->{'udom'},
+                                           $self->{'uname'});
+    if ((scalar @tmp > 0) && ($tmp[0] !~ /^error:/)) {
+        %cachedstores = @tmp;
     }
-
-    function insertrow(cn) {
-	document.sheet.unewfield.value='insertrow';
-        document.sheet.unewformula.value=cn;
-        document.sheet.submit();
+    undef @tmp;
+    # 
+    my @assessdata=();
+    foreach my $cell ($self->A_column()) {
+        my $value = $formulas{$cell};
+        if(defined($c) && ($c->aborted())) {
+            last;
+        }
+        my ($row)=($cell=~/A(\d+)/);
+        next if (($value =~ /^[!~-]/) || ($row==0));
+        my ($usy,$ufn)=split(/__&&&\__/,$value);
+        @assessdata=$self->exportsheet($self->{'uname'},
+                                        $self->{'udom'},
+                                        'assesscalc',$usy,$ufn,$r);
+        my $index=0;
+        foreach my $col ('A','B','C','D','E','F','G','H','I','J','K','L','M',
+                         'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
+            if (defined($assessdata[$index])) {
+                if ($assessdata[$index]=~/\D/) {
+                    $constants{$col.$row}="'".$assessdata[$index]."'";
+                } else {
+                    $constants{$col.$row}=$assessdata[$index];
+                }
+                $formulas{$col.$row}='import' if ($col ne 'A');
+            }
+            $index++;
+        }
     }
+    $cachedassess='';
+    undef %cachedstores;
+    $self->formulas(\%formulas);
+    $self->constants(\%constants);
+}
 
-</script>
-ENDSCRIPT
-    }
-    $r->print('</head>'.&Apache::loncommon::bodytag('Grades Spreadsheet').
-              '<form action="'.$r->uri.'" name="sheet" method="post">');
-    $r->print(&hiddenfield('uname',$ENV{'form.uname'}).
-              &hiddenfield('udom',$ENV{'form.udom'}).
-              &hiddenfield('usymb',$ENV{'form.usymb'}).
-              &hiddenfield('unewfield','').
-              &hiddenfield('unewformula',''));
-    $r->rflush();
+# --------------------------------------------------- Load data for one student
+#
+sub loadcourse {
+    my $self = shift;
+    my ($r,$c)=@_;
     #
-    # Full recalc?
+    my %constants=();
+    my %formulas=$self->formulas();
     #
-    if ($ENV{'form.forcerecalc'}) {
-        $r->print('<h4>Completely Recalculating Sheet ...</h4>');
-        undef %spreadsheets;
-        undef %courserdatas;
+    my $total=0;
+    foreach ($self->A_column()) {
+        $total++ if ($formulas{$_} !~ /^[!~-]/);
+    }
+    my $now=0;
+    my $since=time;
+    $r->print(<<ENDPOP);
+<script>
+    popwin=open('','popwin','width=400,height=100');
+    popwin.document.writeln('<html><body bgcolor="#FFFFFF">'+
+      '<h3>Spreadsheet Calculation Progress</h3>'+
+      '<form name=popremain>'+
+      '<input type=text size=45 name=remaining value=Starting></form>'+
+      '</body></html>');
+    popwin.document.close();
+</script>
+ENDPOP
+    $r->rflush();
+    foreach ($self->A_column()) {
+        if(defined($c) && ($c->aborted())) {
+            last;
+        }
+        my ($row)=(/A(\d+)/);
+        next if (($formulas{$_}=~/^[\!\~\-]/)  || ($row==0));
+        my ($sname,$sdom) = split(':',$formulas{$_});
+        my $started = time;
+        my @studentdata=$self->exportsheet($sname,$sdom,'studentcalc',
+                                     undef,undef,$r);
         undef %userrdatas;
-        undef %defaultsheets;
-        undef %rowlabel_cache;
+        $now++;
+        $r->print('<script>popwin.document.popremain.remaining.value="'.
+                  $now.'/'.$total.': '.int((time-$since)/$now*($total-$now)).
+                  ' secs remaining '.(time-$started).' last";</script>');
+        $r->rflush(); 
+        #
+        my $index=0;
+        foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
+                 'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
+            if (defined($studentdata[$index])) {
+                my $col=$_;
+                if ($studentdata[$index]=~/\D/) {
+                    $constants{$col.$row}="'".$studentdata[$index]."'";
+                } else {
+                    $constants{$col.$row}=$studentdata[$index];
+                }
+                unless ($col eq 'A') { 
+                    $formulas{$col.$row}='import';
+                }
+            } 
+            $index++;
+        }
     }
-    # Read new sheet or modified worksheet
-    my ($sheet)=&makenewsheet($aname,$adom,$sheettype,$ENV{'form.usymb'});
-    #
-    # Check user permissions
-    if (($sheet->{'sheettype'} eq 'classcalc'       ) || 
-        ($sheet->{'uname'}     ne $ENV{'user.name'} ) ||
-        ($sheet->{'udom'}      ne $ENV{'user.domain'})) {
-        unless (&Apache::lonnet::allowed('vgr',$sheet->{'cid'})) {
-            $r->print('<h1>Access Permission Denied</h1>'.
-                      '</form></body></html>');
-            return OK;
+    $self->formulas(\%formulas);
+    $self->constants(\%constants);
+    $r->print('<script>popwin.close()</script>');
+    $r->rflush(); 
+}
+
+# ------------------------------------------------ Load data for one assessment
+#
+sub loadassessment {
+    my $self = shift;
+    my ($r,$c)=@_;
+
+    my $uhome = $self->{'uhome'};
+    my $uname = $self->{'uname'};
+    my $udom  = $self->{'udom'};
+    my $symb  = $self->{'usymb'};
+    my $cid   = $self->{'cid'};
+    my $cnum  = $self->{'cnum'};
+    my $cdom  = $self->{'cdom'};
+    my $chome = $self->{'chome'};
+    my $csec  = $self->{'csec'};
+
+    my $namespace;
+    unless ($namespace=$cid) { return ''; }
+    # Get stored values
+    my %returnhash=();
+    if ($cachedassess eq $uname.':'.$udom) {
+        #
+        # get data out of the dumped stores
+        # 
+        if (exists($cachedstores{$symb})) {
+            %returnhash = %{$cachedstores{$symb}};
+        } else {
+            %returnhash = ();
         }
+    } else {
+        #
+        # restore individual
+        #
+        %returnhash = &Apache::lonnet::restore($symb,$namespace,$udom,$uname);
     }
-    # Print out user information
-    $r->print('<h2>'.$sheet->{'coursedesc'}.'</h2>');
-    if ($sheet->{'sheettype'} ne 'classcalc') {
-        $r->print('<h2>'.&gettitle($sheet).'</h2><p>');
+    #
+    # returnhash now has all stores for this resource
+    # convert all "_" to "." to be able to use libraries, multiparts, etc
+    #
+    # This is dumb.  It is also necessary :(
+    my @oldkeys=keys %returnhash;
+    #
+    foreach my $name (@oldkeys) {
+        my $value=$returnhash{$name};
+        delete $returnhash{$name};
+        $name=~s/\_/\./g;
+        $returnhash{$name}=$value;
     }
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
-        $r->print('<b>User:</b> '.$sheet->{'uname'}.
-                  '<br /><b>Domain:</b> '.$sheet->{'udom'}.'<br />');
+    # initialize coursedata and userdata for this user
+    undef %courseopt;
+    undef %useropt;
+
+    my $userprefix=$uname.'_'.$udom.'_';
+
+    unless ($uhome eq 'no_host') { 
+        # Get coursedata
+        unless ((time-$courserdatas{$cid.'.last_cache'})<240) {
+            my %Tmp = &Apache::lonnet::dump('resourcedata',$cdom,$cnum);
+            $courserdatas{$cid}=\%Tmp;
+            $courserdatas{$cid.'.last_cache'}=time;
+        }
+        while (my ($name,$value) = each(%{$courserdatas{$cid}})) {
+            $courseopt{$userprefix.$name}=$value;
+        }
+        # Get userdata (if present)
+        unless ((time-$userrdatas{$uname.'@'.$udom.'.last_cache'})<240) {
+            my %Tmp = &Apache::lonnet::dump('resourcedata',$udom,$uname);
+            $userrdatas{$cid} = \%Tmp;
+            # Most of the time the user does not have a 'resourcedata.db' 
+            # file.  We need to cache that we got nothing instead of bothering
+            # with requesting it every time.
+            $userrdatas{$uname.'@'.$udom.'.last_cache'}=time;
+        }
+        while (my ($name,$value) = each(%{$userrdatas{$cid}})) {
+            $useropt{$userprefix.$name}=$value;
+        }
     }
-    if ($sheet->{'sheettype'} eq 'studentcalc' || 
-        $sheet->{'sheettype'} eq 'assesscalc') {
-        $r->print('<b>Section/Group:</b>'.$sheet->{'csec'}.'</p>');
+    # now courseopt, useropt initialized for this user and course
+    # (used by parmval)
+    #
+    # Load keys for this assessment only
+    #
+    my %thisassess=();
+    my ($symap,$syid,$srcf)=split(/\_\_\_/,$symb);
+    foreach (split(/\,/,&Apache::lonnet::metadata($srcf,'keys'))) {
+        $thisassess{$_}=1;
     } 
     #
-    # If a new formula had been entered, go from work copy
-    if ($ENV{'form.unewfield'}) {
-        $r->print('<h2>Modified Workcopy</h2>');
-        #$ENV{'form.unewformula'}=~s/\'/\"/g;
-        $r->print('<p>Cell '.$ENV{'form.unewfield'}.' = <pre>');
-        $r->print(&HTML::Entities::encode($ENV{'form.unewformula'}).
-                  '</pre></p>');
-        $sheet->{'filename'} = $ENV{'form.ufn'};
-        &tmpread($sheet,$ENV{'form.unewfield'},$ENV{'form.unewformula'});
-    } elsif ($ENV{'form.saveas'}) {
-        $sheet->{'filename'} = $ENV{'form.ufn'};
-        &tmpread($sheet);
-    } else {
-        &readsheet($sheet,$ENV{'form.ufn'});
+    # Load parameters
+    #
+    my %c=();
+    if (tie(%parmhash,'GDBM_File',
+            $self->{'coursefilename'}.'_parms.db',&GDBM_READER(),0640)) {
+        my %f=$self->formulas();
+        foreach my $cell ($self->A_column())  {
+            my $formula = $self->formula($cell);
+            next if ($formula =~/^[\!\~\-]/);
+            if ($formula =~ /^parameter/) {
+                if (defined($thisassess{$formula})) {
+                    my $val   = &parmval($formula,$symb,$uname,$udom,$csec);
+                    $c{$cell}    = $val;
+                    $c{$formula} = $val;
+                }
+            } else {
+                my $ckey=$formula;
+                $formula=~s/^stores\_/resource\./;
+                $formula=~s/\_/\./g;
+                $c{$cell}=$returnhash{$formula};
+                $c{$ckey}=$returnhash{$formula};
+            }
+        }
+        untie(%parmhash);
     }
-    # Additional options
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
-        $r->print('<p><font size=+2>'.
-                  '<a href="/adm/studentcalc?'.
-                  'uname='.$sheet->{'uname'}.
-                  '&udom='.$sheet->{'udom'}.'">'.
-                  'Level up: Student Sheet</a></font></p>');
+    $self->constants(\%c);
+}
+
+
+# =============================================== Update information in a sheet
+#
+# Add new users or assessments, etc.
+#
+sub updatesheet {
+    my $self = shift;
+    if ($self->{'type'} eq 'classcalc') {
+        return $self->updateclasssheet();
+    } else {
+        return $self->updatestudentassesssheet();
     }
-    if (($sheet->{'sheettype'} eq 'studentcalc') && 
-        (&Apache::lonnet::allowed('vgr',$sheet->{'cid'}))) {
-        $r->print ('<p><font size=+2><a href="/adm/classcalc">'.
-                   'Level up: Course Sheet</a></font></p>');
+}
+
+# =================================================== Load the rows for a sheet
+#
+# Import the data for rows
+#
+sub loadrows {
+    my $self = shift;
+    my ($r)=@_;
+    my $c = $r->connection;
+    if ($self->{'type'} eq 'classcalc') {
+        $self->loadcourse($r,$c);
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        $self->loadstudent($r,$c);
+    } else {
+        $self->loadassessment($r,$c);
     }
-    # Recalc button
-    $r->print('<br />'.
-              '<input type="submit" name="forcerecalc" '.
-              'value="Completely Recalculate Sheet"></p>');
-    # Save dialog
-    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
-        my $fname=$ENV{'form.ufn'};
-        $fname=~s/\_[^\_]+$//;
-        if ($fname eq 'default') { $fname='course_default'; }
-        $r->print('<input type=submit name=saveas value="Save as ...">'.
-                  '<input type=text size=20 name=newfn value="'.$fname.'">'.
-                  'make default: <input type=checkbox name="makedefufn"><p>');
+}
+
+# ============================================================== Export handler
+# exportsheet
+# returns the export row for a spreadsheet.
+#
+sub exportsheet {
+    my $self = shift;
+    my ($uname,$udom,$stype,$usymb,$fn,$r)=@_;
+    my $flag = 0;
+    $uname = $uname || $self->{'uname'};
+    $udom  = $udom  || $self->{'udom'};
+    $stype = $stype || $self->{'type'};
+    my @exportarr=();
+    # This handles the assessment sheets for '_feedback', etc
+    if (defined($usymb) && ($usymb=~/^\_(\w+)/) && 
+        (!defined($fn) || $fn eq '')) {
+        $fn='default_'.$1;
     }
-    $r->print(&hiddenfield('ufn',$sheet->{'filename'}));
-    # Load dialog
-    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
-        $r->print('<p><input type=submit name=load value="Load ...">'.
-                  '<select name="loadthissheet">'.
-                  '<option name="default">Default</option>');
-        foreach (&othersheets($sheet)) {
-            $r->print('<option name="'.$_.'"');
-            if ($ENV{'form.ufn'} eq $_) {
-                $r->print(' selected');
+    #
+    # Check if cached
+    #
+    my $key=$uname.':'.$udom.':'.$stype.':'.$usymb;
+    my $found='';
+    if ($Apache::lonspreadsheet::oldsheets{$key}) {
+        foreach (split(/___&\___/,$Apache::lonspreadsheet::oldsheets{$key})) {
+            my ($name,$value)=split(/___=___/,$_);
+            if ($name eq $fn) {
+                $found=$value;
             }
-            $r->print('>'.$_.'</option>');
-        } 
-        $r->print('</select><p>');
-        if ($sheet->{'sheettype'} eq 'studentcalc') {
-            &setothersheets($sheet,
-                            &othersheets($sheet,'assesscalc'));
+        }
+    }
+    unless ($found) {
+        &cachedssheets($self,$uname,$udom);
+        if ($Apache::lonspreadsheet::oldsheets{$key}) {
+            foreach (split(/___&\___/,$Apache::lonspreadsheet::oldsheets{$key})) {
+                my ($name,$value)=split(/___=___/,$_);
+                if ($name eq $fn) {
+                    $found=$value;
+                }
+            } 
         }
     }
     #
-    # Set up caching mechanisms
+    # Check if still valid
     #
-    &load_spreadsheet_expirationdates();
-    # Clear out old caches if we have not seen this class before.
-    if (exists($oldsheets{'course'}) &&
-        $oldsheets{'course'} ne $sheet->{'cid'}) {
-        undef %oldsheets;
-        undef %loadedcaches;
+    if ($found) {
+        if (&forcedrecalc($uname,$udom,$stype,$usymb)) {
+            $found='';
+        }
     }
-    $oldsheets{'course'} = $sheet->{'cid'};
-    #
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-        $r->print("Loading previously calculated student sheets ...\n");
-        $r->rflush();
-        &cachedcsheets();
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
-        $r->print("Loading previously calculated assessment sheets ...\n");
-        $r->rflush();
-        &cachedssheets($sheet);
+    if ($found) {
+        #
+        # Return what was cached
+        #
+        @exportarr=split(/___;___/,$found);
+        return @exportarr;
     }
-    # Update sheet, load rows
-    $r->print("Loaded sheet(s), updating rows ...<br>\n");
-    $r->rflush();
     #
-    &updatesheet($sheet);
-    $r->print("Updated rows, loading row data ...\n");
-    $r->rflush();
+    # Not cached
     #
-    &loadrows($sheet,$r);
-    $r->print("Loaded row data, calculating sheet ...<br>\n");
-    $r->rflush();
+    my $newsheet = Apache::lonspreadsheet::Spreadsheet->new($uname,$udom,
+                                                         $stype,$usymb);
+    $newsheet->readsheet($fn);
+    $newsheet->updatesheet();
+    $newsheet->loadrows($r);
+    $newsheet->calcsheet(); 
+    @exportarr=$newsheet->exportdata();
+    ##
+    ## Store now
+    ##
     #
-    my $calcoutput=&calcsheet($sheet);
-    $r->print('<h3><font color=red>'.$calcoutput.'</h3></font>');
-    # See if something to save
-    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
-        my $fname='';
-        if ($ENV{'form.saveas'} && ($fname=$ENV{'form.newfn'})) {
-            $fname=~s/\W/\_/g;
-            if ($fname eq 'default') { $fname='course_default'; }
-            $fname.='_'.$sheet->{'sheettype'};
-            $sheet->{'filename'} = $fname;
-            $ENV{'form.ufn'}=$fname;
-            $r->print('<p>Saving spreadsheet: '.
-                      &writesheet($sheet,$ENV{'form.makedefufn'}).
-                      '<p>');
-        }
-    }
+    # load in the old value
     #
-    # Write the modified worksheet
-    $r->print('<b>Current sheet:</b> '.$sheet->{'filename'}.'</p>');
-    &tmpwrite($sheet);
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
-        $r->print('<p>Show rows with empty A column: ');
+    my %currentlystored=();
+    if ($stype eq 'studentcalc') {
+        my @tmp = &Apache::lonnet::get('nohist_calculatedsheets',
+                                       [$key],
+                                       $self->{'cdom'},$self->{'cnum'});
+        if ($tmp[0]!~/^error/) {
+            # We only got one key, so we will access it directly.
+            foreach (split('___&___',$tmp[1])) {
+                my ($key,$value) = split('___=___',$_);
+                $key = '' if (! defined($key));
+                $currentlystored{$key} = $value;
+            }
+        }
     } else {
-        $r->print('<p>Show empty rows: ');
+        my @tmp = &Apache::lonnet::get('nohist_calculatedsheets_'.
+                                       $self->{'cid'},[$key],
+                                       $self->{'udom'},$self->{'uname'});
+        if ($tmp[0]!~/^error/) {
+            # We only got one key, so we will access it directly.
+            foreach (split('___&___',$tmp[1])) {
+                my ($key,$value) = split('___=___',$_);
+                $key = '' if (! defined($key));
+                $currentlystored{$key} = $value;
+            }
+        }
     }
     #
-    $r->print(&hiddenfield('userselhidden','true').
-              '<input type="checkbox" name="showall" onClick="submit()"');
+    # Add the new line
     #
-    if ($ENV{'form.showall'}) { 
-        $r->print(' checked'); 
-    } else {
-        unless ($ENV{'form.userselhidden'}) {
-            unless 
-                ($ENV{'course.'.$sheet->{'cid'}.'.hideemptyrows'} eq 'yes') {
-                    $r->print(' checked');
-                    $ENV{'form.showall'}=1;
-                }
-        }
-    }
-    $r->print('>');
+    $currentlystored{$fn}=join('___;___',@exportarr);
     #
-    # output format select box 
-    $r->print(' Output as <select name="output" size="1" onChange="submit()">'.
-              "\n");
-    foreach my $mode (qw/HTML CSV Excel/) {
-        $r->print('<option value="'.$mode.'"');
-        if ($ENV{'form.output'} eq $mode) {
-            $r->print(' selected ');
-        } 
-        $r->print('>'.$mode.'</option>'."\n");
-    }
-#
-#    Mulit-sheet excel takes too long and does not work at all for large
-#    classes.  Future inclusion of this option may be possible with the
-#    Spreadsheet::WriteExcel::Big and speed improvements.
-#
-#    if ($sheet->{'sheettype'} eq 'classcalc') {
-#        $r->print('<option value="recursive excel"');
-#        if ($ENV{'form.output'} eq 'recursive excel') {
-#            $r->print(' selected ');
-#        } 
-#        $r->print(">Multi-Sheet Excel</option>\n");
-#    }
-    $r->print("</select>\n");
+    # Stick everything back together
     #
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-        $r->print('&nbsp;Student Status: '.
-                  &Apache::lonhtmlcommon::StatusOptions
-                  ($ENV{'form.Status'},'sheet'));
+    my $newstore='';
+    foreach (keys(%currentlystored)) {
+        if ($newstore) { $newstore.='___&___'; }
+        $newstore.=$_.'___=___'.$currentlystored{$_};
     }
+    my $now=time;
     #
-    # Buttons to insert rows
-#    $r->print(<<ENDINSERTBUTTONS);
-#<br>
-#<input type='button' onClick='insertrow("top");' 
-#value='Insert Row Top'>
-#<input type='button' onClick='insertrow("bottom");' 
-#value='Insert Row Bottom'><br>
-#ENDINSERTBUTTONS
-    # Print out sheet
-    &outsheet($sheet,$r);
-    $r->print('</form></body></html>');
-    #  Done
-    return OK;
+    # Store away the new value
+    #
+    my $timekey = $key.'.time';
+    if ($stype eq 'studentcalc') {
+        my $result = &Apache::lonnet::put('nohist_calculatedsheets',
+                                          { $key     => $newstore,
+                                            $timekey => $now },
+                                          $self->{'cdom'},
+                                          $self->{'cnum'});
+    } else {
+        my $result = &Apache::lonnet::put('nohist_calculatedsheets_'.$self->{'cid'},
+                                          { $key     => $newstore,
+                                            $timekey => $now },
+                                          $self->{'udom'},
+                                          $self->{'uname'});
+    }
+    return @exportarr;
 }
 
 1;
+
 __END__
 
 

--matthew1043857568--