--- loncom/interface/Attic/lonspreadsheet.pm	2003/01/15 19:34:03	1.163
+++ loncom/interface/Attic/lonspreadsheet.pm	2003/01/29 16:26:08	1.164
@@ -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
 #
@@ -50,12 +50,434 @@ built-in functions.
 
 =cut
 
+
 package Apache::lonspreadsheet;
             
 use strict;
 use Apache::Constants qw(:common :http);
 use Apache::lonnet;
 use Apache::lonhtmlcommon;
+use HTML::Entities();
+
+# --------------------------------------------------------- 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.'">';
+}
+
+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;
+
+# ================================================================ 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
+    #
+    # 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') {
+        $nothing = "'javascript:void(0);'";
+    }
+
+    if ($ENV{'request.role'} !~ /^st\./) {
+        $r->print(<<ENDSCRIPT);
+<script language="JavaScript">
+
+    var editwin;
+
+    function celledit(cellname,cellformula) {
+        var edit_text = '';
+        // cellformula may contain less-than and greater-than symbols, so
+        // we need to escape them?  
+        edit_text +='<html><head><title>Cell Edit Window</title></head><body>';
+        edit_text += '<form name="editwinform">';
+        edit_text += '<center><h3>Cell '+cellname+'</h3>';
+        edit_text += '<textarea name="newformula" cols="40" rows="6"';
+        edit_text += ' wrap="off" >'+cellformula+'</textarea>';
+        edit_text += '</br>';
+        edit_text += '<input type="button" name="accept" value="Accept"';
+        edit_text += ' onClick=\\\'javascript:';
+        edit_text += 'opener.document.sheet.unewfield.value=';
+        edit_text +=     '"'+cellname+'";';
+        edit_text += 'opener.document.sheet.unewformula.value=';
+        edit_text +=     'document.editwinform.newformula.value;';
+        edit_text += 'opener.document.sheet.submit();';
+        edit_text += 'self.close()\\\' />';
+        edit_text += '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
+        edit_text += '<input type="button" name="abort" ';
+        edit_text +=     'value="Discard Changes"';
+        edit_text += ' onClick="javascript:self.close()" />';
+        edit_text += '</center></body></html>';
+
+        if (editwin != null && !(editwin.closed) ) {
+            editwin.close();
+        }
+
+        editwin = window.open($nothing,'CellEditWin','height=200,width=350,scrollbars=no,resizeable=yes,alwaysRaised=yes,dependent=yes',true);
+        editwin.document.write(edit_text);
+    }
+
+    function changesheet(cn) {
+	document.sheet.unewfield.value=cn;
+        document.sheet.unewformula.value='changesheet';
+        document.sheet.submit();
+    }
+
+    function insertrow(cn) {
+	document.sheet.unewfield.value='insertrow';
+        document.sheet.unewformula.value=cn;
+        document.sheet.submit();
+    }
+
+</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();
+    #
+    # Full recalc?
+    #
+    # 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();
+    }
+    #
+    # 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;
+        }
+    }
+    # Print out user information
+    $r->print('<h2>'.$sheet->{'coursedesc'}.'</h2>');
+    if ($sheet->{'type'} ne 'classcalc') {
+        $r->print('<h2>'.$sheet->gettitle().'</h2><p>');
+    }
+    if ($sheet->{'type'} eq 'assesscalc') {
+        $r->print('<b>User:</b> '.$sheet->{'uname'}.
+                  '<br /><b>Domain:</b> '.$sheet->{'udom'}.'<br />');
+    }
+    if ($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 {
+        $sheet->readsheet($ENV{'form.ufn'});
+    }
+    # Additional options
+    if ($sheet->{'type'} eq 'assesscalc') {
+        $r->print('<p><font size=+2>'.
+                  '<a href="/adm/studentcalc?'.
+                  'uname='.$sheet->{'uname'}.
+                  '&udom='.$sheet->{'udom'}.'">'.
+                  'Level up: Student Sheet</a></font></p>');
+    }
+    if (($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>');
+    }
+    # 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>');
+    }
+    $r->print(&hiddenfield('ufn',$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'));
+        }
+    }
+    #
+    # 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;
+    }
+    $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();
+    }
+    # 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>');
+        }
+    }
+    #
+    # 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 {
+        $r->print('<p>Show empty rows: ');
+    }
+    #
+    $r->print(&hiddenfield('userselhidden','true').
+              '<input type="checkbox" name="showall" onClick="submit()"');
+    #
+    if ($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;
+                }
+        }
+    }
+    $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;
+
+#############################################################
+#############################################################
+#############################################################
+
+package Apache::lonspreadsheet::Spreadsheet;
+            
+use strict;
+use Apache::Constants qw(:common :http);
+use Apache::lonnet;
 use Apache::loncoursedata;
 use Apache::File();
 use Safe;
@@ -65,6 +487,13 @@ 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;
 
 #
 # Caches for coursewide information 
@@ -74,58 +503,299 @@ my %Section;
 #
 # Caches for previously calculated spreadsheets
 #
-
-my %oldsheets;
-my %loadedcaches;
 my %expiredates;
 
 #
 # Cache for stores of an individual user
 #
-
 my $cachedassess;
 my %cachedstores;
 
 #
-# These cache hashes need to be independent of user, resource and course
-# (user and course can/should be in the keys)
+# Some hashes for stats on timing and performance
 #
+my %starttimes;
+my %usedtimes;
+my %numbertimes;
+
+#
+# Directories
+#
+my $includedir;
+my $tmpdir;
+
+sub includedir {
+    my $self = shift;
+    $includedir = shift;
+}
+
+sub tmpdir {
+    my $self = shift;
+    $tmpdir = shift;
+}
 
 my %spreadsheets;
+my %loadedcaches;
 my %courserdatas;
 my %userrdatas;
 my %defaultsheets;
 my %rowlabel_cache;
+my %oldsheets;
+
+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 $formulas;
+}
 
 #
-# These global hashes are dependent on user, course and resource, 
-# and need to be initialized every time when a sheet is calculated
+# Load previously cached student spreadsheets for this course
 #
-my %courseopt;
-my %useropt;
-my %parmhash;
+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;
+    }
+}
 
+# ===================================================== Calculated sheets cache
 #
-# Some hashes for stats on timing and performance
+# 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;
+        }
+    }
+}
 
-my %starttimes;
-my %usedtimes;
-my %numbertimes;
+#
+# 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;
+        }
+    }    
+}
 
-# Stuff that only the screen handler can know
+# ======================================================= Forced recalculation?
+sub checkthis {
+    my ($keyname,$time)=@_;
+    if (! exists($expiredates{$keyname})) {
+        return 0;
+    } else {
+        return ($time<$expiredates{$keyname});
+    }
+}
 
-my $includedir;
-my $tmpdir;
+sub forcedrecalc {
+    my ($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; 
+}
+
+
+##################################################
+##################################################
+
+=pod
+
+=item &parmval()
+
+Determine the value of a parameter.
+
+Inputs: $what, the parameter needed, $symb, $uname, $udom, $csec 
+
+Returns: The value of a parameter, or '' if none.
+
+This function cascades through the possible levels searching for a value for
+a parameter.  The levels are checked in the following order:
+user, course (at section level and course level), map, and lonnet::metadata.
+This function uses %parmhash, which must be tied prior to calling it.
+This function also requires %courseopt and %useropt to be initialized for
+this user and course.
+
+=cut
+
+##################################################
+##################################################
+sub parmval {
+    my ($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}));
+    }
+    # 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 $courseopt{$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');
+}
 
-# =============================================================================
-# ===================================== Implements an instance of a spreadsheet
+#
+# 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;
+}
 
 ##
 ## mask - used to reside in the safe space.  
 ##
+{
+
+my %memoizer;
+
 sub mask {
     my ($lower,$upper)=@_;
+    my $key = $lower.'_'.$upper;
+    if (exists($memoizer{$key})) {
+        return $memoizer{$key};
+    }
     $upper = $lower if (! defined($upper));
     #
     my ($la,$ld) = ($lower=~/([A-Za-z]|\*)(\d+|\*)/);
@@ -195,81 +865,16 @@ sub mask {
            }
        }
     }
-    return '^'.$alpha.$num."\$";
+    my $expression ='^'.$alpha.$num."\$";
+    $memoizer{$key} = $expression;
+    return $expression;
 }
 
-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 = '';
-
+}
 
+sub add_hash_to_safe {
+    my $self = shift;
+    my $code = <<'END';
 #-------------------------------------------------------
 
 =item UWCALC(hashname,modules,units,date) 
@@ -536,6 +1141,75 @@ sub HASH {
     }
     return $Values[-1];
 }
+END
+    $self->{'safe'}->reval($code);
+    return;
+}
+
+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 = '';
 
 #-------------------------------------------------------
 
@@ -547,14 +1221,14 @@ returns the number of items in the range
 
 #-------------------------------------------------------
 sub NUM {
-    my $mask=mask(@_);
+    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 $mask=&mask($lower,$upper);
     my $num=0;
     foreach (grep /$mask/,keys(%sheet_values)) {
         if (($sheet_values{$_}>=$low) && ($sheet_values{$_}<=$high)) {
@@ -575,7 +1249,7 @@ returns the sum of items in the range.
 
 #-------------------------------------------------------
 sub SUM {
-    my $mask=mask(@_);
+    my $mask=&mask(@_);
     my $sum=0;
     foreach (grep /$mask/,keys(%sheet_values)) {
         $sum+=$sheet_values{$_};
@@ -593,7 +1267,8 @@ compute the average of the items in the
 
 #-------------------------------------------------------
 sub MEAN {
-    my $mask=mask(@_);
+    my $mask=&mask(@_);
+#    $errorlog.='(mask = '.$mask.' )';
     my $sum=0; 
     my $num=0;
     foreach (grep /$mask/,keys(%sheet_values)) {
@@ -617,7 +1292,8 @@ compute the standard deviation of the it
 
 #-------------------------------------------------------
 sub STDDEV {
-    my $mask=mask(@_);
+    my $mask=&mask(@_);
+#    $errorlog.='(mask = '.$mask.' )';
     my $sum=0; my $num=0;
     foreach (grep /$mask/,keys(%sheet_values)) {
         $sum+=$sheet_values{$_};
@@ -642,7 +1318,7 @@ compute the product of the items in the
 
 #-------------------------------------------------------
 sub PROD {
-    my $mask=mask(@_);
+    my $mask=&mask(@_);
     my $prod=1;
     foreach (grep /$mask/,keys(%sheet_values)) {
         $prod*=$sheet_values{$_};
@@ -660,7 +1336,7 @@ compute the maximum of the items in the
 
 #-------------------------------------------------------
 sub MAX {
-    my $mask=mask(@_);
+    my $mask=&mask(@_);
     my $max='-';
     foreach (grep /$mask/,keys(%sheet_values)) {
         unless ($max) { $max=$sheet_values{$_}; }
@@ -679,7 +1355,7 @@ compute the minimum of the items in the
 
 #-------------------------------------------------------
 sub MIN {
-    my $mask=mask(@_);
+    my $mask=&mask(@_);
     my $min='-';
     foreach (grep /$mask/,keys(%sheet_values)) {
         unless ($max) { $max=$sheet_values{$_}; }
@@ -702,7 +1378,7 @@ compute the sum of the largest 'num' ite
 #-------------------------------------------------------
 sub SUMMAX {
     my ($num,$lower,$upper)=@_;
-    my $mask=mask($lower,$upper);
+    my $mask=&mask($lower,$upper);
     my @inside=();
     foreach (grep /$mask/,keys(%sheet_values)) {
 	push (@inside,$sheet_values{$_});
@@ -727,7 +1403,7 @@ compute the sum of the smallest 'num' it
 #-------------------------------------------------------
 sub SUMMIN {
     my ($num,$lower,$upper)=@_;
-    my $mask=mask($lower,$upper);
+    my $mask=&mask($lower,$upper);
     my @inside=();
     foreach (grep /$mask/,keys(%sheet_values)) {
 	$inside[$#inside+1]=$sheet_values{$_};
@@ -786,20 +1462,58 @@ sub MAXPARM {
     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; 
+            }
+        }
+        $depth++;
+        if ($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;
+}
+
+
+#
+# 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=();
-        undef %values;
-	foreach ( @vars ) {
-            my $varname=$_;
+	foreach my $varname ( @vars ) {
             if ($varname=~/\D/) {
                $formula=~s/$varname/'$c{\''.$varname.'\'}'/ge;
                $varname=~s/$var/\(\\w\+\)/g;
-	       foreach (keys(%c)) {
+	       foreach (keys(%{$self->{'constants'}})) {
 		  if ($_=~/$varname/) {
 		      $values{$1}=1;
                   }
@@ -829,18 +1543,21 @@ sub expandnamed {
         my @matches = ();
         $#matches = -1;
         study $expression;
-        foreach $parameter (keys(%c)) {
+        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{\''.$_.'\'}';
                 }
             }
@@ -853,27 +1570,29 @@ sub expandnamed {
     }
 }
 
+#
+# sett used to reside in the safe space
+#
 sub sett {
-    %t=();
+    my $self = shift;
+    my %t=();
     my $pattern='';
-    if ($sheettype eq 'assesscalc') {
+    if ($self->{'type'} eq 'assesscalc') {
 	$pattern='A';
     } else {
         $pattern='[A-Z]';
     }
     # Deal with the template row
-    foreach (keys(%f)) {
-	next if ($_!~/template\_(\w)/);
-        my $col=$1;
+    foreach ($self->template_cells()) {
+        my ($col) = ($_=~/template\_(\w)/);
         next if ($col=~/^$pattern/);
-        foreach (keys(%f)) {
-            next if ($_!~/A(\d+)/);
-            my $trow=$1;
+        foreach ($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}=$f{'template_'.$col};
+            $t{$lb}=$self->formula('template_'.$col);
             # Replace '#' with the row number
             $t{$lb}=~s/\#/$trow/g;
             # Replace '....' with ','
@@ -881,110 +1600,93 @@ sub sett {
             # 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;
+            $t{$lb}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.$self->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($2)/ge;
+    foreach ($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($2)/ge;
         }
     }
     # For inserted lines, [B-Z] is also valid
-    unless ($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($2)/ge;
-               }
-           }
-       }
+    if ($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.
-    $t{'A0'}=$f{'A0'};
+    $t{'A0'}=$self->formula('A0');
     $t{'A0'}=~s/\.\.+/\,/g;
     $t{'A0'}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$sheet_values\{\'$2\'\}/g;
-    $t{'A0'}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.&expandnamed($2)/ge;
-}
-
-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 '';
+    $t{'A0'}=~s/(^|[^\"\'])\[([^\]]+)\]/$1.$self->expandnamed($2)/ge;
+    # Put %t into the safe space
+    %{$self->{'safe'}->varglob('t')}=%t;
 }
 
-# ------------------------------------------- End of "Inside of the safe space"
-ENDDEFS
-    $safeeval->reval($code);
-    return $safeeval;
-}
 
+###########################################
+###          Row output routines        ###
+###########################################
 #
-# 
+# get_row: Produce output row n from sheet by calling the appropriate routine
 #
+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 {
+        ($rowlabel,@rowdata) = $self->outrow($n);
+    }
+    return ($rowlabel,@rowdata);
+}
+
 sub templaterow {
-    my $sheet = shift;
+    my $self = 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') {
+    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 => $sheet->{'f'}->{'template_'.$_},
-                     value   => $sheet->{'f'}->{'template_'.$_} });
+                     formula => $self->formula('template_'.$n),
+                     value   => $self->value('template_'.$n) });
     }
     return ($rowlabel,@cols);
 }
 
 sub outrowassess {
+    my $self = shift;
     # $n is the current row number
-    my ($sheet,$n) = @_;
+    my ($n) = @_;
     my @cols=();
     my $rowlabel='';
     if ($n) {
-        my ($usy,$ufn)=split(/__&&&\__/,$sheet->{'f'}->{'A'.$n});
-        if (exists($sheet->{'rowlabel'}->{$usy})) {
+        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 = $sheet->{'rowlabel'}->{$usy}.':'.
+            $rowlabel = $self->{'rowlabel'}->{$usy}.':'.
                 &Apache::lonnet::escape($ufn);
         } else { 
             $rowlabel = '';
@@ -999,20 +1701,21 @@ sub outrowassess {
 	     '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}});
+                     formula => $self->formula($_.$n),
+                     value   => $self->value($_.$n)});
     }
     return ($rowlabel,@cols);
 }
 
 sub outrow {
-    my ($sheet,$n)=@_;
+    my $self = shift;
+    my ($n)=@_;
     my @cols=();
     my $rowlabel;
     if ($n) {
-        $rowlabel = $sheet->{'rowlabel'}->{$sheet->{'f'}->{'A'.$n}};
+        $rowlabel = $self->{'rowlabel'}->{$self->formula('A'.$n)};
     } else {
-        if ($sheet->{'sheettype'} eq 'classcalc') {
+        if ($self->{'type'} eq 'classcalc') {
             $rowlabel = 'Summary</td><td>0';
         } else {
             $rowlabel = 'Export</td><td>0';
@@ -1023,94 +1726,266 @@ sub outrow {
 	     '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}});
+                     formula => $self->formula($_.$n),
+                     value   => $self->value($_.$n)});
     }
     return ($rowlabel,@cols);
 }
 
-# ------------------------------------------------ Add or change formula values
-sub setformulas {
-    my ($sheet)=shift;
-    %{$sheet->{'safe'}->varglob('f')}=%{$sheet->{'f'}};
+########################################################
+####         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;
 }
 
-# ------------------------------------------------ Add or change formula values
-sub setconstants {
-    my ($sheet)=shift;
+##
+## 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 (! ref($constants)) {
-        my %tmp = @_;
-        $constants = \%tmp;
+    if (defined($constants)) {
+        if (! ref($constants)) {
+            my %tmp = @_;
+            $constants = \%tmp;
+        }
+        $self->{'constants'} = $constants;
+        return;
+    } else {
+        return %{$self->{'constants'}};
+    }
+}
+    
+##
+## 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'} = [];
+        $self->{'template_cells'} = [];
+        return;
+    } else {
+        return %{$self->{'formulas'}};
     }
-    $sheet->{'constants'} = $constants;
-    return %{$sheet->{'safe'}->varglob('c')}=%{$sheet->{'constants'}};
 }
 
-# --------------------------------------------- Set names of other spreadsheets
-sub setothersheets {
-    my $sheet = shift;
-    my @othersheets = @_;
-    $sheet->{'othersheets'} = \@othersheets;
-    @{$sheet->{'safe'}->varglob('os')}=@othersheets;
-    return;
+##
+## 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'}});
 }
 
-# ------------------------------------------------ Add or change formula values
-sub setrowlabels {
-    my $sheet=shift;
-    my ($rowlabel) = @_;
-    if (! ref($rowlabel)) {
-        my %tmp = @_;
-        $rowlabel = \%tmp;
+##
+## 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};
     }
-    $sheet->{'rowlabel'}=$rowlabel;
+    return '';
 }
 
-# ------------------------------------------------------- Calculate spreadsheet
-sub calcsheet {
-    my $sheet=shift;
-    my $result =  $sheet->{'safe'}->reval('&calc();');
-    %{$sheet->{'values'}} = %{$sheet->{'safe'}->varglob('sheet_values')};
-    return $result;
+##
+## 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);
 }
 
-# ---------------------------------------------------------------- Get formulas
-# Return a copy of the formulas
-sub getformulas {
-    my $sheet = shift;
-    return %{$sheet->{'safe'}->varglob('f')};
+##
+## 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("--------------------------------------------------------");}
+
+##
+## 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 '';
 }
 
-sub geterrorlog {
-    my $sheet = shift;
-    return ${$sheet->{'safe'}->varglob('errorlog')};    
+##
+## 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;
+}
+
+##
+## 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'}};
+}
+
+##
+## 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'}};
+}
+
+##
+## 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'}));
+    }
 }
 
+##
+## gettitle: returns a title for the spreadsheet.
+##
 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'};
+    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 $title;
         }
-        return if (! defined($sheet->{'mapid'}) || 
-                   $sheet->{'mapid'} !~ /^\d+$/);
-        my $mapid = $sheet->{'mapid'};
-        return if (! defined($sheet->{'resid'}) || 
-                   $sheet->{'resid'} !~ /^\d+$/);
-        my $resid = $sheet->{'resid'};
+        return if (! defined($self->{'mapid'}) || 
+                   $self->{'mapid'} !~ /^\d+$/);
+        my $mapid = $self->{'mapid'};
+        return if (! defined($self->{'resid'}) || 
+                   $self->{'resid'} !~ /^\d+$/);
+        my $resid = $self->{'resid'};
         my %course_db;
-        tie(%course_db,'GDBM_File',$sheet->{'coursefilename'}.'.db',
+        tie(%course_db,'GDBM_File',$self->{'coursefilename'}.'.db',
             &GDBM_READER(),0640);
         return if (! tied(%course_db));
         my $key = 'title_'.$mapid.'.'.$resid;
@@ -1118,94 +1993,68 @@ sub gettitle {
         if (exists($course_db{$key})) {
             $title = $course_db{$key};
         } else {
-            $title = $sheet->{'usymb'};
+            $title = $self->{'usymb'};
         }
         untie (%course_db);
         return $title;
     }
 }
 
-# ----------------------------------------------------- Get value of $f{'A'.$n}
-sub getfa {
-    my $sheet = shift;
-    my ($n)=@_;
-    return $sheet->{'safe'}->reval('$f{"A'.$n.'"}');
-}
-
-# ------------------------------------------------------------- Export of A-row
+#
+# Export of A-row
+#
 sub exportdata {
-    my $sheet=shift;
+    my $self=shift;
     my @exportarray=();
     foreach ('A','B','C','D','E','F','G','H','I','J','K','L','M',
 	     'N','O','P','Q','R','S','T','U','V','W','X','Y','Z') {
-        if (exists($sheet->{'values'}->{$_.'0'})) {
-            push(@exportarray,$sheet->{'values'}->{$_.'0'});
-        } else {
-            push(@exportarray,'');
-        }
+        push(@exportarray,$self->value($_.'0'));
     } 
     return @exportarray;
 }
 
-
-
+##
+## update_student_sheet: experimental function
+##
 sub update_student_sheet{
-    my ($sheet,$r,$c) = @_;
+    my $self = shift;
+    my ($r,$c) = @_;
     # Load in the studentcalc sheet
-    &readsheet($sheet,'default_studentcalc');
+    $self->readsheet('default_studentcalc');
     # Determine the structure (contained assessments, etc) of the sheet
-    &updatesheet($sheet);
+    $self->updatesheet();
     # Load in the cached sheets for this student
-    &cachedssheets($sheet);
+    $self->cachedssheets();
     # Load in the (possibly cached) data from the assessment sheets        
-    &loadstudent($sheet,$r,$c);
+    $self->loadstudent($r,$c);
     # Compute the sheet
-    &calcsheet($sheet);
+    $self->calcsheet();
 }
 
-# ========================================================== End of Spreadsheet
-# =============================================================================
 #
-# Procedures for spreadsheet output
+# sort_indicies: returns an ordered list of the rows of the spreadsheet
 #
-# --------------------------------------------- Produce output row n from sheet
-
-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);
-    } else {
-        ($rowlabel,@rowdata) = &outrow($sheet,$n);
-    }
-    return ($rowlabel,@rowdata);
-}
-
-########################################################################
-########################################################################
 sub sort_indicies {
-    my $sheet = shift;
+    my $self = shift;
     my @sortidx=();
     #
-    if ($sheet->{'sheettype'} eq 'classcalc') {
+    if ($self->{'type'} eq 'classcalc') {
         my @sortby=(undef);
         # Skip row 0
-        for (my $row=1;$row<=$sheet->{'maxrow'};$row++) {
+        for (my $row=1;$row<=$self->{'maxrow'};$row++) {
             my (undef,$sname,$sdom,$fullname,$section,$id) = 
-                split(':',$sheet->{'rowlabel'}->{$sheet->{'f'}->{'A'.$row}});
+                split(':',$self->{'rowlabel'}->{$self->formula('A'.$row)});
             push (@sortby, lc($fullname));
             push (@sortidx, $row);
         }
         @sortidx = sort { $sortby[$a] cmp $sortby[$b]; } @sortidx;
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
+    } elsif ($self->{'type'} 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};
+        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);
@@ -1224,8 +2073,9 @@ sub sort_indicies {
     } else {
         my @sortby=(undef);
         # Skip row 0
-        for (my $row=1;$row<=$sheet->{'maxrow'};$row++) {
-            push (@sortby, $sheet->{'safe'}->reval('$f{"A'.$row.'"}'));
+        $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;
@@ -1284,18 +2134,19 @@ sub html_uneditable_cell {
 }
 
 sub outsheet_html  {
-    my ($sheet,$r) = @_;
+    my $self = shift;
+    my ($r) = @_;
     my ($num_uneditable,$realm,$row_type);
     my $requester_is_student = ($ENV{'request.role'} =~ /^st\./);
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
+    if ($self->{'type'} eq 'assesscalc') {
         $num_uneditable = 1;
         $realm = 'Assessment';
         $row_type = 'Item';
-    } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
+    } elsif ($self->{'type'} eq 'studentcalc') {
         $num_uneditable = 26;
         $realm = 'User';
         $row_type = 'Assessment';
-    } elsif ($sheet->{'sheettype'} eq 'classcalc') {
+    } elsif ($self->{'type'} eq 'classcalc') {
         $num_uneditable = 26;
         $realm = 'Course';
         $row_type = 'Student';
@@ -1334,8 +2185,8 @@ END
     my ($num_cols_output,$row_html,$rowlabel,@rowdata);
     
     if (! $requester_is_student) {
-        ($rowlabel,@rowdata) = &get_row($sheet,'-');
-        $row_html = '<tr><td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
+        ($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 || 
@@ -1354,8 +2205,8 @@ END
     ####################################
     # Print out summary/export row
     ####################################
-    ($rowlabel,@rowdata) = &get_row($sheet,'0');
-    $row_html = '<tr><td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
+    ($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 && ! $requester_is_student) {
@@ -1373,18 +2224,18 @@ END
     ####################################
     # Prepare to output rows
     ####################################
-    my @Rows = &sort_indicies($sheet);
+    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) = &get_row($sheet,$rownum);
+        my ($rowlabel,@rowdata) = $self->get_row($rownum);
         next if ($rowlabel =~ /^\s*$/);
-        next if (($sheet->{'sheettype'} eq 'assesscalc') && 
+        next if (($self->{'type'} eq 'assesscalc') && 
                  (! $ENV{'form.showall'})                &&
                  ($rowdata[0]->{'value'} =~ /^\s*$/));
         if (! $ENV{'form.showall'} &&
-            $sheet->{'sheettype'} =~ /^(studentcalc|classcalc)$/) {
+            $self->{'type'} =~ /^(studentcalc|classcalc)$/) {
             my $row_is_empty = 1;
             foreach my $cell (@rowdata) {
                 if ($cell->{'value'} !~  /^\s*$/) {
@@ -1400,20 +2251,19 @@ END
         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,$rowlabel).'</td>';
+        if ($self->{'type'} eq 'classcalc') {
+            $row_html.='<td>'.$self->format_html_rowlabel($rowlabel).'</td>';
             # Output links for each student?
             # Nope, that is already done for us in format_html_rowlabel 
             # (for now)
-        } elsif ($sheet->{'sheettype'} eq 'studentcalc') {
+        } elsif ($self->{'type'} eq 'studentcalc') {
             my $ufn = (split(/:/,$rowlabel))[5];
-            $row_html.='<td>'.&format_html_rowlabel($sheet,$rowlabel);
+            $row_html.='<td>'.$self->format_html_rowlabel($rowlabel);
             $row_html.= '<br>'.
                 '<select name="sel_'.$rownum.'" '.
                     'onChange="changesheet('.$rownum.')">'.
                         '<option name="default">Default</option>';
-
-            foreach (@{$sheet->{'othersheets'}}) {
+            foreach (@{$self->{'othersheets'}}) {
                 $row_html.='<option name="'.$_.'"';
                 if ($ufn eq $_) {
                     $row_html.=' selected';
@@ -1421,8 +2271,8 @@ END
                 $row_html.='>'.$_.'</option>';
             }
             $row_html.='</select></td>';
-        } elsif ($sheet->{'sheettype'} eq 'assesscalc') {
-            $row_html.='<td>'.&format_html_rowlabel($sheet,$rowlabel).'</td>';
+        } elsif ($self->{'type'} eq 'assesscalc') {
+            $row_html.='<td>'.$self->format_html_rowlabel($rowlabel).'</td>';
         }
         #
         my $shown_cells = 0;
@@ -1470,7 +2320,7 @@ END
     # Debugging code (be sure to uncomment errorlog code in safe space):
     #
     # $r->print("\n<pre>");
-    # $r->print(&geterrorlog($sheet));
+    # $r->print(&geterrorlog($self));
     # $r->print("\n</pre>");
     return 1;
 }
@@ -1479,20 +2329,21 @@ END
 ##         csv output routines            ##
 ############################################
 sub outsheet_csv   {
-    my ($sheet,$r) = @_;
+    my $self = shift;
+    my ($r) = @_;
     my $csvdata = '';
     my @Values;
     ####################################
     # Prepare to output rows
     ####################################
-    my @Rows = &sort_indicies($sheet);
+    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) = &get_row($sheet,$rownum);
+        my ($rowlabel,@rowdata) = $self->get_row($rownum);
         next if ($rowlabel =~ /^\s*$/);
-        push (@Values,&format_csv_rowlabel($sheet,$rowlabel));
+        push (@Values,$self->format_csv_rowlabel($rowlabel));
         foreach my $cell (@rowdata) {
             push (@Values,'"'.$cell->{'value'}.'"');
         }
@@ -1526,17 +2377,18 @@ sub outsheet_csv   {
 ##        Excel output routines           ##
 ############################################
 sub outsheet_recursive_excel {
-    my ($sheet,$r) = @_;
+    my $self = shift;
+    my ($r) = @_;
     my $c = $r->connection;
-    return undef if ($sheet->{'sheettype'} ne 'classcalc');
-    my ($workbook,$filename) = &create_excel_spreadsheet($sheet,$r);
+    return undef if ($self->{'type'} ne 'classcalc');
+    my ($workbook,$filename) = $self->create_excel_spreadsheet($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 %f=$self->formulas();
     my $count = 0;
     $r->print(<<END);
 <p>
@@ -1553,18 +2405,19 @@ A link to the spreadsheet will be availa
 END
     $r->rflush();
     my $starttime = time;
-    foreach my $rownum (&sort_indicies($sheet)) {
+    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 $studentsheet = &makenewsheet($sname,$sdom,'studentcalc',undef);
+        my $studentsheet = &Apache::lonspreadsheet::Spreadsheet->new
+                                   ($sname,$sdom,'studentcalc',undef);
         # Read in the spreadsheet definition
-        &update_student_sheet($studentsheet,$r,$c);
+        $studentsheet->update_student_sheet($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));
+        $studentsheet->export_sheet_as_excel($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. '.
@@ -1581,7 +2434,7 @@ END
         $r->rflush();
         #
         # &export_sheet_as_excel fills $worksheet with the data from $sheet
-        &export_sheet_as_excel($sheet,$main_worksheet);
+        $self->export_sheet_as_excel($main_worksheet);
         #
         $workbook->close();
         # Okay, the spreadsheet is taken care of, so give the user a link.
@@ -1595,21 +2448,22 @@ END
 }
 
 sub outsheet_excel {
-    my ($sheet,$r) = @_;
-    my ($workbook,$filename) = &create_excel_spreadsheet($sheet,$r);
+    my $self = shift;
+    my ($r) = @_;
+    my ($workbook,$filename) = $self->create_excel_spreadsheet($r);
     return undef if (! defined($workbook));
     my $sheetname;
-    if ($sheet->{'sheettype'} eq 'classcalc') {
+    if ($self->{'type'} 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';
+    } 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);
     #
     # &export_sheet_as_excel fills $worksheet with the data from $sheet
-    &export_sheet_as_excel($sheet,$worksheet);
+    $self->export_sheet_as_excel($worksheet);
     #
     $workbook->close();
     # Okay, the spreadsheet is taken care of, so give the user a link.
@@ -1619,7 +2473,8 @@ sub outsheet_excel {
 }
 
 sub create_excel_spreadsheet {
-    my ($sheet,$r) = @_;
+    my $self = shift;
+    my ($r) = @_;
     my $filename = '/prtspool/'.
         $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
         time.'_'.rand(1000000000).'.xls';
@@ -1632,7 +2487,7 @@ sub create_excel_spreadsheet {
         return undef;
     }
     #
-    # The spreadsheet stores temporary data in files, then put them
+    # 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.
@@ -1643,7 +2498,7 @@ sub create_excel_spreadsheet {
 }
 
 sub export_sheet_as_excel {
-    my $sheet = shift;
+    my $self = shift;
     my $worksheet = shift;
     #
     my $rows_output = 0;
@@ -1651,8 +2506,8 @@ sub export_sheet_as_excel {
     ####################################
     #    Write an identifying row      #
     ####################################
-    my @Headerinfo = ($sheet->{'coursedesc'});
-    my $title = &gettitle($sheet);
+    my @Headerinfo = ($self->{'coursedesc'});
+    my $title = $self->gettitle();
     $cols_output = 0;    
     if (defined($title)) {
         $worksheet->write($rows_output++,$cols_output++,$title);
@@ -1660,8 +2515,8 @@ sub export_sheet_as_excel {
     ####################################
     #   Write the summary/export row   #
     ####################################
-    my ($rowlabel,@rowdata) = &get_row($sheet,'0');
-    my $label = &format_excel_rowlabel($sheet,$rowlabel);
+    my ($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 $cell (@rowdata) {
@@ -1671,16 +2526,16 @@ sub export_sheet_as_excel {
     ####################################
     # Prepare to output rows
     ####################################
-    my @Rows = &sort_indicies($sheet);
+    my @Rows = &sort_indicies($self);
     #
     # Loop through the rows and output them one at a time
     foreach my $rownum (@Rows) {
-        my ($rowlabel,@rowdata) = &get_row($sheet,$rownum);
+        my ($rowlabel,@rowdata) = &get_row($self,$rownum);
         next if ($rowlabel =~ /^[\s]*$/);
         $cols_output = 0;
-        my $label = &format_excel_rowlabel($sheet,$rowlabel);
+        my $label = &format_excel_rowlabel($self,$rowlabel);
         if ( ! $ENV{'form.showall'} &&
-             $sheet->{'sheettype'} =~ /^(studentcalc|classcalc)$/) {
+             $self->{'type'} =~ /^(studentcalc|classcalc)$/) {
             my $row_is_empty = 1;
             foreach my $cell (@rowdata) {
                 if ($cell->{'value'} !~  /^\s*$/) {
@@ -1706,7 +2561,8 @@ sub export_sheet_as_excel {
 ##          XML output routines           ##
 ############################################
 sub outsheet_xml   {
-    my ($sheet,$r) = @_;
+    my $self = shift;
+    my ($r) = @_;
     ## Someday XML
     ## Will be rendered for the user
     ## But not on this day
@@ -1716,32 +2572,35 @@ sub outsheet_xml   {
 ## Outsheet - calls other outsheet_* functions
 ##
 sub outsheet {
-    my ($sheet,$r)=@_;
+    my $self = shift;
+    my ($r)=@_;
     if (! exists($ENV{'form.output'})) {
         $ENV{'form.output'} = 'HTML';
     }
     if (lc($ENV{'form.output'}) eq 'csv') {
-        &outsheet_csv($sheet,$r);
+        $self->outsheet_csv($r);
     } elsif (lc($ENV{'form.output'}) eq 'excel') {
-        &outsheet_excel($sheet,$r);
+        $self->outsheet_excel($r);
     } elsif (lc($ENV{'form.output'}) eq 'recursive excel') {
-        &outsheet_recursive_excel($sheet,$r);
+        $self->outsheet_recursive_excel($r);
 #    } elsif (lc($ENV{'form.output'}) eq 'xml' ) {
-#        &outsheet_xml($sheet,$r);
+#        $self->outsheet_xml($r);
     } else {
-        &outsheet_html($sheet,$r);
+        $self->outsheet_html($r);
     }
 }
 
-########################################################################
-########################################################################
+#
+# othersheets: Returns the list of other spreadsheets available 
+#
 sub othersheets {
-    my ($sheet,$stype)=@_;
-    $stype = $sheet->{'sheettype'} if (! defined($stype));
-    #
-    my $cnum  = $sheet->{'cnum'};
-    my $cdom  = $sheet->{'cdom'};
-    my $chome = $sheet->{'chome'};
+    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);
@@ -1753,7 +2612,7 @@ sub othersheets {
 }
 
 #
-# -------------------------------------- Parse a spreadsheet
+# Parse a spreadsheet
 # 
 sub parse_sheet {
     # $sheetxml is a scalar reference or a scalar
@@ -1780,16 +2639,14 @@ sub parse_sheet {
     return \%f;
 }
 
-#
-# -------------------------------------- Read spreadsheet formulas for a course
-#
 sub readsheet {
-    my ($sheet,$fn)=@_;
+    my $self = shift;
+    my ($fn)=@_;
     #
-    my $stype = $sheet->{'sheettype'};
-    my $cnum  = $sheet->{'cnum'};
-    my $cdom  = $sheet->{'cdom'};
-    my $chome = $sheet->{'chome'};
+    my $stype = $self->{'type'};
+    my $cnum  = $self->{'cnum'};
+    my $cdom  = $self->{'cdom'};
+    my $chome = $self->{'chome'};
     #
     if (! defined($fn)) {
         # There is no filename. Look for defaults in course and global, cache
@@ -1810,13 +2667,14 @@ sub readsheet {
         }
     }
     # $fn now has a value
-    $sheet->{'filename'} = $fn;
+    $self->{'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);
+        $self->formulas(\%tmp);
+#        $self->logthis('readsheet found cached ');
+#        $self->dump_formulas_to_log();
     } else {
         # Not cached, need to read
         my %f=();
@@ -1851,7 +2709,7 @@ sub readsheet {
                 # Unable to grab the specified spreadsheet,
                 # so we get the default ones instead.
                 $fn = 'default_'.$stype;
-                $sheet->{'filename'} = $fn;
+                $self->{'filename'} = $fn;
                 my $dfn = $fn;
                 $dfn =~ s/\_/\./g;
                 my $sheetxml;
@@ -1866,62 +2724,24 @@ sub readsheet {
         }
         # Cache and set
         $spreadsheets{$cnum.'_'.$cdom.'_'.$stype.'_'.$fn}=join('___;___',%f);  
-        $sheet->{'f'}=\%f;
-        &setformulas($sheet);
-    }
-}
-
-# -------------------------------------------------------- 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/) {
-        $initstring.= qq{\$$_="$sheet->{$_}";};
+        $self->formulas(\%f);
+#        $self->logthis('readsheet loaded ');
+#        $self->dump_formulas_to_log();
     }
-    $sheet->{'safe'}->reval($initstring);
-    return $sheet;
 }
 
 # ------------------------------------------------------------ Save spreadsheet
 sub writesheet {
-    my ($sheet,$makedef)=@_;
-    my $cid=$sheet->{'cid'};
+    my $self = shift;
+    my ($makedef)=@_;
+    my $cid=$self->{'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   = $sheet->{'filename'};
+        my %f=$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.'_'.$fn}=join('___;___',%f);
         # Write sheet
@@ -1939,8 +2759,8 @@ sub writesheet {
                                     {'spreadsheet_default_'.$stype => $fn },
                                                   $cdom,$cnum);
                     if ($reply eq 'ok' && 
-                        ($sheet->{'sheettype'} eq 'studentcalc' ||
-                         $sheet->{'sheettype'} eq 'assesscalc')) {
+                        ($self->{'type'} eq 'studentcalc' ||
+                         $self->{'type'} eq 'assesscalc')) {
                         # Expire the spreadsheets of the other students.
                         &Apache::lonnet::expirespread('','','studentcalc','');
                     }
@@ -1959,27 +2779,29 @@ sub writesheet {
 # "Modified workcopy" - interactive only
 #
 sub tmpwrite {
-    my ($sheet) = @_;
+    my $self = shift;
     my $fn=$ENV{'user.name'}.'_'.
-        $ENV{'user.domain'}.'_spreadsheet_'.$sheet->{'usymb'}.'_'.
-           $sheet->{'filename'};
+        $ENV{'user.domain'}.'_spreadsheet_'.$self->{'usymb'}.'_'.
+           $self->{'filename'};
     $fn=~s/\W/\_/g;
     $fn=$tmpdir.$fn.'.tmp';
     my $fh;
     if ($fh=Apache::File->new('>'.$fn)) {
-        my %f = &getformulas($sheet);
+        my %f = $self->formulas();
         while( my ($cell,$formula) = each(%f)) {
             print $fh &Apache::lonnet::escape($cell)."=".&Apache::lonnet::escape($formula)."\n";
         }
     }
 }
 
+
 # ---------------------------------------------------------- Read the temp copy
 sub tmpread {
-    my ($sheet,$nfield,$nform)=@_;
+    my $self = shift;
+    my ($nfield,$nform)=@_;
     my $fn=$ENV{'user.name'}.'_'.
-           $ENV{'user.domain'}.'_spreadsheet_'.$sheet->{'usymb'}.'_'.
-           $sheet->{'filename'};
+           $ENV{'user.domain'}.'_spreadsheet_'.$self->{'usymb'}.'_'.
+           $self->{'filename'};
     $fn=~s/\W/\_/g;
     $fn=$tmpdir.$fn.'.tmp';
     my $fh;
@@ -1994,116 +2816,22 @@ sub tmpread {
             $fo{$cell} = $formula;
         }
     }
-#            chomp($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}='~~~ '.$newrow;
-#        }
     } else {
        if ($nfield) { $fo{$nfield}=$nform; }
     }
-    $sheet->{'f'}=\%fo;
-    &setformulas($sheet);
-}
-
-##################################################
-##################################################
-
-=pod
-
-=item &parmval()
-
-Determine the value of a parameter.
-
-Inputs: $what, the parameter needed, $sheet, the safe space
-
-Returns: The value of a parameter, or '' if none.
-
-This function cascades through the possible levels searching for a value for
-a parameter.  The levels are checked in the following order:
-user, course (at section level and course level), map, and lonnet::metadata.
-This function uses %parmhash, which must be tied prior to calling it.
-This function also requires %courseopt and %useropt to be initialized for
-this user and course.
-
-=cut
-
-##################################################
-##################################################
-sub parmval {
-    my ($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}));
-    }
-    # 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 $courseopt{$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');
+    $self->formulas(\%fo);
 }
 
-
 ##################################################################
 ##                  Row label formatting routines               ##
 ##################################################################
 sub format_html_rowlabel {
-    my $sheet = shift;
+    my $self = shift;
     my $rowlabel = shift;
     return '' if ($rowlabel eq '');
     my ($type,$labeldata) = split(':',$rowlabel,2);
@@ -2115,7 +2843,7 @@ sub format_html_rowlabel {
         $symb  = &Apache::lonnet::unescape($symb);
         $title = &Apache::lonnet::unescape($title);
         $result = '<a href="/adm/assesscalc?usymb='.$symb.
-            '&uname='.$sheet->{'uname'}.'&udom='.$sheet->{'udom'}.
+            '&uname='.$self->{'uname'}.'&udom='.$self->{'udom'}.
                 '&ufn='.$ufn.
                     '&mapid='.$mapid.'&resid='.$resid.'">'.$title.'</a>';
     } elsif ($type eq 'student') {
@@ -2135,7 +2863,7 @@ sub format_html_rowlabel {
 }
 
 sub format_csv_rowlabel {
-    my $sheet = shift;
+    my $self = shift;
     my $rowlabel = shift;
     return '' if ($rowlabel eq '');
     my ($type,$labeldata) = split(':',$rowlabel,2);
@@ -2159,7 +2887,7 @@ sub format_csv_rowlabel {
 }
 
 sub format_excel_rowlabel {
-    my $sheet = shift;
+    my $self = shift;
     my $rowlabel = shift;
     return '' if ($rowlabel eq '');
     my ($type,$labeldata) = split(':',$rowlabel,2);
@@ -2187,11 +2915,11 @@ sub format_excel_rowlabel {
 
 # ---------------------------------------------- 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'};
+    my $self = shift;
+    my $cnum  =$self->{'cnum'};
+    my $cdom  =$self->{'cdom'};
+    my $cid   =$self->{'cid'};
+    my $chome =$self->{'chome'};
     #
     %Section = ();
     #
@@ -2215,62 +2943,57 @@ sub updateclasssheet {
     #
     # Find discrepancies between the course row table and this
     #
-    my %f=&getformulas($sheet);
+    my %f=$self->formulas();
     my $changed=0;
     #
-    $sheet->{'maxrow'}=0;
+    $self->{'maxrow'}=0;
     my %existing=();
     #
     # Now obsolete rows
-    foreach (keys(%f)) {
-        if ($_=~/^A(\d+)/) {
-            if ($1 > $sheet->{'maxrow'}) {
-                $sheet->{'maxrow'}= $1;
-            }
-            $existing{$f{$_}}=1;
-            unless ((defined($currentlist{$f{$_}})) || (!$1) ||
-                    ($f{$_}=~/^(~~~|---)/)) {
-                $f{$_}='!!! Obsolete';
-                $changed=1;
-            }
+    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;
         }
     }
     #
     # New and unknown keys
     foreach my $student (sort keys(%currentlist)) {
-        unless ($existing{$student}) {
-            $changed=1;
-            $sheet->{'maxrow'}++;
-            $f{'A'.$sheet->{'maxrow'}}=$student;
-        }
-    }
-    if ($changed) { 
-        $sheet->{'f'} = \%f;
-        &setformulas($sheet,%f); 
+        next if ($existing{$student});
+        $changed=1;
+        $self->{'maxrow'}++;
+        $f{'A'.$self->{'maxrow'}}=$student;
     }
+    $self->formulas(\%f) if ($changed);
     #
-    &setrowlabels($sheet,\%currentlist);
+    $self->rowlabels(\%currentlist);
 }
 
 # ----------------------------------- Update rows for student and assess sheets
 sub get_student_rowlabels {
-    my ($sheet) = @_;
+    my $self = shift;
     #
     my %course_db;
     #
-    my $stype = $sheet->{'sheettype'};
-    my $uname = $sheet->{'uname'};
-    my $udom  = $sheet->{'udom'};
+    my $stype = $self->{'type'};
+    my $uname = $self->{'uname'};
+    my $udom  = $self->{'udom'};
     #
-    $sheet->{'rowlabel'} = {};
+    $self->{'rowlabel'} = {};
     #
-    my $identifier =$sheet->{'coursefilename'}.'_'.$stype;
+    my $identifier =$self->{'coursefilename'}.'_'.$stype;
     if  ($rowlabel_cache{$identifier}) {
-        %{$sheet->{'rowlabel'}}=split(/___;___/,$rowlabel_cache{$identifier});
+        %{$self->{'rowlabel'}}=split(/___;___/,$rowlabel_cache{$identifier});
     } else {
         # Get the data and store it in the cache
         # Tie hash
-        tie(%course_db,'GDBM_File',$sheet->{'coursefilename'}.'.db',
+        tie(%course_db,'GDBM_File',$self->{'coursefilename'}.'.db',
             &GDBM_READER(),0640);
         if (! tied(%course_db)) {
             return 'Could not access course data';
@@ -2299,31 +3022,31 @@ sub get_student_rowlabels {
         }
         untie(%course_db);
         # Store away the data
-        $sheet->{'rowlabel'} = \%assesslist;
-        $rowlabel_cache{$identifier}=join('___;___',%{$sheet->{'rowlabel'}});
+        $self->{'rowlabel'} = \%assesslist;
+        $rowlabel_cache{$identifier}=join('___;___',%{$self->{'rowlabel'}});
     }
-
+    
 }
 
 sub get_assess_rowlabels {
-    my ($sheet) = @_;
+    my $self = shift;
     #
     my %course_db;
     #
-    my $stype = $sheet->{'sheettype'};
-    my $uname = $sheet->{'uname'};
-    my $udom  = $sheet->{'udom'};
-    my $usymb = $sheet->{'usymb'};
+    my $stype = $self->{'type'};
+    my $uname = $self->{'uname'};
+    my $udom  = $self->{'udom'};
+    my $usymb = $self->{'usymb'};
     #
-    $sheet->{'rowlabel'} = {};
-    my $identifier =$sheet->{'coursefilename'}.'_'.$stype.'_'.$usymb;
+    $self->rowlabels({});
+    my $identifier =$self->{'coursefilename'}.'_'.$stype.'_'.$usymb;
     #
     if  ($rowlabel_cache{$identifier}) {
-        %{$sheet->{'rowlabel'}}=split(/___;___/,$rowlabel_cache{$identifier});
+        $self->rowlabels(split(/___;___/,$rowlabel_cache{$identifier}));
     } else {
         # Get the data and store it in the cache
         # Tie hash
-        tie(%course_db,'GDBM_File',$sheet->{'coursefilename'}.'.db',
+        tie(%course_db,'GDBM_File',$self->{'coursefilename'}.'.db',
             &GDBM_READER(),0640);
         if (! tied(%course_db)) {
             return 'Could not access course data';
@@ -2362,82 +3085,82 @@ sub get_assess_rowlabels {
         }
         untie(%course_db);
         # Store away the results
-        $sheet->{'rowlabel'} = \%parameter_labels;
-        $rowlabel_cache{$identifier}=join('___;___',%{$sheet->{'rowlabel'}});
+        $self->rowlabels(\%parameter_labels);
+        $rowlabel_cache{$identifier}=join('___;___',$self->rowlabels());
     }
         
 }
 
 sub updatestudentassesssheet {
-    my $sheet = shift;
-    if ($sheet->{'sheettype'} eq 'studentcalc') {
-        &get_student_rowlabels($sheet);
+    my $self = shift;
+    if ($self->{'type'} eq 'studentcalc') {
+        $self->get_student_rowlabels();
     } else {
-        &get_assess_rowlabels($sheet);
+        $self->get_assess_rowlabels();
     }
     # Determine if any of the information has changed
-    my %f=&getformulas($sheet);
+    my %f=$self->formulas();
     my $changed=0;
-    
-    $sheet->{'maxrow'} = 0;
+    $self->{'maxrow'} = 0;
     my %existing=();
     # Now obsolete rows
-    foreach my $cell (keys(%f)) {
+    foreach my $cell ($self->A_column()) {
         my $formula = $f{$cell};
-        next if ($cell !~ /^A(\d+)/);
-        $sheet->{'maxrow'} = $1 if ($1 > $sheet->{'maxrow'});
+        my ($n)= ($cell =~ /A(\d+)/);
+        next if ($n eq '0');
+        $self->{'maxrow'} = $n if ($n > $self->{'maxrow'});
         my ($usy,$ufn)=split(/__&&&\__/,$formula);
         $existing{$usy}=1;
-        unless ((exists($sheet->{'rowlabel'}->{$usy}) && 
-                 (defined($sheet->{'rowlabel'}->{$usy})) || (!$1) ||
-                 ($formula =~ /^(~~~|---)/) )) {
+        if ( ! exists($self->{'rowlabel'}->{$usy})  ||
+             ! defined($self->{'rowlabel'}->{$usy}) ||
+             ($formula =~ /^(~~~|---)/) ||
+             ($formula =~ /^\s*$/)) {
             $f{$cell}='!!! Obsolete';
+#            $self->logthis('obsoleted row '.$n);
             $changed=1;
         }
     }
     # New and unknown keys
-    foreach (keys(%{$sheet->{'rowlabel'}})) {
+    my %keys_hates_me = $self->rowlabels();
+    foreach (keys(%keys_hates_me)) {
         unless ($existing{$_}) {
             $changed=1;
-            $sheet->{'maxrow'}++;
-            $f{'A'.$sheet->{'maxrow'}}=$_;
+            $self->{'maxrow'}++;
+            $f{'A'.$self->{'maxrow'}}=$_;
         }
     }
-    if ($changed) { 
-        $sheet->{'f'} = \%f;
-        &setformulas($sheet); 
-    }
+    $self->formulas(\%f) if ($changed);
+#    $self->dump_formulas_to_log();    
 }
 
 # ------------------------------------------------ Load data for one assessment
-
 sub loadstudent{
-    my ($sheet,$r,$c)=@_;
-    my %constants=();
-    my %formulas=&getformulas($sheet);
-    $cachedassess=$sheet->{'uname'}.':'.$sheet->{'udom'};
+    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($sheet->{'cid'},
-                                           $sheet->{'udom'},
-                                           $sheet->{'uname'});
+    my @tmp = &Apache::lonnet::currentdump($self->{'cid'},
+                                           $self->{'udom'},
+                                           $self->{'uname'});
     if ((scalar @tmp > 0) && ($tmp[0] !~ /^error:/)) {
         %cachedstores = @tmp;
     }
     undef @tmp;
     # 
     my @assessdata=();
-    foreach my $cell (keys(%formulas)) {
+    foreach my $cell ($self->A_column()) {
         my $value = $formulas{$cell};
         if(defined($c) && ($c->aborted())) {
             last;
         }
-	next if ($cell !~ /^A(\d+)/);
-        my $row=$1;
+        my ($row)=($cell=~/A(\d+)/);
         next if (($value =~ /^[!~-]/) || ($row==0));
         my ($usy,$ufn)=split(/__&&&\__/,$value);
-        @assessdata=&exportsheet($sheet,$sheet->{'uname'},
-                                 $sheet->{'udom'},
-                                 'assesscalc',$usy,$ufn,$r);
+        @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') {
@@ -2454,24 +3177,22 @@ sub loadstudent{
     }
     $cachedassess='';
     undef %cachedstores;
-    $sheet->{'f'} = \%formulas;
-    &setformulas($sheet);
-    &setconstants($sheet,\%constants);
+    $self->formulas(\%formulas);
+    $self->constants(\%constants);
 }
 
 # --------------------------------------------------- Load data for one student
 #
 sub loadcourse {
-    my ($sheet,$r,$c)=@_;
+    my $self = shift;
+    my ($r,$c)=@_;
     #
     my %constants=();
-    my %formulas=&getformulas($sheet);
+    my %formulas=$self->formulas();
     #
     my $total=0;
-    foreach (keys(%formulas)) {
-	if ($_=~/^A(\d+)/) {
-	    unless ($formulas{$_}=~/^[\!\~\-]/) { $total++; }
-        }
+    foreach ($self->A_column()) {
+        $total++ if ($formulas{$_} !~ /^[!~-]/);
     }
     my $now=0;
     my $since=time;
@@ -2481,27 +3202,27 @@ sub loadcourse {
     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>'+
+      '<input type=text size=45 name=remaining value=Starting></form>'+
       '</body></html>');
     popwin.document.close();
 </script>
 ENDPOP
     $r->rflush();
-    foreach (keys(%formulas)) {
+    foreach ($self->A_column()) {
         if(defined($c) && ($c->aborted())) {
             last;
         }
-	next if ($_!~/^A(\d+)/);
-        my $row=$1;
+        my ($row)=(/A(\d+)/);
         next if (($formulas{$_}=~/^[\!\~\-]/)  || ($row==0));
         my ($sname,$sdom) = split(':',$formulas{$_});
-        my @studentdata=&exportsheet($sheet,$sname,$sdom,'studentcalc',
+        my $started = time;
+        my @studentdata=$self->exportsheet($sname,$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>');
+                  ' secs remaining '.(time-$started).' last";</script>');
         $r->rflush(); 
         #
         my $index=0;
@@ -2521,9 +3242,8 @@ ENDPOP
             $index++;
         }
     }
-    $sheet->{'f'}=\%formulas;
-    &setformulas($sheet);
-    &setconstants($sheet,\%constants);
+    $self->formulas(\%formulas);
+    $self->constants(\%constants);
     $r->print('<script>popwin.close()</script>');
     $r->rflush(); 
 }
@@ -2531,16 +3251,18 @@ ENDPOP
 # ------------------------------------------------ Load data for one assessment
 #
 sub loadassessment {
-    my ($sheet,$r,$c)=@_;
+    my $self = shift;
+    my ($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 $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 ''; }
@@ -2618,66 +3340,41 @@ sub loadassessment {
     #
     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;
+            $self->{'coursefilename'}.'_parms.db',&GDBM_READER(),0640)) {
+        my %f=$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 $key=$f{$cell};
-                my $ckey=$key;
-                $key=~s/^stores\_/resource\./;
-                $key=~s/\_/\./g;
-                $c{$cell}=$returnhash{$key};
-                $c{$ckey}=$returnhash{$key};
+                my $ckey=$formula;
+                $formula=~s/^stores\_/resource\./;
+                $formula=~s/\_/\./g;
+                $c{$cell}=$returnhash{$formula};
+                $c{$ckey}=$returnhash{$formula};
             }
         }
         untie(%parmhash);
     }
-    &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="'.$value.'">';
-}
-
-sub hiddenfield {
-    my ($name,$value)=@_;
-    return "\n".'<input type=hidden name="'.$name.'" value="'.$value.'">';
+    $self->constants(\%c);
 }
 
-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>';
-}
 
 # =============================================== Update information in a sheet
 #
 # Add new users or assessments, etc.
 #
-
 sub updatesheet {
-    my ($sheet)=@_;
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-	return &updateclasssheet($sheet);
+    my $self = shift;
+    if ($self->{'type'} eq 'classcalc') {
+        return $self->updateclasssheet();
     } else {
-        return &updatestudentassesssheet($sheet);
+        return $self->updatestudentassesssheet();
     }
 }
 
@@ -2685,54 +3382,17 @@ sub updatesheet {
 #
 # Import the data for rows
 #
-
 sub loadrows {
-    my ($sheet,$r)=@_;
+    my $self = shift;
+    my ($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);
+    if ($self->{'type'} eq 'classcalc') {
+        $self->loadcourse($r,$c);
+    } elsif ($self->{'type'} eq 'studentcalc') {
+        $self->loadstudent($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;
-        }
+        $self->loadassessment($r,$c);
     }
-    return 0; 
 }
 
 # ============================================================== Export handler
@@ -2740,11 +3400,12 @@ sub forcedrecalc {
 # returns the export row for a spreadsheet.
 #
 sub exportsheet {
-    my ($sheet,$uname,$udom,$stype,$usymb,$fn,$r)=@_;
+    my $self = shift;
+    my ($uname,$udom,$stype,$usymb,$fn,$r)=@_;
     my $flag = 0;
-    $uname = $uname || $sheet->{'uname'};
-    $udom  = $udom  || $sheet->{'udom'};
-    $stype = $stype || $sheet->{'sheettype'};
+    $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+)/) && 
@@ -2756,8 +3417,8 @@ sub exportsheet {
     #
     my $key=$uname.':'.$udom.':'.$stype.':'.$usymb;
     my $found='';
-    if ($oldsheets{$key}) {
-        foreach (split(/___&\___/,$oldsheets{$key})) {
+    if ($Apache::lonspreadsheet::oldsheets{$key}) {
+        foreach (split(/___&\___/,$Apache::lonspreadsheet::oldsheets{$key})) {
             my ($name,$value)=split(/___=___/,$_);
             if ($name eq $fn) {
                 $found=$value;
@@ -2765,9 +3426,9 @@ sub exportsheet {
         }
     }
     unless ($found) {
-        &cachedssheets($sheet,$uname,$udom);
-        if ($oldsheets{$key}) {
-            foreach (split(/___&\___/,$oldsheets{$key})) {
+        &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;
@@ -2793,12 +3454,13 @@ sub exportsheet {
     #
     # Not cached
     #
-    my ($newsheet)=&makenewsheet($uname,$udom,$stype,$usymb);
-    &readsheet($newsheet,$fn);
-    &updatesheet($newsheet);
-    &loadrows($newsheet,$r);
-    &calcsheet($newsheet); 
-    @exportarr=&exportdata($newsheet);
+    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
     ##
@@ -2809,7 +3471,7 @@ sub exportsheet {
     if ($stype eq 'studentcalc') {
         my @tmp = &Apache::lonnet::get('nohist_calculatedsheets',
                                        [$key],
-                                       $sheet->{'cdom'},$sheet->{'cnum'});
+                                       $self->{'cdom'},$self->{'cnum'});
         if ($tmp[0]!~/^error/) {
             # We only got one key, so we will access it directly.
             foreach (split('___&___',$tmp[1])) {
@@ -2820,8 +3482,8 @@ sub exportsheet {
         }
     } else {
         my @tmp = &Apache::lonnet::get('nohist_calculatedsheets_'.
-                                       $sheet->{'cid'},[$key],
-                                       $sheet->{'udom'},$sheet->{'uname'});
+                                       $self->{'cid'},[$key],
+                                       $self->{'udom'},$self->{'uname'});
         if ($tmp[0]!~/^error/) {
             # We only got one key, so we will access it directly.
             foreach (split('___&___',$tmp[1])) {
@@ -2852,470 +3514,20 @@ sub exportsheet {
         my $result = &Apache::lonnet::put('nohist_calculatedsheets',
                                           { $key     => $newstore,
                                             $timekey => $now },
-                                          $sheet->{'cdom'},
-                                          $sheet->{'cnum'});
+                                          $self->{'cdom'},
+                                          $self->{'cnum'});
     } else {
-        my $result = &Apache::lonnet::put('nohist_calculatedsheets_'.$sheet->{'cid'},
+        my $result = &Apache::lonnet::put('nohist_calculatedsheets_'.$self->{'cid'},
                                           { $key     => $newstore,
                                             $timekey => $now },
-                                          $sheet->{'udom'},
-                                          $sheet->{'uname'});
+                                          $self->{'udom'},
+                                          $self->{'uname'});
     }
     return @exportarr;
 }
 
-# ============================================================ 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;
-    }
-}
-
-# ===================================================== 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} = $value;
-        }
-    }
-}
-
-# ===================================================== Calculated sheets cache
-#
-# Load previously cached assessment spreadsheets for this student
-#
-
-sub cachedssheets {
-    my ($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;
-        }
-    }
-    
-}
-
-# ===================================================== 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
-    #
-    # 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;
-    }
-    #
-    # Global directory configs
-    #
-    $includedir = $r->dir_config('lonIncludes');
-    $tmpdir = $r->dir_config('lonDaemons').'/tmp/';
-    #
-    # 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') {
-        $nothing = "'javascript:void(0);'";
-    }
-
-    if ($ENV{'request.role'} !~ /^st\./) {
-        $r->print(<<ENDSCRIPT);
-<script language="JavaScript">
-
-    var editwin;
-
-    function celledit(cellname,cellformula) {
-        var edit_text = '';
-        // cellformula may contain less-than and greater-than symbols, so
-        // we need to escape them?  
-        edit_text +='<html><head><title>Cell Edit Window</title></head><body>';
-        edit_text += '<form name="editwinform">';
-        edit_text += '<center><h3>Cell '+cellname+'</h3>';
-        edit_text += '<textarea name="newformula" cols="40" rows="6"';
-        edit_text += ' wrap="off" >'+cellformula+'</textarea>';
-        edit_text += '</br>';
-        edit_text += '<input type="button" name="accept" value="Accept"';
-        edit_text += ' onClick=\\\'javascript:';
-        edit_text += 'opener.document.sheet.unewfield.value=';
-        edit_text +=     '"'+cellname+'";';
-        edit_text += 'opener.document.sheet.unewformula.value=';
-        edit_text +=     'document.editwinform.newformula.value;';
-        edit_text += 'opener.document.sheet.submit();';
-        edit_text += 'self.close()\\\' />';
-        edit_text += '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
-        edit_text += '<input type="button" name="abort" ';
-        edit_text +=     'value="Discard Changes"';
-        edit_text += ' onClick="javascript:self.close()" />';
-        edit_text += '</center></body></html>';
-
-        if (editwin != null && !(editwin.closed) ) {
-            editwin.close();
-        }
-
-        editwin = window.open($nothing,'CellEditWin','height=200,width=350,scrollbars=no,resizeable=yes,alwaysRaised=yes,dependent=yes',true);
-        editwin.document.write(edit_text);
-    }
-
-    function changesheet(cn) {
-	document.sheet.unewfield.value=cn;
-        document.sheet.unewformula.value='changesheet';
-        document.sheet.submit();
-    }
-
-    function insertrow(cn) {
-	document.sheet.unewfield.value='insertrow';
-        document.sheet.unewformula.value=cn;
-        document.sheet.submit();
-    }
-
-</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',''));
-    $r->rflush();
-    #
-    # Full recalc?
-    #
-    if ($ENV{'form.forcerecalc'}) {
-        $r->print('<h4>Completely Recalculating Sheet ...</h4>');
-        undef %spreadsheets;
-        undef %courserdatas;
-        undef %userrdatas;
-        undef %defaultsheets;
-        undef %rowlabel_cache;
-    }
-    # Read new sheet or modified worksheet
-    my ($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;
-        }
-    }
-    # Print out user information
-    $r->print('<h2>'.$sheet->{'coursedesc'}.'</h2>');
-    if ($sheet->{'sheettype'} ne 'classcalc') {
-        $r->print('<h2>'.&gettitle($sheet).'</h2><p>');
-    }
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
-        $r->print('<b>User:</b> '.$sheet->{'uname'}.
-                  '<br /><b>Domain:</b> '.$sheet->{'udom'}.'<br />');
-    }
-    if ($sheet->{'sheettype'} eq 'studentcalc' || 
-        $sheet->{'sheettype'} 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'} = $ENV{'form.ufn'};
-        &tmpread($sheet,$ENV{'form.unewfield'},$ENV{'form.unewformula'});
-    } elsif ($ENV{'form.saveas'}) {
-        $sheet->{'filename'} = $ENV{'form.ufn'};
-        &tmpread($sheet);
-    } else {
-        &readsheet($sheet,$ENV{'form.ufn'});
-    }
-    # Additional options
-    if ($sheet->{'sheettype'} eq 'assesscalc') {
-        $r->print('<p><font size=+2>'.
-                  '<a href="/adm/studentcalc?'.
-                  'uname='.$sheet->{'uname'}.
-                  '&udom='.$sheet->{'udom'}.'">'.
-                  'Level up: Student Sheet</a></font></p>');
-    }
-    if (($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>');
-    }
-    # 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>');
-    }
-    $r->print(&hiddenfield('ufn',$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');
-            }
-            $r->print('>'.$_.'</option>');
-        } 
-        $r->print('</select><p>');
-        if ($sheet->{'sheettype'} eq 'studentcalc') {
-            &setothersheets($sheet,
-                            &othersheets($sheet,'assesscalc'));
-        }
-    }
-    #
-    # Set up caching mechanisms
-    #
-    &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;
-    }
-    $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);
-    }
-    # 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");
-    $r->rflush();
-    #
-    &loadrows($sheet,$r);
-    $r->print("Loaded row data, calculating sheet ...<br>\n");
-    $r->rflush();
-    #
-    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>');
-        }
-    }
-    #
-    # 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: ');
-    } else {
-        $r->print('<p>Show empty rows: ');
-    }
-    #
-    $r->print(&hiddenfield('userselhidden','true').
-              '<input type="checkbox" name="showall" onClick="submit()"');
-    #
-    if ($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;
-                }
-        }
-    }
-    $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->{'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");
-#    }
-    $r->print("</select>\n");
-    #
-    if ($sheet->{'sheettype'} eq 'classcalc') {
-        $r->print('&nbsp;Student Status: '.
-                  &Apache::lonhtmlcommon::StatusOptions
-                  ($ENV{'form.Status'},'sheet'));
-    }
-    #
-    # Buttons to insert rows
-#    $r->print(<<ENDINSERTBUTTONS);
-#<br>
-#<input type='button' onClick='insertrow("top");' 
-#value='Insert Row Top'>
-#<input type='button' onClick='insertrow("bottom");' 
-#value='Insert Row Bottom'><br>
-#ENDINSERTBUTTONS
-    # Print out sheet
-    &outsheet($sheet,$r);
-    $r->print('</form></body></html>');
-    #  Done
-    return OK;
-}
-
 1;
+
 __END__