--- loncom/homework/response.pm	2003/09/22 20:49:01	1.85
+++ loncom/homework/response.pm	2009/04/17 01:00:15	1.214
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # various response type definitons response definition
 #
-# $Id: response.pm,v 1.85 2003/09/22 20:49:01 albertel Exp $
+# $Id: response.pm,v 1.214 2009/04/17 01:00:15 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,21 +25,44 @@
 #
 # http://www.lon-capa.org/
 #
-# 11/23,11/24,11/28 Gerd Kortemeyer
-# Guy Albertelli
-# 08/04,08/07 Gerd Kortemeyer
+
+=pod
+
+=head1 NAME
+
+Apache::resonse.pm
+
+=head1 SYNOPSIS
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org.
+
+
+=head1 NOTABLE SUBROUTINES
+
+=over
+
+=item 
+
+=back
+
+=cut
+
 
 package Apache::response;
 use strict;
+use Apache::lonlocal;
+use Apache::lonnet;
+use Apache::lonmaxima();
+use Apache::lonr();
 
 BEGIN {
-    &Apache::lonxml::register('Apache::response',('responseparam','parameter','dataresponse'));
+    &Apache::lonxml::register('Apache::response',('responseparam','parameter','dataresponse','customresponse','mathresponse'));
 }
 
 sub start_response {
     my ($parstack,$safeeval)=@_;
-    my $id= &Apache::lonxml::get_param('id',$parstack,$safeeval);
-    if ($id eq '') { $id = $Apache::lonxml::curdepth; }
+    my $id = &Apache::lonxml::get_id($parstack,$safeeval);
     if ($#Apache::inputtags::import > -1) {
 	&Apache::lonxml::debug("Turning :$id: into");
 	$id = join('_',@Apache::inputtags::import).'_'.$id;
@@ -48,6 +71,17 @@ sub start_response {
     push (@Apache::inputtags::response,$id);
     push (@Apache::inputtags::responselist,$id);
     @Apache::inputtags::inputlist=();
+    if ($Apache::inputtags::part eq '' && 
+	!$Apache::lonhomework::ignore_response_errors) {
+	&Apache::lonxml::error(&HTML::Entities::encode(&mt("Found a <*response> outside of a <part> in a <part>ed problem"),'<>&"'));
+    }
+    if ($Apache::inputtags::response_with_no_part &&
+	$Apache::inputtags::part ne '0') {
+	&Apache::lonxml::error(&HTML::Entities::encode(&mt("<*response>s are both inside of <part> and outside of <part>, this is not a valid problem, errors in grading may occur."),'<>&"').'<br />');
+    }
+    if ($Apache::inputtags::part eq '0') {
+	$Apache::inputtags::response_with_no_part=1;
+    }
     return $id;
 }
 
@@ -59,16 +93,15 @@ sub end_response {
 
 sub start_hintresponse {
     my ($parstack,$safeeval)=@_;
-    my $id= &Apache::lonxml::get_param('id',$parstack,$safeeval);
-    if ($id eq '') { $id = $Apache::lonxml::curdepth; }
-    push (@Apache::inputtags::response,$id);
-    push (@Apache::inputtags::responselist,$id);
+    my $id = &Apache::lonxml::get_id($parstack,$safeeval);
+    push (@Apache::inputtags::hint,$id);
+    push (@Apache::inputtags::hintlist,$id);
     push (@Apache::inputtags::paramstack,[%Apache::inputtags::params]);
     return $id;
 }
 
 sub end_hintresponse {
-    pop @Apache::inputtags::response;
+    pop @Apache::inputtags::hint;
     if (defined($Apache::inputtags::paramstack[-1])) {
 	%Apache::inputtags::params=
 	    @{ pop(@Apache::inputtags::paramstack) };
@@ -76,35 +109,93 @@ sub end_hintresponse {
     return '';
 }
 
-# used by response to set the non-safe space random number generator to something
-# that is stable and unique based on the part number and response number
-sub setrandomnumber {
-    my $rndseed;
-    if ($ENV{'request.state'} eq "construct") {
-	$rndseed=$ENV{'form.rndseed'};
-	if (!$rndseed) { $rndseed=time; }
+my @randomseeds;
+sub pushrandomnumber {
+    my $rand_alg=&Apache::lonnet::get_rand_alg();
+    if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
+	$rand_alg eq '64bit2') {
+	# do nothing
+    } else {
+	my @seed=&Math::Random::random_get_seed();
+	push(@randomseeds,\@seed);
+    }
+    &Apache::response::setrandomnumber(@_);
+}
+sub poprandomnumber {
+    my $rand_alg=&Apache::lonnet::get_rand_alg();
+    if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
+	$rand_alg eq '64bit2') {
+	return;
+    }
+    my $seed=pop(@randomseeds);
+    if ($seed) {
+	&Math::Random::random_set_seed(@$seed);
     } else {
-	$rndseed=&Apache::lonnet::rndseed();
+	&Apache::lonxml::error("Unable to restore random algorithm.");
     }
+}
+
+sub setrandomnumber {
+    my ($ignore_id2) = @_;
+    my $rndseed;
+    $rndseed=&Apache::structuretags::setup_rndseed();
+    if (!defined($rndseed)) { $rndseed=&Apache::lonnet::rndseed(); }
     &Apache::lonxml::debug("randseed $rndseed");
     #  $rndseed=unpack("%32i",$rndseed);
-    my $rndmod=(&Apache::lonnet::numval($Apache::inputtags::part) << 10);
-    if (defined($Apache::inputtags::response['-1'])) {
-       $rndmod+=&Apache::lonnet::numval($Apache::inputtags::response[-1]);
-    }
-    if ($rndseed =~/,/) {
-	{
-	    use integer;
-	    my ($num1,$num2)=split(/,/,$rndseed);
-	    $num1+=$rndmod;
-	    $num2+=$rndmod;
-	    $rndseed="$num1,$num2";
+    my $rand_alg=&Apache::lonnet::get_rand_alg();
+    my ($rndmod,$rndmod2);
+
+    my ($id1,$id2,$shift_amt);
+    if ($Apache::lonhomework::parsing_a_problem) {
+	$id1=$Apache::inputtags::part;
+	if (defined($Apache::inputtags::response[-1])) {
+	    $id2=$Apache::inputtags::response[-1];
+	}
+	$shift_amt=scalar(@Apache::inputtags::responselist);
+    } elsif ($Apache::lonhomework::parsing_a_task) {
+	$id1=&Apache::bridgetask::get_dim_id();
+	if (!$ignore_id2 && ref($Apache::bridgetask::instance{$id1})) {
+	    $id2=$Apache::bridgetask::instance{$id1}[-1];
+	    $shift_amt=scalar(@{$Apache::bridgetask::instance{$id1}});
+	} else {
+	    $shift_amt=0;
+	}
+    } 
+    &Apache::lonxml::debug("id1: $id1, id2: $id2, shift_amt: $shift_amt");
+    if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
+	$rand_alg eq '64bit2') {
+	$rndmod=(&Apache::lonnet::numval($id1) << 10);
+	if (defined($id2)) { $rndmod+=&Apache::lonnet::numval($id2); }
+    } elsif ($rand_alg eq '64bit3') {
+	$rndmod=(&Apache::lonnet::numval2($id1) << 10);
+	if (defined($id2)) { $rndmod+=&Apache::lonnet::numval2($id2); }
+    } elsif ($rand_alg eq '64bit4') {
+	my $shift=(4*$shift_amt)%30;
+	$rndmod=(&Apache::lonnet::numval3($id1) << (($shift+15)%30));
+	if (defined($id2)) {
+	    $rndmod+=(&Apache::lonnet::numval3($id2) << $shift );
 	}
     } else {
+	($rndmod,$rndmod2)=&Apache::lonnet::digest("$id1,$id2");
+    }
+
+    if ($rndseed =~/([,:])/) {
+	my $char=$1;
+	use integer;
+	my ($num1,$num2)=split(/\Q$char\E/,$rndseed);
+	$num1+=$rndmod;
+	$num2+= ((defined($rndmod2)) ? $rndmod2 : $rndmod);
+	if($Apache::lonnet::_64bit) { $num1=(($num1<<32)>>32); $num2=(($num2<<32)>>32); }
+	$rndseed=$num1.$char.$num2;
+    } else {
 	$rndseed+=$rndmod;
+	if($Apache::lonnet::_64bit) {
+	    use integer;
+	    $rndseed=(($rndseed<<32)>>32);
+	}
     }
+    &Apache::lonxml::debug("randseed $rndmod $rndseed");
     &Apache::lonnet::setup_random_from_rndseed($rndseed);
-    &Apache::lonxml::debug("randseed $rndseed");
     return '';
 }
 
@@ -118,8 +209,8 @@ sub meta_parameter_write {
     }
     $result.=            ' name="'.$name.'"'.
                          ' type="'.$type.'"'.
-($default?' default="'.$default.'"':'').
-($display?' display="'.$display.' [Part: '.$partref.']"':'')
+(defined($default)?' default="'.$default.'"':'').
+(defined($display)?' display="'.$display.' [Part: '.$partref.']"':'')
              .'></parameter>'
              ."\n";
     return $result;
@@ -149,43 +240,54 @@ sub meta_stores_write {
 		      "></stores>\n";
 }
 
+=pod
+
+=item mandatory_part_meta()
+
+Autogenerate metadata for mandatory
+input (from RAT or lonparmset) and
+output (to lonspreadsheet)
+of each part
+
+Note: responseid-specific data 'submission' and 'awarddetail'
+not available to spreadsheet -> skip here
+
+=cut
+
+
 sub mandatory_part_meta {
-#
-# Autogenerate metadata for mandatory
-# input (from RAT or lonparmset) and 
-# output (to lonspreadsheet)
-# of each part
-#
-    return
-#    &meta_parameter_write('opendate','date_start','',
-#                          'Opening Date').
-#    &meta_parameter_write('duedate','date_end','',
-#                          'Due Date').
-#    &meta_parameter_write('answerdate','date_start','',
-#                          'Show Answer Date').
-#    &meta_parameter_write('weight','int_zeropos','',
-#                          'Available Points').
-#    &meta_parameter_write('maxtries','int_pos','',
-#                          'Maximum Number of Tries').
-	&meta_package_write('part').
-        &meta_stores_write('solved','string',
-			   'Problem Status').
-        &meta_stores_write('tries','int_zeropos',
-			   'Number of Attempts').
-        &meta_stores_write('awarded','float',
-			   'Partial Credit Factor');
-#
-# Note: responseid-specific data 'submission' and 'awarddetail'
-# not available to spreadsheet -> skip here
-#
+    return &meta_package_write('part').
+           &meta_stores_write('solved','string','Problem Status').
+           &meta_stores_write('tries','int_zeropos','Number of Attempts').
+           &meta_stores_write('awarded','float','Partial Credit Factor');
+}
+
+sub meta_part_order {
+    if (@Apache::inputtags::partlist) {
+	my @parts=@Apache::inputtags::partlist;
+	shift(@parts);
+	return '<partorder>'.join(',',@parts).'</partorder>'."\n";
+    } else {
+	return '<partorder>0</partorder>'."\n";
+    }
+}
+
+sub meta_response_order {
+    if (@Apache::inputtags::responselist) {
+	return '<responseorder>'.join(',',@Apache::inputtags::responselist).
+	    '</responseorder>'."\n";
+    }
 }
 
 sub check_for_previous {
-    my ($curresponse,$partid,$id) = @_;
+    my ($curresponse,$partid,$id,$last) = @_;
     my %previous;
     $previous{'used'} = 0;
     foreach my $key (sort(keys(%Apache::lonhomework::history))) {
-	if ($key =~ /resource\.$partid\.$id\.submission/) {
+	if ($key =~ /resource\.\Q$partid\E\.\Q$id\E\.submission$/) {
+	    if ( $last && $key =~ /^(\d+):/ ) {
+		next if ($1 >= $last);
+	    }
 	    &Apache::lonxml::debug("Trying $key");
 	    my $pastresponse=$Apache::lonhomework::history{$key};
 	    if ($pastresponse eq $curresponse) {
@@ -201,6 +303,7 @@ sub check_for_previous {
 		    $previous{'last'}='1';
 		}
 		if (! $previous{'award'} ) { $previous{'award'} = 'UNKNOWN';	}
+                if ($previous{'award'} eq 'INTERNAL_ERROR') { $previous{'used'}=0; }
 		&Apache::lonxml::debug("got a match :$previous{'award'}:$previous{'used'}:");
 	    }
 	}
@@ -214,17 +317,18 @@ sub handle_previous {
     if ($$previous{'used'} && ($$previous{'award'} eq $ad) ) {
 	if ($$previous{'last'}) {
 	    push(@Apache::inputtags::previous,'PREVIOUSLY_LAST');
-	} else {
+	    push(@Apache::inputtags::previous_version,$$previous{'version'});
+	} elsif ($Apache::lonhomework::type ne 'survey') {
 	    push(@Apache::inputtags::previous,'PREVIOUSLY_USED');
+	    push(@Apache::inputtags::previous_version,$$previous{'version'});
 	}
-	push(@Apache::inputtags::previous_version,$$previous{'version'});
     }
 }
 
 sub view_or_modify {
-    my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+    my ($symb,$courseid,$domain,$name) = &Apache::lonnet::whichuser();
     my $myself=0;
-    if ( ($name eq $ENV{'user.name'}) && ($domain eq $ENV{'user.domain'}) ) {
+    if ( ($name eq $env{'user.name'}) && ($domain eq $env{'user.domain'}) ) {
 	$myself=1;
     }
     my $vgr=&Apache::lonnet::allowed('vgr',$courseid);
@@ -255,14 +359,14 @@ sub end_dataresponse {
     my $result;
     if ( $target eq 'web' ) {
     } elsif ($target eq 'grade' ) {
-	if ( defined $ENV{'form.submitted'}) {
-	    my ($symb,$courseid,$domain,$name)=&Apache::lonxml::whichuser();
+	if ( defined $env{'form.submitted'}) {
+	    my ($symb,$courseid,$domain,$name)=&Apache::lonnet::whichuser();
 	    my $allowed=&Apache::lonnet::allowed('mgr',$courseid);
 	    if ($allowed) {
-		&Apache::response::setup_params('dataresponse');
+		&Apache::response::setup_params('dataresponse',$safeeval);
 		my $partid = $Apache::inputtags::part;
 		my $id = $Apache::inputtags::response['-1'];
-		my $response = $ENV{'form.HWVAL_'.$id};
+		my $response = $env{'form.HWVAL_'.$id};
 		my $name = &Apache::lonxml::get_param('name',$parstack,$safeeval);
 		if ( $response =~ /[^\s]/) {
 		    $Apache::lonhomework::results{"resource.$partid.$id.$name"}=$response;
@@ -278,6 +382,289 @@ sub end_dataresponse {
     return $result;
 }
 
+sub start_customresponse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $id = &Apache::response::start_response($parstack,$safeeval);
+    push(@Apache::lonxml::namespace,'customresponse');
+    my $result;
+    @Apache::response::custom_answer=();
+    @Apache::response::custom_answer_type=();
+    &Apache::lonxml::register('Apache::response',('answer'));
+    if ($target eq 'web') {
+  	if (  &Apache::response::show_answer() ) {
+	    my $answer = &Apache::lonxml::get_param('answerdisplay',$parstack,
+						   $safeeval);
+	    $Apache::inputtags::answertxt{$id}=[$answer];
+	}
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token);
+	$result.=&Apache::edit::text_arg('String to display for answer:',
+					 'answerdisplay',$token);
+	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag;
+	$constructtag=&Apache::edit::get_new_args($token,$parstack,
+						  $safeeval,'answerdisplay');
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    } elsif ($target eq 'answer' || $target eq 'grade') {
+	&Apache::response::reset_params();
+    } elsif ($target eq 'meta') {
+	$result .= &Apache::response::meta_package_write('customresponse');
+    }
+    return $result;
+}
+
+sub end_customresponse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    my $part=$Apache::inputtags::part;
+    my $id=$Apache::inputtags::response[-1];
+    if ( $target eq 'grade' && &Apache::response::submitted() ) {
+	my $response = &Apache::response::getresponse();
+	if ($Apache::lonhomework::type eq 'exam' ||
+	    &Apache::response::submitted('scantron')) {
+	    &Apache::response::scored_response($part,$id);
+	} elsif ( $response =~ /[^\s]/ && 
+		  $Apache::response::custom_answer_type[-1] eq 'loncapa/perl') {
+	    if (!$Apache::lonxml::default_homework_loaded) {
+		&Apache::lonxml::default_homework_load($safeeval);
+	    }
+	    my %previous = &Apache::response::check_for_previous($response,
+								 $part,$id);
+	    $Apache::lonhomework::results{"resource.$part.$id.submission"}=
+		$response;
+	    my $error;
+	    ${$safeeval->varglob('LONCAPA::customresponse_submission')}=
+		$response;
+	    
+	    my $award = &Apache::run::run('{ my $submission=$LONCAPA::customresponse_submission;'.$Apache::response::custom_answer[-1].'}',$safeeval);
+	    if (!&Apache::inputtags::valid_award($award)) {
+		$error = $award;
+		$award = 'ERROR';
+	    }
+	    &Apache::response::handle_previous(\%previous,$award);
+	    $Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=
+		$award;
+	    if ($error) {
+		$Apache::lonhomework::results{"resource.$part.$id.awardmsg"}=
+		    $error;
+	    }
+	}
+    } elsif ( $target eq 'answer') {
+	$result  = &Apache::response::answer_header('customresponse');
+	my $answer = &Apache::lonxml::get_param('answerdisplay',$parstack,
+						$safeeval);
+	if ($env{'form.answer_output_mode'} ne 'tex') {
+	    $answer = '<b>'.$answer.'</b>';
+	}
+	$result .= &Apache::response::answer_part('customresponse',$answer);
+	$result .= &Apache::response::answer_footer('customresponse');
+    }
+    if ($target eq 'web') {
+	&setup_prior_tries_hash(\&format_prior_response_math);
+    }
+    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
+	$target eq 'tex' || $target eq 'analyze') {
+	&Apache::lonxml::increment_counter(&Apache::response::repetition(),
+					   "$part.$id");
+	if ($target eq 'analyze') {
+            $Apache::lonhomework::analyze{"$part.$id.type"} = 'customresponse';
+	    &Apache::lonhomework::set_bubble_lines();
+	}
+    }
+    pop(@Apache::lonxml::namespace);
+    pop(@Apache::response::custom_answer);
+    pop(@Apache::response::custom_answer_type);
+    &Apache::lonxml::deregister('Apache::response',('answer'));
+    &Apache::response::end_response();
+    return $result;
+}
+
+sub format_prior_response_custom {
+    my ($mode,$answer) =@_;
+    return '<span class="LC_prior_custom">'.
+	    &HTML::Entities::encode($answer,'"<>&').'</span>';
+}
+
+sub start_mathresponse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $id = &Apache::response::start_response($parstack,$safeeval);
+    push(@Apache::lonxml::namespace,'mathresponse');
+    my $result;
+    @Apache::response::custom_answer=();
+    @Apache::response::custom_answer_type=();
+    &Apache::lonxml::register('Apache::response',('answer'));
+    if ($target eq 'web') {
+  	if (  &Apache::response::show_answer() ) {
+	    my $answer = &Apache::lonxml::get_param('answerdisplay',$parstack,
+						   $safeeval);
+	    $Apache::inputtags::answertxt{$id}=[$answer];
+	}
+
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token);
+	$result.=&Apache::edit::text_arg('String to display for answer:',
+					 'answerdisplay',$token);
+	$result.=&Apache::edit::select_arg('Algebra System:',
+					   'cas',
+					   ['maxima','R'],
+					   $token);
+	$result.=&Apache::edit::text_arg('Argument Array:',
+					 'args',$token).
+                 &Apache::loncommon::help_open_topic('Maxima_Argument_Array');
+        $result.=&Apache::edit::text_arg('Libraries:',
+                                         'libraries',$token).
+                 &Apache::loncommon::help_open_topic('Maxima_Libraries');
+	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag;
+	$constructtag=&Apache::edit::get_new_args($token,$parstack,
+						  $safeeval,'answerdisplay','cas','args','libraries');
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    } elsif ($target eq 'answer' || $target eq 'grade') {
+	&Apache::response::reset_params();
+    } elsif ($target eq 'meta') {
+	$result .= &Apache::response::meta_package_write('mathresponse');
+    }
+    return $result;
+}
+
+sub edit_mathresponse_button {
+    my ($id,$field)=@_;
+    my $button=&mt('Edit Answer');
+#    my $helplink=&Apache::loncommon::help_open_topic('Formula_Editor');
+    my $iconpath=$Apache::lonnet::perlvar{'lonIconsURL'};
+    return(<<ENDFORMULABUTTON);
+<script type="text/javascript" language="JavaScript">
+function edit_${id}_${field} (textarea) {
+    thenumber = textarea;
+    thedata = document.forms['lonhomework'].elements[textarea].value;
+    newwin = window.open("/adm/dragmath/applet/MaximaPopup.html","","width=565,height=400,resizable");
+}
+</script>
+<a href="javascript:edit_${id}_${field}('${field}');void(0);"><img class="stift" src='$iconpath/stift.gif' alt='$button' title='$button'/></a>
+ENDFORMULABUTTON
+}
+
+sub end_mathresponse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    my $part=$Apache::inputtags::part;
+    my $id=$Apache::inputtags::response[-1];
+    if ( $target eq 'grade' && &Apache::response::submitted() ) {
+	my $response = &Apache::response::getresponse();
+	if ( $response =~ /[^\s]/ ) {
+	    if (!$Apache::lonxml::default_homework_loaded) {
+		&Apache::lonxml::default_homework_load($safeeval);
+	    }
+	    my %previous = &Apache::response::check_for_previous($response,
+								 $part,$id);
+	    $Apache::lonhomework::results{"resource.$part.$id.submission"}=
+		$response;
+	    my $error;
+	    my $award;
+	    my $cas = &Apache::lonxml::get_param('cas',$parstack,$safeeval);
+            if ($cas eq 'maxima') {
+                my $args = [&Apache::lonxml::get_param_var('args',$parstack,$safeeval)];
+                $award=&Apache::lonmaxima::maxima_run($Apache::response::custom_answer[-1],$response,$args,
+                                                      &Apache::lonxml::get_param('libraries',$parstack,$safeeval));
+            }
+            if ($cas eq 'R') {
+                my $args = [&Apache::lonxml::get_param_var('args',$parstack,$safeeval)];
+                $award=&Apache::lonr::r_run($Apache::response::custom_answer[-1],$response,$args,
+                                            &Apache::lonxml::get_param('libraries',$parstack,$safeeval));
+            }
+
+	    if (!&Apache::inputtags::valid_award($award)) {
+		$error = $award;
+		$award = 'ERROR';
+	    }
+	    &Apache::response::handle_previous(\%previous,$award);
+	    $Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=
+		$award;
+	    if ($error) {
+		$Apache::lonhomework::results{"resource.$part.$id.awardmsg"}=
+		    $error;
+	    }
+	}
+    }
+    if ($target eq 'web') {
+	&setup_prior_tries_hash(\&format_prior_response_math);
+        my $partid = $Apache::inputtags::part;
+        my $id = $Apache::inputtags::response[-1];
+        if (($Apache::inputtags::status['-1'] eq 'CAN_ANSWER')
+           && (&Apache::lonnet::EXT('resource.'.$partid.'_'.$id.'.turnoffeditor') ne 'yes')) {
+            $result.=&edit_mathresponse_button($id,"HWVAL_$id");
+        }
+    }
+
+    pop(@Apache::lonxml::namespace);
+    pop(@Apache::response::custom_answer);
+    pop(@Apache::response::custom_answer_type);
+    &Apache::lonxml::deregister('Apache::response',('answer'));
+    &Apache::response::end_response();
+    return $result;
+}
+
+sub format_prior_response_math {
+    my ($mode,$answer) =@_;
+    return '<span class="LC_prior_math">'.
+	    &HTML::Entities::encode($answer,'"<>&').'</span>';
+}
+
+sub implicit_multiplication {
+    my ($expression)=@_;
+# Escape scientific notation, so 3e8 does not become 3*e*8
+# 3e8 -> 3&8; 3e-8 -> 3&-8; 3E+8 -> e&+8
+    $expression=~s/(\d+)e([\+\-]*\d+)/$1\&\($2\)/gsi;
+# 3x10^8 -> 3&8; 3*10^-8 -> 3&-8
+    $expression=~s/(\d+)(?:x|\*)10(?:\^|\*\*)([\+\-]*\d+)/$1\&\($2\)/gsi;
+# Fill in multiplication signs
+# a b -> a*b;3 b -> 3*b;3 4 -> 3*4
+    $expression=~s/([A-Za-z0-9])\s+(?=[A-Za-z0-9])/$1\*/gs;
+# )( -> )*(; ) ( -> )*(
+    $expression=~s/\)\s*\(/\)\*\(/gs;
+# 3a -> 3*a; 3( -> 3*(; 3 ( -> 3*(; 3A -> 3*A
+    $expression=~s/(\d)\s*([a-zA-Z\(])/$1\*$2/gs;
+# a ( -> a*(
+    $expression=~s/([A-Za-z0-9])\s+\(/$1\*\(/gs;
+# )a -> )*a; )3 -> )*3; ) 3 -> )*3
+    $expression=~s/\)\s*([A-Za-z0-9])/\)\*$1/gs;
+# 3&8 -> 3e8; 3&-4 -> 3e-4
+    $expression=~s/(\d+)\&\(([\+\-]*\d+)\)/$1e$2/gs;
+    return $expression;
+}
+
+sub start_answer {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    push(@Apache::response::custom_answer,
+	&Apache::lonxml::get_all_text_unbalanced("/answer",$parser));
+    push(@Apache::response::custom_answer_type,
+	lc(&Apache::lonxml::get_param('type',$parstack,$safeeval)));
+    $Apache::response::custom_answer_type[-1] =~ s/\s+//g;
+    if ($target eq "edit" ) {
+	$result=&Apache::edit::tag_start($target,$token,'Answer algorithm');
+	$result.=&Apache::edit::editfield($token->[1],
+					  $Apache::response::custom_answer[-1],
+					  '',80,4);
+    } elsif ( $target eq "modified" ) {
+	$result=$token->[4].&Apache::edit::modifiedfield('/answer',$parser);
+    }
+    return $result;
+}
+
+sub end_answer {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    if ($target eq 'edit' ) {
+	return &Apache::edit::end_table();
+    }
+}
+
 sub decide_package {
     my ($tagstack)=@_;
     my $package;
@@ -315,7 +702,7 @@ sub start_responseparam {
 	    }
 	}
 	if (defined($optionlist)) {
-	    $result.='Use template: <select name="'.
+	    $result.=&mt('Use template:').' <select name="'.
 		&Apache::edit::html_element_name('parameter_package').'">'.
 		    '<option value=""></option>'.$optionlist.'</select><br />';
 	}
@@ -330,8 +717,8 @@ sub start_responseparam {
 						     $safeeval,'name','type',
 						     'description','default');
 	my $element=&Apache::edit::html_element_name('parameter_package');
-	if (defined($ENV{"form.$element"}) && $ENV{"form.$element"} ne '') {
-	    my $name=$ENV{"form.$element"};
+	if (defined($env{"form.$element"}) && $env{"form.$element"} ne '') {
+	    my $name=$env{"form.$element"};
 	    my $tag=&decide_package($tagstack);
 	    $token->[2]->{'name'}=$name;
 	    $token->[2]->{'type'}=
@@ -340,15 +727,15 @@ sub start_responseparam {
 		$Apache::lonnet::packagetab{"$tag&$name&display"};
 	    $token->[2]->{'default'}=
 		$Apache::lonnet::packagetab{"$tag&$name&default"};
+            $token->[3] = ['name','type','description','default'];
 	    $constructtag=1;
 	}
 	if ($constructtag) {
 	    $result = &Apache::edit::rebuild_tag($token);
-	    $result.=&Apache::edit::handle_insert();
 	}
     } elsif ($target eq 'grade' || $target eq 'answer' || $target eq 'web' ||
 	     $target eq 'tex' || $target eq 'analyze' ) {
-	if ($ENV{'request.state'} eq 'construct') {
+	if ($env{'request.state'} eq 'construct') {
 	    my $name   =&Apache::lonxml::get_param('name',$parstack,$safeeval);
 	    my $default=&Apache::lonxml::get_param('default',$parstack,
 						     $safeeval);
@@ -365,13 +752,11 @@ sub end_responseparam {
 }
 
 sub start_parameter {
-    my $result = &start_responseparam(@_);
-    return $result;
+    return &start_responseparam(@_);
 }
 
 sub end_parameter {
-    my $result = &end_responseparam(@_);
-    return $result;
+    return &end_responseparam(@_);
 }
 
 sub reset_params {
@@ -379,12 +764,12 @@ sub reset_params {
 }
 
 sub setup_params {
-    my ($tag) = @_;
+    my ($tag,$safeeval) = @_;
 
-    if ($ENV{'request.state'} eq 'construct') { return; }
+    if ($env{'request.state'} eq 'construct') { return; }
     my %paramlist=();
     foreach my $key (keys(%Apache::lonnet::packagetab)) {
-	if ($key =~ /^$tag/) {
+	if ($key =~ /^\Q$tag\E/) {
 	    my ($package,$name) = split(/&/,$key);
 	    $paramlist{$name}=1;
 	}
@@ -402,32 +787,88 @@ sub setup_params {
 	    &Apache::lonxml::debug("using nothing");
 	    $Apache::inputtags::params{$key}='';
 	} else {
-	    &Apache::lonxml::debug("using value");
+	    my $string="{return qq\0".$value."\0}";
+	    my $newvalue=&Apache::run::run($string,$safeeval,1);
+	    if (defined($newvalue)) { $value=$newvalue; }
 	    $Apache::inputtags::params{$key}=$value;
 	}
     }
 }
 
+{
+    my @answer_bits;
+    my $need_row_start;
+
 sub answer_header {
+    my ($type,$increment,$rows) = @_;
+    my $result;
+    if ($env{'form.answer_output_mode'} eq 'tex') {
+	undef(@answer_bits);
+	my $bit;
+	if ($Apache::lonhomework::type eq 'exam') {
+	    $bit = ($Apache::lonxml::counter+$increment).') ';
+	} else {
+	    $bit .= ' Answer for Part: \verb|'.
+		$Apache::inputtags::part.'| ';
+	}
+	push(@answer_bits,$bit);
+    } else {
+	my $td = '<td '.(defined($rows)?'rowspan="'.$rows.'"':'').'>';
+	$result  = '<table border="1"><tr>';
+	if ($Apache::lonhomework::type eq 'exam') {
+	    $result .= $td.($Apache::lonxml::counter+$increment). ')</td>';
+	} else {
+	    $result .= $td.&mt('Answer for Part: [_1]',
+			       $Apache::inputtags::part).'</td>';
+	}
+	$result .= "\n";
+	$need_row_start = 0;
+    }
+    return $result;
+}
+
+sub next_answer {
     my ($type) = @_;
     my $result;
-    if ($ENV{'form.answer_output_mode'} eq 'tex') {
-	$result = ' \vskip 0 mm \begin{tabular}{|c|}\hline Answer for Part: \verb|'.
-                  $Apache::inputtags::part.'| \\\\ \hline ';
+    if ($env{'form.answer_output_mode'} eq 'tex') {
+	# FIXME ... need to do something with tex mode
     } else {
-	$result = '<table border="1"><tr><td>Answer for Part:'.
-	    $Apache::inputtags::part. '</td>'."\n";
+	$result .= "</tr>";
+	$need_row_start = 1;
     }
     return $result;
 }
 
 sub answer_part {
-    my ($type,$answer) = @_;
+    my ($type,$answer,$args) = @_;
     my $result;
-    if ($ENV{'form.answer_output_mode'} eq 'tex') {
-	$result = ' \verb|'.$answer.'|\\\\ \hline ';
+    if ($env{'form.answer_output_mode'} eq 'tex') {
+	if (!$args->{'no_verbatim'}) {
+	    my $to_use='|';
+	    foreach my $value (32..126) {
+		my $char=pack('c',$value);
+		if ($answer !~ /\Q$char\E/) {
+		    $to_use=$char;
+		    last;
+		}
+	    }
+            my $fullanswer=$answer;
+            $answer='';
+            foreach my $element (split(/[\;]/,$fullanswer)) {
+	       if ($element ne '') {
+	 	  $answer.= '\verb'.$to_use.$element.$to_use.' \newline';
+	       }
+            }
+	}
+	if ($answer ne '') {
+	    push(@answer_bits,$answer);
+	}
     } else {
-	$result = '<td>'.$answer.'</td>';
+	if ($need_row_start) {
+	    $result .= '<tr>';
+	    $need_row_start = 0;
+	}
+	$result .= '<td>'.$answer.'</td>';
     }
     return $result;
 }
@@ -435,68 +876,180 @@ sub answer_part {
 sub answer_footer {
     my ($type) = @_;
     my $result;
-    if ($ENV{'form.answer_output_mode'} eq 'tex') {
-	$result = ' \end{tabular} \vskip 0 mm ';
+    if ($env{'form.answer_output_mode'} eq 'tex') {
+	$result  = ' \vskip 0 mm \noindent \begin{tabular}{|p{1.5cm}|p{6.8cm}|}\hline ';
+	$result .= $answer_bits[0].'&\vspace*{-4mm}\begin{itemize}';
+        for (my $i=1;$i<=$#answer_bits;$i++) {
+            $result.='\item '.$answer_bits[$i].'\vspace*{-7mm}';
+        }
+	$result .= ' \end{itemize} \\\\ \hline \end{tabular} \vskip 0 mm ';
     } else {
-	$result = '</tr></table>';
+	if (!$need_row_start) {
+	    $result .= '</tr>';
+	}
+	$result .= '</table>';
     }
     return $result;
 }
 
+}
+
 sub showallfoils {
-    my $return=0;
-    if (defined($ENV{'form.showallfoils'}) &&
-	$ENV{'request.state'} eq 'construct') {
-	$return=1;
+    if (defined($env{'form.showallfoils'})) {
+	my ($symb)=&Apache::lonnet::whichuser();
+	if (($env{'request.state'} eq 'construct') || 
+	    ($env{'user.adv'} && $symb eq '')      ||
+            ($Apache::lonhomework::viewgrades) ) {
+	    return 1;
+	}
     }
-    return $return;
+    if ($Apache::lonhomework::type eq 'survey') { return 1; }
+    return 0;
 }
 
+=pod
+
+=item &getresponse();
+
+Retreives the current submitted response, helps out in the case of
+scantron mode.
+
+Returns either the exact text of the submission, or a bubbled response
+converted to something usable.
+
+Optional Arguments:
+  $offset - (defaults to 1) if a problem has more than one bubble
+            response, pass in the number of the bubble wanted, (the
+            first bubble associated with a problem has an offset of 1,
+            the second bubble is 2
+
+  $resulttype - undef    -> a number between 0 and 25
+                'A is 1' -> a number between 1 and 26
+                'letter' -> a letter between 'A' and 'Z'
+  $lines  - undef problem only needs a single line of bubbles.
+            nonzero  Problem wants the first nonempty response in 
+                      $lines lines of bubbles.
+  $bubbles_per_line - Must be provided if lines is defined.. number of
+                      bubbles on a line.
+
+=cut
+
 sub getresponse {
-    my ($temp)=@_;
+    my ($offset,$resulttype, $lines, $bubbles_per_line)=@_;
     my $formparm='form.HWVAL_'.$Apache::inputtags::response['-1'];
     my $response;
-    if (!defined($temp)) {
-	$temp=1;
+    if (!defined($offset)) {
+	$offset=1;
     } else {
-	$formparm.=":$temp";
+	$formparm.=":$offset";
+    }
+    if (!defined($lines)) {
+	$lines = 1;
     }
     my %let_to_num=('A'=>0,'B'=>1,'C'=>2,'D'=>3,'E'=>4,'F'=>5,'G'=>6,'H'=>7,
 		    'I'=>8,'J'=>9,'K'=>10,'L'=>11,'M'=>12,'N'=>13,'O'=>14,
 		    'P'=>15,'Q'=>16,'R'=>17,'S'=>18,'T'=>19,'U'=>20,'V'=>21,
 		    'W'=>22,'X'=>23,'Y'=>24,'Z'=>25);
-    if ($ENV{'form.submitted'} eq 'scantron') {
+    if ($env{'form.submitted'} eq 'scantron') {
 	my $part  = $Apache::inputtags::part;
 	my $id    = $Apache::inputtags::response[-1];
-	$response = $ENV{'scantron.'.($Apache::lonxml::counter+$temp-1).
-			 '.answer'};
+	
+	my $line;
+	my $startline = $env{'form.scantron_questnum_start.'.$part.'.'.$id};
+        if (!$startline) {
+            $startline = $Apache::lonxml::counter;
+        }
+	for ($line = 0; $line < $lines; $line++) {
+            my $theline = $startline+$offset-1+$line;
+	    $response = $env{"scantron.$theline.answer"};
+	    if ((defined($response)) && ($response ne "") && ($response ne " ")) {
+		last;
+	    }
+ 
+	}
+
 	# save bubbled letter for later
 	$Apache::lonhomework::results{"resource.$part.$id.scantron"}.=
 	    $response;
-	$response = $let_to_num{$response};
+	if ($resulttype ne 'letter') {
+	    if ($resulttype eq 'A is 1') {
+		$response = $let_to_num{$response}+1;
+	    } else {
+		$response = $let_to_num{$response};
+	    }
+	    if ($response ne "") {
+		$response += $line * $bubbles_per_line;
+	    }
+	} else {
+	    if ($response ne "") {
+		$response = chr(ord($response) + $line * $bubbles_per_line);
+	    }
+	}
+
     } else {
-	$response = $ENV{$formparm};
+	$response = $env{$formparm};
     }
+    # 
+    #  If we have a nonempty answer, correct the numeric value
+    #  of the answer for the line on which it was found.
+    #
+
     return $response;
 }
 
+=pod
+
+=item &repetition();
+
+Returns the number of lines that are required to encode the weight.
+(Currently expects that there are 10 bubbles per line)
+
+=cut
+
 sub repetition {
     my $id = $Apache::inputtags::part;
     my $weight = &Apache::lonnet::EXT("resource.$id.weight");
-    my $repetition = int $weight/9;
-    if ($weight % 9 != 0) {$repetition++;} 
+    if (!defined($weight) || ($weight eq '')) { $weight=1; }
+    my $repetition = int($weight/10);
+    if ($weight % 10 != 0) { $repetition++; } 
     return $repetition;
 }
 
+=pod
+
+=item &scored_response();
+
+Sets the results hash elements
+
+   resource.$part_id.$response_id.awarded - to the floating point
+     number between 0 and 1 that was awarded on the bubbled input
+
+   resource.$part_id.$response_id.awarddetail - to 'ASSIGNED_SCORE'
+
+Returns
+
+   the number of bubble sheet lines that were used (and likely need to
+     be passed to &Apache::lonxml::increment_counter()
+
+Arguments
+
+   $part_id - id of the part to grade
+   $response_id - id of the response to grade
+  
+
+=cut
+
 sub scored_response {
     my ($part,$id)=@_;
     my $repetition=&repetition();
     my $score=0;
     for (my $i=0;$i<$repetition;$i++) {
+	# A is 1, B is 2, etc. (get response return 0-9 and then we add 1)
 	my $increase=&Apache::response::getresponse($i+1);
 	if ($increase ne '') { $score+=$increase+1; }
     }
     my $weight = &Apache::lonnet::EXT("resource.$part.weight");
+    if (!defined($weight) || $weight eq '' || $weight eq 0) { $weight = 1; }
     my $pcr=$score/$weight;
     $Apache::lonhomework::results{"resource.$part.$id.awarded"}=$pcr;
     $Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=
@@ -552,7 +1105,6 @@ sub whichorder {
     for (my $i=0;$i<=$#bottomlist;$i++) {
 	if ($bottomlist[$i]) { push(@whichopt,$bottomlist[$i]) }
     }
-
     return @whichopt;
 }
 
@@ -561,9 +1113,223 @@ sub show_answer {
     my $award  = $Apache::lonhomework::history{"resource.$part.solved"};
     my $status = $Apache::inputtags::status[-1];
     return  ( ($award =~ /^correct/
-	       && lc($Apache::lonhomework::problemstatus) ne 'no')
+	       && &Apache::lonhomework::show_problem_status())
 	      || $status eq "SHOW_ANSWER");
 }
+
+sub analyze_store_foilgroup {
+    my ($shown,$attrs)=@_;
+    my $part_id="$Apache::inputtags::part.$Apache::inputtags::response[-1]";
+    foreach my $name (@{ $Apache::response::foilgroup{'names'} }) {
+	if (defined($Apache::lonhomework::analyze{"$part_id.foil.value.$name"})) { next; }
+	push (@{ $Apache::lonhomework::analyze{"$part_id.foils"} },$name);
+	foreach my $attr (@$attrs) {
+	    $Apache::lonhomework::analyze{"$part_id.foil.".$attr.".$name"} =
+		$Apache::response::foilgroup{"$name.".$attr};
+	}
+    }
+    push (@{ $Apache::lonhomework::analyze{"$part_id.shown"} }, @{ $shown });
+}
+
+sub check_if_computed {
+    my ($token,$parstack,$safeeval,$name)=@_;
+    my $value = &Apache::lonxml::get_param($name,$parstack,$safeeval);
+    if (ref($token->[2]) eq 'HASH' && $value ne $token->[2]{$name}) {
+	my $part_id="$Apache::inputtags::part.$Apache::inputtags::response[-1]";
+	$Apache::lonhomework::analyze{"$part_id.answercomputed"} = 1;
+    }
+}
+
+sub pick_foil_for_concept {
+    my ($target,$attrs,$hinthash,$parstack,$safeeval)=@_;
+    if (not defined(@{ $Apache::response::conceptgroup{'names'} })) { return; }
+    my @names = @{ $Apache::response::conceptgroup{'names'} };
+    my $pick=int(&Math::Random::random_uniform() * ($#names+1));
+    my $name=$names[$pick];
+    push @{ $Apache::response::foilgroup{'names'} }, $name;
+    foreach my $attr (@$attrs) {
+	$Apache::response::foilgroup{"$name.".$attr} =
+	    $Apache::response::conceptgroup{"$name.".$attr};
+    }
+    my $concept = &Apache::lonxml::get_param('concept',$parstack,$safeeval);
+    $Apache::response::foilgroup{"$name.concept"} = $concept;
+    &Apache::lonxml::debug("Selecting $name in $concept");
+    my $part_id="$Apache::inputtags::part.$Apache::inputtags::response[-1]";
+    if ($target eq 'analyze') {
+	push (@{ $Apache::lonhomework::analyze{"$part_id.concepts"} },
+	      $concept);
+	$Apache::lonhomework::analyze{"$part_id.concept.$concept"}=
+	    $Apache::response::conceptgroup{'names'};
+	foreach my $name (@{ $Apache::response::conceptgroup{'names'} }) {
+	    push (@{ $Apache::lonhomework::analyze{"$part_id.foils"} },
+		  $name);
+	    foreach my $attr (@$attrs) {
+		$Apache::lonhomework::analyze{"$part_id.foil.$attr.$name"}=
+		    $Apache::response::conceptgroup{"$name.$attr"};
+	    }
+	}
+    }
+    push(@{ $hinthash->{"$part_id.concepts"} },$concept);
+    $hinthash->{"$part_id.concept.$concept"}=
+	$Apache::response::conceptgroup{'names'};
+
+}
+
+=pod
+
+=item get_response_param()
+
+Get a parameter associated with a problem.
+Parameters:
+	$id        - the id of the paramater, either a part id, 
+              or a partid and responspe id joined by _
+	$name      - Name of the parameter to fetch
+	$default   - Default value for the paramter.
+
+=cut
+
+sub get_response_param {
+    my ($id,$name,$default)=@_;
+    my $parameter;
+    if ($env{'request.state'} eq 'construct' &&
+	defined($Apache::inputtags::params{$name})) {
+	$parameter=$Apache::inputtags::params{$name};
+    } else {
+	$parameter=&Apache::lonnet::EXT("resource.$id.$name");
+    }
+    if (!defined($parameter) ||	$parameter eq '') {
+	$parameter = $default;
+    }
+    return $parameter;
+}
+
+sub submitted {
+    my ($who)=@_;
+    
+    # when scatron grading any submission is a submission
+    if ($env{'form.submitted'} eq 'scantron') { return 1; }
+    # if the caller only cared if this was a scantron submission
+    if ($who eq 'scantron') { return 0; }
+    # if the Submit Answer button for this particular part was pressed
+    my $partid=$Apache::inputtags::part;
+    if ($env{'form.submitted'} eq "part_$partid") {
+	return 1;
+    }
+    if ($env{'form.submitted'} eq "yes"
+	&& defined($env{'form.submit_'.$partid})) {
+	return 1;
+    }
+    # Submit All button on a .page was pressed
+    if (defined($env{'form.all_submit'})) { return 1; }
+    # otherwise no submission occurred
+    return 0;
+}
+
+sub add_to_gradingqueue {
+    my ($symb,$courseid,$domain,$name) = &Apache::lonnet::whichuser();
+    if (   $courseid eq ''
+	|| $symb eq ''
+	|| $env{'request.state'} eq 'construct'
+	|| $Apache::lonhomework::type ne 'problem') {
+	return;
+    }
+
+    my %queue_info = ( 'type' => 'problem',
+		       'time' => time);
+
+    if (exists($Apache::lonhomework::history{"resource.0.checkedin.slot"})) {
+	$queue_info{'slot'}=
+	     $Apache::lonhomework::history{"resource.0.checkedin.slot"};
+    }
+
+    my $result=&Apache::bridgetask::add_to_queue('gradingqueue',\%queue_info);
+    if ($result ne 'ok') {
+	&Apache::lonxml::error("add_to_queue said $result");
+    }
+}
+
+=pod 
+
+=item check_status()
+
+basically undef and 0 (both false) mean that they still have work to do
+and all true values mean that they can't do any more work
+
+	a return of undef means it is unattempted
+	a return of 0 means it is attmpted and wrong but still has tries
+	a return of 1 means it is marked correct
+	a return of 2 means they have exceed maximum number of tries
+	a return of 3 means it after the answer date
+
+=cut
+
+sub check_status {
+    my ($id)=@_;
+    if (!defined($id)) { $id=$Apache::inputtags::part; }
+    my $curtime=&Apache::lonnet::EXT('system.time');
+    my $opendate=&Apache::lonnet::EXT("resource.$id.opendate");
+    my $duedate=&Apache::lonnet::EXT("resource.$id.duedate");
+    my $answerdate=&Apache::lonnet::EXT("resource.$id.answerdate");
+    if ( $opendate && $curtime > $opendate &&
+         $duedate && $curtime > $duedate &&
+         $answerdate && $curtime > $answerdate) {
+        return 3;
+    }
+    my $status=&Apache::lonnet::EXT("user.resource.resource.$id.solved");
+    if ($status =~ /^correct/) { return 1; }
+    if (!$status) { return undef; }
+    my $maxtries=&Apache::lonnet::EXT("resource.$id.maxtries");
+    if ($maxtries eq '') { $maxtries=2; }
+    my $curtries=&Apache::lonnet::EXT("user.resource.resource.$id.tries");
+    if ($curtries < $maxtries) { return 0; }
+    return 2;
+}
+
+=pod
+
+=item setup_prior_tries_hash()
+
+  Foreach each past .submission $func is called with 3 arguments
+     - the mode to set things up for (currently always 'grade')
+     - the stored .submission string
+     - The expansion of $data
+
+  $data is an array ref containing elements that are either
+    - scalars that are other elements of the history hash to pass to $func
+    - ref to data to be passed untouched to $func
+
+=cut
+
+sub setup_prior_tries_hash {
+    my ($func,$data) = @_;
+    my $part = $Apache::inputtags::part;
+    my $id   = $Apache::inputtags::response[-1];	
+    foreach my $i (1..$Apache::lonhomework::history{'version'}) {
+	my $sub_key   = "$i:resource.$part.$id.submission";
+	next if (!exists($Apache::lonhomework::history{$sub_key}));
+	my @other_data;
+	foreach my $datum (@{ $data }) {
+	    if (ref($datum)) {
+		push(@other_data,$datum);
+	    } else {
+		my $info_key = "$i:resource.$part.$id.$datum";
+		push(@other_data,$Apache::lonhomework::history{$info_key});
+	    }
+	}
+
+	my $output =
+	    &$func('grade',
+		   $Apache::lonhomework::history{$sub_key},
+		   \@other_data);
+	if (defined($output)) {
+	    $Apache::inputtags::submission_display{$sub_key} = $output;
+	}
+    }
+}
+
 1;
 __END__
  
+=pod
+
+=cut