--- loncom/homework/response.pm	2006/06/19 16:32:35	1.140
+++ loncom/homework/response.pm	2007/10/08 09:22:50	1.179
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # various response type definitons response definition
 #
-# $Id: response.pm,v 1.140 2006/06/19 16:32:35 www Exp $
+# $Id: response.pm,v 1.179 2007/10/08 09:22:50 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -30,6 +30,7 @@ package Apache::response;
 use strict;
 use Apache::lonlocal;
 use Apache::lonnet;
+use Apache::lonmaxima();
 
 BEGIN {
     &Apache::lonxml::register('Apache::response',('responseparam','parameter','dataresponse','customresponse','mathresponse'));
@@ -128,11 +129,13 @@ sub setrandomnumber {
 	}
 	$shift_amt=scalar(@Apache::inputtags::responselist);
     } elsif ($Apache::lonhomework::parsing_a_task) {
-	$id1=$Apache::bridgetask::dimension;
-	if (!$ignore_id2 && defined($Apache::bridgetask::instance[-1])) {
-	    $id2=$Apache::bridgetask::instance[-1];
+	$id1=&Apache::bridgetask::get_dim_id();
+	if (!$ignore_id2 && ref($Apache::bridgetask::instance{$id1})) {
+	    $id2=$Apache::bridgetask::instance{$id1}[-1];
+	    $shift_amt=scalar(@{$Apache::bridgetask::instance{$id1}});
+	} else {
+	    $shift_amt=0;
 	}
-	$shift_amt=scalar(@Apache::bridgetask::instance);
     } 
     &Apache::lonxml::debug("id1: $id1, id2: $id2, shift_amt: $shift_amt");
     if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
@@ -262,11 +265,14 @@ sub meta_response_order {
 }
 
 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 ( $last && $key =~ /^(\d+):/ ) {
+		next if ($1 >= $last);
+	    }
 	    &Apache::lonxml::debug("Trying $key");
 	    my $pastresponse=$Apache::lonhomework::history{$key};
 	    if ($pastresponse eq $curresponse) {
@@ -304,7 +310,7 @@ sub handle_previous {
 }
 
 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'}) ) {
 	$myself=1;
@@ -338,7 +344,7 @@ sub end_dataresponse {
     if ( $target eq 'web' ) {
     } elsif ($target eq 'grade' ) {
 	if ( defined $env{'form.submitted'}) {
-	    my ($symb,$courseid,$domain,$name)=&Apache::lonxml::whichuser();
+	    my ($symb,$courseid,$domain,$name)=&Apache::lonnet::whichuser();
 	    my $allowed=&Apache::lonnet::allowed('mgr',$courseid);
 	    if ($allowed) {
 		&Apache::response::setup_params('dataresponse',$safeeval);
@@ -365,13 +371,14 @@ sub start_customresponse {
     my $id = &Apache::response::start_response($parstack,$safeeval);
     push(@Apache::lonxml::namespace,'customresponse');
     my $result;
-    undef($Apache::response::custom_answer);
+    @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;
+	    $Apache::inputtags::answertxt{$id}=[$answer];
 	}
     } elsif ($target eq 'edit') {
 	$result.=&Apache::edit::tag_start($target,$token);
@@ -384,7 +391,6 @@ sub start_customresponse {
 						  $safeeval,'answerdisplay');
 	if ($constructtag) {
 	    $result = &Apache::edit::rebuild_tag($token);
-	    $result.=&Apache::edit::handle_insert();
 	}
     } elsif ($target eq 'answer' || $target eq 'grade') {
 	&Apache::response::reset_params();
@@ -401,8 +407,11 @@ sub end_customresponse {
     my $id=$Apache::inputtags::response[-1];
     if ( $target eq 'grade' && &Apache::response::submitted() ) {
 	my $response = &Apache::response::getresponse();
-	if ( $response =~ /[^\s]/ && 
-	     $Apache::response::custom_answer_type eq 'loncapa/perl') {
+	if ($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);
 	    }
@@ -414,7 +423,7 @@ sub end_customresponse {
 	    ${$safeeval->varglob('LONCAPA::customresponse_submission')}=
 		$response;
 	    
-	    my $award = &Apache::run::run('{ my $submission=$LONCAPA::customresponse_submission;'.$Apache::response::custom_answer.'}',$safeeval);
+	    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';
@@ -427,39 +436,72 @@ sub end_customresponse {
 		    $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(),
+					   $part);
+	if ($target eq 'analyze') {
+	    &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 $result;
-    undef($Apache::response::custom_answer);
+    @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;
+	    $Apache::inputtags::answertxt{$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'],
+					   $token);
+	$result.=&Apache::edit::text_arg('Argument Array:',
+					 'args',$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');
+						  $safeeval,'answerdisplay','cas','args');
 	if ($constructtag) {
 	    $result = &Apache::edit::rebuild_tag($token);
-	    $result.=&Apache::edit::handle_insert();
 	}
     } elsif ($target eq 'answer' || $target eq 'grade') {
 	&Apache::response::reset_params();
@@ -476,8 +518,7 @@ sub end_mathresponse {
     my $id=$Apache::inputtags::response[-1];
     if ( $target eq 'grade' && &Apache::response::submitted() ) {
 	my $response = &Apache::response::getresponse();
-	if ( $response =~ /[^\s]/ && 
-	     $Apache::response::custom_answer_type eq 'loncapa/perl') {
+	if ( $response =~ /[^\s]/ ) {
 	    if (!$Apache::lonxml::default_homework_loaded) {
 		&Apache::lonxml::default_homework_load($safeeval);
 	    }
@@ -486,10 +527,12 @@ sub end_mathresponse {
 	    $Apache::lonhomework::results{"resource.$part.$id.submission"}=
 		$response;
 	    my $error;
-	    ${$safeeval->varglob('LONCAPA::mathresponse_submission')}=
-		$response;
-	    
-	    my $award = &Apache::run::run('{ my $submission=$LONCAPA::mathresponse_submission;'.$Apache::response::custom_answer.'}',$safeeval);
+	    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);
+            }
 	    if (!&Apache::inputtags::valid_award($award)) {
 		$error = $award;
 		$award = 'ERROR';
@@ -503,25 +546,59 @@ sub end_mathresponse {
 	    }
 	}
     }
+    if ($target eq 'web') {
+	&setup_prior_tries_hash(\&format_prior_response_math);
+    }
+
     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;
-    $Apache::response::custom_answer=
-	&Apache::lonxml::get_all_text_unbalanced("/answer",$parser);
-    $Apache::response::custom_answer_type=
-	lc(&Apache::lonxml::get_param('type',$parstack,$safeeval));
-    $Apache::response::custom_answer_type =~ s/\s+//g;
+    push(@Apache::response::custom_answer,
+	&Apache::lonxml::get_all_text_unbalanced("/answer",$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,
+					  $Apache::response::custom_answer[-1],
 					  '',80,4);
     } elsif ( $target eq "modified" ) {
 	$result=$token->[4].&Apache::edit::modifiedfield('/answer',$parser);
@@ -602,7 +679,6 @@ sub start_responseparam {
 	}
 	if ($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' || $target eq 'analyze' ) {
@@ -640,7 +716,7 @@ sub setup_params {
     if ($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;
 	}
@@ -668,9 +744,10 @@ sub setup_params {
 
 {
     my @answer_bits;
+    my $need_row_start;
 
 sub answer_header {
-    my ($type,$increment) = @_;
+    my ($type,$increment,$rows) = @_;
     my $result;
     if ($env{'form.answer_output_mode'} eq 'tex') {
 	undef(@answer_bits);
@@ -683,34 +760,58 @@ sub answer_header {
 	}
 	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>';
+	    $result .= $td.($Apache::lonxml::counter+$increment). ')</td>';
 	} else {
-	    $result .= '<td>Answer for Part:'.$Apache::inputtags::part.'</td>';
+	    $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') {
+	# FIXME ... need to do something with tex mode
+    } else {
+	$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') {
-	my $to_use='|';
-	foreach my $value (32..126) {
-	    my $char=pack('c',$value);
-	    if ($answer !~ /\Q$char\E/) {
-		$to_use=$char;
-		last;
+	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;
+		}
+	    }
+	    if ($answer ne '') {
+		$answer = '\verb'.$to_use.$answer.$to_use;
 	    }
 	}
 	if ($answer ne '') {
-	    push(@answer_bits,'\verb'.$to_use.$answer.$to_use);
+	    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;
 }
@@ -733,7 +834,7 @@ sub answer_footer {
 
 sub showallfoils {
     if (defined($env{'form.showallfoils'})) {
-	my ($symb)=&Apache::lonxml::whichuser();
+	my ($symb)=&Apache::lonnet::whichuser();
 	if (($env{'request.state'} eq 'construct') || 
 	    ($env{'user.adv'} && $symb eq '')      ||
             ($Apache::lonhomework::viewgrades) ) {
@@ -744,15 +845,46 @@ sub showallfoils {
     return 0;
 }
 
+=pod
+
+=item &getresponse($offset,$resulttype);
+
+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,$resulttype)=@_;
+    my ($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)) {
+	$lines = 1;
+    }
+
     my %let_to_num=('A'=>0,'B'=>1,'C'=>2,'D'=>3,'E'=>4,'F'=>5,'G'=>6,'H'=>7,
 		    'I'=>8,'J'=>9,'K'=>10,'L'=>11,'M'=>12,'N'=>13,'O'=>14,
 		    'P'=>15,'Q'=>16,'R'=>17,'S'=>18,'T'=>19,'U'=>20,'V'=>21,
@@ -760,24 +892,57 @@ sub getresponse {
     if ($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 $line;
+	for ($line = 0; $line < $lines; $line++) {
+	    $response = $env{'scantron.'.
+				 ($Apache::lonxml::counter+$offset-1+$line).
+				 '.answer'};
+	    if ($response ne "") {
+		last;
+	    }
+	    
+	}
+
 	# save bubbled letter for later
 	$Apache::lonhomework::results{"resource.$part.$id.scantron"}.=
 	    $response;
+
 	if ($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};
     }
+    # 
+    #  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");
@@ -787,6 +952,30 @@ sub repetition {
     return $repetition;
 }
 
+=pod
+
+=item &scored_response($part_id,$response_id);
+
+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();
@@ -922,7 +1111,17 @@ sub pick_foil_for_concept {
 	$Apache::response::conceptgroup{'names'};
 
 }
-
+#------------------------------------------------------------
+#
+#  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
+#  $default   - Default value for the paramter.
+#
+#  
+#
 sub get_response_param {
     my ($id,$name,$default)=@_;
     my $parameter;
@@ -947,7 +1146,13 @@ sub submitted {
     if ($who eq 'scantron') { return 0; }
     # if the Submit Answer button for this particular part was pressed
     my $partid=$Apache::inputtags::part;
-    if (defined($env{'form.submit_'.$partid})) { return 1; }
+    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 occured
@@ -955,7 +1160,7 @@ sub submitted {
 }
 
 sub add_to_gradingqueue {
-    my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+    my ($symb,$courseid,$domain,$name) = &Apache::lonnet::whichuser();
     if (   $courseid eq ''
 	|| $symb eq ''
 	|| $env{'request.state'} eq 'construct'
@@ -987,7 +1192,7 @@ sub add_to_gradingqueue {
 # a return of 3 means it after the answer date
 sub check_status {
     my ($id)=@_;
-    if (!$id) {	$id=$Apache::linputtags::part; }
+    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");
@@ -1007,6 +1212,48 @@ sub check_status {
     return 2;
 }
 
+=pod
+
+=item setup_prior_tries_hash($func,$data)
+
+  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__
  
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