--- loncom/homework/inputtags.pm	2004/07/15 19:44:54	1.148
+++ loncom/homework/inputtags.pm	2005/01/31 22:00:40	1.156
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # input  definitons
 #
-# $Id: inputtags.pm,v 1.148 2004/07/15 19:44:54 albertel Exp $
+# $Id: inputtags.pm,v 1.156 2005/01/31 22:00:40 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -317,7 +317,7 @@ sub finalizeawards {
 			       'BAD_FORMULA', 'SIG_FAIL', 'INCORRECT', 
 			       'MISORDERED_RANK', 'INVALID_FILETYPE',
 			       'DRAFT', 'SUBMITTED', 'ASSIGNED_SCORE',
-			       'APPROX_ANS', 'EXACT_ANS') {
+			       'APPROX_ANS', 'EXACT_ANS','COMMA_FAIL') {
 	($result,$msg)=&checkstatus($possibleaward,$awardref,$msgref);
 	if (defined($result)) { return ($result,$msg); }
     }
@@ -347,8 +347,8 @@ sub decideoutput {
 		$message = '\textbf{'.&mt('You are correct.').'}';
 	    } else {
 		$message = "<b>".&mt('You are correct.')."</b>";
+		$message.=" ".&mt("Computer's answer now shown above.");
 	    }
-	    $message.=" ".&mt("Computer's answer now shown.");
 	    $added_computer_text=1;
 	    unless ($ENV{'course.'.
 			     $ENV{'request.course.id'}.
@@ -380,8 +380,8 @@ sub decideoutput {
 		$message = '\textbf{'.&mt('You are correct.').'}';
 	    } else {
 		$message = "<b>".&mt('You are correct.')."</b>";
+		$message.=" ".&mt("Computer's answer now shown above.");
 	    }
-	    $message.=" ".&mt("Computer's answer now shown.");
 	    $added_computer_text=1;
 	    unless ($ENV{'course.'.
 			     $ENV{'request.course.id'}.
@@ -439,17 +439,17 @@ sub decideoutput {
 	$bgcolor=$possiblecolors{'not_charged_try'};
 	$button=1;
     } elsif ($award eq 'UNIT_INVALID_STUDENT') {
-	$message = &mt('Unable to interpret units. Computer reads units as "[_1]"','<tt>'.$awardmsg.'</tt>.');
+	$message = &mt('Unable to interpret units. Computer reads units as "[_1]".',&markup_unit($awardmsg,$target));
 	if ($target ne 'tex') {$message.=&Apache::loncommon::help_open_topic('Physical_Units');} 
 	$bgcolor=$possiblecolors{'not_charged_try'};
 	$button=1;
     } elsif ($award eq 'UNIT_FAIL' || $award eq 'UNIT_IRRECONCIBLE') {
-	$message = &mt('Incompatible units. No conversion found between "[_1]" and the required units ','<tt>'.$awardmsg.'</tt>.');
+	$message = &mt('Incompatible units. No conversion found between "[_1]" and the required units.',&markup_unit($awardmsg,$target));
 	if ($target ne 'tex') {$message.=&Apache::loncommon::help_open_topic('Physical_Units');} 
 	$bgcolor=$possiblecolors{'not_charged_try'};
 	$button=1;
     } elsif ($award eq 'UNIT_NOTNEEDED') {
-	$message = &mt('Only a number required. Computer reads units of "[_1]"','<tt>'.$awardmsg.'</tt>.');
+	$message = &mt('Only a number required. Computer reads units of "[_1]".',&markup_unit($awardmsg,$target));
 	$bgcolor=$possiblecolors{'not_charged_try'};
 	$button=1;
     } elsif ($award eq 'NO_UNIT') {
@@ -457,6 +457,10 @@ sub decideoutput {
 	if ($target ne 'tex') {$message.=&Apache::loncommon::help_open_topic('Physical_Units')};
 	$bgcolor=$possiblecolors{'not_charged_try'};
 	$button=1;
+    } elsif ($award eq 'COMMA_FAIL') {
+	$message = &mt("Proper comma separation is required").'.';
+	$bgcolor=$possiblecolors{'not_charged_try'};
+	$button=1;
     } elsif ($award eq 'BAD_FORMULA') {
 	$message = &mt("Unable to understand formula");
 	$bgcolor=$possiblecolors{'not_charged_try'};
@@ -491,13 +495,22 @@ sub decideoutput {
 	$button=1;
     }
     if ($Apache::inputtags::status[-1] eq 'SHOW_ANSWER' && 
-	!$added_computer_text) {
-	$message.=" ".&mt("Computer's answer now shown.");
+	!$added_computer_text && $target ne 'tex') {
+	$message.=" ".&mt("Computer's answer now shown above.");
 	$added_computer_text=1;
     }
     return ($button,$bgcolor,$message,$previousmsg);
 }
 
+sub markup_unit {
+    my ($unit,$target)=@_;
+    if ($target eq 'tex') {
+	return '\texttt{'.&Apache::lonxml::latex_special_symbols($unit).'}'; 
+    } else {
+	return "<tt>".$unit."</tt>";
+    }
+}
+
 sub removealldata {
     my ($id)=@_;
     foreach my $key (keys(%Apache::lonhomework::results)) {
@@ -524,10 +537,15 @@ sub hidealldata {
 
 sub setgradedata {
     my ($award,$msg,$id,$previously_used) = @_;
-    # if the student already has it correct, don't modify the status
-    if ($Apache::lonhomework::scantronmode && defined($ENV{'form.CODE'})) {
+    if ($Apache::lonhomework::scantronmode && 
+	&Apache::lonnet::validCODE($ENV{'form.CODE'})) {
 	$Apache::lonhomework::results{"resource.CODE"}=$ENV{'form.CODE'};
+    } elsif ($Apache::lonhomework::scantronmode && 
+	     $ENV{'form.CODE'} eq '' &&
+	     $Apache::lonhomework::history{"resource.CODE"} ne '') {
+	$Apache::lonhomework::results{"resource.CODE"}='';
     }
+
     if (!$Apache::lonhomework::scantronmode &&
 	$Apache::inputtags::status['-1'] ne 'CAN_ANSWER' &&
 	$Apache::inputtags::status['-1'] ne 'CANNOT_ANSWER') {
@@ -536,7 +554,10 @@ sub setgradedata {
     } elsif ( $Apache::lonhomework::history{"resource.$id.solved"} !~
 	      /^correct/ || $Apache::lonhomework::scantronmode ||
 	      lc($Apache::lonhomework::problemstatus) eq 'no') {
-	#handle assignment of tries and solved status
+        # the student doesn't already have it correct,
+	# or we are in a mode (scantron orno problem status) where a correct 
+        # can become incorrect
+	# handle assignment of tries and solved status
 	my $solvemsg;
 	if ($Apache::lonhomework::scantronmode) {
 	    $solvemsg='correct_by_scantron';
@@ -570,7 +591,8 @@ sub setgradedata {
 	} elsif ( $award eq 'INCORRECT' ) {
 	    $Apache::lonhomework::results{"resource.$id.tries"} =
 		$Apache::lonhomework::history{"resource.$id.tries"} + 1;
-	    if (lc($Apache::lonhomework::problemstatus) eq 'no') {
+	    if (lc($Apache::lonhomework::problemstatus) eq 'no' ||
+		$Apache::lonhomework::scantronmode) {
 		$Apache::lonhomework::results{"resource.$id.awarded"} = 0;
 	    }
 	    $Apache::lonhomework::results{"resource.$id.solved"} =
@@ -589,7 +611,8 @@ sub setgradedata {
 	} else {
 	    $Apache::lonhomework::results{"resource.$id.solved"} =
 		'incorrect_attempted';
-	    if (lc($Apache::lonhomework::problemstatus) eq 'no') {
+	    if (lc($Apache::lonhomework::problemstatus) eq 'no' ||
+		$Apache::lonhomework::scantronmode) {
 		$Apache::lonhomework::results{"resource.$id.tries"} =
 		    $Apache::lonhomework::history{"resource.$id.tries"} + 1;
 		$Apache::lonhomework::results{"resource.$id.awarded"} = 0;
@@ -737,7 +760,7 @@ sub gradestatus {
 	if ( $status eq 'SHOW_ANSWER' || $status eq 'CANNOT_ANSWER') {$showbutton = 0;}
 	if ( $showbutton ) { 
 	    if ($target ne 'tex') {
-		$button = '<input type="submit" name="submit" value="'.&mt('Submit Answer').'" />';
+		$button = '<input type="submit" name="submit_'.$id.'" value="'.&mt('Submit Answer').'" />';
 	    }
 	}
 	if ($Apache::lonhomework::history{"resource.$id.afterduedate"}) {