--- loncom/xml/lonplot.pm	2007/08/04 00:01:52	1.127
+++ loncom/xml/lonplot.pm	2007/08/09 06:25:43	1.128
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.127 2007/08/04 00:01:52 albertel Exp $
+# $Id: lonplot.pm,v 1.128 2007/08/09 06:25:43 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -757,10 +757,45 @@ sub end_key {
     return $result;
 }
 
-sub gnuplot_protect {
-    my ($string) = @_;
-    $string =~ s{([_^&~\{\}]|\\\\)}{\\\\$1}g;
-    return $string;
+sub parse_label {
+    my ($target,$text) = @_;
+    my $parser=HTML::LCParser->new(\$text);
+    my $result;
+    while (my $token=$parser->get_token) {
+	if ($token->[0] eq 'S') {
+	    if ($token->[1] eq 'sub') {
+		$result .= '_{';
+	    } elsif ($token->[1] eq 'sup') {
+		$result .= '^{';
+	    } else {
+		$result .= $token->[4];
+	    }
+	} elsif ($token->[0] eq 'E') {
+	    if ($token->[1] eq 'sub'
+		|| $token->[1] eq 'sup') {
+		$result .= '}';
+	    } else {
+		$result .= $token->[2];
+	    }
+	} elsif ($token->[0] eq 'T') {
+	    $result .= &replace_entities($target,$token->[1]);
+	}
+    }
+    return $result;
+}
+
+
+my %lookup = 
+    ('(pi|#960)' => {'tex' => '{/Symbol p}', 'web' => "\x{3C0}"},);
+
+sub replace_entities {
+    my ($target,$text) = @_;
+    $text =~ s{([_^~\{\}]|\\\\)}{\\\\$1}g;
+    while (my ($re, $replace) = each(%lookup)) {
+	$text =~ s/&$re;/$replace->{$target}/g;
+    }
+    $text =~ s{(&)}{\\\\$1}g;
+    return $text;
 }
 
 ##------------------------------------------------------------------- title
@@ -774,7 +809,7 @@ sub start_title {
 	if (length($title) > $max_str_len) {
 	    $title = substr($title,0,$max_str_len);
 	}
-	$title = &gnuplot_protect($title);
+	$title = &parse_label($target,$title);
     } elsif ($target eq 'edit') {
 	$result.=&Apache::edit::tag_start($target,$token,'Plot Title');
 	my $text=&Apache::lonxml::get_all_text("/title",$parser,$style);
@@ -806,7 +841,7 @@ sub start_xlabel {
 	if (length($xlabel) > $max_str_len) {
 	    $xlabel = substr($xlabel,0,$max_str_len);
 	}
-	$xlabel = &gnuplot_protect($xlabel);
+	$xlabel = &parse_label($target,$xlabel);
     } elsif ($target eq 'edit') {
 	$result.=&Apache::edit::tag_start($target,$token,'Plot Xlabel');
 	my $text=&Apache::lonxml::get_all_text("/xlabel",$parser,$style);
@@ -839,7 +874,7 @@ sub start_ylabel {
 	if (length($ylabel) > $max_str_len) {
 	    $ylabel = substr($ylabel,0,$max_str_len);
 	}
-	$ylabel = &gnuplot_protect($ylabel);
+	$ylabel = &parse_label($target,$ylabel);
     } elsif ($target eq 'edit') {
 	$result .= &Apache::edit::tag_start($target,$token,'Plot Ylabel');
 	my $text = &Apache::lonxml::get_all_text("/ylabel",$parser,$style);
@@ -873,7 +908,7 @@ sub start_label {
 	$text = &Apache::run::evaluate($text,$safeeval,$$parstack[-1]);
 	$text =~ s/\n/ /g;
 	$text = substr($text,0,$max_str_len) if (length($text) > $max_str_len);
-	$label{'text'} = &gnuplot_protect($text);
+	$label{'text'} = &parse_label($target,$text);
 	push(@labels,\%label);
     } elsif ($target eq 'edit') {
 	$result .= &Apache::edit::tag_start($target,$token,'Plot Label');
@@ -1371,7 +1406,8 @@ sub write_gnuplot_file {
 	}
     }
     # Write the output to a file.
-    my $fh=Apache::File->new(">$tmpdir$filename.data");
+    open (my $fh,">$tmpdir$filename.data");
+    binmode($fh, ":utf8");
     print $fh $gnuplot_input;
     close($fh);
     # That's all folks.