--- loncom/homework/default_homework.lcpm	2011/10/06 17:15:40	1.161
+++ loncom/homework/default_homework.lcpm	2017/01/04 19:54:47	1.172
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
 #
-# $Id: default_homework.lcpm,v 1.161 2011/10/06 17:15:40 raeburn Exp $
+# $Id: default_homework.lcpm,v 1.172 2017/01/04 19:54:47 damieng Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -816,6 +816,7 @@ sub cos { CORE::cos(shift) }
 sub exp { CORE::exp(shift) }
 sub int { CORE::int(shift) }
 sub log { CORE::log(shift) }
+sub ln { CORE::log(shift) }
 sub atan2 { CORE::atan2($_[0],$_[1]) }
 sub sqrt { CORE::sqrt(shift) }
 
@@ -901,11 +902,19 @@ sub chemparse {
     my $formula = '';
     foreach my $token (@tokens) {
 	if ($token eq '->' ) {
-	    $formula .= '<m>\ensuremath{\rightarrow}</m> ';
+            if ($external::target eq 'web') {
+                $formula .= '&rarr; ';
+            } else {
+                $formula .= '<m>\ensuremath{\rightarrow}</m> ';
+	    }
 	    next;
 	}
 	if ($token eq '<-' ) {
-	    $formula .= '<m>\ensuremath{\leftarrow}</m> ';
+            if ($external::target eq 'web') {
+                $formula .= '&larr; ';
+            } else {
+                $formula .= '<m>\ensuremath{\leftarrow}</m> ';
+	    }
 	    next;
 	}  
 	if ($token eq '<=>') {
@@ -1042,16 +1051,47 @@ sub format_significant_figures {
     my ($zeros) = ($xint =~ /(0+)$/);
     # return number to original magnitude
     my $numSig = $xint*10**($x10-$sig+$power);
-    # insert trailing zero's if have decimal point
-    $numSig =~ s/^(\d+)\.(\d+)(\e?(.*)?)$/$1\.$2$zeros$3/;
-    # put a decimal pt for number ending with 0 and length = # of sig fig
-    $numSig.='.' if (length($numSig) == $sig && $numSig =~ /0$/);
-    if (length($numSig) < $sig) {
-	$numSig.='.'.substr($zeros,0,($sig-length($numSig)));
+    if ($numSig =~ /^(\d+)\.(\d+)/) {
+        # insert trailing zero's if have decimal point
+        my @digarray = split('',$1.$2);
+        my $sigcount;
+        while (@digarray > 0) {
+            my $item = shift(@digarray);
+            if ($item) {
+                $sigcount = 1 + @digarray;
+                last;
+            }
+        }
+        if (($sigcount) && ($sig >= $sigcount)) {
+            $zeros = substr($zeros,0,($sig - $sigcount));
+        }
+        $numSig =~ s/^(\d+)\.(\d+)(\e?(.*)?)$/$1\.$2$zeros$3/;
+    } else {
+        if ($numSig =~ /^(\d+)e([\+\-]\d+)$/i) {
+            my $pre_exp = $1;
+            my $exponent = $2;
+            $numSig = $pre_exp.'.'.$zeros.'E'.$exponent;
+        } elsif ($numSig =~ /0$/) {
+            # add decimal pt for number ending with 0 and length == # of sig figs
+            if (length($numSig) == $sig) {
+                $numSig.='.';
+            } elsif (length($numSig) > $sig) {
+                # exponential form for number ending with 0 and length > # of sig figs
+                my $fmtsig = $sig-1;
+                if ($fmtsig) {
+                    $numSig = sprintf('%.'.$fmtsig.'E',$numSig);
+                }
+            } elsif (length($numSig) < $sig) {
+                $numSig.='.'.substr($zeros,0,($sig-length($numSig)));
+            }
+        } else {
+            if (length($numSig) < $sig) {
+                $numSig.='.'.substr($zeros,0,($sig-length($numSig)));
+            }
+        }
     }
     # return number with sign
     return $sign.$numSig;
-
 }
 
 sub map {
@@ -1196,10 +1236,78 @@ sub sec {
 }
 
 sub submission {
-   my ($partid,$responseid,$subnumber)=@_;
+   my ($partid,$responseid,$subnumber,$encode,$cleanupnum,$mapalias)=@_;
    my $sub='';
    if ($subnumber) { $sub=$subnumber.':'; }
-   return &EXT('user.resource.'.$sub.'resource.'.$partid.'.'.$responseid.'.submission');
+   my $output =
+       &EXT('user.resource.'.$sub.'resource.'.$partid.'.'.$responseid.'.submission',$mapalias);
+   if (ref($output) eq 'ARRAY') {
+       my @items = @{$output};
+       if ($encode) {
+           @items = map { &encode_response($_); } @items;
+       }
+       if (ref($cleanupnum) eq 'HASH') {
+           @items = map { &cleanup_numerical_response($cleanupnum,$_); } @items;
+       }
+       return \@items;
+   } else {
+       if ($encode) {
+           $output = &encode_response($output);
+       }
+       if (ref($cleanupnum) eq 'HASH') {
+           $output = &cleanup_numerical_response($cleanupnum,$output);
+       }
+       return $output;
+   }
+}
+
+sub encode_response {
+    my ($value) = @_;
+    $value =~ s/&/&amp;/g;
+    $value =~ s/</&lt;/g;
+    $value =~ s/>/&gt;/g;
+    $value =~ s/"/&quot;/g;
+    return $value;
+}
+
+sub cleanup_numerical_response {
+    my ($cleanupnum,$value) = @_;
+    if (ref($cleanupnum) eq 'HASH') {
+        if ($cleanupnum->{exponent}) {
+            if ($value =~ m{^(.*)[\*xX]\s*10\s*\^\s*(\+|\-)?\s*(\d+)(.*)$}) {
+                my $pre_exp = $1;
+                my $sign = $2;
+                my $exponent = $3;
+                my $post_exp = $4;
+                if ($pre_exp !~ /\./) {
+                    $pre_exp .= '.';
+                }
+                if ($sign eq '') {
+                    $sign = '+';
+                }
+                $value = $pre_exp.'E'.$sign.$exponent.$post_exp;
+            }
+        }
+        if ($cleanupnum->{comma}) {
+            $value =~ s{(\d+),(\d+)}{$1$2};
+        }
+        if ($cleanupnum->{letterforzero}) {
+            $value =~ s/^\s*o(\.\d+)/0$1/i;
+        }
+        if ($cleanupnum->{spaces}) {
+            $value =~ s{^\s+|\s+$}{}g;
+            if ($value =~ m{^(.*)\.\s+(\d+)(.*)$}) {
+                my $pre_pt = $1;
+                my $decimal = $2;
+                my $post_dec = $3;
+                $value = $pre_pt.'.'.$decimal.$post_dec;
+            }
+        }
+        if ($cleanupnum->{format} =~ /^\d+s$/i) {
+            $value = &format_significant_figures($value,$cleanupnum->{format});
+        }
+    }
+    return $value;
 }
 
 sub currentpart {
@@ -1358,3 +1466,8 @@ sub proper_path {
     }
 }
 
+sub input_id {
+    my ($part_id, $response_id, $textline_id) = @_;
+    return 'HWVAL_'.$part_id.'_'.$response_id.'_'.$textline_id;
+}
+