--- loncom/xml/run.pm	2000/06/29 20:27:44	1.5
+++ loncom/xml/run.pm	2002/03/29 18:21:00	1.24
@@ -1,20 +1,96 @@
 package Apache::run;
+#
+# $Id: run.pm,v 1.24 2002/03/29 18:21:00 albertel Exp $
+#
+# Copyright Michigan State University Board of Trustees
+#
+# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
+#
+# LON-CAPA is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# LON-CAPA is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with LON-CAPA; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# /home/httpd/html/adm/gpl.txt
+#
+# http://www.lon-capa.org/
+#
+
+$Apache::run::EVALUATE_STRING=<<'ENDEVALUATE';  
+  my %_LONCAPA_INTERNAL_oldexpressions=();
+  my $i=0;
+  while (!$_LONCAPA_INTERNAL_oldexpressions{$_}) {
+    $_LONCAPA_INTERNAL_oldexpressions{$_}=1;
+    $_ =~s/((?:\$|\&)(?:[\#|\$]*[A-Za-z][\w]*|\{[A-Za-z][\w]*\}))([\[\{][^\$\&\]\}]+[\]\}])*?(\([^\$\&\)]+\))*?(?=[^\[\{\(]|$)/eval(defined(eval($1.$2))?eval('$1.$2.$3'):'$1.$2.$3')/seg;
+    if ($i++ > 10 ) { last; }
+  }
+ENDEVALUATE
 
 sub evaluate {
   my ($expression,$safeeval,$decls) = @_;
-# print "inside2 evaluate with $expression\n";
-# gerd's old method interpolates unset vars
-# $safeeval->reval('return qq('.$expression.');');
-  unless (defined $expression) { return ''; }
-  $safeeval->reval('$_=\''.$expression.'\';');
-  $safeeval->reval('{'.$decls.'$_=~s/(\$\{?[A-Za-z]\w*\}?)/(defined(eval($1))?eval($1):$1)/ge;}');
-  $safeeval->reval('return $_;');
+  unless (defined($expression)) { return ''; }
+  if (!$Apache::lonxml::evaluate) { return $expression; }
+  my $result = '';
+  $@='';
+  $safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression.
+		   "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}');
+#  $safeeval->reval('{'.$decls.';<< &evaluate(q|'.$expression.'|);}');
+  if ($@ eq '') {
+    $result = $safeeval->reval('return $_;');
+    chomp $result;
+  } else {
+    &Apache::lonxml::error("substitution on:$expression:with:$decls:caused $@");
+  }  
+  return $result
 }
 
 sub run {
-  my ($code,$safeeval) = @_;
+  my ($code,$safeeval,$hideerrors) = @_;
 #  print "inside run\n";
-  $safeeval->reval($code);
+  $@='';
+  my (@result)=$safeeval->reval($code);
+  if ($@ ne '' && !$hideerrors) {
+    &Apache::lonxml::error(":$@: occured while running :$code:");
+  }
+  if ( $#result < '1') {
+    return $result[0];
+  } else {
+    &Apache::lonxml::debug("<b>Got lots results</b>:$#result:");
+    return (@result);
+  }
+}
+
+sub dump {
+  my ($target,$safeeval)=@_;
+  my $dump='';
+  foreach my $symname (sort keys %{$safeeval->varglob('main::')}) {
+    if (($symname!~/^\_/) && ($symname!~/\:$/)) {
+      if ($safeeval->reval('defined($'.$symname.')')) {
+	$dump.='$'.$symname.'='.$safeeval->reval('$'.$symname)."\n";
+      }	
+      if ($safeeval->reval('defined(@'.$symname.')')) {
+	$dump.='@'.$symname.'=('.
+	  $safeeval->reval('join(",",@'.$symname.')').")\n";
+      }
+      if ($safeeval->reval('defined(%'.$symname.')')) {
+	$dump.='%'.$symname.'=(';
+	$dump.=$safeeval->reval('join(",",map { $_."=>".$'.
+				$symname.'{$_} } sort keys %'.
+				$symname.')').")\n";
+      }
+    }
+  }
+  $dump.='';
+  return $dump;
 }
 
 1;