--- loncom/xml/scripttag.pm	2002/11/14 16:47:41	1.83
+++ loncom/xml/scripttag.pm	2006/10/17 15:11:37	1.138
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # <script> definiton
 #
-# $Id: scripttag.pm,v 1.83 2002/11/14 16:47:41 matthew Exp $
+# $Id: scripttag.pm,v 1.138 2006/10/17 15:11:37 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,8 +25,6 @@
 #
 # http://www.lon-capa.org/
 #
-# 2/21 Guy
-# 8/20 Gerd Kortemeyer
 
 package Apache::scripttag;
 
@@ -43,16 +41,57 @@ BEGIN {
   &Apache::lonxml::register('Apache::scripttag',
 			    ('script','scriptlib','parserlib','import',
 			     'window','display','storetc','physnet',
-			     'standalone','comment',
-			     'LONCAPA_INTERNAL_TURN_STYLE_ON'));
+			     'standalone','comment','num','parse','algebra',
+			     'LONCAPA_INTERNAL_TURN_STYLE_ON',
+			     'LONCAPA_INTERNAL_TURN_STYLE_OFF',
+			     'LONCAPA_INTERNAL_LONHTTPD_PORT'));
 }
 
 sub start_LONCAPA_INTERNAL_TURN_STYLE_ON {
     $Apache::lonxml::usestyle=1;
+    $Apache::lonxml::style_values='';
     return ('','no');
 }
 
 sub end_LONCAPA_INTERNAL_TURN_STYLE_ON {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $end=&Apache::lonxml::get_param('end',$parstack,$safeeval);
+    if (defined($end)) {
+	&Apache::lonxml::end_tag($tagstack,$parstack,$token);
+    }
+    return ('','no');
+}
+
+sub start_LONCAPA_INTERNAL_TURN_STYLE_OFF {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    $Apache::lonxml::usestyle=0;
+    my $end=&Apache::lonxml::get_param('end',$parstack,$safeeval);
+    if (!$end) {
+	$Apache::lonxml::style_values=$$parstack[-1];
+	$Apache::lonxml::style_end_values=$$parstack[-1];
+    } else {
+	$Apache::lonxml::style_values=$Apache::lonxml::style_end_values;
+	$Apache::lonxml::style_end_values='';
+    }
+    return ('','no');
+}
+
+sub end_LONCAPA_INTERNAL_TURN_STYLE_OFF {
+    return ('','no');
+}
+
+sub start_LONCAPA_INTERNAL_LONHTTPD_PORT {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    if ($target eq 'web' || $target eq 'webgrade') {
+	my $lonhttpdPort=$Apache::lonnet::perlvar{'lonhttpdPort'};
+	if (!defined($lonhttpdPort)) { $lonhttpdPort='8080'; }
+	return '<script type="text/javascript">var lonhttpdport=\''.
+	    $lonhttpdPort.'\';</script>';
+    }
+    return ('','no');
+}
+
+sub end_LONCAPA_INTERNAL_LONHTTPD_PORT {
     return ('','no');
 }
 
@@ -63,36 +102,56 @@ sub start_script {
   my $type= &Apache::lonxml::get_param('type',$parstack,$safeeval);
   &Apache::lonxml::debug("found type of $type");
   if ($type eq "loncapa/perl") {
-    my $bodytext=&Apache::lonxml::get_all_text("/script",$$parser[$#$parser]);
     if ( $target eq "modified" ) {
-      $result=$token->[4].&Apache::edit::modifiedfield();
+	$result=$token->[4].&Apache::edit::modifiedfield('/script',$parser);
     } elsif ( $target eq 'web' || $target eq 'tex' ||
-	      $target eq 'grade' || $target eq 'answer' ||
-	      $target eq 'analyze' ) {
+	      $target eq 'grade' || $target eq 'webgrade' ||
+	      $target eq 'answer' || $target eq 'analyze' ) {
+	my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
 	if (!$Apache::lonxml::default_homework_loaded) {
 	    &Apache::lonxml::default_homework_load($safeeval);
 	}
 	&Apache::run::run($bodytext,$safeeval);
-	if (($target eq 'answer') && ($Apache::lonhomework::viewgrades == 'F')) {
+	if (($target eq 'answer') &&
+	    ($env{'form.answer_output_mode'} ne 'tex') &&
+	    ($Apache::lonhomework::viewgrades == 'F')) {
 	    $Apache::lonxml::evaluate--;
-	    $result.="<a href=\"javascript:newWindow=open(\'\',\'new_W\',\'width=500,height=200,scrollbars=1\');newWindow.document.open(\'text/html\',\'replace\');newWindow.document.writeln(\'&lt;html&gt;&lt;head&gt;&lt;title&gt;newwindow&lt;/title&gt;&lt;/head&gt;&lt;body bgcolor=&quot;#FFFFFF&quot;&gt;&lt;pre&gt;";
-	    my $listing= &HTML::Entities::encode(&Apache::run::dump($target,$safeeval));
-
+	    my (undef,undef,$udom,$uname)=&Apache::lonnet::whichuser();
+	    my $windowopen=&Apache::lonhtmlcommon::javascript_docopen();
+	    my $start_page =
+		&Apache::loncommon::start_page('Script Vars', undef,
+					       {'only_body' => 1,
+						'bgcolor'   => '#FFFFFF',
+						'js_ready'  => 1,});
+	    my $end_page =
+		&Apache::loncommon::end_page({'js_ready' => 1,});
+
+	    $result.="<script type=\"text/javascript\">
+// <![CDATA[
+    function LONCAPA_scriptvars_".$uname."_".$udom."_"."$Apache::lonxml::curdepth() {newWindow=open('','new_W','width=500,height=500,scrollbars=1,resizable=yes');newWindow.$windowopen;newWindow.document.writeln('$start_page<pre>";
+	    my $listing=&Apache::run::dump($target,$safeeval);
+	    $listing=~s/\\/\\\\/g;
+	    $listing=~s/\'/\\\'/g;
 	    $result.=$listing;
-	    $result.= "&lt;/pre&gt;&lt;/body&gt;&lt;/html&gt;\');newWindow.document.close();void(0);\">Script Vars</a><br />";
+	    $result.= "</pre>$end_page');newWindow.document.close();newWindow.focus()}
+// ]]>
+</script><a href=\"javascript:LONCAPA_scriptvars_".$uname."_".$udom."_$Apache::lonxml::curdepth();void(0);\">Script Vars</a><br />";
 	}
     } elsif ($target eq "edit" ) {
       #&Apache::run::run($bodytext,$safeeval);
       #$result="<br /> &lt;$token->[1]&gt; output: <br />$bodytext<br />Source:<br />";
-      $result=&Apache::edit::tag_start($target,$token,'Script');
-      $result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,4);
+	my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
+	$result=&Apache::edit::tag_start($target,$token,'Script');
+	$result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,4);
+    } elsif ($target eq 'meta') {
+	my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
     }
   } else {
-    if ($target ne "meta") {
-      $result = $token->[4];
-      my $bodytext=&Apache::lonxml::get_all_text("/script",$$parser[$#$parser]);
-      $result.=$bodytext;
-    }
+      my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
+      if ($target ne "meta" && $target ne 'tex') {
+	  $result = $token->[4];
+	  $result.=$bodytext;
+      }
   }
   return $result;
 }
@@ -103,7 +162,7 @@ sub end_script {
   my $type = &Apache::lonxml::get_param('type',$parstack,$safeeval);
   my $result='';
   #other script blocks need to survive
-  if ($type ne "loncapa/perl") {
+  if ($type ne "loncapa/perl" && $target ne 'tex') {
     return $token->[2];
   } elsif ($target eq 'edit' ) {
     return &Apache::edit::end_table();
@@ -115,29 +174,36 @@ sub end_script {
 
 sub start_display {
   my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
-
+  @Apache::scripttag::parser_env = @_;
   my $result;
-  my $bodytext=&Apache::lonxml::get_all_text("/display",$$parser[$#$parser]);
 
   if ( $target eq "modified" ) {
-    $result=$token->[4].&Apache::edit::modifiedfield();
+      $result=$token->[4].&Apache::edit::modifiedfield("/display",$parser);
   } elsif ( $target eq 'web' || $target eq 'tex' ||
-	    $target eq 'grade' || $target eq 'answer' ||
-	      $target eq 'analyze') {
+	    $target eq 'grade' || $target eq 'webgrade' ||
+	    $target eq 'answer' || $target eq 'analyze') {
+      my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/display",$parser);
       if (!$Apache::lonxml::default_homework_loaded) {
 	  &Apache::lonxml::default_homework_load($safeeval);
       }
       $result=&Apache::run::run($bodytext,$safeeval);
       if ($target eq 'grade' || $target eq 'answer' ||
 	  $target eq 'analyze') {
-	  $result=''; # grade should produce no output
+	  # grade/answer/analyxe should produce no output but if we
+	  # are redirecting, the redirecter should know what to do
+	  # with the output
+	  if (!$Apache::lonxml::redirection) { $result=''; }
       }
+      $Apache::lonxml::post_evaluate=0;
   } elsif ($target eq "edit" ) {
+    my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/display",$parser);
     #$result = 
     #  "<br /> &lt;$token->[1]&gt; output: <br />$bodytext<br />Source:<br />";
     #$result.=&Apache::edit::editfield($token->[1],$bodytext,'',40,1);
     $result=&Apache::edit::tag_start($target,$token,'Script With Display');
     $result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,1)
+  } elsif ($target eq 'meta') {
+      my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/display",$parser);
   }
   return $result;
 }
@@ -154,8 +220,9 @@ sub start_scriptlib {
   my $result ='';
   my $error='';
 
-  if ($target eq 'web' || $target eq 'grade' || $target eq 'meta' || 
-      $target eq 'edit' || $target eq 'answer' || $target eq 'analyze') {
+  if ($target eq 'web' || $target eq 'tex' || $target eq 'grade' ||
+      $target eq 'meta' || $target eq 'edit' || $target eq 'answer' ||
+      $target eq 'analyze' || $target eq 'webgrade') {
     $bodytext=$$parser[$#$parser]->get_text("/scriptlib");
     $bodytext=&Apache::run::evaluate($bodytext,$safeeval,
 				     $$parstack[$#$parstack]);
@@ -182,9 +249,7 @@ sub start_scriptlib {
 	    &Apache::edit::end_table();
   }
   if ($target eq "modified" ) {
-    $bodytext=$$parser[$#$parser]->get_text("/scriptlib");
-    $result=$token->[4].&Apache::edit::modifiedfield($token);
-    &Apache::lonxml::debug($result);
+      $result=$token->[4].&Apache::edit::modifiedfield("/scriptlib",$parser);
   }
   return $result;
 }
@@ -201,8 +266,9 @@ sub start_parserlib {
   my $bodytext;
   my $result ="";
   my $error='';
-  if ($target eq 'web' || $target eq 'grade' || $target eq 'meta' ||
-      $target eq 'edit' || $target eq 'answer' || $target eq 'analyze') {
+  if ($target eq 'web' || $target eq 'tex' || $target eq 'grade' ||
+      $target eq 'meta' || $target eq 'edit' || $target eq 'answer' ||
+      $target eq 'analyze' || $target eq 'webgrade') {
     $bodytext=$$parser[$#$parser]->get_text("/parserlib");
     $bodytext=&Apache::run::evaluate($bodytext,$safeeval,
 				     $$parstack[$#$parstack]);
@@ -228,9 +294,7 @@ sub start_parserlib {
 	    &Apache::edit::end_table();
   }
   if ($target eq "modified" ) {
-    $bodytext=$$parser[$#$parser]->get_text("/parserlib");
-    $result=$token->[4].&Apache::edit::modifiedfield($token);
-    &Apache::lonxml::debug($result);
+      $result=$token->[4].&Apache::edit::modifiedfield("/parserlib",$parser);
   }
   return $result;
 }
@@ -243,23 +307,58 @@ sub end_parserlib {
 }
 
 sub start_window {
-  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
-  my $result = '';
-  if ($target eq 'web') {
-    &Apache::lonxml::startredirection;
-  }  elsif ($target eq 'tex') {
-       $result = '\unskip\footnote{';
-   }
-  return $result;  
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result = '';
+    if ($target eq 'web' || $target eq 'webgrade') {
+	&Apache::lonxml::startredirection;
+    } elsif ($target eq 'tex') {
+	$result = '\unskip\footnote{';
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token);
+	$result.=&Apache::edit::text_arg('Text of Link:','linktext',$token,70);
+	$result.=&Apache::edit::text_arg('Height:','height',$token,5);
+	$result.=&Apache::edit::text_arg('Width:','width',$token,5);
+	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'linktext',
+						     'width','height');
+	if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
+    }
+    return $result;  
 }
 
 sub end_window {
   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
   my $result;
-  if ($target eq 'web') {
+  if ($target eq 'web' || $target eq 'webgrade') {
     my $output=&Apache::lonxml::endredirection;
-    $output =~ s/\"/\&quot\;/g;
-    $result = "<a href=\"javascript:newWindow=open(\'\',\'new_W\',\'width=500,height=200,scrollbars=1\');newWindow.document.open(\'text/html\',\'replace\');newWindow.document.writeln(\'<html><head><title>newwindow</title></head><body bgcolor=&quot;#FFFFFF&quot;> $output </body></html>\');newWindow.document.close();void(0);\"><sup>*</sup></a>";
+    $output =~ s/[\n\r]/ /g;
+#    $output = &HTML::Entities::encode($output,'<>&"\'');
+    $output =~ s/\'/\\\'/g;
+    my $linktext= &Apache::lonxml::get_param('linktext',$parstack,$safeeval);
+    if (!$linktext) { $linktext='<sup>*</sup>'; }
+    my $width= &Apache::lonxml::get_param('width',$parstack,$safeeval);
+    if (!$width) { $width='500'; }
+    my $height= &Apache::lonxml::get_param('height',$parstack,$safeeval);
+    if (!$height) { $height='200'; }
+
+    my $start_page =
+	&Apache::loncommon::start_page($linktext, undef,
+				       {'only_body' => 1,
+					'bgcolor'   => '#FFFFFF',
+					'js_ready'  => 1,});
+    my $end_page =
+	&Apache::loncommon::end_page({'js_ready' => 1,});
+    $result = "<script type=\"text/javascript\">
+//<!--
+ function LONCAPA_newwindow_$Apache::lonxml::curdepth() {
+newWindow=open(".&Apache::lonhtmlcommon::javascript_nothing().",'new_W','width=$width,height=$height,scrollbars=1');
+newWindow.".&Apache::lonhtmlcommon::javascript_docopen().";
+newWindow.document.writeln('$start_page $output $end_page');
+newWindow.document.close();}
+//-->
+</script><a href=\"javascript:LONCAPA_newwindow_$Apache::lonxml::curdepth();void(0);\">$linktext</a>";
   } elsif ($target eq 'tex') {
       $result = '}';
   } else {
@@ -275,8 +374,8 @@ sub start_import {
 
   $bodytext=Apache::run::evaluate($bodytext,$safeeval,$$parstack[$#$parstack]);
 
-  if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
-      $target eq 'tex' || $target eq 'analyze' ) {
+  if ($target eq 'web' ||  $target eq 'webgrade' || $target eq 'grade' 
+      || $target eq 'answer' || $target eq 'tex' || $target eq 'analyze' ) {
     # FIXME this probably needs to be smart about construction vs.
     # non construction space.
     my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],$bodytext);
@@ -292,7 +391,10 @@ sub start_import {
     my $id= &Apache::lonxml::get_param('id',$parstack,$safeeval);
     if (!$id) { $id=$Apache::lonxml::curdepth; }
     push(@Apache::inputtags::import,$id);
-    &Apache::lonxml::newparser($parser,\$file,$dir);
+    push(@Apache::inputtags::importlist,$id);
+
+	&Apache::lonxml::newparser($parser,\$file,$dir);
+
   } elsif ($target eq "edit" ) {
     $result.=&Apache::edit::tag_start($target,$token);
     $result.=&Apache::edit::editline($token->[1],$bodytext,'',40);
@@ -301,9 +403,7 @@ sub start_import {
     #my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],$bodytext);
     #$result.="Click<a href=\"$location\">here</a> to edit<br />"
   } elsif ($target eq 'modified') {
-    $bodytext=$$parser[$#$parser]->get_text("/import");
-    $result=$token->[4].&Apache::edit::modifiedfield($token);
-    &Apache::lonxml::debug($result);
+      $result=$token->[4].&Apache::edit::modifiedfield("/import",$parser);
   } elsif ($target eq 'meta') {
     my $id= &Apache::lonxml::get_param('id',$parstack,$safeeval);
     $result.='<import part="'.$Apache::inputtags::part;
@@ -321,7 +421,8 @@ sub end_import {
   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
   pop(@Apache::inputtags::import);
   my $result;
-  if ($target eq 'edit' ) { $result=&Apache::edit::end_table(); }
+  if ($target eq 'edit' ) { $result=&Apache::edit::end_row.
+				&Apache::edit::end_table(); }
   return $result;
 }
 
@@ -363,9 +464,9 @@ sub end_physnet {
 sub start_standalone {
   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
   my $result='';
-  if ($target eq 'web' ) {
-    if ( $ENV{'request.course.id'} ) {
-      my $inside = &Apache::lonxml::get_all_text("/standalone",$$parser[-1]);
+  if ($target eq 'web' || $target eq 'webgrade') {
+    if ( $env{'request.course.id'} ) {
+      my $inside = &Apache::lonxml::get_all_text("/standalone",$parser,$style);
     } else {
       $result='<table bgcolor="#E1E1E1" border="2"><tr><td>';
     }
@@ -376,8 +477,8 @@ sub start_standalone {
 sub end_standalone {
   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
   my $result='';
-  if ($target eq 'web' ) {
-    if ( $ENV{'request.course.id'} ) {
+  if ($target eq 'web' || $target eq 'webgrade' ) {
+    if ( $env{'request.course.id'} ) {
     } else {
       $result='</td></tr></table>';
     }
@@ -390,14 +491,15 @@ sub start_comment {
   my $result='';
   if ($target eq 'edit') {
     $result=&Apache::edit::tag_start($target,$token);
-    my $bodytext=&Apache::lonxml::get_all_text("/comment",$$parser[$#$parser]);
+    my $bodytext=&Apache::lonxml::get_all_text("/comment",$parser,$style);
     $result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,4)
   } elsif ( $target eq 'modified') {
-    $result=$token->[4].&Apache::edit::modifiedfield($token);
-  } elsif ( $target eq 'web' || $target eq 'tex' || $target eq 'grade' ||
-	    $target eq 'answer' || $target eq 'meta' || $target eq 'analyze') {
+    $result=$token->[4].&Apache::edit::modifiedfield("/comment",$parser);
+  } elsif ( $target eq 'web'    || $target eq 'tex'  || $target eq 'grade'   ||
+	    $target eq 'answer' || $target eq 'meta' || $target eq 'analyze' ||
+	    $target eq 'webgrade') {
     #normally throw away comments
-    my $bodytext=&Apache::lonxml::get_all_text("/comment",$$parser[$#$parser]);
+    my $bodytext=&Apache::lonxml::get_all_text("/comment",$parser,$style);
   }
   return $result;
 }
@@ -411,16 +513,102 @@ sub end_comment {
 
 sub xmlparse {
   my ($string) = @_;
-  &Apache::lonxml::debug("Got $string");
+  &Apache::lonxml::debug("xmlparse recursion starting with $string");
+  # Apache::run::evaluate does an 'eval' on the name of the subroutine
+  # if it detects something that looks like a subroutine, this ends up calling
+  # things without any arguments and since perl is nice enough to pass
+  # along the default arguments when you don't explicitly say no arguments
+  # if you call &xmlparse, it gets &xmlparse passed as it argument.
+  # Same thing soccurs with &chemparse.
+  if ($string eq '&xmlparse') { return '&xmlparse'; }
+  if ($string eq '&chemparse') { return '&chemparse'; }
   my ($target,$token,$tagstack,$parstack,$oldparser,$safeeval,$style)=
     @Apache::scripttag::parser_env;
   my @parser;
   &Apache::lonxml::newparser(\@parser,\$string);
+  &Apache::lonxml::startredirection();
   my $result=&Apache::lonxml::inner_xmlparse($target,$tagstack,
 					     $parstack,\@parser,
 					     $safeeval,$style);
+  $result.=&Apache::lonxml::endredirection();
+  &Apache::lonxml::debug("target is $target xmlparse recursion ending with $result");
   return $result;
 }
 
+sub start_num {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    my $inside = &Apache::lonxml::get_all_text_unbalanced("/num",$parser);
+    if ($target eq 'tex' || $target eq 'web' || $target eq 'webgrade') {
+	$inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	@Apache::scripttag::parser_env = @_;
+	my $format=&Apache::lonxml::get_param('format',$parstack,$safeeval);
+	$result=&Apache::run::run("return &prettyprint(q\0$inside\0,q\0$format\0);",$safeeval);
+    }    
+    return $result;
+}
+
+sub end_num {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
+sub start_parse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    if ( $target eq 'web'    || $target eq 'tex'    ||
+	 $target eq 'grade'  || $target eq 'answer' ||
+	 $target eq 'analyze'|| $target eq 'webgrade') {
+	my $inside = &Apache::lonxml::get_all_text_unbalanced("/parse",$parser);
+	$inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	@Apache::scripttag::parser_env = @_;
+	$result=&Apache::run::run("return &xmlparse(q\0$inside\0);",$safeeval);
+	if ($target eq 'grade' || $target eq 'answer' ||
+	    $target eq 'analyze') {
+	    # grade/answer/analyxe should produce no output but if we
+	    # are redirecting, the redirecter should know what to do
+	    # with the output
+	    if (!$Apache::lonxml::redirection) { $result=''; }
+	}
+    }
+    return $result;
+}
+
+sub end_parse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
+sub start_algebra {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    if ( $target eq 'web'     || $target eq 'tex'    ||
+	 $target eq 'grade'   || $target eq 'answer' ||
+	 $target eq 'analyze' || $target eq 'webgrade') {
+	my $inside = &Apache::lonxml::get_all_text_unbalanced("/algebra",$parser);
+	$inside = &Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
+	    my $style=&Apache::lonxml::get_param('style',$parstack,$safeeval);
+	    $result=&Apache::lontexconvert::algebra($inside,$target,$style);
+	}
+	$Apache::lonxml::post_evaluate=0;
+    }
+    return $result;
+}
+
+sub end_algebra {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
 1;
 __END__