# The LearningOnline Network with CAPA
# XML Parser Module 
#
# $Id: lonxml.pm,v 1.251 2003/05/03 21:09:03 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/
#
# Copyright for TtHfunc and TtMfunc by Ian Hutchinson. 
# TtHfunc and TtMfunc (the "Code") may be compiled and linked into 
# binary executable programs or libraries distributed by the 
# Michigan State University (the "Licensee"), but any binaries so 
# distributed are hereby licensed only for use in the context
# of a program or computational system for which the Licensee is the 
# primary author or distributor, and which performs substantial 
# additional tasks beyond the translation of (La)TeX into HTML.
# The C source of the Code may not be distributed by the Licensee
# to any other parties under any circumstances.
#
# last modified 06/26/00 by Alexander Sakharuk
# 11/6 Gerd Kortemeyer
# 6/1/1 Gerd Kortemeyer
# 2/21,3/13 Guy
# 3/29,5/4 Gerd Kortemeyer
# 5/26 Gerd Kortemeyer
# 5/27 H. K. Ng
# 6/2,6/3,6/8,6/9 Gerd Kortemeyer
# 6/12,6/13 H. K. Ng
# 6/16 Gerd Kortemeyer
# 7/27 H. K. Ng
# 8/7,8/9,8/10,8/11,8/15,8/16,8/17,8/18,8/20,8/23,8/24 Gerd Kortemeyer
# Guy Albertelli
# 9/26 Gerd Kortemeyer
# Dec Guy Albertelli
# YEAR=2002
# 1/1 Gerd Kortemeyer
# 1/2 Matthew Hall
# 1/3 Gerd Kortemeyer
#

package Apache::lonxml; 
use vars 
qw(@pwd @outputstack $redirection $import @extlinks $metamode $evaluate %insertlist @namespace $prevent_entity_encode $errorcount $warningcount);
use strict;
use HTML::LCParser();
use HTML::TreeBuilder();
use HTML::Entities();
use Safe();
use Safe::Hole();
use Math::Cephes();
use Math::Random();
use Opcode();

sub register {
  my ($space,@taglist) = @_;
  foreach my $temptag (@taglist) {
    push(@{ $Apache::lonxml::alltags{$temptag} },$space);
  }
}

sub deregister {
  my ($space,@taglist) = @_;
  foreach my $temptag (@taglist) {
    my $tempspace = $Apache::lonxml::alltags{$temptag}[-1];
    if ($tempspace eq $space) {
      pop(@{ $Apache::lonxml::alltags{$temptag} });
    }
  }
  #&printalltags();
}

use Apache::Constants qw(:common);
use Apache::lontexconvert();
use Apache::style();
use Apache::run();
use Apache::londefdef();
use Apache::scripttag();
use Apache::edit();
use Apache::lonnet();
use Apache::File();
use Apache::loncommon();
use Apache::lonfeedback();
use Apache::lonmsg();
use Apache::loncacc();

#==================================================   Main subroutine: xmlparse  
#debugging control, to turn on debugging modify the correct handler
$Apache::lonxml::debug=0;

# keeps count of the number of warnings and errors generated in a parse
$warningcount=0;
$errorcount=0;

#path to the directory containing the file currently being processed
@pwd=();

#these two are used for capturing a subset of the output for later processing,
#don't touch them directly use &startredirection and &endredirection
@outputstack = ();
$redirection = 0;

#controls wheter the <import> tag actually does
$import = 1;
@extlinks=();

# meta mode is a bit weird only some output is to be turned off
#<output> tag turns metamode off (defined in londefdef.pm)
$metamode = 0;

# turns on and of run::evaluate actually derefencing var refs
$evaluate = 1;

# data structure for eidt mode, determines what tags can go into what other tags
%insertlist=();

# stores the list of active tag namespaces
@namespace=();

# if 0 all high ASCII characters will be encoded into HTML Entities
$prevent_entity_encode=0;

# has the dynamic menu been updated to know about this resource
$Apache::lonxml::registered=0;

# a pointer the the Apache request object
$Apache::lonxml::request='';

# a problem number counter, and check on ether it is used
$Apache::lonxml::counter=1;
$Apache::lonxml::counter_changed=0;

#internal check on whether to look at style defs
$Apache::lonxml::usestyle=1;

sub xmlbegin {
  my $output='';
  if ($ENV{'browser.mathml'}) {
      $output='<?xml version="1.0"?>'
            .'<?xml-stylesheet type="text/css" href="/adm/MathML/mathml.css"?>'
            .'<!DOCTYPE html SYSTEM "/adm/MathML/mathml.dtd" '
            .'[<!ENTITY mathns "http://www.w3.org/1998/Math/MathML">]>'
            .'<html xmlns:math="http://www.w3.org/1998/Math/MathML" ' 
		.'xmlns="http://www.w3.org/TR/REC-html40">';
  } else {
      $output='<html>';
  }
  return $output;
}

sub xmlend {
    my ($discussiononly,$symb)=@_;
    my $discussion='';
    if ($ENV{'request.course.id'}) {
       my $crs='/'.$ENV{'request.course.id'};
       if ($ENV{'request.course.sec'}) {
          $crs.='_'.$ENV{'request.course.sec'};
       }                 
       $crs=~s/\_/\//g;
       my $seeid=&Apache::lonnet::allowed('rin',$crs);
       unless ($symb) {
           $symb=&Apache::lonnet::symbread();
       }
       if ($symb) {
          my %contrib=&Apache::lonnet::restore($symb,$ENV{'request.course.id'},
                     $ENV{'course.'.$ENV{'request.course.id'}.'.domain'},
		     $ENV{'course.'.$ENV{'request.course.id'}.'.num'});
          if ($contrib{'version'}) {
              unless ($discussiononly) {
                 $discussion.=
                  '<address><hr />';
	     }
              my $idx;
              for ($idx=1;$idx<=$contrib{'version'};$idx++) {
		my $hidden=($contrib{'hidden'}=~/\.$idx\./);
		my $deleted=($contrib{'deleted'}=~/\.$idx\./);
		unless ((($hidden) && (!$seeid)) || ($deleted)) {
                 my $message=$contrib{$idx.':message'};
                 $message=~s/\n/\<br \/\>/g;
		 $message=&Apache::lontexconvert::msgtexconverted($message);
                 if ($contrib{$idx.':attachmenturl'}) {
                     my ($fname,$ft)
                        =($contrib{$idx.':attachmenturl'}=~/\/(\w+)\.(\w+)$/);
		     $message.='<p>Attachment: <a href="'.
	       &Apache::lonnet::tokenwrapper($contrib{$idx.':attachmenturl'}).
                     '"><tt>'.$fname.'.'.$ft.'</tt></a>';
                 }
                 if ($message) {
                  if ($hidden) {
		      $message='<font color="#888888">'.$message.'</font>';
                  }
                  my $screenname=&Apache::loncommon::screenname(
                               $contrib{$idx.':sendername'},
			       $contrib{$idx.':senderdomain'});
                  my $plainname=&Apache::loncommon::nickname(
                               $contrib{$idx.':sendername'},
			       $contrib{$idx.':senderdomain'});

                  my $sender='Anonymous';
                  if ((!$contrib{$idx.':anonymous'}) || ($seeid)) {
                      $sender=&Apache::loncommon::aboutmewrapper(
                               $plainname,
                               $contrib{$idx.':sendername'},
                               $contrib{$idx.':senderdomain'}).' ('.
                              $contrib{$idx.':sendername'}.' at '.
		      $contrib{$idx.':senderdomain'}.')';
                      if ($contrib{$idx.':anonymous'}) {
			  $sender.=' [anonymous] '.
                                     $screenname;
                      }
                      if ($seeid) {
			  if ($hidden) {
                             $sender.=' <a href="/adm/feedback?unhide='.
				 $symb.':::'.$idx.'">Make Visible</a>';
                          } else {
                             $sender.=' <a href="/adm/feedback?hide='.
				 $symb.':::'.$idx.'">Hide</a>';
			  }                     
                          $sender.=' <a href="/adm/feedback?deldisc='.
				 $symb.':::'.$idx.'">Delete</a>';
                      }
                  } else {
                      if ($screenname) {
			  $sender='<i>'.$screenname.'</i>';
                      }
                  }
		  $discussion.='<p><b>'.$sender.'</b> ('.
                      localtime($contrib{$idx.':timestamp'}).
                      '):<blockquote>'.$message.
                      '</blockquote></p>';
	        }
               } 
              }
              unless ($discussiononly) {
                 $discussion.='</address>';
	      }
          }
          if ($discussiononly) {
	      $discussion.=(<<ENDDISCUSS);
<form action="/adm/feedback" method="post" name="mailform" enctype="multipart/form-data">
<input type="submit" name="discuss" value="Post Discussion" />
<input type="submit" name="anondiscuss" value="Post Anonymous Discussion" />
<input type="hidden" name="symb" value="$symb" />
<input type="hidden" name="sendit" value="true" />
<br />
<font size="1">Note: in anonymous discussion, your name is visible only to
course faculty</font><br />
<textarea name=comment cols=60 rows=10 wrap=hard></textarea>
<p>
Attachment (128 KB max size): <input type="file" name="attachment" />
</p>
</form>
ENDDISCUSS
             $discussion.=&Apache::lonfeedback::generate_preview_button();
          }
       }
    }
    return $discussion.($discussiononly?'':'</html>');
}

sub tokeninputfield {
    my $defhost=$Apache::lonnet::perlvar{'lonHostID'};
    $defhost=~tr/a-z/A-Z/;
    return (<<ENDINPUTFIELD)
<script type="text/javascript">
    function updatetoken() {
	var comp=new Array;
        var barcode=unescape(document.tokeninput.barcode.value);
        comp=barcode.split('*');
        if (typeof(comp[0])!="undefined") {
	    document.tokeninput.codeone.value=comp[0];
	}
        if (typeof(comp[1])!="undefined") {
	    document.tokeninput.codetwo.value=comp[1];
	}
        if (typeof(comp[2])!="undefined") {
            comp[2]=comp[2].toUpperCase();
	    document.tokeninput.codethree.value=comp[2];
	}
        document.tokeninput.barcode.value='';
    }  
</script>
<form method="post" name="tokeninput">
<table border="2" bgcolor="#FFFFBB">
<tr><th>DocID Checkin</th></tr>
<tr><td>
<table>
<tr>
<td>Scan in Barcode</td>
<td><input type="text" size="22" name="barcode" 
onChange="updatetoken()"/></td>
</tr>
<tr><td><i>or</i> Type in DocID</td>
<td>
<input type="text" size="5" name="codeone" />
<b><font size="+2">*</font></b>
<input type="text" size="5" name="codetwo" />
<b><font size="+2">*</font></b>
<input type="text" size="10" name="codethree" value="$defhost" 
onChange="this.value=this.value.toUpperCase()" />
</td></tr>
</table>
</td></tr>
<tr><td><input type="submit" value="Check in DocID" /></td></tr>
</table>
</form>
ENDINPUTFIELD
}

sub maketoken {
    my ($symb,$tuname,$tudom,$tcrsid)=@_;
    unless ($symb) {
	$symb=&Apache::lonnet::symbread();
    }
    unless ($tuname) {
	$tuname=$ENV{'user.name'};
        $tudom=$ENV{'user.domain'};
        $tcrsid=$ENV{'request.course.id'};
    }

    return &Apache::lonnet::checkout($symb,$tuname,$tudom,$tcrsid);
}

sub printtokenheader {
    my ($target,$token,$tsymb,$tcrsid,$tudom,$tuname)=@_;
    unless ($token) { return ''; }

    my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
    unless ($tsymb) {
	$tsymb=$symb;
    }
    unless ($tuname) {
	$tuname=$name;
        $tudom=$domain;
        $tcrsid=$courseid;
    }

    my %reply=&Apache::lonnet::get('environment',
              ['firstname','middlename','lastname','generation'],
              $tudom,$tuname);
    my $plainname=$reply{'firstname'}.' '. 
                  $reply{'middlename'}.' '.
                  $reply{'lastname'}.' '.
		  $reply{'generation'};

    if ($target eq 'web') {
        my %idhash=&Apache::lonnet::idrget($tudom,($tuname));
	return 
 '<img align="right" src="/cgi-bin/barcode.png?encode='.$token.'" />'.
               'Checked out for '.$plainname.
               '<br />User: '.$tuname.' at '.$tudom.
	       '<br />ID: '.$idhash{$tuname}.
	       '<br />CourseID: '.$tcrsid.
	       '<br />Course: '.$ENV{'course.'.$tcrsid.'.description'}.
               '<br />DocID: '.$token.
               '<br />Time: '.localtime().'<hr />';
    } else {
        return $token;
    }
}

sub fontsettings() {
    my $headerstring='';
    if (($ENV{'browser.os'} eq 'mac') && (!$ENV{'browser.mathml'})) { 
	$headerstring.=
	    '<meta Content-Type="text/html; charset=x-mac-roman">';
    } elsif (!$ENV{'browser.mathml'}) {
	$headerstring.=
	    '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />';
    }
    return $headerstring;
}

sub printalltags {
  my $temp;
  foreach $temp (sort keys %Apache::lonxml::alltags) {
    &Apache::lonxml::debug("$temp -- ".
		  join(',',@{ $Apache::lonxml::alltags{$temp} }));
  }
}

sub xmlparse {
 my ($request,$target,$content_file_string,$safeinit,%style_for_target) = @_;

 &setup_globals($request,$target);
 &Apache::inputtags::initialize_inputtags();
 &Apache::outputtags::initialize_outputtags();
 &Apache::edit::initialize_edit();

#
# do we have a course style file?
#

 if ($ENV{'request.course.id'} && $ENV{'request.state'} ne 'construct') {
     my $bodytext=
	 $ENV{'course.'.$ENV{'request.course.id'}.'.default_xml_style'};
     if ($bodytext) {
       my $location=&Apache::lonnet::filelocation('',$bodytext);
       my $styletext=&Apache::lonnet::getfile($location);
       if ($styletext ne '-1') {
          %style_for_target = (%style_for_target,
                          &Apache::style::styleparser($target,$styletext));
       }
    }
 }

 #&printalltags();
 my @pars = ();
 my $pwd=$ENV{'request.filename'};
 $pwd =~ s:/[^/]*$::;
 &newparser(\@pars,\$content_file_string,$pwd);

 my $safeeval = new Safe;
 my $safehole = new Safe::Hole;
 &init_safespace($target,$safeeval,$safehole,$safeinit);
#-------------------- Redefinition of the target in the case of compound target

 ($target, my @tenta) = split('&&',$target);

 my @stack = ();
 my @parstack = ();
 &initdepth;

 my $finaloutput = &inner_xmlparse($target,\@stack,\@parstack,\@pars,
				   $safeeval,\%style_for_target);
 if ($ENV{'request.uri'}) {
    &writeallows($ENV{'request.uri'});
 }
 if ($Apache::lonxml::counter_changed) { &store_counter() }
 return $finaloutput;
}

sub htmlclean {
    my ($raw,$full)=@_;

    my $tree = HTML::TreeBuilder->new;
    $tree->ignore_unknown(0);

    $tree->parse($raw);

    my $output= $tree->as_HTML(undef,' ');

    $output=~s/\<(br|hr|img|meta|allow)(.*?)\>/\<$1$2 \/\>/gis;
    $output=~s/\<\/(br|hr|img|meta|allow)\>//gis;
    unless ($full) {
       $output=~s/\<[\/]*(body|head|html)\>//gis;
    }

    $tree = $tree->delete;

    return $output;
}

sub latex_special_symbols {
    my ($current_token,$stack,$parstack,$where)=@_;
    if ($where eq 'header') {
	$current_token =~ s/(\\|_|\^)/ /g;
	$current_token =~ s/(\$|%|\#|&|\{|\})/\\$1/g;
    } else {
	$current_token=~s/\\ /\\char92 /g;
	$current_token=~s/\^/\\char94 /g;
	$current_token=~s/\~/\\char126 /g;
	$current_token=~s/(&[^A-Za-z\#])/\\$1/g;
	$current_token=~s/([^&])\#/$1\\#/g;
	$current_token=~s/(\$|_|{|})/\\$1/g;
	$current_token=~s/\\char92 /\\texttt{\\char92}/g;
	$current_token=~s/(>|<)/\$$1\$/g; #more or less
	if ($current_token=~m/\d%/) {$current_token =~ s/(\d)%/$1\\%/g;} #percent after digit
	if ($current_token=~m/\s%/) {$current_token =~ s/(\s)%/$1\\%/g;} #persent after space
    }
    return $current_token;
}

sub inner_xmlparse {
  my ($target,$stack,$parstack,$pars,$safeeval,$style_for_target)=@_;
  my $finaloutput = '';
  my $result;
  my $token;
  while ( $#$pars > -1 ) {
    while ($token = $$pars['-1']->get_token) {
      if (($token->[0] eq 'T') || ($token->[0] eq 'C') || ($token->[0] eq 'D') ) {
	if ($metamode<1) {
	    my $text=$token->[1];
	    if ($token->[0] eq 'C' && $target eq 'tex') {
		$text = '';
#		$text = '%'.$text."\n";
	    }
	    $result.=$text;
	}
      } elsif ($token->[0] eq 'PI') {
	if ($metamode<1) {
	  $result=$token->[2];
	}
      } elsif ($token->[0] eq 'S') {
	# add tag to stack
	push (@$stack,$token->[1]);
	# add parameters list to another stack
	push (@$parstack,&parstring($token));
	&increasedepth($token);
	if ($Apache::lonxml::usestyle &&
	    exists($$style_for_target{$token->[1]})) {
	    $Apache::lonxml::usestyle=0;
	    my $string=$$style_for_target{$token->[1]}.
	      '<LONCAPA_INTERNAL_TURN_STYLE_ON />';
	    &Apache::lonxml::newparser($pars,\$string);
	} else {
	  $result = &callsub("start_$token->[1]", $target, $token, $stack,
			     $parstack, $pars, $safeeval, $style_for_target);
	}
      } elsif ($token->[0] eq 'E') {
	#clear out any tags that didn't end
	while ($token->[1] ne $$stack['-1'] && ($#$stack > -1)) {
	  my $lasttag=$$stack[-1];
	  if ($token->[1] =~ /^$lasttag$/i) {
	    &Apache::lonxml::warning('Using tag &lt;/'.$token->[1].'&gt; on line '.$token->[3].' as end tag to &lt;'.$$stack[-1].'&gt;');
	    last;
	  } else {
	    &Apache::lonxml::warning('Found tag &lt;/'.$token->[1].'&gt; on line '.$token->[3].' when looking for &lt;/'.$$stack[-1].'&gt; in file');
	    &end_tag($stack,$parstack,$token);
	  }
	}

	if ($Apache::lonxml::usestyle &&
	    exists($$style_for_target{'/'."$token->[1]"})) {
	    $Apache::lonxml::usestyle=0;
	    my $string=$$style_for_target{'/'.$token->[1]}.
	      '<LONCAPA_INTERNAL_TURN_STYLE_ON />';
	    &Apache::lonxml::newparser($pars,\$string);
	} else {
	  $result = &callsub("end_$token->[1]", $target, $token, $stack,
			     $parstack, $pars,$safeeval, $style_for_target);
	}
      } else {
	&Apache::lonxml::error("Unknown token event :$token->[0]:$token->[1]:");
      }
      #evaluate variable refs in result
      if ($result ne "") {
	if ( $#$parstack > -1 ) {
	  $result=&Apache::run::evaluate($result,$safeeval,$$parstack[-1]);
	} else {
	  $result= &Apache::run::evaluate($result,$safeeval,'');
	}
      }
      if (($token->[0] eq 'T') || ($token->[0] eq 'C') || ($token->[0] eq 'D') ) {
	  #Style file definitions should be correct
	  if ($target eq 'tex' && ($Apache::lonxml::usestyle)) {
	      $result=&latex_special_symbols($result,$stack,$parstack);
	  }
      }

      # Encode any high ASCII characters
      if (!$Apache::lonxml::prevent_entity_encode) {
	$result=&HTML::Entities::encode($result,"\200-\377");
      }
      if ($Apache::lonxml::redirection) {
	$Apache::lonxml::outputstack['-1'] .= $result;
      } else {
	$finaloutput.=$result;
      }
      $result = '';

      if ($token->[0] eq 'E') { 
	&end_tag($stack,$parstack,$token);
      }
    }	
    if ($#$pars > -1) {
	pop @$pars;
	pop @Apache::lonxml::pwd;
    }
  }

  # if ($target eq 'meta') {
  #   $finaloutput.=&endredirection;
  # }


  if (($ENV{'QUERY_STRING'}) && ($target eq 'web')) {
    $finaloutput=&afterburn($finaloutput);
  }	    
  return $finaloutput;
}

sub callsub {
  my ($sub,$target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  my $currentstring='';
  my $nodefault;
  {
    my $sub1;
    no strict 'refs';
    my $tag=$token->[1];
# get utterly rid of extended html tags
    if ($tag=~/^x\-/i) { return ''; }
    my $space=$Apache::lonxml::alltags{$tag}[-1];
    if (!$space) {
     	$tag=~tr/A-Z/a-z/;
	$sub=~tr/A-Z/a-z/;
	$space=$Apache::lonxml::alltags{$tag}[-1]
    }

    my $deleted=0;
    $Apache::lonxml::curdepth=join('_',@Apache::lonxml::depthcounter);
    if (($token->[0] eq 'S') && ($target eq 'modified')) {
      $deleted=&Apache::edit::handle_delete($space,$target,$token,$tagstack,
					     $parstack,$parser,$safeeval,
					     $style);
    }
    if (!$deleted) {
      if ($space) {
	#&Apache::lonxml::debug("Calling sub $sub in $space $metamode");
	$sub1="$space\:\:$sub";
	($currentstring,$nodefault) = &$sub1($target,$token,$tagstack,
					     $parstack,$parser,$safeeval,
					     $style);
      } else {
	#&Apache::lonxml::debug("NOT Calling sub $sub in $space $metamode");
	if ($metamode <1) {
	  if (defined($token->[4]) && ($metamode < 1)) {
	    $currentstring = $token->[4];
	  } else {
	    $currentstring = $token->[2];
	  }
	}
      }
      #    &Apache::lonxml::debug("nodefalt:$nodefault:");
      if ($currentstring eq '' && $nodefault eq '') {
	if ($target eq 'edit') {
	  #&Apache::lonxml::debug("doing default edit for $token->[1]");
	  if ($token->[0] eq 'S') {
	    $currentstring = &Apache::edit::tag_start($target,$token);
	  } elsif ($token->[0] eq 'E') {
	    $currentstring = &Apache::edit::tag_end($target,$token);
	  }
	} elsif ($target eq 'modified') {
	  if ($token->[0] eq 'S') {
	    $currentstring = $token->[4];
	    $currentstring.=&Apache::edit::handle_insert();
	  } elsif ($token->[0] eq 'E') {
	    $currentstring = $token->[2];
            $currentstring.=&Apache::edit::handle_insertafter($token->[1]);
	  } else {
	    $currentstring = $token->[2];
	  }
	}
      }
    }
    use strict 'refs';
  }
  return $currentstring;
}

sub setup_globals {
  my ($request,$target)=@_;
  $Apache::lonxml::request=$request;
  $Apache::lonxml::registered = 0;
  $errorcount=0;
  $warningcount=0;
  $Apache::lonxml::default_homework_loaded=0;
  $Apache::lonxml::usestyle=1;
  &init_counter();
  @Apache::lonxml::pwd=();
  @Apache::lonxml::extlinks=();
  if ($target eq 'meta') {
    $Apache::lonxml::redirection = 0;
    $Apache::lonxml::metamode = 1;
    $Apache::lonxml::evaluate = 1;
    $Apache::lonxml::import = 0;
  } elsif ($target eq 'answer') {
    $Apache::lonxml::redirection = 0;
    $Apache::lonxml::metamode = 1;
    $Apache::lonxml::evaluate = 1;
    $Apache::lonxml::import = 1;
  } elsif ($target eq 'grade') {
    &startredirection;
    $Apache::lonxml::metamode = 0;
    $Apache::lonxml::evaluate = 1;
    $Apache::lonxml::import = 1;
  } elsif ($target eq 'modified') {
    $Apache::lonxml::redirection = 0;
    $Apache::lonxml::metamode = 0;
    $Apache::lonxml::evaluate = 0;
    $Apache::lonxml::import = 0;
  } elsif ($target eq 'edit') {
    $Apache::lonxml::redirection = 0;
    $Apache::lonxml::metamode = 0;
    $Apache::lonxml::evaluate = 0;
    $Apache::lonxml::import = 0;
  } elsif ($target eq 'analyze') {
    $Apache::lonxml::redirection = 0;
    $Apache::lonxml::metamode = 0;
    $Apache::lonxml::evaluate = 1;
    $Apache::lonxml::import = 1;
  } else {
    $Apache::lonxml::redirection = 0;
    $Apache::lonxml::metamode = 0;
    $Apache::lonxml::evaluate = 1;
    $Apache::lonxml::import = 1;
  }
}

sub init_safespace {
  my ($target,$safeeval,$safehole,$safeinit) = @_;
  $safeeval->permit("entereval");
  $safeeval->permit(":base_math");
  $safeeval->permit("sort");
  $safeeval->deny(":base_io");
  $safehole->wrap(\&Apache::scripttag::xmlparse,$safeeval,'&xmlparse');
  $safehole->wrap(\&Apache::outputtags::multipart,$safeeval,'&multipart');
  $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
  
  $safehole->wrap(\&Math::Cephes::asin,$safeeval,'&asin');
  $safehole->wrap(\&Math::Cephes::acos,$safeeval,'&acos');
  $safehole->wrap(\&Math::Cephes::atan,$safeeval,'&atan');
  $safehole->wrap(\&Math::Cephes::sinh,$safeeval,'&sinh');
  $safehole->wrap(\&Math::Cephes::cosh,$safeeval,'&cosh');
  $safehole->wrap(\&Math::Cephes::tanh,$safeeval,'&tanh');
  $safehole->wrap(\&Math::Cephes::asinh,$safeeval,'&asinh');
  $safehole->wrap(\&Math::Cephes::acosh,$safeeval,'&acosh');
  $safehole->wrap(\&Math::Cephes::atanh,$safeeval,'&atanh');
  $safehole->wrap(\&Math::Cephes::erf,$safeeval,'&erf');
  $safehole->wrap(\&Math::Cephes::erfc,$safeeval,'&erfc');
  $safehole->wrap(\&Math::Cephes::j0,$safeeval,'&j0');
  $safehole->wrap(\&Math::Cephes::j1,$safeeval,'&j1');
  $safehole->wrap(\&Math::Cephes::jn,$safeeval,'&jn');
  $safehole->wrap(\&Math::Cephes::jv,$safeeval,'&jv');
  $safehole->wrap(\&Math::Cephes::y0,$safeeval,'&y0');
  $safehole->wrap(\&Math::Cephes::y1,$safeeval,'&y1');
  $safehole->wrap(\&Math::Cephes::yn,$safeeval,'&yn');
  $safehole->wrap(\&Math::Cephes::yv,$safeeval,'&yv');
  
  $safehole->wrap(\&Math::Cephes::bdtr  ,$safeeval,'&bdtr'  );
  $safehole->wrap(\&Math::Cephes::bdtrc ,$safeeval,'&bdtrc' );
  $safehole->wrap(\&Math::Cephes::bdtri ,$safeeval,'&bdtri' );
  $safehole->wrap(\&Math::Cephes::btdtr ,$safeeval,'&btdtr' );
  $safehole->wrap(\&Math::Cephes::chdtr ,$safeeval,'&chdtr' );
  $safehole->wrap(\&Math::Cephes::chdtrc,$safeeval,'&chdtrc');
  $safehole->wrap(\&Math::Cephes::chdtri,$safeeval,'&chdtri');
  $safehole->wrap(\&Math::Cephes::fdtr  ,$safeeval,'&fdtr'  );
  $safehole->wrap(\&Math::Cephes::fdtrc ,$safeeval,'&fdtrc' );
  $safehole->wrap(\&Math::Cephes::fdtri ,$safeeval,'&fdtri' );
  $safehole->wrap(\&Math::Cephes::gdtr  ,$safeeval,'&gdtr'  );
  $safehole->wrap(\&Math::Cephes::gdtrc ,$safeeval,'&gdtrc' );
  $safehole->wrap(\&Math::Cephes::nbdtr ,$safeeval,'&nbdtr' );
  $safehole->wrap(\&Math::Cephes::nbdtrc,$safeeval,'&nbdtrc');
  $safehole->wrap(\&Math::Cephes::nbdtri,$safeeval,'&nbdtri');
  $safehole->wrap(\&Math::Cephes::ndtr  ,$safeeval,'&ndtr'  );
  $safehole->wrap(\&Math::Cephes::ndtri ,$safeeval,'&ndtri' );
  $safehole->wrap(\&Math::Cephes::pdtr  ,$safeeval,'&pdtr'  );
  $safehole->wrap(\&Math::Cephes::pdtrc ,$safeeval,'&pdtrc' );
  $safehole->wrap(\&Math::Cephes::pdtri ,$safeeval,'&pdtri' );
  $safehole->wrap(\&Math::Cephes::stdtr ,$safeeval,'&stdtr' );
  $safehole->wrap(\&Math::Cephes::stdtri,$safeeval,'&stdtri');

#  $safehole->wrap(\&Math::Cephes::new_fract,$safeeval,'&new_fract');
#  $safehole->wrap(\&Math::Cephes::radd,$safeeval,'&radd');
#  $safehole->wrap(\&Math::Cephes::rsub,$safeeval,'&rsub');
#  $safehole->wrap(\&Math::Cephes::rmul,$safeeval,'&rmul');
#  $safehole->wrap(\&Math::Cephes::rdiv,$safeeval,'&rdiv');
#  $safehole->wrap(\&Math::Cephes::euclid,$safeeval,'&euclid');

  $safehole->wrap(\&Math::Random::random_beta,$safeeval,'&math_random_beta');
  $safehole->wrap(\&Math::Random::random_chi_square,$safeeval,'&math_random_chi_square');
  $safehole->wrap(\&Math::Random::random_exponential,$safeeval,'&math_random_exponential');
  $safehole->wrap(\&Math::Random::random_f,$safeeval,'&math_random_f');
  $safehole->wrap(\&Math::Random::random_gamma,$safeeval,'&math_random_gamma');
  $safehole->wrap(\&Math::Random::random_multivariate_normal,$safeeval,'&math_random_multivariate_normal');
  $safehole->wrap(\&Math::Random::random_multinomial,$safeeval,'&math_random_multinomial');
  $safehole->wrap(\&Math::Random::random_noncentral_chi_square,$safeeval,'&math_random_noncentral_chi_square');
  $safehole->wrap(\&Math::Random::random_noncentral_f,$safeeval,'&math_random_noncentral_f');
  $safehole->wrap(\&Math::Random::random_normal,$safeeval,'&math_random_normal');
  $safehole->wrap(\&Math::Random::random_permutation,$safeeval,'&math_random_permutation');
  $safehole->wrap(\&Math::Random::random_permuted_index,$safeeval,'&math_random_permuted_index');
  $safehole->wrap(\&Math::Random::random_uniform,$safeeval,'&math_random_uniform');
  $safehole->wrap(\&Math::Random::random_poisson,$safeeval,'&math_random_poisson');
  $safehole->wrap(\&Math::Random::random_uniform_integer,$safeeval,'&math_random_uniform_integer');
  $safehole->wrap(\&Math::Random::random_negative_binomial,$safeeval,'&math_random_negative_binomial');
  $safehole->wrap(\&Math::Random::random_binomial,$safeeval,'&math_random_binomial');
  $safehole->wrap(\&Math::Random::random_seed_from_phrase,$safeeval,'&random_seed_from_phrase');
  $safehole->wrap(\&Math::Random::random_set_seed_from_phrase,$safeeval,'&random_set_seed_from_phrase');
  $safehole->wrap(\&Math::Random::random_get_seed,$safeeval,'&random_get_seed');
  $safehole->wrap(\&Math::Random::random_set_seed,$safeeval,'&random_set_seed');

#need to inspect this class of ops
# $safeeval->deny(":base_orig");
  $safeinit .= ';$external::target="'.$target.'";';
  my $rndseed;
  my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
  $rndseed=&Apache::lonnet::rndseed($symb,$courseid,$domain,$name);
  $safeinit .= ';$external::randomseed='.$rndseed.';';
  &Apache::lonxml::debug("Setting rndseed to $rndseed");
  &Apache::run::run($safeinit,$safeeval);
}

sub default_homework_load {
    my ($safeeval)=@_;
    &Apache::lonxml::debug('Loading default_homework');
    my $default=&Apache::lonnet::getfile('/home/httpd/html/res/adm/includes/default_homework.lcpm');
    if ($default eq -1) {
	&Apache::lonxml::error("<b>Unable to find <i>default_homework.lcpm</i></b>");
    } else {
	&Apache::run::run($default,$safeeval);
	$Apache::lonxml::default_homework_loaded=1;
    }
}

sub startredirection {
  $Apache::lonxml::redirection++;
  push (@Apache::lonxml::outputstack, '');
}

sub endredirection {
  if (!$Apache::lonxml::redirection) {
    &Apache::lonxml::error("Endredirection was called, before a startredirection, perhaps you have unbalanced tags. Some debuging information:".join ":",caller);
    return '';
  }
  $Apache::lonxml::redirection--;
  pop @Apache::lonxml::outputstack;
}

sub end_tag {
  my ($tagstack,$parstack,$token)=@_;
  pop(@$tagstack);
  pop(@$parstack);
  &decreasedepth($token);
}

sub initdepth {
  @Apache::lonxml::depthcounter=();
  $Apache::lonxml::depth=-1;
  $Apache::lonxml::olddepth=-1;
}

sub increasedepth {
  my ($token) = @_;
  $Apache::lonxml::depth++;
  $Apache::lonxml::depthcounter[$Apache::lonxml::depth]++;
  if ($Apache::lonxml::depthcounter[$Apache::lonxml::depth]==1) {
    $Apache::lonxml::olddepth=$Apache::lonxml::depth;
  }
  my $curdepth=join('_',@Apache::lonxml::depthcounter);
  &Apache::lonxml::debug("s $Apache::lonxml::depth : $Apache::lonxml::olddepth : $curdepth : $token->[1]\n");
#print "<br />s $Apache::lonxml::depth : $Apache::lonxml::olddepth : $curdepth : $token->[1]\n";
}

sub decreasedepth {
  my ($token) = @_;
  $Apache::lonxml::depth--;
  if ($Apache::lonxml::depth<$Apache::lonxml::olddepth-1) {
    $#Apache::lonxml::depthcounter--;
    $Apache::lonxml::olddepth=$Apache::lonxml::depth+1;
  }
  if (  $Apache::lonxml::depth < -1) {
    &Apache::lonxml::warning("Missing tags, unable to properly run file.");
    $Apache::lonxml::depth='-1';
  }
  my $curdepth=join('_',@Apache::lonxml::depthcounter);
  &Apache::lonxml::debug("e $Apache::lonxml::depth : $Apache::lonxml::olddepth : $token->[1] : $curdepth\n");
#print "<br />e $Apache::lonxml::depth : $Apache::lonxml::olddepth : $token->[1] : $curdepth\n";
}

sub get_all_text_unbalanced {
#there is a copy of this in lonpublisher.pm
 my($tag,$pars)= @_;
 my $token;
 my $result='';
 $tag='<'.$tag.'>';
 while ($token = $$pars[-1]->get_token) {
   if (($token->[0] eq 'T')||($token->[0] eq 'C')||($token->[0] eq 'D')) {
     $result.=$token->[1];
   } elsif ($token->[0] eq 'PI') {
     $result.=$token->[2];
   } elsif ($token->[0] eq 'S') {
     $result.=$token->[4];
   } elsif ($token->[0] eq 'E')  {
     $result.=$token->[2];
   }
   if ($result =~ /(.*)\Q$tag\E(.*)/s) {
     &Apache::lonxml::debug('Got a winner with leftovers ::'.$2);
     &Apache::lonxml::debug('Result is :'.$1);
     $result=$1;
     my $redo=$tag.$2;
     &Apache::lonxml::newparser($pars,\$redo);
     last;
   }
 }
 return $result
}

sub increment_counter {
    my ($increment) = @_;
    if (defined($increment) && $increment gt 0) {
	$Apache::lonxml::counter+=$increment;
    } else {
	$Apache::lonxml::counter++;
    }
    $Apache::lonxml::counter_changed=1;
}

sub init_counter {
    if (defined($ENV{'form.counter'})) {
	$Apache::lonxml::counter=$ENV{'form.counter'};
	$Apache::lonxml::counter_changed=0;
    } else {
	$Apache::lonxml::counter=1;
	$Apache::lonxml::counter_changed=1;
    }
}

sub store_counter {
    &Apache::lonnet::appenv(('form.counter' => $Apache::lonxml::counter));
    return '';
}

sub get_all_text {
 my($tag,$pars)= @_;
 &Apache::lonxml::debug("Got a ".ref($pars));
 my $gotfullstack=1;
 if (ref($pars) ne 'ARRAY') {
     $gotfullstack=0;
     $pars=[$pars];
 }
 my $depth=0;
 my $token;
 my $result='';
 if ( $tag =~ m:^/: ) { 
   my $tag=substr($tag,1); 
   #&Apache::lonxml::debug("have:$tag:");
   my $top_empty=0;
   while (($depth >=0) && ($#$pars > -1) && (!$top_empty)) {
     while (($depth >=0) && ($token = $$pars[-1]->get_token)) {
       #&Apache::lonxml::debug("e token:$token->[0]:$depth:$token->[1]:".$#$pars.":".$#Apache::lonxml::pwd);
       if (($token->[0] eq 'T')||($token->[0] eq 'C')||($token->[0] eq 'D')) {
	 $result.=$token->[1];
       } elsif ($token->[0] eq 'PI') {
	 $result.=$token->[2];
       } elsif ($token->[0] eq 'S') {
	 if ($token->[1] =~ /^$tag$/i) { $depth++; }
	 $result.=$token->[4];
       } elsif ($token->[0] eq 'E')  {
	 if ( $token->[1] =~ /^$tag$/i) { $depth--; }
	 #skip sending back the last end tag
	 if ($depth > -1) { $result.=$token->[2]; } else {
	   $$pars[-1]->unget_token($token);
	 }
       }
     }
     if (($depth >=0) && ($#$pars == 0) ) { $top_empty=1; }
     if (($depth >=0) && ($#$pars > 0) ) {
       pop(@$pars);
       pop(@Apache::lonxml::pwd);
     }
   }
   if ($top_empty && $depth >= 0) {
       #never found the end tag ran out of text, throw error send back blank
       &error('Never found end tag for &lt;'.$tag.'&gt;');
       if ($gotfullstack) {
	   my $newstring='</'.$tag.'>'.$result;
	   &Apache::lonxml::newparser($pars,\$newstring);
       }
       $result='';
   }
 } else {
     while ($#$pars > -1) {
	 while ($token = $$pars[-1]->get_token) {
	     #&Apache::lonxml::debug("s token:$token->[0]:$depth:$token->[1]");
	     if (($token->[0] eq 'T')||($token->[0] eq 'C')||
		 ($token->[0] eq 'D')) {
		 $result.=$token->[1];
	     } elsif ($token->[0] eq 'PI') {
		 $result.=$token->[2];
	     } elsif ($token->[0] eq 'S') {
		 if ( $token->[1] =~ /^$tag$/i) {
		     $$pars[-1]->unget_token($token); last;
		 } else {
		     $result.=$token->[4];
		 }
	     } elsif ($token->[0] eq 'E')  {
		 $result.=$token->[2];
	     }
	 }
	 if (($#$pars > 0) ) {
	     pop(@$pars);
	     pop(@Apache::lonxml::pwd);
	 } else { last; }
     }
 }
 if ($result =~ m|<LONCAPA_INTERNAL_TURN_STYLE_ON />|) {
     $Apache::lonxml::usestyle=1;
 }
 #&Apache::lonxml::debug("Exit:$result:");
 return $result
}

sub newparser {
  my ($parser,$contentref,$dir) = @_;
  push (@$parser,HTML::LCParser->new($contentref));
  $$parser['-1']->xml_mode('1');
  if ( $dir eq '' ) {
    push (@Apache::lonxml::pwd, $Apache::lonxml::pwd[$#Apache::lonxml::pwd]);
  } else {
    push (@Apache::lonxml::pwd, $dir);
  } 
#  &Apache::lonxml::debug("pwd:$#Apache::lonxml::pwd");
#  &Apache::lonxml::debug("pwd:$Apache::lonxml::pwd[$#Apache::lonxml::pwd]");
}

sub parstring {
  my ($token) = @_;
  my $temp='';
  foreach (@{$token->[3]}) {
    unless ($_=~/\W/) {
      my $val=$token->[2]->{$_};
      $val =~ s/([\%\@\\\"\'])/\\$1/g;
      #if ($val =~ m/^[\%\@]/) { $val="\\".$val; }
      $temp .= "my \$$_=\"$val\";"
    }
  }
  return $temp;
}

sub writeallows {
    unless ($#extlinks>=0) { return; }
    my $thisurl='/res/'.&Apache::lonnet::declutter(shift);
    if ($ENV{'httpref.'.$thisurl}) {
	$thisurl=$ENV{'httpref.'.$thisurl};
    }
    my $thisdir=$thisurl;
    $thisdir=~s/\/[^\/]+$//;
    my %httpref=();
    foreach (@extlinks) {
       $httpref{'httpref.'.
 	        &Apache::lonnet::hreflocation($thisdir,$_)}=$thisurl;
    }
    @extlinks=();
    &Apache::lonnet::appenv(%httpref);
}

#
# Afterburner handles anchors, highlights and links
#
sub afterburn {
    my $result=shift;
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
					    ['highlight','anchor','link']);
    if ($ENV{'form.highlight'}) {
       foreach (split(/\,/,$ENV{'form.highlight'})) {
           my $anchorname=$_;
	   my $matchthis=$anchorname;
           $matchthis=~s/\_+/\\s\+/g;
           $result=~s/($matchthis)/\<font color=\"red\"\>$1\<\/font\>/gs;
       }
    }
    if ($ENV{'form.link'}) {
       foreach (split(/\,/,$ENV{'form.link'})) {
           my ($anchorname,$linkurl)=split(/\>/,$_);
	   my $matchthis=$anchorname;
           $matchthis=~s/\_+/\\s\+/g;
           $result=~s/($matchthis)/\<a href=\"$linkurl\"\>$1\<\/a\>/gs;
       }
    }
    if ($ENV{'form.anchor'}) {
        my $anchorname=$ENV{'form.anchor'};
	my $matchthis=$anchorname;
        $matchthis=~s/\_+/\\s\+/g;
        $result=~s/($matchthis)/\<a name=\"$anchorname\"\>$1\<\/a\>/s;
        $result.=(<<"ENDSCRIPT");
<script type="text/javascript">
    document.location.hash='$anchorname';
</script>
ENDSCRIPT
    }
    return $result;
}

sub storefile {
    my ($file,$contents)=@_;
    if (my $fh=Apache::File->new('>'.$file)) {
	print $fh $contents;
        $fh->close();
    } else {
      &warning("Unable to save file $file");
    }
}

sub createnewhtml {
  my $filecontents=(<<SIMPLECONTENT);
<html>
<head>
<title>
                           Title of Document Goes Here
</title>
</head>
<body bgcolor="#FFFFFF">

                           Body of Document Goes Here

</body>
</html>
SIMPLECONTENT
  return $filecontents;
}


sub inserteditinfo {
      my ($result,$filecontents)=@_;
      $filecontents = &HTML::Entities::encode($filecontents);
#      my $editheader='<a href="#editsection">Edit below</a><hr />';
      my $xml_help = '<table><tr><td>'.
	  &Apache::loncommon::help_open_topic("Greek_Symbols",'Greek Symbols',
					      undef,undef,600)
	      .'</td><td>'.
          &Apache::loncommon::help_open_topic("Other_Symbols",'Other Symbols',
					      undef,undef,600)
	      .'</td></tr></table>';
      my $buttons=(<<BUTTONS);
<input type="submit" name="attemptclean" 
       value="Save and then attempt to clean HTML" />
<input type="submit" name="savethisfile" value="Save this" />
<input type="submit" name="viewmode" value="View" />
BUTTONS
      my $editfooter=(<<ENDFOOTER);
<hr />
<a name="editsection" />
<form method="post">
$xml_help
<input type="hidden" name="editmode" value="Edit" />
$buttons<br />
<textarea cols="80" rows="40" name="filecont">$filecontents</textarea>
<br />$buttons
<br />
</form>
ENDFOOTER
#      $result=~s/(\<body[^\>]*\>)/$1$editheader/is;
      $result=~s/(\<\/body\>)/$editfooter/is;
      return $result;
}

sub get_target {
  my $viewgrades=&Apache::lonnet::allowed('vgr',$ENV{'request.course.id'});
  if ( $ENV{'request.state'} eq 'published') {
    if ( defined($ENV{'form.grade_target'})
	 && ($viewgrades == 'F' )) {
      return ($ENV{'form.grade_target'});
    } elsif (defined($ENV{'form.grade_target'})) {
      if (($ENV{'form.grade_target'} eq 'web') ||
	  ($ENV{'form.grade_target'} eq 'tex') ) {
	return $ENV{'form.grade_target'}
      } else {
	return 'web';
      }
    } else {
      return 'web';
    }
  } elsif ($ENV{'request.state'} eq 'construct') {
    if ( defined($ENV{'form.grade_target'})) {
      return ($ENV{'form.grade_target'});
    } else {
      return 'web';
    }
  } else {
    return 'web';
  }
}

sub handler {
  my $request=shift;

  my $target=&get_target();

  $Apache::lonxml::debug=0;

  if ($ENV{'browser.mathml'}) {
    $request->content_type('text/xml');
  } else {
    $request->content_type('text/html');
  }
  &Apache::loncommon::no_cache($request);
  $request->send_http_header;

  return OK if $request->header_only;


  my $file=&Apache::lonnet::filelocation("",$request->uri);
#
# Edit action? Save file.
#
  unless ($ENV{'request.state'} eq 'published') {
      if (($ENV{'form.savethisfile'}) || ($ENV{'form.attemptclean'})) {
	  &storefile($file,$ENV{'form.filecont'});
      }
  }
  my %mystyle;
  my $result = '';
  my $filecontents=&Apache::lonnet::getfile($file);
  if ($filecontents eq -1) {
    $result=(<<ENDNOTFOUND);
<html>
<head>
<title>File not found</title>
</head>
<body bgcolor="#FFFFFF">
<b>File not found: $file</b>
</body>
</html>
ENDNOTFOUND
    $filecontents='';
    if ($ENV{'request.state'} ne 'published') {
      $filecontents=&createnewhtml();
      $ENV{'form.editmode'}='Edit'; #force edit mode
    }
  } else {
    unless ($ENV{'request.state'} eq 'published') {
      if ($ENV{'form.attemptclean'}) {
	$filecontents=&htmlclean($filecontents,1);
      }
    }
    if (!$ENV{'form.editmode'} || $ENV{'form.viewmode'}) {
      $result = &Apache::lonxml::xmlparse($request,$target,$filecontents,
					  '',%mystyle);
    }
  }

#
# Edit action? Insert editing commands
#
  unless ($ENV{'request.state'} eq 'published') {
    if ($ENV{'form.editmode'} && (!($ENV{'form.viewmode'}))) {
	my $displayfile=$request->uri;
        $displayfile=~s/^\/[^\/]*//;
      $result='<html><body bgcolor="#FFFFFF"><h3>'.$displayfile.
              '</h3></body></html>';
      $result=&inserteditinfo($result,$filecontents);
    }
  }

  writeallows($request->uri);

  $request->print($result);

  return OK;
}

sub debug {
  if ($Apache::lonxml::debug eq 1) {
    $|=1;
    print('<font size="-2"<pre>DEBUG:'.&HTML::Entities::encode($_[0])."</pre></font>\n");
  }
}

sub error {
  $errorcount++;
  if (($Apache::lonxml::debug eq 1) || ($ENV{'request.state'} eq 'construct') ) {
    # If printing in construction space, put the error inside <pre></pre>
    print "<b>ERROR:</b>".join("\n",@_)."\n";
  } else {
    print "<b>An Error occured while processing this resource. The instructor has been notified.</b> <br />";
    #notify author
    &Apache::lonmsg::author_res_msg($ENV{'request.filename'},join('<br />',@_));
    #notify course
    if ( $ENV{'request.course.id'} ) {
      my (undef,%users)=&Apache::lonfeedback::decide_receiver(undef,0,1,1,1);
      my $declutter=&Apache::lonnet::declutter($ENV{'request.filename'});
      foreach (keys %users) {
	my ($user,$domain) = split(/:/, $_);
	&Apache::lonmsg::user_normal_msg($user,$domain,
        "Error [$declutter]",join('<br />',@_));
      }
    }

    #FIXME probably shouldn't have me get everything forever.
    &Apache::lonmsg::user_normal_msg('albertel','msu',"Error in $ENV{'request.filename'}",join('<br />',@_));
    #&Apache::lonmsg::user_normal_msg('albertel','103',"Error in $ENV{'request.filename'}",$_[0]);
  }
}

sub warning {
  $warningcount++;
  if ($ENV{'request.state'} eq 'construct') {
    print "<b>W</b>ARNING<b>:</b>".join('<br />',@_)."<br />\n";
  }
}

sub get_param {
    my ($param,$parstack,$safeeval,$context,$case_insensitive) = @_;
    if ( ! $context ) { $context = -1; }
    my $args ='';
    if ( $#$parstack > (-2-$context) ) { $args=$$parstack[$context]; }
    if ( ! $args ) { return undef; }
    if ( $case_insensitive ) {
	if ($args =~ s/(my \$)(\Q$param\E)(=\")/$1.lc($2).$3/ei) {
	    return &Apache::run::run("{$args;".'return $'.$param.'}',
                                     $safeeval); #'
	} else {
	    return undef;
	}
    } else {
	if ( $args =~ /my \$\Q$param\E=\"/ ) {
	    return &Apache::run::run("{$args;".'return $'.$param.'}',
                                     $safeeval); #'
	} else {
	    return undef;
	}
    }
}

sub get_param_var {
  my ($param,$parstack,$safeeval,$context,$case_insensitive) = @_;
  if ( ! $context ) { $context = -1; }
  my $args ='';
  if ( $#$parstack > (-2-$context) ) { $args=$$parstack[$context]; }
  &Apache::lonxml::debug("Args are $args param is $param");
  if ($case_insensitive) {
      if (! ($args=~s/(my \$)(\Q$param\E)(=\")/$1.lc($2).$3/ei)) {
	  return undef;
      }
  } elsif ( $args !~ /my \$\Q$param\E=\"/ ) { return undef; }
  my $value=&Apache::run::run("{$args;".'return $'.$param.'}',$safeeval); #'
  &Apache::lonxml::debug("first run is $value");
  if ($value =~ /^[\$\@\%]\w+$/) {
      &Apache::lonxml::debug("doing second");
      my @result=&Apache::run::run("return $value",$safeeval,1);
      if (!defined($result[0])) {
	  return $value
      } else {
	  if (wantarray) { return @result; } else { return $result[0]; }
      }
  } else {
    return $value;
  }
}

sub register_insert {
  my @data = split /\n/, &Apache::lonnet::getfile('/home/httpd/lonTabs/insertlist.tab');
  my $i;
  my $tagnum=0;
  my @order;
  for ($i=0;$i < $#data; $i++) {
    my $line = $data[$i];
    if ( $line =~ /^\#/ || $line =~ /^\s*\n/) { next; }
    if ( $line =~ /TABLE/ ) { last; }
    my ($tag,$descrip,$color,$function,$show) = split(/,/, $line);
    if ($tag) {
      $insertlist{"$tagnum.tag"} = $tag;
      $insertlist{"$tagnum.description"} = $descrip;
      $insertlist{"$tagnum.color"} = $color;
      $insertlist{"$tagnum.function"} = $function;
      if (!defined($show)) { $show='yes'; }
      $insertlist{"$tagnum.show"}= $show;
      $insertlist{"$tag.num"}=$tagnum;
      $tagnum++;
    }
  }
  $i++; #skipping TABLE line
  $tagnum = 0;
  for (;$i < $#data;$i++) {
    my $line = $data[$i];
    my ($mnemonic,@which) = split(/ +/,$line);
    my $tag = $insertlist{"$tagnum.tag"};
    for (my $j=0;$j <=$#which;$j++) {
      if ( $which[$j] eq 'Y' ) {
	if ($insertlist{"$j.show"} ne 'no') {
	  push(@{ $insertlist{"$tag.which"} },$j);
	}
      }
    }
    $tagnum++;
  }
}

sub description {
  my ($token)=@_;
  my $tagnum;
  my $tag=$token->[1];
  foreach my $namespace (reverse @Apache::lonxml::namespace) {
    my $testtag=$namespace.'::'.$tag;
    $tagnum=$insertlist{"$testtag.num"};
    if (defined($tagnum)) { last; }
  }
  if (!defined ($tagnum)) { $tagnum=$Apache::lonxml::insertlist{"$tag.num"}; }
  return $insertlist{$tagnum.'.description'};
}

# ----------------------------------------------------------------- whichuser
# returns a list of $symb, $courseid, $domain, $name that is correct for
# calls to lonnet functions for this setup.
# - looks for form.grade_ parameters
sub whichuser {
  my ($symb,$courseid,$domain,$name,$publicuser);
  if (defined($ENV{'form.grade_symb'})) {
    my $tmp_courseid=$ENV{'form.grade_courseid'};
    my $allowed=&Apache::lonnet::allowed('mgr',$tmp_courseid);
    if ($allowed) {
      $symb=$ENV{'form.grade_symb'};
      $courseid=$ENV{'form.grade_courseid'};
      $domain=$ENV{'form.grade_domain'};
      $name=$ENV{'form.grade_username'};
    }
  } else {
      $symb=&Apache::lonnet::symbread();
      $courseid=$ENV{'request.course.id'};
      $domain=$ENV{'user.domain'};
      $name=$ENV{'user.name'};
      if ($name eq 'public' && $domain eq 'public') {
	  if (!defined($ENV{'form.username'})) {
	      $ENV{'form.username'}.=time.rand(10000000);
	  }
	  $name.=$ENV{'form.username'};
      }
  }
  return ($symb,$courseid,$domain,$name,$publicuser);
}

1;
__END__