--- loncom/homework/structuretags.pm	2000/08/16 18:32:58	1.3
+++ loncom/homework/structuretags.pm	2003/05/09 22:24:05	1.169
@@ -1,33 +1,1027 @@
-# The LearningOnline Network with CAPA
-# <script> definiton
+# The LearningOnline Network with CAPA 
+# definition of tags that give a structure to a document
+#
+# $Id: structuretags.pm,v 1.169 2003/05/09 22:24:05 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/
+#
+# 2/19 Guy
+# 6/26/2001 fixed extra web display at end of <web></web> tags
+# 8/17,8/18,8/20 Gerd Kortemeyer
 
 
 package Apache::structuretags; 
 
 use strict;
 use Apache::lonnet;
+use Apache::File();
+use Apache::lonmenu;
 
-sub BEGIN {
-  &Apache::lonxml::register('Apache::structuretags',('block'));
+BEGIN {
+    &Apache::lonxml::register('Apache::structuretags',('block','languageblock','while','randomlist','problem','library','web','tex','part','preduedate','postanswerdate','solved','notsolved','startouttext','endouttext'));
+}
+
+sub start_web {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $bodytext=&Apache::lonxml::get_all_text("/web",$parser);
+    if ($target eq 'web') {
+	return $bodytext;
+    }
+    return '';
+}
+
+sub end_web {
+    return '';
+}
+
+sub start_tex {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $bodytext=&Apache::lonxml::get_all_text("/tex",$parser);
+    if ($target eq 'tex') {
+	return $bodytext.' ';
+    }
+    return '';
+}
+
+sub end_tex {
+    return '';
+}
+
+sub page_start {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my %found;
+    foreach my $taginside ($tagstack) {
+	foreach my $taglookedfor ('html','body','form') {
+	    if ($taginside =~ /^$taglookedfor$/i) {$found{$taglookedfor} = 1;}
+	}
+    }
+
+    my $result;
+    my $head_tag_start;
+    if (!defined($found{'html'})) {
+	$result=&Apache::londefdef::start_html($target,$token,$tagstack,
+					       $parstack,$parser,$safeeval);
+	$head_tag_start='<head>'.&Apache::lonmenu::registerurl(undef,$target);
+    }
+    my $body_tag_start;
+    if (!defined($found{'body'})) {
+	$body_tag_start='<body onLoad="'.&Apache::lonmenu::loadevents().'" '.
+	    'onUnload="'.&Apache::lonmenu::unloadevents().'" ';
+	my $background=&Apache::lonxml::get_param('background',$parstack,
+						  $safeeval);
+	if ($background) {
+	    $Apache::lonxml::extlinks[$#Apache::lonxml::extlinks+1]=
+		$background;
+	    $body_tag_start.='background="'.$background.'" ';
+	} else {
+	    my $bgcolor=&Apache::lonxml::get_param('bgcolor',$parstack,
+						   $safeeval);
+	    if ($bgcolor) {
+		$body_tag_start.='bgcolor="'.$bgcolor.'" ';
+	    } else {
+		$body_tag_start.='bgcolor="#ffffff"';
+	    }
+	}
+	$body_tag_start.='>'.&Apache::lonmenu::menubuttons(undef,$target,1);
+	if ($target eq 'web' && $ENV{'request.state'} ne 'construct') {
+	    my ($symb,undef,undef,undef,$publicuser)=
+		&Apache::lonxml::whichuser();
+	    if ($symb eq '' && !$publicuser) {
+		my $help = &Apache::loncommon::help_open_topic("Ambiguous_Reference");
+		$help="Browsing resource, all submissions are temporary.<br />";
+		$body_tag_start.=$help;
+	    }
+	}
+    }
+    my $form_tag_start;
+    if (!defined($found{'form'})) {
+	$form_tag_start='<form name="lonhomework" method="POST" action="'.
+	    $ENV{'request.uri'}.'">';
+    }
+    return ($result,$head_tag_start,$body_tag_start,$form_tag_start);
+}
+
+#use Time::HiRes();
+sub get_resource_name {
+    my ($parstack,$safeeval)=@_;
+    my $name=&Apache::lonnet::gettitle();
+    if ($name eq '') {
+	$name=&Apache::lonnet::EXT('resource.title');
+	if ($name eq 'con_lost') { $name = ''; }
+    }
+    $Apache::lonhomework::name=$name;
+    return $name;
+}
+
+sub setup_rndseed {
+    my ($safeeval)=@_;
+    my $rndseed;
+    my ($symb)=&Apache::lonxml::whichuser();
+    if ($ENV{'request.state'} eq "construct" || $symb eq '') {
+	$rndseed=$ENV{'form.rndseed'};
+	if (!$rndseed) {
+	    $rndseed=$Apache::lonhomework::history{'rndseed'};
+	    if (!$rndseed) {
+		$rndseed=time;
+		$ENV{'form.rndseed'}=$rndseed;
+	    }
+	}
+	if ($ENV{'form.resetdata'} eq 'New Problem Variation') {
+	    $rndseed=time;
+	    $ENV{'form.rndseed'}=$rndseed;
+	}
+	&Apache::lonxml::debug("Setting rndseed to $rndseed");
+	&Apache::run::run('$external::randomseed='.$rndseed.';',$safeeval);
+    }
+    return $rndseed;
+}
+
+sub problem_edit_header {
+    return '<input type="hidden" name="submitted" value="edit" />
+       <input type="hidden" name="problemmode" value="Edit" />
+       <input type="submit" name="problemmode" value="Discard Edits and View" />
+       <input type="submit" name="problemmode" value="EditXML" />
+       <input type="submit" name="Undo" value="undo" /> <hr />
+       <input type="submit" name="submit" value="Submit Changes and Edit" />
+       <input type="submit" name="submit" value="Submit Changes and View" /><br /><p>&nbsp;</p><table border="0"><tr><td bgcolor="#DDDDDD">
+      ';
+}
+
+sub problem_edit_footer {
+    return '</td></tr></table><br /><input type="submit" name="submit" value="Submit Changes and Edit" />
+    <input type="submit" name="submit" value="Submit Changes and View" />';
+}
+
+sub problem_web_to_edit_header {
+    my ($rndseed)=@_;
+    my $result.='<input type="hidden" name="problemmode" value="View" />
+             <input type="submit" name="problemmode" value="Edit" />
+             <input type="submit" name="problemmode" value="EditXML" />
+             Random Seed:<input type="text" name="rndseed" width="10" value="'.
+	       $rndseed.'" />
+             <input type="submit" name="changerandseed" value="Change" />
+             <input type="submit" name="resetdata" value="Reset Submissions" />
+             <input type="checkbox" name="showallfoils" ';
+    if (defined($ENV{'form.showallfoils'})) { $result.='checked="on"'; }
+    $result.= ' />&nbsp;Show&nbsp;All&nbsp;Foils
+             <hr />';
+    my $numtoanalyze=$ENV{'form.numtoanalyze'};
+    if (!$numtoanalyze) { $numtoanalyze=100; }
+    $result.= '<input type="submit" name="problemmode" value="Answer Distribution" />
+             <input type="text" name="numtoanalyze" value="'.
+		 $numtoanalyze.'" size="5" /> <hr />';
+    return $result;
+}
+
+sub initialize_storage {
+    %Apache::lonhomework::results=();
+    %Apache::lonhomework::history=();
+    my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+    if ($ENV{'request.state'} eq 'construct' || $symb eq '') {
+	%Apache::lonhomework::history=
+	    &Apache::lonnet::tmprestore($ENV{'request.uri'},'',$domain,$name);
+	my ($temp)=keys %Apache::lonhomework::history ;
+	&Apache::lonxml::debug("Return message of $temp");
+    } else {
+	%Apache::lonhomework::history=
+	    &Apache::lonnet::restore($symb,$courseid,$domain,$name);
+    }
+    #ignore error conditions
+    my ($temp)=keys %Apache::lonhomework::history ;
+    if ($temp =~ m/^error:.*/) { %Apache::lonhomework::history=(); }
+}
+
+# -------------------------------------------------------------finalize_storage
+# Stores away the result has to a student's environment
+# checks form.grade_ for specific values, other wises stores
+# to the running users environment
+sub finalize_storage {
+    my $result;
+    my ($temp) = keys %Apache::lonhomework::results;
+    if ( $temp ne '' ) {
+	my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+	if ($ENV{'request.state'} eq 'construct' || $symb eq '') {
+	    $Apache::lonhomework::results{'rndseed'}=$ENV{'form.rndseed'};
+	    $result=&Apache::lonnet::tmpstore(\%Apache::lonhomework::results,
+					$ENV{'request.uri'},'',$domain,$name);
+	    &Apache::lonxml::debug('Construct Store return message:'.$result);
+	} else {
+	    $result=&Apache::lonnet::cstore(\%Apache::lonhomework::results,
+					    $symb,$courseid,$domain,$name);
+	    &Apache::lonxml::debug('Store return message:'.$result);
+	}
+    }
+    return $result;
+}
+
+sub checkout_msg {
+    return (<<ENDCHECKOUT);
+<h2>The resource needs to be checked out</h2>
+As a resource gets checked out, a unique timestamped ID is given to it, and a
+permanent record is left in the system.<p />
+<font color=red>
+Checking out resources is subject to course policies, and may exclude future
+credit even if done erroneously.<p />
+</font>
+<form name="checkout" method="POST" action="$ENV{'request.uri'}">
+<input type="hidden" name="doescheckout" value="yes" />
+<input type="button" name="checkoutbutton" value="Check out Exam for Viewing" onClick="javascript:if (confirm('Check out Exam?')) { document.checkout.submit(); }" />
+</form>
+ENDCHECKOUT
+}
+
+sub start_problem {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+
+    $Apache::lonhomework::parsing_a_problem=1;
+    # meta is called from lonpublisher, which doesn't uses the normal
+    # lonhomework method of parsing the file which means that inputtags 
+    # won't get reset
+    if ( $Apache::inputtags::part ne '' && $target != 'meta' ) {
+	&Apache::lonxml::error('Only one problem allowed in a .problem file');
+	my $bodytext=&Apache::lonxml::get_all_text("/problem",$parser);
+	return '';
+    }
+#initialize globals
+    $Apache::inputtags::part='0';
+    @Apache::inputtags::responselist = ();
+    @Apache::inputtags::previous=();
+    @Apache::inputtags::previous_version=();
+    $Apache::structuretags::printanswer='No';
+    @Apache::structuretags::whileconds=();
+    @Apache::structuretags::whilebody=();
+    @Apache::structuretags::whileline=();
+    $Apache::lonhomework::scantronmode=0;
+    $Apache::lonhomework::problemstatus=
+	&Apache::lonnet::EXT('resource.0.problemstatus');
+
+    if (defined($ENV{'scantron.maxquest'})) {
+	$Apache::lonhomework::scantronmode=1;
+    }
+
+    if ($target ne 'analyze') {
+	&initialize_storage();
+	if ($target eq 'web') {
+	    &Apache::lonhomework::showhash(%Apache::lonhomework::history);
+	}
+	$Apache::lonhomework::type=&Apache::lonnet::EXT('resource.0.type');
+	&Apache::lonxml::debug("Found this to be of type :$Apache::lonhomework::type:");
+    }
+    if ($Apache::lonhomework::type eq '' ) {
+	my $uri=$ENV{'request.uri'};
+	if ($uri=~/\.(\w+)$/) {
+	    $Apache::lonhomework::type=$1;
+	    &Apache::lonxml::debug("Using type of $1");
+	} else {
+	    $Apache::lonhomework::type='problem';
+	    &Apache::lonxml::debug("Using default type, problem, :$uri:");
+	}
+    }
+
+    #added vars to the scripting enviroment
+    my $expression='$external::part='.$Apache::inputtags::part.';';
+    &Apache::run::run($expression,$safeeval);
+    my $status;
+    my $accessmsg;
+
+    #should get back a <html> or the neccesary stuff to start XML/MathML
+    my ($result,$head_tag_start,$body_tag_start,$form_tag_start)=
+	&page_start($target,$token,$tagstack,$parstack,$parser,$safeeval);
+    if ($target eq 'tex' and $ENV{'request.symb'} =~ m/\.page_/) {$result='';}
+
+    if ($target eq 'analyze') { my $rndseed=&setup_rndseed($safeeval); }
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex') {
+	#handle exam checkout
+	if ($Apache::lonhomework::type eq 'exam') {
+	    my $token=
+		$Apache::lonhomework::history{"resource.0.outtoken"};
+	    if (($ENV{'form.doescheckout'}) && (!$token)) {
+		$token=&Apache::lonxml::maketoken();
+		$Apache::lonhomework::history{"resource.0.outtoken"}=
+		    $token;
+	    }
+	    $body_tag_start.=&Apache::lonxml::printtokenheader($target,$token);
+	}
+
+	#handle rand seed in construction space
+	my $rndseed=&setup_rndseed($safeeval);
+	my ($symb)=&Apache::lonxml::whichuser();
+	if ($ENV{'request.state'} ne "construct" && $symb eq '') {
+	    $form_tag_start.='<input type="hidden" name="rndseed" value="'.
+		$rndseed.'" />'.
+		    '<input type="submit" name="resetdata"
+                             value="New Problem Variation" />'.
+		    '<input type="hidden" name="username"
+                             value="'.$ENV{'form.username'}.'" />';
+	}
+	($status,$accessmsg) = &Apache::lonhomework::check_access('0');
+	push (@Apache::inputtags::status,$status);
+	my $expression='$external::datestatus="'.$status.'";';
+	$expression.='$external::gradestatus="'.$Apache::lonhomework::history{"resource.0.solved"}.'";';
+	&Apache::run::run($expression,$safeeval);
+	&Apache::lonxml::debug("Got $status");
+	if (( $status eq 'CLOSED' ) ||
+	    ( $status eq 'UNCHECKEDOUT') ||
+	    ( $status eq 'BANNED') ||
+	    ( $status eq 'UNAVAILABLE')) {
+	    my $bodytext=&Apache::lonxml::get_all_text("/problem",$parser);
+	    if ( $target eq "web" ) {
+		$result.= $head_tag_start.'</head>';
+		my $msg=$body_tag_start;
+		if ($status eq 'UNAVAILABLE') {
+		    $result.='<h1>Unable to determine if this resource is open due to network problems. Please try again later.</h1>';
+		} else {
+		    $result.='<h1>Not open to be viewed</h1>';
+		}
+		if ($status eq 'CLOSED') {
+		    $msg.='The problem '.$accessmsg;
+		} elsif ($status eq 'UNCHECKEDOUT') {
+		    $msg.=&checkout_msg;
+		}
+		$result.=$msg.'<br />';
+	    } elsif ($target eq 'tex') {
+		$result.='\begin{document}\noindent \vskip 1 mm  \begin{minipage}{\textwidth}\vskip 0 mm';
+		if ($status eq 'UNAVAILABLE') {
+		    $result.='Unable to determine if this resource is open due to network problems. Please try again later.\vskip 0 mm ';
+		} else {
+		    $result.="Problem is not open to be viewed. It $accessmsg \\vskip 0 mm ";
+		}
+	    }
+	} elsif ($target eq 'web') {
+	    my $name= &get_resource_name($parstack,$safeeval);
+	    if ($status eq 'CAN_ANSWER') {
+		# create a page header and exit
+		$result.="$head_tag_start<title>$name</title></head>
+              $body_tag_start \n $form_tag_start".	
+		  '<input type="hidden" name="submitted" value="yes" />';
+		if ($ENV{'request.state'} eq "construct") {
+		    $result.= &problem_web_to_edit_header($rndseed);
+		}
+		# if we are viewing someone else preserve that info
+		if (defined $ENV{'form.grade_symb'}) {
+		    foreach my $field ('symb','courseid','domain','username') {
+			$result .= '<input type="hidden" name="grade_'.$field.
+			    '" value="'.$ENV{"form.grade_$field"}.'" />'."\n";
+		    }
+		}
+	    } elsif ($status eq 'SHOW_ANSWER' || $status eq 'CANNOT_ANSWER'
+		     || $status eq 'CLOSED' || $status eq 'UNAVALAILABLE') {
+		$result.=$head_tag_start.
+		    "<title>$name</title></head>\n$body_tag_start\n";
+	    }
+	} elsif ($target eq 'tex') {
+	    my $name= &Apache::lonxml::get_param('name',$parstack,$safeeval);
+	    if ($name eq '') {
+		$name=&Apache::lonnet::EXT('resource.title');
+		if ($name eq 'con_lost') { $name = ''; }
+	    }
+	    $Apache::lonhomework::name=$name;
+	    my $id = $Apache::inputtags::part;
+	    my $weight = &Apache::lonnet::EXT("resource.$id.weight");
+	    my $allkeys=&Apache::lonnet::metadata($ENV{'request.uri'},'keys');
+	    my @allkeys = split /,/,$allkeys;
+	    my $allow_print_points = 0;
+	    foreach my $partial_key (@allkeys) {
+		if ($partial_key=~m/weight/) {
+		    $allow_print_points++;
+		}
+	    }
+	    my $duedate = &Apache::lonnet::EXT("resource.$id.duedate"); 
+	    $duedate = POSIX::strftime("%c",localtime($duedate));
+	    my $temp_file;
+	    my $filename = "/home/httpd/prtspool/$ENV{'user.name'}_$ENV{'user.domain'}_printout.due";
+	    if (-e $filename) {
+		$temp_file = Apache::File->new($filename);
+	    } else {
+		$temp_file = Apache::File->new('>>'.$filename);
+	    }
+	    my @due_file_content = <$temp_file>;
+	    my $due_file_content = $due_file_content[$#due_file_content];
+	    chomp $due_file_content;
+	    my $name_of_resourse= &get_resource_name($parstack,$safeeval);
+	    if ($due_file_content ne $duedate) {
+		$temp_file = Apache::File->new('>'.$filename);
+		print $temp_file "$duedate\n";
+		if (not $ENV{'request.symb'} =~ m/\.page_/) {
+		    if(not $duedate=~m/1969/ and $Apache::lonhomework::type ne 'exam') {
+			$result .= '\begin{document} \typeout{STAMPOFPASSEDRESOURCESTART Resource <h2>"'.$name_of_resourse.'"</h2> located in <br /><small><b>'.$ENV{'request.uri'}.'</b></small><br /> STAMPOFPASSEDRESOURCEEND} \noindent\textit{Due date: '.$duedate.'} \vskip 1 mm\noindent \begin{minipage}{\textwidth}';	
+		    } else {
+			$result .= '\begin{document} \typeout{STAMPOFPASSEDRESOURCESTART Resource <h2>"'.$name_of_resourse.'"</h2> located in <br /><small><b>'.$ENV{'request.uri'}.'</b></small><br /> STAMPOFPASSEDRESOURCEEND} \noindent \vskip 1 mm \noindent\begin{minipage}{\textwidth}';
+			if ($Apache::lonhomework::type eq 'exam' and $allow_print_points==1) { $result .= '\fbox{\textit{'.$weight.' pt}}';}
+		    }
+		} else {
+		    $result .= '\vskip 1mm\textit{Due date: '.$duedate.'} \\\\\\\\';
+		}
+	    } else {
+		if (not $ENV{'request.symb'} =~ m/\.page_/) {
+		    $result .= '\begin{document} \typeout{STAMPOFPASSEDRESOURCESTART Resource <h2>"'.$name_of_resourse.'"</h2> located in <br /><small><b>'.$ENV{'request.uri'}.'</b></small><br /> STAMPOFPASSEDRESOURCEEND} \noindent \vskip 1 mm\noindent\begin{minipage}{\textwidth}';	
+		    if (($Apache::lonhomework::type eq 'exam') and ($allow_print_points==1)) { $result .= '\fbox{\textit{'.$weight.' pt}}';}
+		} else {
+		    $result .= '\vskip 1mm \\\\\\\\';
+		}
+	    }
+	}
+    } elsif ($target eq 'edit') {
+	$result.=$head_tag_start."</head>".$body_tag_start.$form_tag_start.
+	    &problem_edit_header();
+	my $temp=&Apache::edit::insertlist($target,$token);
+	$result.=$temp;
+    } elsif ($target eq 'modified') {
+	$result=$token->[4];
+	$result.=&Apache::edit::handle_insert();
+    } else {
+	# page_start returned a starting result, delete it if we don't need it
+	$result = '';
+    }
+    return $result;
+}
+
+sub end_problem {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result='';
+    my $status=$Apache::inputtags::status['-1'];
+    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' ||
+	$target eq 'tex') {
+	if ( $target eq 'grade' && $Apache::inputtags::part eq '0' &&
+	     $status eq 'CAN_ANSWER' ) {
+	    # if part is zero, no <part>s existed, so we need to the grading
+	    &Apache::inputtags::grade;
+	} elsif ( ($target eq 'web' || $target eq 'tex') &&
+		  $Apache::inputtags::part eq '0' &&
+		  $status ne 'UNCHECKEDOUT') {
+	    # if part is zero, no <part>s existed, so we need show the current
+	    # grading status
+	    my $gradestatus = &Apache::inputtags::gradestatus($Apache::inputtags::part,$target);
+	    $result.= $gradestatus;
+	}
+	if (
+	    (($target eq 'web') && ($ENV{'request.state'} ne 'construct')) ||
+	    ($target eq 'answer') || ($target eq 'tex')
+	   ) {
+	    if ($status eq 'CAN_ANSWER') {
+		if ($target ne 'tex') {
+		    $result.="</form></body>\n";
+		}
+	    } elsif ($status eq 'SHOW_ANSWER' || $status eq 'CANNOT_ANSWER' ||
+		     $status eq 'UNCHECKEDOUT' ) {
+		if ($target ne 'tex') {
+		    $result.="</body>\n";
+		}
+	    }
+	    if ($target eq 'web') {
+		$result.=&Apache::lonxml::xmlend();
+	    } elsif ($target eq 'tex') {
+		$result .= '\vskip 0.5mm\noindent\makebox[\textwidth/$number_of_columns][b]{\hrulefill}';
+		if (not $ENV{'request.symb'} =~ m/\.page_/) {
+		    $result .= '\end{minipage}\end{document} ';
+		} else {
+		    $result .= '';
+		}
+	    }
+	}
+	if ($target eq 'grade') {
+	    &Apache::lonhomework::showhash(%Apache::lonhomework::results);
+	    &finalize_storage();
+	}
+	if ($target eq 'answer' && ($ENV{'request.state'} eq 'construct') ) {
+	    $result.='</html>'; #normally we get it from xmlend, but in CSTR
+	                        # we always show answer mode too.
+	}
+    } elsif ($target eq 'meta') {
+	if ($Apache::inputtags::part eq '0') {
+	    $result=&Apache::response::mandatory_part_meta;
+	}
+    } elsif ($target eq 'edit') {
+	&Apache::lonxml::debug("in end_problem with $target, edit");
+	$result = &problem_edit_footer();
+    }
+
+    undef(%Apache::lonhomework::history);
+    undef(%Apache::lonhomework::results);
+    undef($Apache::inputtags::part);
+    undef($Apache::lonhomework::parsing_a_problem);
+
+    return $result;
+}
+
+
+sub start_library {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my ($result,$head_tag_start,$body_tag_start,$form_tag_start);
+
+    if ($target eq 'edit') {
+	($result,$head_tag_start,$body_tag_start,$form_tag_start)=
+	    &page_start($target,$token,$tagstack,$parstack,$parser,$safeeval);
+	$result.=$head_tag_start."</head>".$body_tag_start.$form_tag_start.
+	    &problem_edit_header();
+	my $temp=&Apache::edit::insertlist($target,$token);
+	$result.=$temp;
+    } elsif ($target eq 'modified') {
+	$result=$token->[4];
+	$result.=&Apache::edit::handle_insert();
+    } elsif ($target eq 'web' && $$tagstack[0] ne 'problem' &&
+	     $ENV{'request.state'} eq "construct" ) {
+	($result,$head_tag_start,$body_tag_start,$form_tag_start)=
+	    &page_start($target,$token,$tagstack,$parstack,$parser,$safeeval);
+	my $name=&get_resource_name($parstack,$safeeval);
+	my $rndseed=&setup_rndseed($safeeval);
+	$result.="$head_tag_start<title>$name</title></head>
+              $body_tag_start \n $form_tag_start".	
+		  '<input type="hidden" name="submitted" value="yes" />';
+	$result.=&problem_web_to_edit_header($rndseed);
+    }
+    return $result;
+}
+
+sub end_library {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result='';
+    if ($target eq 'edit') {
+	$result=&problem_edit_footer();
+    } elsif ($target eq 'web' && $$tagstack[0] ne 'problem' &&
+	     $ENV{'request.state'} eq "construct") {
+	$result.='</form></body>'.&Apache::lonxml::xmlend();
+    }
+    return $result;
 }
 
 sub start_block {
-  my ($target,$token,$parstack,$parser,$safeeval)=@_;
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
 
-  my $code = @$parstack[$#$parstack];
-  $code =~ s/\"//g;
-  $code .=';return $condition;';
-#  print "<br>$code<br>";
-  my $result = &Apache::run::run($code,$safeeval);
-  if ( ! $result ) { 
-#    my $skip=$$parser[$#$parser]->get_text("/block");
-    my $skip=&Apache::lonxml::get_all_text("block",$$parser[$#$parser]);
-#    print "skipped $skip";
-  }
-  return "";
+    my $result;
+
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex' || $target eq 'analyze') {
+	my $code = $token->[2]->{'condition'};
+	if ($code) {
+	    if (!$Apache::lonxml::default_homework_loaded) {
+		&Apache::lonxml::default_homework_load($safeeval);
+	    }
+	    $result = &Apache::run::run($code,$safeeval);
+	    &Apache::lonxml::debug("block :$code: returned :$result:");
+	} else {
+	    $result='1';
+	}
+	if ( ! $result ) {
+	    my $skip=&Apache::lonxml::get_all_text("/block",$parser);
+	    &Apache::lonxml::debug("skipping ahead :$skip: $$parser[-1]");
+	}
+	$result='';
+    } elsif ($target eq 'edit') {
+	$result .=&Apache::edit::tag_start($target,$token);
+	$result .=&Apache::edit::text_arg('Test Condition:','condition',
+					  $token,40);
+	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'condition');
+	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
+    }
+    return $result;
 }
 
 sub end_block {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    if ($target eq "edit") {
+	$result.= &Apache::edit::tag_end($target,$token,'');
+    }
+    return $result;
+}
+
+sub start_languageblock {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+
+    my $result;
+
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex' || $target eq 'analyze') {
+	my $include = $token->[2]->{'include'};
+	my $exclude = $token->[2]->{'exclude'};
+        my %languages=&Apache::loncommon::display_languages();
+        $result='1';
+	if ($include) {
+            $result='';
+            foreach (split(/\,/,$include)) {
+                if ($languages{$_}) { $result='1'; }
+            }
+	}
+        if ($exclude) {
+            foreach (split(/\,/,$exclude)) {
+                if ($languages{$_}) { $result='0'; }
+            }
+	}
+	if ( ! $result ) {
+	    my $skip=&Apache::lonxml::get_all_text("/languageblock",$parser);
+	    &Apache::lonxml::debug("skipping ahead :$skip: $$parser[-1]");
+	}
+	$result='';
+    } elsif ($target eq 'edit') {
+	$result .=&Apache::edit::tag_start($target,$token);
+	$result .=&Apache::edit::text_arg('Include Language:','include',
+					  $token,40);
+	$result .=&Apache::edit::text_arg('Exclude Language:','exclude',
+					  $token,40);
+	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'include',
+						     'exclude');
+	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
+    }
+    return $result;
+}
+
+sub end_languageblock {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    if ($target eq "edit") {
+	$result.= &Apache::edit::tag_end($target,$token,'');
+    }
+    return $result;
+}
+
+sub start_while {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+
+    my $result;
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex' || $target eq 'analyze') {
+	my $code = $token->[2]->{'condition'};
+
+	push( @Apache::structuretags::whileconds, $code);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	my $result = &Apache::run::run($code,$safeeval);
+	my $bodytext=&Apache::lonxml::get_all_text("/while",$parser);
+	push( @Apache::structuretags::whilebody, $bodytext);
+	push( @Apache::structuretags::whileline, $token->[5]);
+	&Apache::lonxml::debug("s code $code got -$result-");
+	if ( $result ) {
+	    &Apache::lonxml::newparser($parser,\$bodytext);
+	}
+    } elsif ($target eq 'edit') {
+	$result .=&Apache::edit::tag_start($target,$token);
+	$result .=&Apache::edit::text_arg('Test Condition:','condition',
+					  $token,40);
+	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'condition');
+	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
+    }
+    return $result;
+}
+
+sub end_while {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex' || $target eq 'analyze') {
+	my $code = pop(@Apache::structuretags::whileconds);
+	my $bodytext = pop(@Apache::structuretags::whilebody);
+	my $line = pop(@Apache::structuretags::whileline);
+	my $return = &Apache::run::run($code,$safeeval);
+	my $starttime=time;
+	my $error=0;
+	while ($return) {
+	    if (time-$starttime >
+		$Apache::lonnet::perlvar{'lonScriptTimeout'}) {
+		$return = 0; $error=1; next;
+	    }
+	    $result.=&Apache::scripttag::xmlparse($bodytext);
+	    $return = &Apache::run::run($code,$safeeval);
+	}
+	if ($error) {
+	    &Apache::lonxml::error('<pre>Code ran too long. It ran for more than '.$Apache::lonnet::perlvar{'lonScriptTimeout'}.' seconds occured while running &lt;while$gt; on line '.$line.'</pre>');
+	}
+    } elsif ($target eq "edit") {
+	$result.= &Apache::edit::tag_end($target,$token,'');
+    }
+    return $result;
+}
+
+# <randomlist show="1">
+#  <tag1>..</tag1>
+#  <tag2>..</tag2>
+#  <tag3>..</tag3>
+#  ...
+# </randomlist>
+sub start_randomlist {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    if ($target eq 'answer' || $target eq 'grade' || $target eq 'web' ||
+	$target eq 'tex' || $target eq 'analyze') {
+	my $body= &Apache::lonxml::get_all_text("/randomlist",$parser);
+	my $b_parser= HTML::TokeParser->new(\$body);
+	my $b_tok;
+	my @randomlist;
+	my $list_item;
+	while($b_tok = $b_parser->get_token() ) {
+	    if($b_tok->[0] eq 'S') { # start tag
+		# get content of the tag until matching end tag
+		# get all text upto the matching tag
+		# and push the content into @randomlist
+		$list_item = &Apache::lonxml::get_all_text('/'.$b_tok->[1],
+							   $b_parser);
+		$list_item = "$b_tok->[4]"."$list_item"."</$b_tok->[1]>";
+		push(@randomlist,$list_item);
+		#  print "<br /><b>START-TAG $b_tok->[1], $b_tok->[4],
+                #         $list_item</b>";
+	    }
+	    if($b_tok->[0] eq 'T') { # text
+		# what to do with text in between tags?
+		#  print "<b>TEXT $b_tok->[1]</b><br />";
+	    }
+	    # if($b_tok->[0] eq 'E') { # end tag, should not happen
+	    #  print "<b>END-TAG $b_tok->[1]</b><br />";
+	    # }
+	}
+	my @idx_arr = (0 .. $#randomlist);
+	&Apache::structuretags::shuffle(\@idx_arr);
+	my $bodytext = '';
+	my $show=$#randomlist;
+	my $showarg=&Apache::lonxml::get_param('show',$parstack,$safeeval);
+	$showarg--;
+	if ( ($showarg >= 0) && ($showarg < $show) ) { $show = $showarg; }
+	for(0 .. $show) {
+	    $bodytext .= "$randomlist[ $idx_arr[$_] ]";
+	}
+	&Apache::lonxml::newparser($parser,\$bodytext);
+    } elsif ($target eq 'edit' ) {
+	$result .=&Apache::edit::tag_start($target,$token);
+	$result .=&Apache::edit::text_arg('Maximum Tags to Show:','show',
+					   $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,'show');
+	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
+    }
+    return $result;
+}
+
+sub shuffle {
+    my $a=shift;
+    my $i;
+    if (defined(@$a)) {
+	&Apache::response::setrandomnumber();
+	for($i=@$a;--$i;) {
+	    my $j=int(&Math::Random::random_uniform() * ($i+1));
+	    next if $i == $j;
+	    @$a[$i,$j] = @$a[$j,$i];
+	}
+    }
+}
+
+sub end_randomlist {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result;
+    if ($target eq 'edit' ) {
+	$result=&Apache::edit::tag_end($target,$token,
+				       'End Randomly Parsed Block');
+    }
+    return $result;
+}
+
+sub start_part {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result='';
+    my $id= &Apache::lonxml::get_param('id',$parstack,$safeeval);
+    if ($id eq '') { $id = $Apache::lonxml::curdepth; }
+    $Apache::inputtags::part=$id;
+    @Apache::inputtags::responselist = ();
+    @Apache::inputtags::previous=();
+    @Apache::inputtags::previous_version=();
+    $Apache::lonhomework::problemstatus=
+	&Apache::lonnet::EXT("resource.$id.problemstatus");
+    my $hidden=&Apache::loncommon::check_if_partid_hidden($Apache::inputtags::part);
+
+    if ($target eq 'meta') {
+	return &Apache::response::mandatory_part_meta;
+    } elsif ($target eq 'web' || $target eq 'grade' ||
+	     $target eq 'answer' || $target eq 'tex') {
+	if ($hidden) {
+	    my $bodytext=&Apache::lonxml::get_all_text("/part",$parser);
+	} else {
+	    my ($status,$accessmsg) = &Apache::lonhomework::check_access($id);
+	    push (@Apache::inputtags::status,$status);
+	    my $expression='$external::datestatus="'.$status.'";';
+	    $expression.='$external::gradestatus="'.$Apache::lonhomework::history{"resource.$id.solved"}.'";';
+	    &Apache::run::run($expression,$safeeval);
+	    if ( $status eq 'CLOSED' ) {
+		my $bodytext=&Apache::lonxml::get_all_text("/part",$parser);
+		if ( $target eq "web" ) {
+		    $result="<br />Part is not open to be viewed. It $accessmsg<br />";
+		} elsif ( $target eq 'tex' ) {
+		    $result="\\end{minipage}\\vskip 0 mm Part is not open to be viewed. It $accessmsg \\\\\\begin{minipage}{\\textwidth}";
+		}
+	    } else {
+		if ($target eq 'tex') {
+		    $result.='\noindent \end{minipage}\vskip 0 mm \noindent \begin{minipage}{\textwidth}\noindent';
+		    my $weight = &Apache::lonnet::EXT("resource.$id.weight");
+		    if ($Apache::lonhomework::type eq 'exam') { $result .= '\fbox{\textit{'.$weight.' pt}}';}
+		}
+	    }
+	}
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token);
+	$result.=&Apache::edit::text_arg('Part ID:','id',$token).
+	    &Apache::loncommon::help_open_topic("Part_Tag_Edit_Help").
+		&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'id');
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	    $result.=&Apache::edit::handle_insert();
+	}
+    }
+    return $result;
+}
+
+sub end_part {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    &Apache::lonxml::debug("in end_part $target ");
+    my $status=$Apache::inputtags::status['-1'];
+    my $hidden=&Apache::loncommon::check_if_partid_hidden($Apache::inputtags::part);
+    my $result='';
+    if ( $target eq 'meta' ) {
+	$result='';
+    } elsif ( $target eq 'grade' && $status eq 'CAN_ANSWER' && !$hidden) {
+	$result=&Apache::inputtags::grade;
+    } elsif (($target eq 'web' || $target eq 'tex') && !$hidden ) {
+	my $gradestatus=&Apache::inputtags::gradestatus($Apache::inputtags::part,
+							$target);
+	if ($Apache::lonhomework::type eq 'exam') {$gradestatus='';}
+	$result=$gradestatus;
+    }
+    pop @Apache::inputtags::status;
+    $Apache::inputtags::part='';
+    return $result;
+}
+
+sub start_preduedate {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' || $target eq 'tex') {
+	if ($Apache::inputtags::status['-1'] ne 'CAN_ANSWER' &&
+	    $Apache::inputtags::status['-1'] ne 'CANNOT_ANSWER' &&
+	    $Apache::inputtags::status['-1'] ne 'SHOW_ANSWER') {
+	    &Apache::lonxml::get_all_text("/preduedate",$parser);
+	}
+    }
+    return '';
+}
+
+sub end_preduedate {
+    return '';
+}
+
+sub start_postanswerdate {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'tex') {
+	if ($Apache::inputtags::status['-1'] ne 'SHOW_ANSWER') {
+	    &Apache::lonxml::get_all_text("/postanswerdate",$parser);
+	}
+    } elsif ($target eq 'tex') {
+	return '\vskip 0 mm \noindent';
+    }
+    return '';
+}
+
+sub end_postanswerdate {
+    return '';
+}
+
+sub start_notsolved {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex') {
+	my $gradestatus=$Apache::lonhomework::history{"resource.$Apache::inputtags::part.solved"};
+	&Apache::lonxml::debug("not solved has :$gradestatus:");
+	if ($gradestatus =~ /^correct/) {
+	    &Apache::lonxml::debug("skipping");
+	    &Apache::lonxml::get_all_text("/notsolved",$parser);
+	}
+    }
+    return '';
+}
+
+sub end_notsolved {
+    return '';
+}
+
+sub start_solved {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' ||
+	$target eq 'tex') {
+	my $gradestatus=$Apache::lonhomework::history{"resource.$Apache::inputtags::part.solved"};
+	if ($gradestatus !~ /^correct/) {
+	    &Apache::lonxml::get_all_text("/solved",$parser);
+	}
+    }
+    return '';
+}
+
+sub end_solved {
+    return '';
+}
+
+sub start_startouttext {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my @result=(''.'');
+    if ($target eq 'edit' || $target eq 'modified' ) { @result=('','no'); }
+    return (@result);
+}
+
+sub end_startouttext {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result='';
+    my $text='';
+
+    if ($target eq 'edit') {
+	$text=&Apache::lonxml::get_all_text("endouttext",$parser);
+	$result.=&Apache::edit::start_table($token)."<tr><td>Text Block</td>
+<td>Delete:".
+                 &Apache::edit::deletelist($target,$token)
+		 ."</td>
+<td>".
+                 &Apache::edit::insertlist($target,$token).
+		 &Apache::edit::end_row().
+                 &Apache::edit::start_spanning_row()."\n"
+		 .'<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>'.
+		 &Apache::edit::editfield($token->[1],$text,"",80,4);
+    }
+    if ($target eq 'modified') {
+	$text=&Apache::lonxml::get_all_text("endouttext",$parser);
+	$result='<startouttext />'.&Apache::edit::modifiedfield();
+    }
+    if ($target eq 'tex') {
+	$result .= '\noindent ';
+    }
+    return $result;
+}
+
+sub start_endouttext {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $result='';
+    if ($target eq "edit" ) { $result="</td></tr>".&Apache::edit::end_table()."\n"; }
+    if ($target eq "modified") {
+	$result='<endouttext />'.
+	    &Apache::edit::handle_insertafter('startouttext'); }
+    return $result;
+}
+
+sub end_endouttext {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my @result=('','');
+    if ($target eq "edit" || $target eq 'modified') { @result=('','no'); }
+    return (@result);
+}
+
+sub delete_startouttext {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    #  my $text=&Apache::lonxml::get_all_text("endouttext",$parser);
+    my $text=$$parser['-1']->get_text("/endouttext");
+    my $ntoken=$$parser['-1']->get_token();
+    &Apache::lonxml::debug("Deleting :$text: and :$ntoken->[0]:$ntoken->[1]:$ntoken->[2]: for startouttext");
+    &Apache::lonxml::end_tag($tagstack,$parstack,$ntoken);
+    # Deleting 2 parallel tag pairs, but we need the numbers later to look like
+    # they did the last time round
+    &Apache::lonxml::increasedepth($ntoken);
+    &Apache::lonxml::decreasedepth($ntoken);
+    return 1;
 }
 
 1;
