# The LearningOnline Network with CAPA
# caparesponse definition
#
# $Id: caparesponse.pm,v 1.263 2021/10/05 02:41:32 raeburn 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/
#

package Apache::caparesponse;
use strict;
use capa;
use Safe::Hole;
use Apache::lonmaxima();
use Apache::lonlocal;
use Apache::lonnet;
use Apache::lonmsg();
use Apache::response();
use Storable qw(dclone);
use Apache::lonnet;

BEGIN {
    &Apache::lonxml::register('Apache::caparesponse',('numericalresponse','stringresponse','formularesponse'));
}

my %answer;
my @answers;
my @alphabet=('A'..'Z');

sub get_answer { return %answer; };
sub push_answer{ push(@answers,dclone(\%answer)); undef(%answer) }
sub pop_answer { %answer = %{pop(@answers)}; };

my $cur_name;
my $tag_internal_answer_name = 'INTERNAL';

sub start_answer {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    $cur_name = &Apache::lonxml::get_param('name',$parstack,$safeeval);
    if ($cur_name =~ /^\s*$/) { $cur_name = $Apache::lonxml::curdepth; }
    my $type = &Apache::lonxml::get_param('type',$parstack,$safeeval);
    if (!defined($type) && $tagstack->[-2] eq 'answergroup') {
	$type = &Apache::lonxml::get_param('type',$parstack,$safeeval,-2);
    }
    if (!defined($type)) { $type = 'ordered' };
    $answer{$cur_name}= { 'type' => $type,
			  'answers' => [] };
    if ($target eq 'edit') {
  	$result.=&Apache::edit::tag_start($target,$token);
	$result.=&Apache::edit::text_arg('Name:','name',$token);
	$result.=&Apache::edit::select_arg('Type:','type',
					   [['ordered',  'Ordered'  ],
					    ['unordered','Unordered'],],
					   $token);
	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag = &Apache::edit::get_new_args($token,$parstack,
						       $safeeval,'name',
						       'type');
	if ($constructtag) {
	    $result = &Apache::edit::rebuild_tag($token);
	    $result.= &Apache::edit::handle_insert();
	}
    }
    return $result;
}

sub end_answer {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    if ($target eq 'edit') {
	$result .= &Apache::edit::tag_end();
    }

    undef($cur_name);
    return $result;
}

sub insert_answer {
    return '
        <answer>
            <value></value>
        </answer>';
}

sub start_answergroup {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    if ($target eq 'edit') {
  	$result.=&Apache::edit::tag_start($target,$token);
	$result.=&Apache::edit::select_arg('Type:','type',
					   [['ordered',  'Ordered'  ],
					    ['unordered','Unordered'],],
					   $token);
	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag = &Apache::edit::get_new_args($token,$parstack,
						       $safeeval,'name',
						       'type');
	if ($constructtag) {
	    $result = &Apache::edit::rebuild_tag($token);
	    $result.= &Apache::edit::handle_insert();
	}
    }
    return $result;
}

sub end_answergroup {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    if ($target eq 'web') {
    	if (  &Apache::response::show_answer() ) {  
	    my $partid = $Apache::inputtags::part;
	    my $id = $Apache::inputtags::response[-1];
	    &set_answertext($Apache::lonhomework::history{"resource.$partid.$id.answername"},
			    $target,$token,$tagstack,$parstack,$parser,
			    $safeeval,-2);
	}
    } elsif ($target eq 'edit') {
	$result .= &Apache::edit::tag_end();
    }
    return $result;
}

sub insert_answergroup {
    return '
    <answergroup>
        <answer>
            <value></value>
        </answer>
    </answergroup>';
}

sub start_value {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ( $target eq 'web' || $target eq 'tex' ||
	 $target eq 'grade' || $target eq 'webgrade' ||
	 $target eq 'answer' || $target eq 'analyze' ) {
	my $bodytext = &Apache::lonxml::get_all_text("/value",$parser,$style);
	$bodytext = &Apache::run::evaluate($bodytext,$safeeval,
					   $$parstack[-1]);
	
	push(@{ $answer{$cur_name}{'answers'} },[$bodytext]);
	
    } elsif ($target eq 'edit') {
  	$result.=&Apache::edit::tag_start($target,$token);
	my $bodytext = &Apache::lonxml::get_all_text("/value",$parser,$style);
	$result.=&Apache::edit::editline($token->[1],$bodytext,undef,40).
	    &Apache::edit::end_row();
    } elsif ($target eq 'modified') {
	$result=$token->[4].&Apache::edit::modifiedfield('/value',$parser);
    }
    return $result;
}

sub end_value {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    if ($target eq 'edit') {
	$result = &Apache::edit::end_table();
    }
    return $result;
}

sub insert_value {
    return '
            <value></value>';
}

sub start_vector {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ( $target eq 'web' || $target eq 'tex' ||
	 $target eq 'grade' || $target eq 'webgrade' ||
	 $target eq 'answer' || $target eq 'analyze' ) {
	my $bodytext = &Apache::lonxml::get_all_text("/vector",$parser,$style);
	my @values = &Apache::run::run($bodytext,$safeeval,$$parstack[-1]);
	if (@values == 1) {
	    @values = split(',',$values[0]);
	}
	push(@{ $answer{$cur_name}{'answers'} },\@values);
    } elsif ($target eq 'edit') {
  	$result.=&Apache::edit::tag_start($target,$token);
	my $bodytext = &Apache::lonxml::get_all_text("/vector",$parser,$style);
	$result.=&Apache::edit::editline($token->[1],$bodytext,undef,40).
	    &Apache::edit::end_row();
    } elsif ($target eq 'modified') {
	$result=$token->[4].&Apache::edit::modifiedfield('/vector',$parser);
    }
    return $result;
}

sub end_vector {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    if ($target eq 'edit') {
	$result = &Apache::edit::end_table();
    }
    return $result;
}

sub insert_vector {
    return '
            <value></value>';
}

sub start_array {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ( $target eq 'web' || $target eq 'tex' ||
	 $target eq 'grade' || $target eq 'webgrade' ||
	 $target eq 'answer' || $target eq 'analyze' ) {
	my $bodytext = &Apache::lonxml::get_all_text("/array",$parser,$style);
	my @values = &Apache::run::evaluate($bodytext,$safeeval,
					    $$parstack[-1]);
	push(@{ $answer{$cur_name}{'answers'} },@values);
    }
    return $result;
}

sub end_array {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub start_unit {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub end_unit {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub start_numericalresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    &Apache::lonxml::register('Apache::caparesponse',
			      ('answer','answergroup','value','array','unit',
			       'vector'));
    push(@Apache::lonxml::namespace,'caparesponse');
    my $id = &Apache::response::start_response($parstack,$safeeval);
    my $result;
    undef(%answer);
    undef(%{$safeeval->varglob('LONCAPA::CAPAresponse_args')});
    if ($target eq 'edit') {
	$result.=&Apache::edit::tag_start($target,$token);
	$result.=&Apache::edit::text_arg('Answer:','answer',$token);
	if ($token->[1] eq 'numericalresponse') {
	    $result.=&Apache::edit::text_arg('Incorrect Answers:','incorrect',
					     $token).
		&Apache::loncommon::help_open_topic('numerical_wrong_answers');
	    $result.=&Apache::edit::text_arg('Unit:','unit',$token,5).
		&Apache::loncommon::help_open_topic('Physical_Units');
	    $result.=&Apache::edit::text_arg('Format:','format',$token,4).
		&Apache::loncommon::help_open_topic('Numerical_Response_Format');
	} elsif ($token->[1] eq 'formularesponse') {
	    $result.=&Apache::edit::text_arg('Sample Points:','samples',
					     $token,40).
	      &Apache::loncommon::help_open_topic('Formula_Response_Sampling');
	}
        $result.=&Apache::edit::text_arg('Pre-Processor Subroutine:','preprocess',
                                             $token,10);
	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag;
	if ($token->[1] eq 'numericalresponse') {
	    $constructtag=&Apache::edit::get_new_args($token,$parstack,
						      $safeeval,'answer',
 						      'incorrect','unit',
						      'format','preprocess');
	} elsif ($token->[1] eq 'formularesponse') {
	    $constructtag=&Apache::edit::get_new_args($token,$parstack,
						      $safeeval,'answer',
						      'samples','preprocess');
	}
	if ($constructtag) {
	    $result = &Apache::edit::rebuild_tag($token);
	    $result.=&Apache::edit::handle_insert();
	}
    } elsif ($target eq 'meta') {
	$result=&Apache::response::meta_package_write('numericalresponse');
    } elsif ($target eq 'answer' || $target eq 'grade') {
	&Apache::response::reset_params();
    } elsif ($target eq 'web') {
	my $partid = $Apache::inputtags::part;
	my $hideunit=&Apache::lonnet::EXT('resource.'.$partid.'_'.$id.'.turnoffunit');
	&Apache::lonxml::debug("Got unit $hideunit for $partid $id");
	#no way to enter units, with radio buttons
	if ((lc($hideunit) eq "yes") && ($Apache::lonhomework::type ne 'exam')) {
	    my $unit=&Apache::lonxml::get_param_var('unit',$parstack,
						    $safeeval);
	    if ($unit =~ /\S/) { $result.=" (in $unit) "; }
	}
	if (  &Apache::response::show_answer() ) {
	    &set_answertext($tag_internal_answer_name,$target,$token,$tagstack,
			    $parstack,$parser,$safeeval,-1);
	}
    }
    return $result;
}

sub set_answertext {
    my ($name,$target,$token,$tagstack,$parstack,$parser,$safeeval,
	$response_level) = @_;
    &add_in_tag_answer($parstack,$safeeval,$response_level);

    if ($name eq '' || !ref($answer{$name})) {
	if (ref($answer{$tag_internal_answer_name})) {
	    $name = $tag_internal_answer_name;
	} else {
	    $name = (sort(keys(%answer)))[0];
	}
    }
    return if ($name eq '' || !ref($answer{$name}));

    my (@formats)=&Apache::lonxml::get_param_var('format',$parstack,
						 $safeeval,$response_level);
    my $unit=&Apache::lonxml::get_param_var('unit',$parstack,$safeeval,
					    $response_level);

    &Apache::lonxml::debug("answer looks to be $name");
    my @answertxt;
    for (my $i=0; $i < scalar(@{$answer{$name}{'answers'}}); $i++) {
	my $answertxt;
	my $answer=$answer{$name}{'answers'}[$i];
	foreach my $element (@$answer) {
	    if ( scalar(@$tagstack)
		 && $tagstack->[$response_level] ne 'numericalresponse') {
		$answertxt.=$element.',';
	    } else {
		my $format;
		if ($#formats > 0) {
		    $format=$formats[$i];
		} else {
		    $format=$formats[0];
		}
		if ($unit=~/\$/) { $format="\$".$format; $unit=~s/\$//g; }
		if ($unit=~/\,/) { $format="\,".$format; $unit=~s/\,//g; }
		my $formatted=&format_number($element,$format,$target,
					     $safeeval);
		$answertxt.=' '.$formatted.',';
	    }
	    
	}
	chop($answertxt);
	if ($target eq 'web') {
	    $answertxt.=" $unit ";
	}

	push(@answertxt,$answertxt)
    }
	
    my $id = $Apache::inputtags::response[-1];
    $Apache::inputtags::answertxt{$id}=\@answertxt;
}

sub setup_capa_args {
    my ($safeeval,$parstack,$args,$response) = @_;
    my $args_ref= \%{$safeeval->varglob('LONCAPA::CAPAresponse_args')};
    undef(%{ $args_ref });
 
    foreach my $arg (@{$args}) {
	$$args_ref{$arg}=
	    &Apache::lonxml::get_param($arg,$parstack,$safeeval);
    }
    foreach my $key (keys(%Apache::inputtags::params)) {
	$$args_ref{$key}=$Apache::inputtags::params{$key};
    }
    &setup_capa_response($args_ref,$response);
    return $args_ref;
}

sub setup_capa_response {
    my ($args_ref,$response) = @_;   

    if (ref($response)) {
	$$args_ref{'response'}=dclone($response);
    } else {
	$$args_ref{'response'}=dclone(["$response"]);
    }
}

sub check_submission {
    my ($response,$partid,$id,$tag,$parstack,$safeeval,$ignore_sig)=@_;
    my @args = ('type','tol','sig','format','unit','calc','samples','preprocess');
    my $args_ref = &setup_capa_args($safeeval,$parstack,\@args,$response);

    my $hideunit=
	&Apache::lonnet::EXT('resource.'.$partid.'_'.$id.'.turnoffunit');
        #no way to enter units, with radio buttons
    if ($Apache::lonhomework::type eq 'exam' ||
	lc($hideunit) eq "yes") {
	delete($$args_ref{'unit'});
    }
    #sig fig don't make much sense either
    if (($Apache::lonhomework::type eq 'exam' ||
	 &Apache::response::submitted('scantron') ||
	 $ignore_sig) &&
	$tag eq 'numericalresponse') {
	delete($$args_ref{'sig'});
    }
    
    if ($tag eq 'formularesponse') {
	if ($$args_ref{'samples'}) {
	    $$args_ref{'type'}='fml';
	} else {
	    $$args_ref{'type'}='math';
	}
    } elsif ($tag eq 'numericalresponse') {
	$$args_ref{'type'}='float';
    } elsif ($tag eq 'stringresponse') {
        if ($$args_ref{'type'} eq '') {
            $$args_ref{'type'} = 'ci';
        }
    }

    &add_in_tag_answer($parstack,$safeeval);

    if (!%answer) {
	&Apache::lonxml::error("No answers are defined");
    }

    my (@final_awards,@final_msgs,@names);
    foreach my $name (keys(%answer)) {
	&Apache::lonxml::debug(" doing $name with ".join(':',@{ $answer{$name}{'answers'} }));
	
	${$safeeval->varglob('LONCAPA::CAPAresponse_answer')}=dclone($answer{$name});
	&setup_capa_response($args_ref,$response);
	use Time::HiRes;
	my $t0 = [Time::HiRes::gettimeofday()];
	my ($result,@msgs) = 
	    &Apache::run::run("&caparesponse_check_list()",$safeeval);
	&Apache::lonxml::debug("checking $name $result with $response took ".&Time::HiRes::tv_interval($t0));
	&Apache::lonxml::debug('msgs are '.join(':',@msgs));
	my ($awards)=split(/:/,$result);
	my @awards= split(/,/,$awards);
	my ($ad, $msg) = &Apache::inputtags::finalizeawards(\@awards,\@msgs);
	push(@final_awards,$ad);
	push(@final_msgs,$msg);
	push(@names,$name);
    }
    my ($ad, $msg, $name) = &Apache::inputtags::finalizeawards(\@final_awards,
							       \@final_msgs,
							       \@names,1);
    &Apache::lonxml::debug(" name of picked award is $name from ".join(', ',@names));
    return($ad,$msg, $name);
}

sub stringresponse_gradechange {
    my ($part,$id,$previous,$caller,$response,$ad,$type) = @_;
    return unless (ref($previous) eq 'HASH');
    my ($prevarray,$prevaward);
    my %typenames = (
                     cs => 'Case sensitive',
                     ci => 'Case insensitive',
                    );
    if ($caller eq 'cs') {
        return unless (ref($previous->{'version'}) eq 'ARRAY');
        $prevarray = $previous->{'version'};
        $prevaward = $previous->{'award'};
    } elsif ($caller eq 'ci') {
        return unless (ref($previous->{'versionci'}) eq 'ARRAY');
        $prevarray = $previous->{'versionci'};
        $prevaward = $previous->{'awardci'};
    } else {
        return;
    }
    my $count=0;
    my %count_lookup;
    foreach my $i (1..$Apache::lonhomework::history{'version'}) {
        my $prefix = $i.":resource.$part";
        next if (!exists($Apache::lonhomework::history{"$prefix.award"}));
        $count++;
        $count_lookup{$i} = $count;
    }
    my ($symb,$courseid,$domain,$name) = &Apache::lonnet::whichuser();
    my %coursedesc = &Apache::lonnet::coursedescription($courseid);
    my $cdom = $coursedesc{'domain'};
    my $versions = ' (submissions: '.join(', ',map {$count_lookup{$_} } @{$prevarray}).')';
    my $warning = "String Response ($typenames{$type}) grading discrepancy: award for response of $response changed from $prevaward".$versions." to $ad; user: $name:$domain in course: $courseid for part: $part response: $id for symb: $symb";
    &Apache::lonnet::logthis($warning);
    my $origmail = $Apache::lonnet::perlvar{'lonAdmEMail'};
    my $recipients = &Apache::loncommon::build_recipient_list(undef,'errormail',
                                                              $cdom,$origmail);
    if ($recipients ne '') {
        &Apache::lonmsg::sendemail($recipients,'Stringresponse Grading Discrepancy',$warning);
    }
    return;
}

sub add_in_tag_answer {
    my ($parstack,$safeeval,$response_level) = @_;
    my @answer=&Apache::lonxml::get_param_var('answer',$parstack,$safeeval,
					      $response_level);
    &Apache::lonxml::debug('answer is'.join(':',@answer));
    if (@answer && $answer[0] =~ /\S/) {
	$answer{$tag_internal_answer_name}= {'type' => 'ordered',
					     'answers' => [\@answer] };
    }
}

sub capa_formula_fix {
   my ($expression)=@_;
   return &Apache::response::implicit_multiplication($expression);
}

sub end_numericalresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    &Apache::lonxml::deregister('Apache::caparesponse',
			      ('answer','answergroup','value','array','unit',
			       'vector'));
    pop(@Apache::lonxml::namespace);

    my $increment=1;
    my $result = '';
    if (!$Apache::lonxml::default_homework_loaded) {
	&Apache::lonxml::default_homework_load($safeeval);
    }
    my $partid = $Apache::inputtags::part;
    my $id = $Apache::inputtags::response[-1];
    my $tag;
    my $safehole = new Safe::Hole;
    $safeeval->share_from('capa',['&caparesponse_capa_check_answer']);

    if (scalar(@$tagstack)) { $tag=$$tagstack[-1]; }
    if ( $target eq 'grade' && &Apache::response::submitted() ) {
	&Apache::response::setup_params($tag,$safeeval);
	if ($Apache::lonhomework::type eq 'exam' && 
	    (($tag eq 'formularesponse') || ($tag eq 'mathresponse'))) {
	    $increment=&Apache::response::scored_response($partid,$id);
	} else {
	    my $response = &Apache::response::getresponse();
	    if ( $response =~ /[^\s]/) {
		my %previous = &Apache::response::check_for_previous($response,$partid,$id);
		&Apache::lonxml::debug("submitted a $response<br>\n");
		&Apache::lonxml::debug($$parstack[-1] . "\n<br>");
		
		if ( &Apache::response::submitted('scantron')) {
	    &add_in_tag_answer($parstack,$safeeval);
	    my ($values,$display)=&make_numerical_bubbles($partid,$id,
					  $target,$parstack,$safeeval);
	    $response=$values->[$response];
	}
	$Apache::lonhomework::results{"resource.$partid.$id.submission"}=$response;
		my ($ad,$msg,$name)=&check_submission($response,$partid,$id,
						      $tag,$parstack,
						      $safeeval);

		&Apache::lonxml::debug('ad is'.$ad);
		if ($ad eq 'SIG_FAIL') {
		    my ($sig_u,$sig_l)=
			&get_sigrange($Apache::inputtags::params{'sig'});
		    $msg=join(':',$msg,$sig_l,$sig_u);
		    &Apache::lonxml::debug("sigs bad $sig_u $sig_l ".
					   $Apache::inputtags::params{'sig'});
		}
		&Apache::lonxml::debug("\n<br>result:$result:$Apache::lonxml::curdepth<br>\n");
                if (($ad eq 'INCORRECT' || $ad eq 'APPROX_ANS' ||
                     $ad eq 'EXACT_ANS')) {
		    if ($Apache::lonhomework::type eq 'survey') {
		        $ad='SUBMITTED';
		    } elsif ($Apache::lonhomework::type eq 'surveycred') {
                        $ad='SUBMITTED_CREDIT';
                    } elsif ($Apache::lonhomework::type eq 'anonsurvey') {
                        $ad='ANONYMOUS';
                    } elsif ($Apache::lonhomework::type eq 'anonsurveycred') {
                        $ad='ANONYMOUS_CREDIT';                     
                    }
                }
		&Apache::response::handle_previous(\%previous,$ad);
		$Apache::lonhomework::results{"resource.$partid.$id.awarddetail"}=$ad;
		$Apache::lonhomework::results{"resource.$partid.$id.awardmsg"}=$msg;
		$Apache::lonhomework::results{"resource.$partid.$id.answername"}=$name;
		$result='';
	    }
	}
    } elsif ($target eq 'web' || $target eq 'tex') {
	&check_for_answer_errors($parstack,$safeeval);
	my $award = $Apache::lonhomework::history{"resource.$Apache::inputtags::part.solved"};
	my $status = $Apache::inputtags::status['-1'];
	if ($Apache::lonhomework::type eq 'exam') {
	    # FIXME support multi dimensional numerical problems
            #       in exam bubbles
	    my ($bubble_values,$bubble_display)=
		&make_numerical_bubbles($partid,$id,$target,$parstack,
					$safeeval);
	    my $number_of_bubbles = scalar(@{ $bubble_values });
	    my $unit=&Apache::lonxml::get_param_var('unit',$parstack,
						    $safeeval);
	    if ($target eq 'web') {
		if ($tag eq 'numericalresponse') {
		    if ($unit=~/\S/) {$result.=' (in '.$unit.')<br /><br />';}
		    $result.= '<table border="1"><tr>';
		    my $previous=$Apache::lonhomework::history{"resource.$Apache::inputtags::part.$id.submission"};
		    for (my $ind=0;$ind<$number_of_bubbles;$ind++) {
			my $checked='';
			if ($previous eq $bubble_values->[$ind]) {
			    $checked=" checked='on' ";
			}
			$result.='<td><input type="radio" name="HWVAL_'.$id.
			    '" value="'.$bubble_values->[$ind].'" '.$checked
			    .' /><b>'.$alphabet[$ind].'</b>: '.
			    $bubble_display->[$ind].'</td>';
		    }
		    $result.='</tr></table>';
		}
	    } elsif ($target eq 'tex') {
		if ((defined $unit) and ($unit=~/\S/) and ($Apache::lonhomework::type eq 'exam')) {
		    $result.=' \textit{(in} \verb|'.$unit.'|\textit{)} ';
		}
		if ($tag eq 'numericalresponse') {
		    $result .= &make_horizontal_latex_bubbles($bubble_values, $bubble_display,
			'$\bigcirc$');
		} else {
		    $increment = &Apache::response::repetition();
		}
	    }
	}

	&Apache::response::setup_prior_tries_hash(\&format_prior_response_numerical);
    } elsif ($target eq 'edit') {
	$result.='</td></tr>'.&Apache::edit::end_table;
    } elsif ($target eq 'answer' || $target eq 'analyze') {
	my $part_id="$partid.$id";
	if ($target eq 'analyze') {
	    push (@{ $Apache::lonhomework::analyze{"parts"} },$part_id);
	    $Apache::lonhomework::analyze{"$part_id.type"} = $tag;
	    my (@incorrect)=&Apache::lonxml::get_param_var('incorrect',$parstack,$safeeval);
	    if ($#incorrect eq 0) { @incorrect=(split(/,/,$incorrect[0])); }
	    push (@{ $Apache::lonhomework::analyze{"$part_id.incorrect"} }, @incorrect);
	    &Apache::response::check_if_computed($token,$parstack,
						 $safeeval,'answer');
	}
	if (scalar(@$tagstack)) {
	    &Apache::response::setup_params($tag,$safeeval);
	}
	&add_in_tag_answer($parstack,$safeeval);
	my (@formats)=&Apache::lonxml::get_param_var('format',$parstack,$safeeval);

	my $unit=&Apache::lonxml::get_param_var('unit',$parstack,$safeeval);
	my ($needsdollar,$needscomma);
	if ($unit =~ /\$/) {
	    $needsdollar = 1;
	}
	if ($unit =~ /\,/) {
	    $needscomma = 1;
	}

	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_header($tag,undef,
						      scalar(keys(%answer)));
	    if ($tag eq 'numericalresponse'
		&& $Apache::lonhomework::type eq 'exam') {
		my ($bubble_values,undef,$correct) = &make_numerical_bubbles($partid,
					     $id,$target,$parstack,$safeeval);
		$result.=&Apache::response::answer_part($tag,$correct);
	    }
	}
	foreach my $name (sort(keys(%answer))) {
	    my @answers = @{ $answer{$name}{'answers'} };
	    if ($target eq 'analyze') {
		foreach my $info ('answer','ans_high','ans_low','format') {
		    $Apache::lonhomework::analyze{"$part_id.$info"}{$name}=[];
		}
	    }
	    my ($sigline,$tolline);
	    if ($name ne $tag_internal_answer_name 
		|| scalar(keys(%answer)) > 1) {
		$result.=&Apache::response::answer_part($tag,$name);
	    }
	    for(my $i=0;$i<=$#answers;$i++) {
		my $ans=$answers[$i];
		my $fmt=$formats[0];
		if (@formats && $#formats) {$fmt=$formats[$i];}
		my ($sighigh,$siglow);
		if ($Apache::inputtags::params{'sig'}) {
		    ($sighigh,$siglow)=&get_sigrange($Apache::inputtags::params{'sig'});
		}
		my @vector;
		if (ref($ans)) {
		    @vector = @{ $ans };
		} else {
		    @vector = ($ans);
		}
		my @all_answer_info;
		foreach my $element (@vector) {
		    my ($high,$low);
		    if ($Apache::inputtags::params{'tol'}) {
			($high,$low)=&get_tolrange($element,$Apache::inputtags::params{'tol'});
		    }
		    if ($target eq 'answer') {
			if ($fmt && $tag eq 'numericalresponse') {
			    $fmt=~s/e/E/g;
			    if ($unit=~/\$/) { $fmt="\$".$fmt; $unit=~s/\$//g; }
			    if ($unit=~/\,/) { $fmt="\,".$fmt; $unit=~s/\,//g; }
			    $element = &format_number($element,$fmt,$target,$safeeval);
			    #if ($high) {
			    #    $high=&format_number($high,$fmt,$target,$safeeval);
			    #    $low =&format_number($low,$fmt,$target,$safeeval);
			    #}
			}
			if ($high && $tag eq 'numericalresponse') {
			    $element.='; ['.$low.'; '.$high.']';
			    $tolline .= "[$low, $high]";
			}
			if (defined($sighigh) && $tag eq 'numericalresponse') {
			    if ($env{'form.answer_output_mode'} eq 'tex') {
				$element.= "; Sig $siglow - $sighigh";
			    } else {
				$element.= " Sig <i>$siglow - $sighigh</i>";
				$sigline .= "[$siglow, $sighigh]";
			    }
			}
			push(@all_answer_info,$element);
			
		    } elsif ($target eq 'analyze') {
			push (@{ $Apache::lonhomework::analyze{"$part_id.answer"}{$name}[$i] }, $element);
			if ($high) {
			    push (@{ $Apache::lonhomework::analyze{"$part_id.ans_high"}{$name}[$i] }, $high);
			    push (@{ $Apache::lonhomework::analyze{"$part_id.ans_low"}{$name}[$i] }, $low);
			}
			if ($fmt) {
			    push (@{ $Apache::lonhomework::analyze{"$part_id.format"}{$name}[$i] }, $fmt);
			}
		    }
		}
		if ($target eq 'answer') {
		    $result.= &Apache::response::answer_part($tag,join('; ',@all_answer_info));
		}
	    }

	    my @fmt_ans;
	    for(my $i=0;$i<=$#answers;$i++) {
		my $ans=$answers[$i];
		my $fmt=$formats[0];
		if (@formats && $#formats) {$fmt=$formats[$i];}
		my @answers;
		if (ref($ans) eq 'ARRAY') {
		    @answers = (@{$ans});
		}
		foreach my $element (@answers) {		    
		    if ($fmt && $tag eq 'numericalresponse') {
			$fmt=~s/e/E/g;
			if ($unit=~/\$/) { $fmt="\$".$fmt; $unit=~s/\$//g; }
			if ($unit=~/\,/) { $fmt="\,".$fmt; $unit=~s/\,//g; }
			$element = &format_number($element,$fmt,$target,
						  $safeeval);
			if ($fmt=~/\$/ && !$needsdollar) { $element=~s/\$//; }
		    }
		}
		push(@fmt_ans,join(',',@answers));
	    }
	    my $response=\@fmt_ans;

	    my $hideunit=&Apache::lonnet::EXT('resource.'.$partid.'_'.
					      $id.'.turnoffunit');
	    if ($unit ne ''  && 
		! ($Apache::lonhomework::type eq 'exam' ||
		   lc($hideunit) eq "yes") )  {
		my $cleanunit=$unit;
		$cleanunit=~s/[\$,]//g;
		foreach my $ans (@fmt_ans) {
		    $ans.=" $cleanunit";
		}
	    }
	    my ($ad,$msg)=&check_submission($response,$partid,$id,$tag,
					    $parstack,$safeeval);
	    if ($ad ne 'EXACT_ANS' && $ad ne 'APPROX_ANS') {
		my $error;
		if ($tag eq 'formularesponse') {
		    $error=&mt("Computer's answer is incorrect ([_1]).",'"'.join(', ',@$response).'"');
		} else {
		    # answer failed check if it is sig figs that is failing
		    my ($ad,$msg)=&check_submission($response,$partid,$id,
						    $tag,$parstack,
						    $safeeval,1);
		    $error=&mt("Computer's answer is incorrect ([_1]).",'"'.join(', ',@$response).'"').' ';
                    if (($ad eq 'NO_UNIT') && $needsdollar) {
                        $error.=&mt('The unit attribute includes [_1] but the answer format does not.','$').' '.
                                &mt('Either remove the [_1] from the unit or prepend [_1] to the answer format.','$');    
                    } elsif (($ad eq 'COMMA_FAIL') && $needscomma) {
                        $error.=&mt('The unit attribute includes [_1] but the answer format does not.',',').' '.
                                &mt('Either remove the [_1] from the unit or prepend [_1] to the answer format.',',');
                    } elsif ($ad eq 'UNIT_INVALID_STUDENT') {
                        $error.=&mt('Unable to interpret units. Computer reads units as "[_1]".',$msg).' '.
                                &mt('The unit attribute in the numericalresponse item needs to be a supported physical unit.');
		    } elsif ($sigline ne '') {
			$error.=&mt('It is likely that the tolerance range [_1] or significant figures [_2] need to be adjusted.',$tolline,$sigline);
		    } else {
			$error.=&mt('It is likely that the tolerance range [_1] needs to be adjusted.',$tolline);
		    }
		}
		if ($ad ne 'EXACT_ANS' && $ad ne 'APPROX_ANS') {
		    &Apache::lonxml::error($error);
		} else {
		    &Apache::lonxml::warning($error);
		}
	    }

	    if (defined($unit) and ($unit ne '') and
		$tag eq 'numericalresponse') {
		if ($target eq 'answer') {
		    if ($env{'form.answer_output_mode'} eq 'tex') {
			$result.=&Apache::response::answer_part($tag,
								" Unit: $unit ");
		    } else {
			$result.=&Apache::response::answer_part($tag,
								"Unit: <b>$unit</b>");
		    }
		} elsif ($target eq 'analyze') {
		    push (@{ $Apache::lonhomework::analyze{"$part_id.unit"} }, $unit);
		}
	    }
	    if ($tag eq 'formularesponse' && $target eq 'answer') {
		my $samples=&Apache::lonxml::get_param('samples',$parstack,$safeeval);
		$result.=&Apache::response::answer_part($tag,$samples);
	    }
	    $result.=&Apache::response::next_answer($tag,$name);
	}
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_footer($tag);
	}
    }
    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
	$target eq 'tex' || $target eq 'analyze') {
        if (($tag eq 'formularesponse') && ($target eq 'analyze')) {
            my $type = &Apache::lonnet::EXT('resource.'.$partid.'_'.$id.'.type');
            if ($type eq 'exam') {
                $increment = &Apache::response::repetition();
            }
        }
	&Apache::lonxml::increment_counter($increment,"$partid.$id");
	if ($target eq 'analyze') {
	    &Apache::lonhomework::set_bubble_lines();
	}
    }
    &Apache::response::end_response();
    return $result;
}

sub format_prior_response_numerical {
    my ($mode,$answer) = @_;
    if (ref($answer)) {
	my $result = '<table class="LC_prior_numerical"><tr>';
	foreach my $element (@{ $answer }) {
	    $result.= '<td><span class="LC_prior_numerical">'.
		&HTML::Entities::encode($element,'"<>&').'</span></td>';
	}
	$result.='</tr></table>';
	return $result;
    }
    return '<span class="LC_prior_numerical">'.
	    &HTML::Entities::encode($answer,'"<>&').'</span>';

}

sub check_for_answer_errors {
    my ($parstack,$safeeval) = @_;
    &add_in_tag_answer($parstack,$safeeval);
    my %counts;
    foreach my $name (keys(%answer)) {
	push(@{$counts{scalar(@{$answer{$name}{'answers'}})}},$name);
    }
    if (scalar(keys(%counts)) > 1) {
	my $counts = join(' ',map {
	    my $count = $_;
	    &mt("Answers [_1] had [_2] components.",
		'<tt>'.join(', ',@{$counts{$count}}).'</tt>',
		$count);
	} (sort(keys(%counts))));
	&Apache::lonxml::error(&mt("All answers must have the same number of components. Varying numbers of answers were seen. ").$counts);
    }
    my $expected_number_of_inputs = (keys(%counts))[0];
    if ( $expected_number_of_inputs > 0 
	 && $expected_number_of_inputs != scalar(@Apache::inputtags::inputlist)) {
	&Apache::lonxml::error(&mt("Expected [_1] input fields, but there were only [_2] seen.", 
				   $expected_number_of_inputs,
				   scalar(@Apache::inputtags::inputlist)));
    }
}

sub get_table_sizes {
    my ($number_of_bubbles,$rbubble_values)=@_;
    my $scale=2; #mm for one digit
    my $cell_width=0;
    foreach my $member (@$rbubble_values) {
	my $cell_width_real=0;
	if ($member=~/(\+|-)?(\d*)\.?(\d*)\s*\$?\\times\s*10\^\{(\+|-)?(\d+)}\$?/) {
	    $cell_width_real=(length($2)+length($3)+length($5)+7)*$scale;
	} elsif ($member=~/(\d*)\.?(\d*)(E|e)(\+|-)?(\d*)/) {
	    $cell_width_real=(length($1)+length($2)+length($5)+9)*$scale;
        } elsif ($member=~/(\d*)\.(\d*)/) {
	    $cell_width_real=(length($1)+length($2)+3)*$scale;
	} else {
	    $cell_width_real=(length($member)+1)*$scale*0.9;
	}
	if ($cell_width_real>$cell_width) {$cell_width=$cell_width_real;}
    }
    $cell_width+=8; 
    my $textwidth;
    if ($env{'form.textwidth'} ne '') {
	$env{'form.textwidth'}=~/(\d*)\.?(\d*)/;
	$textwidth=$1.'.'.$2;
    } else {
	$env{'form.textwidth'}=~/(\d+)\.?(\d*)/;
	$textwidth=$1.'.'.$2;
    }
    my $bubbles_per_line=int($textwidth/$cell_width);
    if ($bubbles_per_line > $number_of_bubbles) {
	$bubbles_per_line=$number_of_bubbles;
    } elsif (($bubbles_per_line > $number_of_bubbles/2) 
	     && ($number_of_bubbles % 2==0)) {
	$bubbles_per_line=$number_of_bubbles/2;
    }
    if ($bubbles_per_line < 1) {
	$bubbles_per_line=1;
    }
    my $number_of_tables = int($number_of_bubbles/$bubbles_per_line);
    my @table_range = ();
    for (my $i=0;$i<$number_of_tables;$i++) {push @table_range,$bubbles_per_line;}
    if ($number_of_bubbles % $bubbles_per_line) {
	$number_of_tables++;
	push @table_range,($number_of_bubbles % $bubbles_per_line);
    }
    $cell_width-=8;
    $cell_width=$cell_width*3/4;
    return ($cell_width,$number_of_tables,@table_range);
}

sub format_number {
    my ($number,$format,$target,$safeeval)=@_;
    my $ans;
    if ($format eq '') {
	#What is the number? (integer,decimal,floating point)
	if ($number=~/^(\d*\.?\d*)(E|e)[+\-]?(\d*)$/) {
	    $format = '3e';
	} elsif ($number=~/^(\d*)\.(\d*)$/) {
	    $format = '4f';
	} elsif ($number=~/^(\d*)$/) {
	    $format = 'd';
	}
    }
    if (!$Apache::lonxml::default_homework_loaded) {
	&Apache::lonxml::default_homework_load($safeeval);
    }
    $ans=&Apache::run::run("&prettyprint(q\0$number\0,q\0$format\0,q\0$target\0)",$safeeval);
    return $ans;
}

sub make_numerical_bubbles {
    my ($part,$id,$target,$parstack,$safeeval) =@_;

    if (!%answer) {
	&Apache::lonxml::error(&mt("No answers defined for response [_1] in part [_2] to make bubbles for.",$id,$part));
	return ([],[],undef);
    }
    
    my $number_of_bubbles = 
	&Apache::response::get_response_param($part.'_'.$id,'numbubbles',8);

    #
    # Fixes for BZ 6519 - number of bubbles <= 0 or non-integer.
    # 
    $number_of_bubbles = int($number_of_bubbles + 0.5);
    if ($number_of_bubbles <= 0) {
	$number_of_bubbles = 8;
    }
    

    my ($format)=&Apache::lonxml::get_param_var('format',$parstack,$safeeval);
    my $name = (exists($answer{$tag_internal_answer_name}) 
		? $tag_internal_answer_name
		: (sort(keys(%answer)))[0]);

    if ( scalar(@{$answer{$name}{'answers'}}) > 1) {
	&Apache::lonxml::error("Only answers with 1 component are supported in exam mode");
    }
    if (scalar(@{$answer{$name}{'answers'}[0]}) > 1) {
	&Apache::lonxml::error("Vector answers are unsupported in exam mode.");
    }

    my $answer = $answer{$name}{'answers'}[0][0];
    my (@incorrect)=&Apache::lonxml::get_param_var('incorrect',$parstack,
						   $safeeval);
    if ($#incorrect eq 0) { @incorrect=(split(/,/,$incorrect[0])); }
    
    my @bubble_values=();
    my @alphabet=('A'..'Z');

    &Apache::lonxml::debug("answer is $answer incorrect is @incorrect");
    my @oldseed=&Math::Random::random_get_seed();
    if (@incorrect) {
	&Apache::lonxml::debug("inside ".(scalar(@incorrect)+1 gt $number_of_bubbles));
	if (defined($incorrect[0]) &&
	    scalar(@incorrect)+1 >= $number_of_bubbles) {
	    &Apache::lonxml::debug("inside ".(scalar(@incorrect)+1).":$number_of_bubbles");
	    &Apache::response::setrandomnumber();
	    my @rand_inc=&Math::Random::random_permutation(@incorrect);
	    @bubble_values=@rand_inc[0..($number_of_bubbles-2)];
	    @bubble_values=sort {$a <=> $b} (@bubble_values,$answer);
	    &Apache::lonxml::debug("Answer was :$answer: returning :".$#bubble_values.": which are :".join(':',@bubble_values));
	    &Math::Random::random_set_seed(@oldseed);

	    my $correct;
	    for(my $i=0; $i<=$#bubble_values;$i++) {
		if ($bubble_values[$i] eq $answer) {
		    $correct = $alphabet[$i];
		    last;
		}
	    }

	    if (defined($format) && $format ne '') {
		my @bubble_display;
		foreach my $value (@bubble_values) {
		    push(@bubble_display,
			 &format_number($value,$format,$target,$safeeval));
		}
		return (\@bubble_values,\@bubble_display,$correct);
	    } else {
		return (\@bubble_values,\@bubble_values,$correct);
	    }
	}
	if (defined($incorrect[0]) &&
	    scalar(@incorrect)+1 < $number_of_bubbles) {
	    &Apache::lonxml::warning("Not enough incorrect answers were specified in the incorrect array, ignoring the specified incorrect answers and instead generating them (".join(',',@incorrect).").");
	}
    }
    my @factors = (1.13,1.17,1.25,1.33,1.45); #default values of factors
    my @powers = (1..$number_of_bubbles);
    &Apache::response::setrandomnumber();
    my $ind=&Math::Random::random_uniform_integer(1,0,$#powers);
    my $power = $powers[$ind];
    $ind=&Math::Random::random_uniform_integer(1,0,$#factors);
    my $factor = $factors[$ind];
    my @bubble_display;
    my $answerfactor=$answer;
    if ($answer==0) { 
       $answerfactor=&Math::Random::random_uniform_integer(1,1,100)/
                     &Math::Random::random_uniform_integer(1,1,10);
    }
    for ($ind=0;$ind<$number_of_bubbles;$ind++) {
	my $exponent = $power-$powers[$#powers-$ind];
	$bubble_values[$ind] = $answerfactor*($factor**$exponent);

	# If bubble is for correct answer (i.e., exponent = 0), and value
	# of $answerfactor * factor**$exponent is an integer with more than
	# 15 digits, assign $answerfactor itself as bubble value.
	# This prevents a "use fewer digits" issue on 64bit servers
	# when correct answer is >= 1e+16, and when correct bubble is A.

	if ($exponent == 0) {
	    if ($bubble_values[$ind] =~ /^-?(\d+)$/) {
		if (length($1) > 15) {
		    $bubble_values[$ind] = $answerfactor;
		}
	    }
	}

	$bubble_display[$ind] = &format_number($bubble_values[$ind],
					       $format,$target,$safeeval);
    }
    my $correct = $alphabet[$number_of_bubbles-$power];
    if ($answer==0) {
       $correct='A';
       $bubble_values[0]=0;
       $bubble_display[0] = &format_number($bubble_values[0],
                                           $format,$target,$safeeval);
    }
    &Math::Random::random_set_seed(@oldseed);
    return (\@bubble_values,\@bubble_display,$correct);
}

##
# Produce LaTeX bubbles laid out horizontally given a set of bubble values:
#
# @param bubble_values  - reference to an array of bubble 'values'
# @param bubble_display - reference to the array of texts to display to the user
#                         for each bubble_value (this is mostly for numerical response
#                         when the displayed value may not be an exact
#                         representation of the bubble value. 
# @param bubble_fragment- The LaTeX fragment that will be plugged in to make
#                         the bubble itself. Note that the code will autonomously
#                         label each bubble with a lable...and that it's perfectly
#                         acceptable to use "" for the bubble_fragment.
# 
# @return string - the LaTeX fragment that produces the bubbles.
#
sub make_horizontal_latex_bubbles {
    my ($bubble_values, $bubble_display, $bubble_fragment)     = @_;
    my $result;

    my $number_of_bubbles = scalar(@{$bubble_values}); 

    # Get the number of rows and columns in each row of the bubble
    # table:

    my ($celllength, $number_of_tables, @table_range) =
	&get_table_sizes($number_of_bubbles, $bubble_display);

    my $j=0;
    my $cou=0;
    $result.='\vskip 2mm \noindent ';
    $result .= '\textbf{'.$Apache::lonxml::counter.'.} \vskip -3mm ';

    for (my $i=0;$i<$number_of_tables;$i++) {
	if ($i == 0) {
	    $result .= '\vskip -1mm ';
	} else {
	    $result .= '\vskip 1mm ';
	}
	$result.='\noindent \setlength{\tabcolsep}{2 mm}\hskip 2pc\begin{tabular}{';
	for (my $ind=0;$ind<$table_range[$j];$ind++) {
	    $result.='p{4 mm}p{'.$celllength.' mm}';
	}
	$result.='}';
	for (my $ind=$cou;$ind<$cou+$table_range[$j];$ind++) {
	    $result.='\hskip -4 mm {\small \textbf{ '.$alphabet[$ind].'}}'
		. $bubble_fragment 
		. '& \hskip -3 mm {\small '.$bubble_display->[$ind].'} ';
	    if ($ind != $cou+$table_range[$j]-1) {
		$result.=' & ';
	    }
	}
	$cou += $table_range[$j];
	$j++;
	$result.='\\\\\end{tabular}\vskip 0 mm ';
    }
    return $result;
}

sub get_tolrange {
    my ($ans,$tol)=@_;
    my ($high,$low);
    if ($tol =~ /%$/) {
	chop($tol);
	my $change=$ans*($tol/100.0);
	$high=$ans+$change;
	$low=$ans-$change;
    } else {
	$high=$ans+$tol;
	$low=$ans-$tol;
    }
    return ($high,$low);
}

sub get_sigrange {
    my ($sig)=@_;
    #&Apache::lonxml::debug("Got a sig of :$sig:");
    my $courseid=$env{'request.course.id'};
    if ($env{'request.state'} ne 'construct'
	&& lc($env{"course.$courseid.disablesigfigs"}) eq 'yes') {
	return (15,0);
    }
    my $sig_lbound;
    my $sig_ubound;
    if ($sig eq '') {
	$sig_lbound = 0; #SIG_LB_DEFAULT
	$sig_ubound =15; #SIG_UB_DEFAULT
    } else {
	($sig_lbound,$sig_ubound) = split(/,/,$sig);
	if (!defined($sig_lbound)) {
	    $sig_lbound = 0; #SIG_LB_DEFAULT
	    $sig_ubound =15; #SIG_UB_DEFAULT
	}
	if (!defined($sig_ubound)) { $sig_ubound=$sig_lbound; }
    }
    if (($sig_ubound<$sig_lbound) ||
	($sig_lbound > 15) ||
	($sig =~/(\+|-)/ ) ) {
	my $errormsg=&mt("Invalid Significant figures detected")." ($sig)";
	if ($env{'request.state'} eq 'construct') {
	    $errormsg.=
		&Apache::loncommon::help_open_topic('Significant_Figures');
	}
	&Apache::lonxml::error($errormsg);
    }
    return ($sig_ubound,$sig_lbound);
}

sub format_prior_response_string {
    my ($mode,$answer) =@_;
    return '<span class="LC_prior_string">'.
	    &HTML::Entities::encode($answer,'"<>&').'</span>';
}

sub start_stringresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    my $id = &Apache::response::start_response($parstack,$safeeval);
    undef(%answer);
    if ($target eq 'meta') {
	$result=&Apache::response::meta_package_write('stringresponse');
    } elsif ($target eq 'edit') {
	$result.=&Apache::edit::tag_start($target,$token);
	$result.=&Apache::edit::text_arg('Answer:','answer',$token);
	$result.=&Apache::edit::select_arg('Type:','type',
			 [['cs','Case Sensitive'],['ci','Case Insensitive'],
			  ['mc','Case Insensitive, Any Order'],
			  ['re','Regular Expression']],$token);
	$result.=&Apache::edit::text_arg('String to display for answer:',
					 'answerdisplay',$token);
        $result.=&Apache::edit::text_arg('Pre-Processor Subroutine:','preprocess',
                                             $token,10);
	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag;
	$constructtag=&Apache::edit::get_new_args($token,$parstack,
						  $safeeval,'answer',
						  'type','answerdisplay','preprocess');
	if ($constructtag) {
	    $result = &Apache::edit::rebuild_tag($token);
	    $result.=&Apache::edit::handle_insert();
	}
    } elsif ($target eq 'web') {
	if (  &Apache::response::show_answer() ) {
	    my $answer=
	       &Apache::lonxml::get_param('answerdisplay',$parstack,$safeeval);
	    if (!defined $answer || $answer eq '') {
		$answer=
		    &Apache::lonxml::get_param('answer',$parstack,$safeeval);
	    }
	    $Apache::inputtags::answertxt{$id}=[$answer];
	} 
    } elsif ($target eq 'answer' || $target eq 'grade') {
	&Apache::response::reset_params();
    }
    return $result;
}

sub end_stringresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    my $result = '';
    my $part=$Apache::inputtags::part;
    my $id=$Apache::inputtags::response[-1];
    my $answer=&Apache::lonxml::get_param('answer',$parstack,$safeeval);
    my $type=&Apache::lonxml::get_param('type',$parstack,$safeeval);
    my $answerdisplay=&Apache::lonxml::get_param('answerdisplay',$parstack,$safeeval);
    &Apache::lonxml::debug("current $answer ".$token->[2]);
    if (!$Apache::lonxml::default_homework_loaded) {
	&Apache::lonxml::default_homework_load($safeeval);
    }
    if ( $target eq 'grade' && &Apache::response::submitted() ) {
	&Apache::response::setup_params('stringresponse',$safeeval);
	$safeeval->share_from('capa',['&caparesponse_capa_check_answer']);
	if ($Apache::lonhomework::type eq 'exam' ||
	    &Apache::response::submitted('scantron')) {
	    &Apache::response::scored_response($part,$id);

	} else {
	    my $response = &Apache::response::getresponse();
	    if ( $response =~ /[^\s]/) {
		my %previous = &Apache::response::check_for_previous($response,
								    $part,$id,
                                                                    undef,$type);
		&Apache::lonxml::debug("submitted a $response<br>\n");
		&Apache::lonxml::debug($$parstack[-1] . "\n<br>");
		$Apache::lonhomework::results{"resource.$part.$id.submission"}=
		    $response;
		my ($ad,$msg);
		if ($type eq 're' ) { 
		    # if the RE wasn't in a var it likely got munged,
                    # thus grab it from the var directly
#		    my $testans=$token->[2]->{'answer'};
#		    if ($testans !~ m/^\s*\$/) {
#			$answer=$token->[2]->{'answer'};
#		    }
		    ${$safeeval->varglob('LONCAPA::response')}=$response;
                    my $preprocess=&Apache::lonxml::get_param('preprocess',$parstack,$safeeval);
                    $preprocess=~s/^\&//;
                    if (defined($preprocess)) {
                        &Apache::run::run('$LONCAPA::response=&'.$preprocess.'($LONCAPA::response);',$safeeval);
                    }
		    $result = &Apache::run::run('if ($LONCAPA::response=~m'.$answer.') { return 1; } else { return 0; }',$safeeval);
		    &Apache::lonxml::debug("current $response");
		    &Apache::lonxml::debug("current $answer");
		    $ad = ($result) ? 'APPROX_ANS' : 'INCORRECT';
		} else {
		    my @args = ('type','preprocess');
		    my $args_ref = &setup_capa_args($safeeval,$parstack,
						    \@args,$response);
                    if ($$args_ref{'type'} eq '') {
                        $$args_ref{'type'} = 'ci';
                    }
		    &add_in_tag_answer($parstack,$safeeval);
		    my (@final_awards,@final_msgs,@names,%ansstring);
		    foreach my $name (keys(%answer)) {
			&Apache::lonxml::debug(" doing $name with ".join(':',@{ $answer{$name}{'answers'} }));
			${$safeeval->varglob('LONCAPA::CAPAresponse_answer')}=dclone($answer{$name});
			my ($result, @msgs)=&Apache::run::run("&caparesponse_check_list()",$safeeval);
                        if ($$args_ref{'type'} =~ /^c[si]$/) {
                            $ansstring{$name} = pop(@msgs);
                            my $control_chars_removed = pop(@msgs);
                            my $error = pop(@msgs);
                            if (($error ne '') || 
                                ($control_chars_removed)) {
                                my ($symb,$courseid,$sdomain,$sname) =
                                    &Apache::lonnet::whichuser();
                                if ($control_chars_removed) {
                                    my $showresponse = $response;
                                    if ($response =~ /[\000-\037]/) {
                                        $response =~ s/[\000-\037]//g;
                                    }
                                    if ($showresponse  =~ /[\r\n\f]/) {
                                        my @lines = split(/[\r\n\f]+/,$showresponse);
                                        $showresponse = join('\\n',@lines);
                                    }
                                    &Apache::lonnet::logthis("Stringresponse grading: control characters stripped from submission ".$showresponse." for $sname:$sdomain in $courseid for part: $part response: $id and symb: $symb");
                                    $Apache::lonhomework::results{"resource.$part.$id.submission"} = $response;
                                }
                                if ($error ne '') {
                                    &Apache::lonnet::logthis("Stringresponse grading error: $error for $sname:$sdomain in $courseid for part: $part response: $id and symb: $symb");
                                }
                            }
                        }
			&Apache::lonxml::debug('msgs are'.join(':',@msgs));
			my ($awards)=split(/:/,$result);
			my (@awards) = split(/,/,$awards);
			($ad,$msg) = 
			    &Apache::inputtags::finalizeawards(\@awards,\@msgs);
			push(@final_awards,$ad);
			push(@final_msgs,$msg);
			push(@names,$name);
			&Apache::lonxml::debug("\n<br>result:$result:$Apache::lonxml::curdepth<br>\n");
		    }
		    ($ad, $msg, my $name) = 
			&Apache::inputtags::finalizeawards(\@final_awards,
							   \@final_msgs,
							   \@names,1);
                    if (keys(%ansstring) > 0) {
                        $Apache::lonhomework::results{"resource.$part.$id.answerstring"} = &Apache::lonnet::hash2str(%ansstring);
                    }
		}
                if (($ad eq 'INCORRECT' || $ad eq 'APPROX_ANS' ||
                     $ad eq 'EXACT_ANS')) {
		    if ($Apache::lonhomework::type eq 'survey') {
		        $ad='SUBMITTED';
		    } elsif ($Apache::lonhomework::type eq 'surveycred') {
                        $ad='SUBMITTED_CREDIT';
                    } elsif ($Apache::lonhomework::type eq 'anonsurvey') {
                        $ad='ANONYMOUS';
                    } elsif ($Apache::lonhomework::type eq 'anonsurveycred') {
                        $ad='ANONYMOUS_CREDIT';
                    }
                }
                unless (($env{'request.state'} eq 'construct') || 
                        ($Apache::lonhomework::type eq 'randomizetry')) {
                    if (($ad eq 'INCORRECT' || $ad eq 'APPROX_ANS' || $ad eq 'EXACT_ANS')) {
                        if ($previous{'used'}) {
                            if ($ad ne $previous{'award'}) {
                                if (($previous{'award'} eq 'INCORRECT' || 
                                     $previous{'award'} eq 'APPROX_ANS' ||
                                     $previous{'award'} eq 'EXACT_ANS')) {
                                    &stringresponse_gradechange($part,$id,\%previous,
                                                                'cs',$response,$ad,$type);
                                }
                            }
                        } elsif ($previous{'usedci'}) {
                            if ($ad ne $previous{'awardci'}) {
                                if (($previous{'awardci'} eq 'INCORRECT' || 
                                     $previous{'awardci'} eq 'APPROX_ANS' ||
                                     $previous{'awardci'} eq 'EXACT_ANS')) {
                                    &stringresponse_gradechange($part,$id,\%previous,
                                                                'ci',$response,$ad,$type);
                                }
                            }
                        }
                    }
                }
		&Apache::response::handle_previous(\%previous,$ad);
		$Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=$ad;
		$Apache::lonhomework::results{"resource.$part.$id.awardmsg"}=$msg;
	    }
	}
    } elsif ($target eq 'answer' || $target eq 'analyze') {
	&add_in_tag_answer($parstack,$safeeval);
	if ($target eq 'analyze') {
	    push (@{ $Apache::lonhomework::analyze{"parts"} },"$part.$id");
	    $Apache::lonhomework::analyze{"$part.$id.type"} = 'stringresponse';
	    &Apache::response::check_if_computed($token,$parstack,$safeeval,
						 'answer');
	}
	&Apache::response::setup_params('stringresponse',$safeeval);
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_header('stringresponse');
	}
	foreach my $name (keys(%answer)) {
	    my @answers = @{ $answer{$name}{'answers'} };
	    for (my $i=0;$i<=$#answers;$i++) {
		my $answer_part = $answers[$i];
		foreach my $element (@{$answer_part}) {
		    if ($target eq 'answer') {
			$result.=&Apache::response::answer_part('stringresponse',
								$element);
                        if ($env{'form.grade_retrieveanswers'}) {
                            $env{'form.grade_answers.resource.'.$part.'.'.$id} = $element;
                        }
		    } elsif ($target eq 'analyze') {
			push (@{ $Apache::lonhomework::analyze{"$part.$id.answer"}{$name}[$i] },
			      $element);
		    }
		}
		if ($target eq 'answer' && $type eq 're') {
		    $result.=&Apache::response::answer_part('stringresponse',
							    $answerdisplay);
		}
	    }
	}
	my $string='Case Insensitive';
	if ($type eq 'mc') {
	    $string='Multiple Choice';
	} elsif ($type eq 'cs') {
	    $string='Case Sensitive';
	} elsif ($type eq 'ci') {
	    $string='Case Insensitive';
	} elsif ($type eq 're') {
	    $string='Regular Expression';
	}
	if ($target eq 'answer') {
	    if ($env{'form.answer_output_mode'} eq 'tex') {
		$result.=&Apache::response::answer_part('stringresponse',
							"$string");
	    } else {
		$result.=&Apache::response::answer_part('stringresponse',
							"<b>$string</b>");
	    }
	} elsif ($target eq 'analyze') {
	    push (@{$Apache::lonhomework::analyze{"$part.$id.str_type"}},
		  $type);
	}
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_footer('stringresponse');
	}
    } elsif ($target eq 'edit') {
	$result.='</td></tr>'.&Apache::edit::end_table;
    } elsif ($target eq 'web' || $target eq 'tex') {
	&Apache::response::setup_prior_tries_hash(\&format_prior_response_string);
    }
    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
	$target eq 'tex' || $target eq 'analyze') {
        my $repetition = &Apache::response::repetition();
	&Apache::lonxml::increment_counter($repetition,"$part.$id");
	if ($target eq 'analyze') {
	    &Apache::lonhomework::set_bubble_lines();
	}
    }
    &Apache::response::end_response;
    return $result;
}

sub start_formularesponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ($target eq 'meta') {
	&Apache::response::start_response($parstack,$safeeval);
	$result=&Apache::response::meta_package_write('formularesponse');
	&Apache::response::end_response();
    } else {
	$result.=&start_numericalresponse(@_);
    }
    return $result;
}

sub end_formularesponse {
    return end_numericalresponse(@_);
}

1;
__END__