--- loncom/homework/radiobuttonresponse.pm 2001/02/19 20:36:49 1.12 +++ loncom/homework/radiobuttonresponse.pm 2013/04/25 17:58:32 1.156 @@ -1,171 +1,1459 @@ # The LearningOnline Network with CAPA # mutliple choice style responses +# +# $Id: radiobuttonresponse.pm,v 1.156 2013/04/25 17:58:32 bisitz 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::radiobuttonresponse; use strict; +use HTML::Entities(); +use Apache::lonlocal; +use Apache::lonnet; +use Apache::response; +use Apache::caparesponse; + +my $default_bubbles_per_line = 10; +my @alphabet = ( 'A' .. 'Z' ); # Foil labels. + + -sub BEGIN { - &Apache::lonxml::register('Apache::radiobuttonresponse',('radiobuttonresponse')); + +BEGIN { + &Apache::lonxml::register('Apache::radiobuttonresponse',('radiobuttonresponse')); } +#--------------------------------------------------------------------------- +# +# Generic utility subs. + +sub bubble_line_count { + my ($numfoils, $bubbles_per_line) = @_; + my $bubble_lines; + $bubble_lines = int($numfoils / $bubbles_per_line); + if (($numfoils % $bubbles_per_line) != 0) { + $bubble_lines++; + } + return $bubble_lines; + +} + + + +#------------------------------------------------------------------------------ +# +# XML handlers. sub start_radiobuttonresponse { - my ($target,$token,$parstack,$parser,$safeeval,$style)=@_; - #when in a radiobutton response use these - &Apache::lonxml::register('Apache::radiobuttonresponse',('foilgroup','foil')); - my $id = &Apache::response::start_response($parstack,$safeeval); - return ''; + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + my $result; + + #when in a radiobutton response use these + &Apache::lonxml::register('Apache::radiobuttonresponse',('foilgroup','foil','conceptgroup')); + push (@Apache::lonxml::namespace,'radiobuttonresponse'); + my $id = &Apache::response::start_response($parstack,$safeeval); + + %Apache::hint::radiobutton=(); + undef(%Apache::response::foilnames); + if ($target eq 'meta') { + $result=&Apache::response::meta_package_write('radiobuttonresponse'); + } elsif ($target eq 'edit' ) { + $result.=&Apache::edit::start_table($token) + .''.&Apache::lonxml::description($token) + .&Apache::loncommon::help_open_topic('Radio_Response_Problems') + .'' + .''.&mt('Delete?').' ' + .&Apache::edit::deletelist($target,$token) + .'' + .' '.&Apache::edit::end_row() + .&Apache::edit::start_spanning_row(); + $result.= + &Apache::edit::text_arg('Max Number Of Shown Foils:','max', + $token,'4'). + &Apache::edit::select_arg('Randomize Foil Order:','randomize', + ['yes','no'],$token). + &Apache::edit::select_arg('Display Direction:','direction', + ['vertical','horizontal'],$token). + &Apache::edit::end_row(). + &Apache::edit::start_spanning_row()."\n"; + } elsif ($target eq 'modified') { + my $constructtag=&Apache::edit::get_new_args($token,$parstack, + $safeeval,'max', + 'randomize','direction'); + if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); } + + } elsif ( $target eq 'tex' ) { + my $type = + &Apache::lonxml::get_param( 'TeXtype', $parstack, $safeeval, undef, + 0 ); + if ( $type eq '1' ) { + $result .= ' \renewcommand{\labelenumi}{\arabic{enumi}.}'; + } + elsif ( $type eq 'A' ) { + $result .= ' \renewcommand{\labelenumi}{\Alph{enumi}.}'; + } + elsif ( $type eq 'a' ) { + $result .= ' \renewcommand{\labelenumi}{\alph{enumi}.}'; + } + elsif ( $type eq 'i' ) { + $result .= ' \renewcommand{\labelenumi}{\roman{enumi}.}'; + } + else { + $result .= ' \renewcommand{\labelenumi}{\Alph{enumi}.}'; + } + + } + elsif ( $target eq 'analyze' ) { + my $part_id = "$Apache::inputtags::part.$id"; + $Apache::lonhomework::analyze{"$part_id.type"} = 'radiobuttonresponse'; + push (@{ $Apache::lonhomework::analyze{"parts"} },$part_id); + } + return $result; } sub end_radiobuttonresponse { - &Apache::response::end_response; - return ''; + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + my $result; + if ( $target eq 'edit' ) { + $result = &Apache::edit::end_table(); + } + &Apache::response::end_response; + pop @Apache::lonxml::namespace; + &Apache::lonxml::deregister('Apache::radiobuttonresponse',('foilgroup','foil','conceptgroup')); + undef(%Apache::response::foilnames); + return $result; } -%Apache::response::foilgroup={}; +%Apache::response::foilgroup=(); sub start_foilgroup { - %Apache::response::foilgroup={}; - return ''; + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + %Apache::response::foilgroup=(); + $Apache::radiobuttonresponse::conceptgroup=0; + &Apache::response::pushrandomnumber(undef,$target); + return; } -sub setrandomnumber { - my $rndseed=&Apache::lonnet::rndseed(); - $rndseed=unpack("%32i",$rndseed); - $rndseed=$rndseed - +&Apache::lonnet::numval($Apache::inputtags::part) - +&Apache::lonnet::numval($Apache::inputtags::response['-1']); - srand($rndseed); - return ''; +sub storesurvey { + my ($style) = @_; + if ( !&Apache::response::submitted() ) { return ''; } + my $response = $env{'form.HWVAL_'.$Apache::inputtags::response['-1']}; + &Apache::lonxml::debug("Here I am!:$response:"); + if ( $response !~ /[0-9]+/) { return ''; } + my $part = $Apache::inputtags::part; + my $id = $Apache::inputtags::response['-1']; + my @whichfoils=@{ $Apache::response::foilgroup{'names'} }; + my %responsehash; + $responsehash{$whichfoils[$response]}=$response; + my $responsestr=&Apache::lonnet::hash2str(%responsehash); + $Apache::lonhomework::results{"resource.$part.$id.submission"}= + $responsestr; + my %previous=&Apache::response::check_for_previous($responsestr,$part,$id); + my $ad; + if ($style eq 'anonsurvey') { + $ad=$Apache::lonhomework::results{"resource.$part.$id.awarddetail"}='ANONYMOUS'; + } elsif ($style eq 'anonsurveycred') { + $ad=$Apache::lonhomework::results{"resource.$part.$id.awarddetail"}='ANONYMOUS_CREDIT'; + } elsif ($style eq 'surveycred') { + $ad=$Apache::lonhomework::results{"resource.$part.$id.awarddetail"}='SUBMITTED_CREDIT'; + } else { + $ad=$Apache::lonhomework::results{"resource.$part.$id.awarddetail"}='SUBMITTED'; + } + &Apache::response::handle_previous(\%previous,$ad); + &Apache::lonxml::debug("submitted a $response
\n"); + return ''; +} + + +sub grade_response { + my ($answer, $whichfoils, $bubbles_per_line)=@_; + + if ( !&Apache::response::submitted() ) { return; } + my $response; + + if ($env{'form.submitted'} eq 'scantron') { + $response = &Apache::response::getresponse(1,undef, + &bubble_line_count(scalar(@{ $whichfoils}), + $bubbles_per_line), + $bubbles_per_line); + + } else { + $response = $env{'form.HWVAL_'.$Apache::inputtags::response['-1']}; + } + + + if ( $response !~ /[0-9]+/) { return; } + my $part=$Apache::inputtags::part; + my $id = $Apache::inputtags::response['-1']; + my %responsehash; + $responsehash{$whichfoils->[$response]}=$response; + my $responsestr=&Apache::lonnet::hash2str(%responsehash); + my %previous=&Apache::response::check_for_previous($responsestr, + $part,$id); + $Apache::lonhomework::results{"resource.$part.$id.submission"}= + $responsestr; + &Apache::lonxml::debug("submitted a $response
\n"); + my $ad; + if ($response == $answer) { + $ad='EXACT_ANS'; + } else { + $ad='INCORRECT'; + } + $Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=$ad; + &Apache::response::handle_previous(\%previous,$ad); } sub end_foilgroup { - my ($target,$token,$parstack,$parser,$safeeval,$style)=@_; - - my $result; - if ($target ne 'meta') { + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + + my $result; + my $bubble_lines; + my $answer_count; + my $id = $Apache::inputtags::response['-1']; + my $part = $Apache::inputtags::part; + my $bubbles_per_line = &getbubblesnum($part,$id); + + + if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || + $target eq 'tex' || $target eq 'analyze') { + my $style = $Apache::lonhomework::type; + my $direction = &Apache::lonxml::get_param('direction',$parstack, + $safeeval,'-2'); + if ( (($style eq 'survey') || ($style eq 'surveycred') || + ($style eq 'anonsurvey') || ($style eq 'anonsurveycred')) + && ($target ne 'analyze')) { + if ($target eq 'web' || $target eq 'tex') { + $result=&displayallfoils($direction, $target); + } elsif ( $target eq 'answer' ) { + $result=&displayallanswers(); + } elsif ( $target eq 'grade' ) { + $result=&storesurvey($style); + } + $answer_count = scalar(@{$Apache::response::foilgroup{'names'}}); + + } else { + + my $name; + my $max = &Apache::lonxml::get_param('max',$parstack,$safeeval, + '-2'); + my $randomize = &Apache::lonxml::get_param('randomize',$parstack, + $safeeval,'-2'); + my ($answer, @shown) = &whichfoils($max, $randomize); + $answer_count = scalar(@shown); + + if ($target eq 'web' || $target eq 'tex') { + $result=&displayfoils($target, + $answer, \@shown, + $direction, + $bubbles_per_line); + } elsif ($target eq 'answer' ) { + $result=&displayanswers($answer, \@shown, $bubbles_per_line); + } elsif ( $target eq 'grade') { + &grade_response($answer, \@shown, $bubbles_per_line); + } elsif ( $target eq 'analyze') { + my $bubble_lines = &bubble_line_count($answer_count, + $bubbles_per_line); + &Apache::response::analyze_store_foilgroup(\@shown, + ['text','value','location']); + my $part_id="$part.$id"; + push (@{ $Apache::lonhomework::analyze{"$part_id.options"} }, + ('true','false')); + + } + } + $Apache::lonxml::post_evaluate=0; + } + if ($target eq 'web') { + &Apache::response::setup_prior_tries_hash(\&format_prior_answer, + [\%Apache::response::foilgroup]); + } + &Apache::response::poprandomnumber(); + $bubble_lines = &bubble_line_count($answer_count, $bubbles_per_line); + &Apache::lonxml::increment_counter($bubble_lines, + "$part.$id"); + if ($target eq 'analyze') { + &Apache::lonhomework::set_bubble_lines(); + } + return $result; +} +sub getbubblesnum { + my ($part,$id) = @_; + my $bubbles_per_line; + my $default_numbubbles = $default_bubbles_per_line; + if (($env{'form.bubbles_per_row'} =~ /^\d+$/) && + ($env{'form.bubbles_per_row'} > 0)) { + $default_numbubbles = $env{'form.bubbles_per_row'}; + } + $bubbles_per_line = + &Apache::response::get_response_param($part."_$id",'numbubbles', + $default_numbubbles); + return $bubbles_per_line; +} + +sub getfoilcounts { + my @names; + my $truecnt=0; + my $falsecnt=0; my $name; - &setrandomnumber(); - my ($truecnt,$falsecnt,$max) = &getfoilcounts($parstack,$safeeval); + if ( $Apache::response::foilgroup{'names'} ) { + @names= @{ $Apache::response::foilgroup{'names'} }; + } + foreach $name (@names) { + if ($Apache::response::foilgroup{$name.'.value'} eq 'true') { + $truecnt++; + } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'false') { + $falsecnt++; + } + } + return ($truecnt,$falsecnt); +} + +sub format_prior_answer { + my ($mode,$answer,$other_data) = @_; + my $foil_data = $other_data->[0]; + my %response = &Apache::lonnet::str2hash($answer); + my ($name) = keys(%response); + return ''. + $foil_data->{$name.'.text'}.''; + +} + + +## +# Return the last survey response. The logic is slightly different than that of +# get_last_responses. TODO: See if there are chunks of code betweenthis and +# get_last_reponses that are common and can be factored. +# +# @param $part - Problem part under consideration. +# @param $showanswer - True if answers should be shown. +# @param $id - Problem id. +# +# @return hash reference. +# @retval reference to the has indexed by answer selection that +# indicates the most recent answer. +# +sub get_last_survey_response { + my ($part, $showanswer, $id) = @_; + + my $newvariation; + my $lastresponse; # stringified last response. + + if ( + ( + ( + $Apache::lonhomework::history{"resource.$part.type"} eq + 'randomizetry' + ) + || ( $Apache::lonhomework::type eq 'randomizetry' ) + ) + && ( $Apache::inputtags::status[-1] eq 'CAN_ANSWER' ) + ) + { + if ( $env{ 'form.' . $part . '.rndseed' } ne + $Apache::lonhomework::history{"resource.$part.rndseed"} ) + { + $newvariation = 1; + } + } + $showanswer = &Apache::response::show_answer(); + unless ( + ( + ( + $Apache::lonhomework::history{"resource.$part.type"} eq + 'anonsurvey' + ) + || ( $Apache::lonhomework::history{"resource.$part.type"} eq + 'anonsurveycred' ) + ) + && ( defined( $env{'form.grade_symb'} ) ) + || ( $newvariation && !$showanswer ) + ) + { + $lastresponse = + $Apache::lonhomework::history{"resource.$part.$id.submission"}; + } + my %lastresponse = &Apache::lonnet::str2hash($lastresponse); + + + return \%lastresponse; + +} +## +# Removes the names from a foil group that are marked as unused. +# +# @param $names - reference to the array of names to filter. +# +# @return arrayref +# @retval reference to the filtered array. +# +sub remove_unused { + my ($names) = @_; + my @result; + + foreach my $name (@{$names}) { + if ($Apache::response::foilgroup{$name . '.value'} ne 'unused') { + push(@result, $name); + } + } + return \@result; +} +## +# Displays all foils in a survey type problem for HTML rendition. +# TODO: See if there is any logic in this sub that can be shared +# with display_foils_html +# +# @param $names - ref to array of names of the foils to display. +# @param $part - Problem part number. +# @param $showanswer - If true, show the answers. +# @param $lastresponse - Ref to the last response hash. +# @param $direction - Display direction of the radiobuttons. +# +# @return string +# @retval HTML required to display the resource in a browser. +# +sub display_survey_html { + my ($names, $part, $showanswer, $lastresponse, $direction) = @_; + my $result; + + # Figure out a few fragments of html that depend onthe + # orientation of the radiobuttons: + # closing_html - HTML to emit at the end of the resource. + # pre_foil - HTML to emit prior to each foil. + # post_foil - HTML to emit following each foil. + # + # The opening HTML is just added to the $result now + # + # Figuring these outin advance compresses the loop over foils into something + # pretty simple: + # + # NOTE: There's probably a really cool way to do this with style sheets + # and picking the selector based on the orientation, if someone wants to puzzle + # that out. In that case, probably the whole thing lives in a
and each + # foil lives in a

+ # + + + my ($opening_html, $closing_html, $pre_foil, $post_foil) = + &html_direction_fragments($direction); + + $result = $opening_html; + + # Different rendering depending on whether answers are shown: + # I played with different factorings but this seems the most concise/clear... + # although I don't like the $showanswer conditino inside the loop. Other things I tried + # - two loops..much longer code..no gain in clarity. + # - Using a visitor patttern passing it the rendering code chunklets and + # an anonymous hash reference for state data etc. Very cool but + # quite a bit more code and quite a bit less clear. + + my $temp = 0; + foreach my $name (@{$names}) { + $result .= $pre_foil; + + if ($showanswer) { + my $foiltext = $Apache::response::foilgroup{$name . '.text'}; + + # Bold the prior response: + + if (defined($lastresponse->{$name})) { + $result .= '' . $foiltext . ''; + } else { + $result .= $foiltext; + } + } else { + $result .= &html_radiobutton( + $part, $Apache::inputtags::response['-1'], $name, $lastresponse, $temp + ); + } + + $result .= $post_foil; + $temp++; + } + + + $result .= $closing_html; + return $result; + +} + +## +# Generate LaTeX for surveys. +# +# @param $names - names of the foils to display. +# @param $showanswer - flag that is true to display answers. +# @param $lastresponse - Reference to a hash the indicates the last response. +# @param $direction - Orientation of foils ('horiztonal' or otherwise). +# @param $venv - LaTeX name for vertical env. +# +# @return string +# @retval LaTeX rendering of the survey question. + +sub latex_survey { + my ($names, $showanswer, $lastresponse, $direction, $venv) = @_; + + my $result; + if ($showanswer) { + $result .= "\\begin{$venv}"; + foreach my $name (@{$names}) { + + + $result .= '\item \vskip -2mm '; + + if ( defined( $lastresponse->{$name} ) ) { + $result .= '}'; + } + $result .= $Apache::response::foilgroup{ $name . '.text' } . ' '; + } + $result .= "\\end{$venv}"; + + } elsif ( $env{'form.pdfFormFields'} eq 'yes' + && $Apache::inputtags::status[-1] eq 'CAN_ANSWER') { + $result .= &display_pdf_form($names, $direction, $venv); + } else { + if ($direction eq 'horizontal') { + my @foil_texts = &get_foil_texts($names); + $result .= &Apache::caparesponse::make_horizontal_latex_bubbles( + $names, \@foil_texts, '$\bigcirc$'); + } else { + $result .= "\\begin{$venv}"; + + my $temp = 0; + my $i = 0; + foreach my $name (@{$names}) { + + $result .= '\item \vskip -2mm '; + + if ($env{'form.pdfFormFields'} ne 'yes' + or $Apache::inputtags::status[-1] ne 'CAN_ANSWER' ) + { + $result .= + '$\bigcirc$' + . $Apache::response::foilgroup{ $name . '.text' } + . '\\\\'; #' stupid emacs + } + + $i++; + $temp++; + + $result .= '\vskip 0 mm '; + } + $result .= "\\end{$venv}"; + } + } + return $result; +} +## +# Figure out the LaTeX environment in which to wrap the LaTeX vertical output. +# +# @return string +# @retval the environment name. The LaTeX should be wrapped a +# \begin{retval} \end{retval} pair. +# +sub latex_vertical_environment { + if ($env{'form.pdfFormFields'} eq 'yes' + && $Apache::inputtags::status[-1] eq 'CAN_ANSWER') { + return 'itemize'; + } else { + return 'enumerate'; + } +} + +## +# Figure out the key html fragments that depend on the rendering direction: +# +# @param $direction - 'horizontal' for horizontal direction. +# +# @return list +# @retval (part_start, part_end, foil_start, foil_end) +# Where: +# - part_start is the HTML to emit at the start of the part. +# - part_end is the HTML to emit at the end of the part. +# - foil_start is the HTML to emit prior to each foil. +# - foil_end is the HTML to emit after each foil +# +sub html_direction_fragments { + my $direction = shift; + if ($direction eq 'horizontal') { + return ('', '
', '', ''); + } else { + return ('', '
', '
', ''); + } +} + +## +# +# Displays all the foils of a problem in a format suitable for +# surveys, surveys for credit, anonymous surveys and anonymous surveys for credit. +# +# @param $direction - Display direction of the choices ('horiztonal' or not). +# @param $target - Rendering target. +# +# @return string +# @retval Text that renders for the selected target. +# +sub displayallfoils{ + my ( $direction, $target ) = @_; + my $result; + &Apache::lonxml::debug("survey style display"); + + my @names; + + if ( $Apache::response::foilgroup{'names'} ) { + @names = @{ $Apache::response::foilgroup{'names'} }; + } + + + my $id = $Apache::inputtags::response['-1']; + my $part = $Apache::inputtags::part; + + my $showanswer = &Apache::response::show_answer(); + my $lastresponse = &get_last_survey_response($part, $showanswer, $id); + my $used_names = &remove_unused(\@names); + + + if ($target ne 'tex') { + $result .= &display_survey_html( + $used_names, $part, $showanswer, $lastresponse, $direction + ); + } else { + + my $vertical_env = &latex_vertical_environment(); + $result .= &latex_survey( + $used_names, $showanswer, $lastresponse, $direction, $vertical_env + ); + + } + return $result; +} + +sub whichfoils { + my ($max,$randomize)=@_; + + my @truelist; + my @falselist; + my @whichfalse =(); + my ($truecnt,$falsecnt) = &getfoilcounts(); my $count=0; # we will add in 1 of the true statements - if (($falsecnt+1)>$max) { $count=$max } else { $count=$falsecnt+1; } - my $answer = int(rand ($count)); - &Apache::lonxml::debug("Answer is $answer, $count from $max, $falsecnt"); - if ($target eq 'web') { - $result=&displayfoils($max,$answer); - } elsif ( $target eq 'grade') { - if ( defined $ENV{'form.submitted'}) { - my $response = $ENV{'form.HWVAL'.$Apache::inputtags::response['-1']}; - if ( $response =~ /[^\s]/) { - my $id = $Apache::inputtags::response['-1']; - $Apache::lonhomework::results{"resource.$Apache::inputtags::part.$id.submission"}=$response; - &Apache::lonxml::debug("submitted a $response
\n"); - if ($response == $answer) { - $Apache::lonhomework::results{"resource.$Apache::inputtags::part.$id.awarddetail"}='EXACT_ANS'; - } else { - $Apache::lonhomework::results{"resource.$Apache::inputtags::part.$id.awarddetail"}='INCORRECT'; - } + if ( $max>0 && ($falsecnt+1)>$max) { $count=$max } else { $count=$falsecnt+1; $max=$count; } + my $answer=int(&Math::Random::random_uniform() * ($count)); + &Apache::lonxml::debug("Count is $count, $answer is $answer"); + my @names; + if ( $Apache::response::foilgroup{'names'} ) { + @names= @{ $Apache::response::foilgroup{'names'} }; + } + if (&Apache::response::showallfoils()) { + @whichfalse=@names; + } elsif ($randomize eq 'no') { + &Apache::lonxml::debug("No randomization"); + my $havetrue=0; + foreach my $name (@names) { + if ($Apache::response::foilgroup{$name.'.value'} eq 'true') { + if (!$havetrue ) { + push(@whichfalse,$name); $havetrue++; $answer=$#whichfalse; + } + } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'false') { + push (@whichfalse,$name); + } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'unused') { + } else { + &Apache::lonxml::error(&HTML::Entities::encode("No valid value assigned ($Apache::response::foilgroup{$name.'.value'}) for foil $name in ",'<>&"')); + } + } + if ((!$havetrue) && + ($Apache::lonhomework::type ne 'survey') && + ($Apache::lonhomework::type ne 'surveycred') && + ($Apache::lonhomework::type ne 'anonsurvey') && + ($Apache::lonhomework::type ne 'anonsurveycred')) { + &Apache::lonxml::error(&mt('There are no true statements available.').'
'); } - } + } else { + my $current=0; + &Apache::lonhomework::showhash(%Apache::response::foilgroup); + my (%top,%bottom); + #first find out where everyone wants to be + foreach my $name (@names) { + $current++; + if ($Apache::response::foilgroup{$name.'.value'} eq 'true') { + push (@truelist,$name); + if ($Apache::response::foilgroup{$name.'.location'} eq 'top') { + $top{$name}=$current; + } elsif ($Apache::response::foilgroup{$name.'.location'} eq 'bottom') { + $bottom{$name}=$current; + } + } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'false') { + push (@falselist,$name); + if ($Apache::response::foilgroup{$name.'.location'} eq 'top') { + $top{$name}=$current; + } elsif ($Apache::response::foilgroup{$name.'.location'} eq 'bottom') { + $bottom{$name}=$current; + } + } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'unused') { + } else { + &Apache::lonxml::error(&HTML::Entities::encode("No valid value assigned ($Apache::response::foilgroup{$name.'.value'}) for foil $name in ",'<>&"')); + } + } + #pick a true statement + my $notrue=0; + if (scalar(@truelist) == 0) { $notrue=1; } + my $whichtrue = int(&Math::Random::random_uniform() * ($#truelist+1)); + &Apache::lonxml::debug("Max is $max, From $#truelist elms, picking $whichtrue"); + my (@toplist, @bottomlist); + my $topcount=0; + my $bottomcount=0; + # assign everyone to either toplist/bottomlist or whichfalse + # which false is randomized, toplist bottomlist are in order + while ((($#whichfalse+$topcount+$bottomcount) < $max-2) && ($#falselist > -1)) { + &Apache::lonxml::debug("Have $#whichfalse max is $max"); + my $afalse=int(&Math::Random::random_uniform() * ($#falselist+1)); + &Apache::lonxml::debug("From $#falselist elms, picking $afalse"); + $afalse=splice(@falselist,$afalse,1); + &Apache::lonxml::debug("Picked $afalse"); + &Apache::lonhomework::showhash(('names'=>\@names)); + &Apache::lonhomework::showhash(%top); + if ($top{$afalse}) { + $toplist[$top{$afalse}]=$afalse; + $topcount++; + } elsif ($bottom{$afalse}) { + $bottomlist[$bottom{$afalse}]=$afalse; + $bottomcount++; + } else { + push (@whichfalse,$afalse); + } + } + &Apache::lonxml::debug("Answer wants $answer"); + my $truename=$truelist[$whichtrue]; + my $dosplice=1; + if (($notrue) && + ($Apache::lonhomework::type ne 'survey') && + ($Apache::lonhomework::type ne 'surveycred') && + ($Apache::lonhomework::type ne 'anonsurvey') && + ($Apache::lonhomework::type ne 'anonsurveycred')) { + $dosplice=0; + &Apache::lonxml::error(&mt('There are no true statements available.').'
'); + } + #insert the true statement, keeping track of where it wants to be + if ($Apache::response::foilgroup{$truename.'.location'} eq 'top' && $dosplice) { + $toplist[$top{$truename}]=$truename; + $answer=-1; + foreach my $top (reverse(@toplist)) { + if ($top) { $answer++;} + if ($top eq $truename) { last; } + } + $dosplice=0; + } elsif ($Apache::response::foilgroup{$truename.'.location'} eq 'bottom' && $dosplice) { + $bottomlist[$bottom{$truename}]=$truename; + $answer=-1; + foreach my $bot (@bottomlist) { + if ($bot) { $answer++;} + if ($bot eq $truename) { last; } + } + $answer+=$topcount+$#whichfalse+1; + $dosplice=0; + } else { + if ($topcount>0 || $bottomcount>0) { + my $inc = 1; + if (($bottomcount > 0) && ($Apache::lonhomework::type ne 'exam')) { + $inc = 2; + } + $answer=int(&Math::Random::random_uniform() * ($#whichfalse+$inc)) + + $topcount; + } + } + &Apache::lonxml::debug("Answer now wants $answer"); + #add the top items to the top, bottom items to the bottom + for (my $i=0;$i<=$#toplist;$i++) { + if ($toplist[$i]) { unshift(@whichfalse,$toplist[$i]) } + } + for (my $i=0;$i<=$#bottomlist;$i++) { + if ($bottomlist[$i]) { push(@whichfalse,$bottomlist[$i]) } + } + #if the true statement is randomized insert it into the list + if ($dosplice) { splice(@whichfalse,$answer,0,$truelist[$whichtrue]); } } - } - return $result; + &Apache::lonxml::debug("Answer is $answer"); + return ($answer,@whichfalse); } -sub getfoilcounts { - my ($parstack,$safeeval)=@_; - my $rrargs =''; - if ( $#$parstack > 0 ) { $rrargs=$$parstack['-2']; } - my $max = &Apache::run::run("{$rrargs;".'return $max}',$safeeval); - my @names = @{ $Apache::response::foilgroup{'names'} }; - my $truecnt=0; - my $falsecnt=0; - my $name; - - foreach $name (@names) { - if ($Apache::response::foilgroup{$name.'.value'} eq 'true') { - $truecnt++; - } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'false') { - $falsecnt++; +## +# Return a list of foil texts given foil names. +# +# @param $whichfoils - Reference to a list of foil names. +# +# @return array +# @retval foil texts +# +sub get_foil_texts { + my ($whichfoils) = @_; + my @foil_texts; + + foreach my $name (@{$whichfoils}) { + push(@foil_texts, $Apache::response::foilgroup{$name . '.text'}); + } + return @foil_texts; +} + +## +# Generate the HTML for a single html foil. +# @param $part - The part for which the response is being generated. +# @param $fieldname - The basename of the radiobutton field +# @param $name - The foilname. +# @param $last_responses - Reference to a hash that holds the most recent +# responses. +# @param $value - radiobutton value. +# +# @return text +# @retval The generated html. +# +sub html_radiobutton { + my ($part, $fieldname, $name, $last_responses, $value) = @_; + + my $result=''; + + return $result; + +} +## +# Return a reference to the last response hash. This hash has exactly +# one or zero entries. The one entry is keyed by the foil 'name' of +# the prior response +# +# @param $part - Number of the problem part. +# +# @return reference to a hash. +# @retval see above. +# +sub get_last_response { + my ($part) = @_; + + my $id = $Apache::inputtags::response['-1']; + my ( $lastresponse, $newvariation ); + + if ((( $Apache::lonhomework::history{"resource.$part.type"} eq 'randomizetry') + || ( $Apache::lonhomework::type eq 'randomizetry' ) + ) + && ( $Apache::inputtags::status[-1] eq 'CAN_ANSWER' ) + ) + { + + if ( $env{ 'form.' . $part . '.rndseed' } ne + $Apache::lonhomework::history{"resource.$part.rndseed"} ) + { + $newvariation = 1; + } + } + unless ($newvariation) { + $lastresponse = + $Apache::lonhomework::history{"resource.$part.$id.submission"}; + } + my %lastresponse = &Apache::lonnet::str2hash($lastresponse); + + return \%lastresponse; +} + +## +# Display foils in html rendition.: +# +# @param $whichfoils - Set of foils to display. +# @param $target - Rendition target...there are several html targets. +# @param $direction - 'horizontal' if layout is horizontal. +# @param $part - Part of the problem that's being displayed. +# @param $show_answer- True if answers should be shown. +# +# @return string +# @retval generated html. +# +sub display_foils_html { + my ($whichfoils, $target, $direction, $part, $show_answer) = @_; + my $result; + + + # if the answers get shown, we need to label each item as correct or + # incorrect. + + my ($opening_html, $finalclose, $item_pretext, $item_posttext) = + &html_direction_fragments($direction); + + $result .= $opening_html; + + + if ($show_answer) { + + foreach my $name (@{$whichfoils}) { + + # If the item gets further surrounded by tags, this + # holds the closures for those tages. + + my $item_closetag = ''; + + $result .= $item_pretext; + + # Label each foil as correct or incorrect: + + if ($Apache::response::foilgroup{$name . '.value'} eq 'true') { + $result .= &mt('Correct:') . ''; + $item_closetag .= ''; + + } else { + $result .= &mt('Incorrect'); + } + + # Web rendition encloses the + # item text in a label tag as well: + + if ($target eq 'web') { + $result .= '' . $item_closetag; + } + $result .= $Apache::response::foilgroup{$name . '.text'}; + $result .= $item_closetag; + $result .= $item_posttext; + $result .= "\n"; # make the html a bit more readable. + } + + + } else { + my $lastresponse = &get_last_response($part); + + my $item_no = 0; + foreach my $name (@{$whichfoils}) { + $result .= $item_pretext; + $result .= &html_radiobutton( + $part, $Apache::inputtags::response[-1], + $name, $lastresponse, $item_no + ); + $result .= $item_posttext; + $item_no++; + } + } - } - return ($truecnt,$falsecnt,$max); + $result .= $finalclose; + + return $result; } +## +# Display foils in exam mode for latex +# +# @param $whichfoils - Reference to an array that contains the foil names to display +# @param $bubbles_per_line - Number of bubbles on a line. +# @param $direction - Rendering direction 'horizontal' is what we're looking for. +# @param $venv - Name of LaTeX environment to use for vertical rendering. +# +# @return string +# @return the latex rendering of the exam problem. +# +# +sub display_latex_exam { + my ($whichfoils, $bubbles_per_line, $direction, $venv) = @_; + my $result; + my $numlines; + my $bubble_number = 0; + my $line = 0; + my $i = 0; + + + if ($direction eq 'horizontal') { + + # Marshall the display text for each foil and turn things over to + # Apache::response::make_horizontal_bubbles: + + my @foil_texts = &get_foil_texts($whichfoils); + $result .= &Apache::caparesponse::make_horizontal_latex_bubbles( + $whichfoils, \@foil_texts, '$\bigcirc$'); + + } else { + + $result .= '\vskip 2mm \noindent'; + + # This section puts out the prefix that tells the user + # (if necessary) to only choose one bubble in the next n lines + # for problems with more than one line worth of bubbles in the grid sheet: + + my $numitems = scalar( @{$whichfoils} ); + $numlines = int( $numitems / $bubbles_per_line ); + if ( ( $numitems % $bubbles_per_line ) != 0 ) { + $numlines++; + } + if ( $numlines < 1 ) { + $numlines = 1; + } + if ( $numlines > 1 ) { + my $linetext; + for ( my $i = 0 ; $i < $numlines ; $i++ ) { + $linetext .= $Apache::lonxml::counter + $i . ', '; + } + $linetext =~ s/,\s$//; + $result .= + '\small {\textbf{' + . $linetext . '}} ' + . ' {\footnotesize ' + . &mt( '(Bubble once in [_1] lines)', $numlines ) + . '} \hspace*{\fill} \\\\'; + } + else { + $result .= '\textbf{' . $Apache::lonxml::counter . '}.'; + } + + # Now output the bubbles themselves: + + foreach my $name (@{$whichfoils}) { + if ( $bubble_number >= $bubbles_per_line ) { + $line++; + $i = 0; + $bubble_number = 0; + } + my $identifier; + if ( $numlines > 1 ) { + $identifier = $Apache::lonxml::counter + $line; + } + my $preindent; + if ($bubble_number > 0) { + $preindent = '\hspace*{3 mm}'; + } + my $foiltext = $Apache::response::foilgroup{$name . '.text'}; + $foiltext =~ s/\\noindent//; # forgive me for I have sinned.. + $result .= '{\small \textbf{' + . $identifier .$preindent + . $alphabet[$i] + . '}}$\bigcirc$' + . $foiltext + . '\\\\'; #' stupid emacs -- it thinks it needs that apostrophe to close the quote + + $i++; + $bubble_number++; + } + + } + + return $result; + +} + +## +# Display latex when exam mode is not on. +# +# @param $whichfoils - The foils to display +# @param $direction - Display direction ('horizontal' is what matters to us). +# @param $venv - Vertical env. to use for vertical rendering. +# @param $vend - End the vertical environment being used. +# +# @return string +# @retval - The LaTeX rendering of the resource.' +# +sub display_latex { + my ($whichfoils, $direction, $venv) = @_; + my $result; + + # how we render depends on the direction. + # Vertical is some kind of list environment determined by vbegin/vend. + # Horizontal is a table that is generated by + # Apache::caparesponse::make_horizontal_latex_bubbles with an empty string + # for the actual bubble text. + + if ($direction eq 'horizontal') { + my @foil_texts = &get_foil_texts($whichfoils); + $result .= &Apache::caparesponse::make_horizontal_latex_bubbles( + $whichfoils, \@foil_texts, ''); + } else { + $result .= "\\begin{$venv}"; + foreach my $name (@{$whichfoils}) { + $result .= '\vspace*{-2 mm}\item ' + . $Apache::response::foilgroup{ $name . '.text' }; + } + + $result .= "\\end{$venv}"; + } + return $result; +} + + +## +# Render foils for a PDF form. This is a variant of tex rednering that provides +# sufficient markup that the final PDF is a form that can be filled in online, +# or offline. +# +# @param $whichfoils - References an array of foils to display in the order in which +# they should be displayed. +# @param $direction - Rendering direction. 'horiztonal' means inputs are laid out +# horizontally otherwise they are stacked vertically. +# @param $venv - Vertical environment in which to wrap the foils. +# +# @return string +# @retval String containing the rendering of the resource. +# +# TODO: Take into account direction!!! +# +sub display_pdf_form { + my ($whichfoils, $direction, $venv) = @_; + my $temp = 0; + my $result; + + $result .= "\\begin{$venv}"; + foreach my $name ( @{$whichfoils} ) { + + my $fieldname = + $env{'request.symb'} + . '&part_' + . $Apache::inputtags::part + . '&radiobuttonresponse' + . '&HWVAL_' + . $Apache::inputtags::response['-1']; + $result .= '\item[{' + . &Apache::lonxml::print_pdf_radiobutton( $fieldname, + $temp ) + . '}]' + . $Apache::response::foilgroup{ $name . '.text' } + . "\n"; + + $temp++; + } + $result .= "\\end{$venv}"; + + return $result; +} + + +## +# Display selected foils: This is really just a dispatchter to appropriate renderers +# +# @param $target - Target (e.g. 'tex'...). +# @param $answer - True if answers should be shown. +# @param $whichfoils - Array of foil selectors that indicate which foils shouild be +# rendered, in rendering order. +# @param $direction- Rendering direction ('horizontal' is the one we look for, +# otherwise foils are rendered one per line vertically. +# @param $bubbles_per_line - number of exam bubbles per line. +# +# @return string +# @retval The rendered problem. sub displayfoils { - my ($max,$answer)=@_; - my @names = @{ $Apache::response::foilgroup{'names'} }; - my @truelist; - my @falselist; - my $result; - my $name; - - foreach $name (@names) { - #result.="
$name is $Apache::response::foilgroup{$name.'.value'} "; - if ($Apache::response::foilgroup{$name.'.value'} eq 'true') { - push (@truelist,$name); - } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'false') { - push (@falselist,$name); - } elsif ($Apache::response::foilgroup{$name.'.value'} eq 'unused') { - } else { - &Apache::lonxml::error("Unknown state $Apache::response::foilgroup{$name.'.value'} for $name in "); - } - } - my $whichtrue = rand $#truelist; - &Apache::lonxml::debug("Max is $max, From $#truelist elms, picking $whichtrue"); - my @whichfalse =(); - while ((($#whichfalse+2) < $max) && ($#falselist > -1)) { - my $afalse=rand $#falselist; - &Apache::lonxml::debug("From $#falselist elms, picking $afalse"); - $afalse=splice(@falselist,$afalse,1); - &Apache::lonxml::debug("Picked $afalse"); - push (@whichfalse,$afalse); - } - splice(@whichfalse,$answer,0,$truelist[$whichtrue]); - &Apache::lonxml::debug("the true statement is $answer"); - if ($Apache::lonhomework::history{"resource.$Apache::inputtags::part.solved"} =~ /^correct/ ) { - foreach $name (@whichfalse) { - $result.="
"; - if ($Apache::response::foilgroup{$name.'.value'} eq 'true') { - $result.='Correct'; - } else { - $result.='Incorrect'; - } - $result.=":".$Apache::response::foilgroup{$name.'.text'}."\n"; - } - } else { - my $temp=0; - foreach $name (@whichfalse) { - $result.="
".$Apache::response::foilgroup{$name.'.text'}."\n"; - $temp++; + my ($target,$answer,$whichfoils,$direction, $bubbles_per_line)=@_; + my $result; + + + my $part = $Apache::inputtags::part; + my $solved = $Apache::lonhomework::history{"resource.$part.solved"}; + + # Show answers html. + + if ( ( $target ne 'tex' ) + && &Apache::response::show_answer() ) + { + + $result = &display_foils_html( + $whichfoils, $target, $direction, $part, 1); + + # other html + } elsif ($target ne 'tex') { + $result = &display_foils_html($whichfoils, $target, $direction, $part, + 0, 0); + + # LaTeX rendering: + } else { + + + my $id = $Apache::inputtags::response['-1']; + my $part = $Apache::inputtags::part; + my $numlines; + + # Decide how to bracket the list of foils: + + my $vertical_env = &latex_vertical_environment(); + + # Rendering for latex exams. + + if ( ( $Apache::lonhomework::type eq 'exam' ) ) + { + $result .= &display_latex_exam( + $whichfoils, $bubbles_per_line, $direction, $vertical_env); + + $result .= '\vskip 0mm '; + + } else { + + # Different rendering for PDF form than for a + # 'regular' answer direction is honored in both of those + # + + if ( ($env{'form.pdfFormFields'} eq 'yes') + && ($Apache::inputtags::status[-1] eq 'CAN_ANSWER')) + { + $result .= &display_pdf_form($whichfoils, $direction, $vertical_env); + } else { + $result .= &display_latex($whichfoils, $direction, $vertical_env ); + } + $result .= '\vskip 0 mm '; + + } + } + return $result; +} + +sub displayallanswers { + my @names; + if ( $Apache::response::foilgroup{'names'} ) { + @names= @{ $Apache::response::foilgroup{'names'} }; + } + my $result=&Apache::response::answer_header('radiobuttonresponse'); + foreach my $name (@names) { + $result.=&Apache::response::answer_part('radiobuttonresponse', + $Apache::response::foilgroup{$name.'.value'}); + } + $result.=&Apache::response::answer_footer('radiobuttonresponse'); + return $result; +} + +sub displayanswers { + my ($answer, $whichopt, $bubbles_per_line)=@_; + my $result; + + if ($Apache::lonhomework::type eq 'exam') { + my $line = int($answer/$bubbles_per_line); + my $correct = ('A'..'Z')[$answer%$bubbles_per_line]; + $result .= &Apache::response::answer_header('radiobuttonresponse', + $line); + $result .= &Apache::response::answer_part('radiobuttonresponse', + $correct); + } else { + $result .= &Apache::response::answer_header('radiobuttonresponse'); + } + foreach my $name (@{ $whichopt }) { + $result.=&Apache::response::answer_part('radiobuttonresponse', + $Apache::response::foilgroup{$name.'.value'}); + } + $result.=&Apache::response::answer_footer('radiobuttonresponse'); + return $result; +} + +sub start_conceptgroup { + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + $Apache::radiobuttonresponse::conceptgroup=1; + %Apache::response::conceptgroup=(); + my $result; + if ($target eq 'edit') { + $result.=&Apache::edit::tag_start($target,$token); + $result.=&Apache::edit::text_arg('Concept:','concept',$token,'50'). + &Apache::edit::end_row().&Apache::edit::start_spanning_row(); + } elsif ($target eq 'modified') { + my $constructtag=&Apache::edit::get_new_args($token,$parstack, + $safeeval,'concept'); + if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); } + } + return $result; +} + +sub end_conceptgroup { + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + $Apache::radiobuttonresponse::conceptgroup=0; + my $result; + if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' || + $target eq 'tex' || $target eq 'analyze') { + &Apache::response::pick_foil_for_concept($target, + ['value','text','location'], + \%Apache::hint::radiobutton, + $parstack,$safeeval); + } elsif ($target eq 'edit') { + $result=&Apache::edit::end_table(); } - } - return $result."
"; + return $result; +} + +sub insert_conceptgroup { + my $result="\n\t\t".&insert_foil()."\n\t\t\n"; + return $result; } sub start_foil { - $Apache::lonxml::redirection--; - return ''; + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + my $result=''; + if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') { + &Apache::lonxml::startredirection; + if ($target eq 'analyze') { + &Apache::response::check_if_computed($token,$parstack,$safeeval,'value'); + } + } elsif ($target eq 'edit') { + $result=&Apache::edit::tag_start($target,$token); + $result.=&Apache::edit::text_arg('Name:','name',$token); + $result.=&Apache::edit::select_or_text_arg('Correct Option:','value', + ['unused','true','false'], + $token); + my $randomize=&Apache::lonxml::get_param('randomize',$parstack, + $safeeval,'-3'); + if ($randomize ne 'no') { + $result.=&Apache::edit::select_arg('Location:','location', + ['random','top','bottom'],$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,'value','name', + 'location'); + if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); } + } + return $result; } sub end_foil { - my ($target,$token,$parstack,$parser,$safeeval,$style)=@_; - if ($target eq 'web' || $target eq 'grade') { - my $args =''; - if ( $#$parstack > -1 ) { $args=$$parstack[$#$parstack]; } - my $name = &Apache::run::run("{$args;".'return $name}',$safeeval); - push @{ $Apache::response::foilgroup{'names'} }, $name; - my $value = &Apache::run::run("{$args;".'return $value}',$safeeval); - $Apache::response::foilgroup{"$name.value"} = $value; - $Apache::response::foilgroup{"$name.text"} = $Apache::lonxml::outputstack; - } - - $Apache::lonxml::redirection++; - if ($Apache::lonxml::redirection == 1) { - $Apache::lonxml::outputstack=''; - } - return ''; + my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_; + my $text=''; + if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') { + $text=&Apache::lonxml::endredirection; + } + if ($target eq 'web' || $target eq 'grade' || $target eq 'answer' + || $target eq 'tex' || $target eq 'analyze') { + my $value = &Apache::lonxml::get_param('value',$parstack,$safeeval); + if ($value ne 'unused') { + my $name = &Apache::lonxml::get_param('name',$parstack,$safeeval); + if ($name eq "") { + &Apache::lonxml::warning(&mt('Foils without names exist. This can cause problems to malfunction.')); + $name=$Apache::lonxml::curdepth; + } + if (defined($Apache::response::foilnames{$name})) { + &Apache::lonxml::error(&mt('Foil name [_1] appears more than once. Foil names need to be unique.',''.$name.'')); + } + $Apache::response::foilnames{$name}++; + my $location =&Apache::lonxml::get_param('location',$parstack, + $safeeval); + if ( $Apache::radiobuttonresponse::conceptgroup + && !&Apache::response::showallfoils() ) { + push @{ $Apache::response::conceptgroup{'names'} }, $name; + $Apache::response::conceptgroup{"$name.value"} = $value; + $Apache::response::conceptgroup{"$name.text"} = $text; + $Apache::response::conceptgroup{"$name.location"} = $location; + } else { + push @{ $Apache::response::foilgroup{'names'} }, $name; + $Apache::response::foilgroup{"$name.value"} = $value; + $Apache::response::foilgroup{"$name.text"} = $text; + $Apache::response::foilgroup{"$name.location"} = $location; + } + } + } + return ''; +} + +sub insert_foil { + return ' + + + +'; } 1; __END__ + + + +=head1 NAME + +Apache::radiobuttonresponse + +=head1 SYNOPSIS + +Handles multiple-choice style responses. + +This is part of the LearningOnline Network with CAPA project +described at http://www.lon-capa.org. + +=head1 SUBROUTINES + +=over + +=item start_radiobuttonresponse() + +=item bubble_line_count() + +=item end_radiobuttonresponse() + +=item start_foilgroup() + +=item storesurvey() + +=item grade_response() + +=item end_foilgroup() + +=item getfoilcounts() + +=item format_prior_answer() + +=item displayallfoils() + +=item &whichfoils($max,$randomize) + +Randomizes the list of foils. +Respects + - each foils desire to be randomized + - the existance of Concept groups of foils (select 1 foil from each) + - and selects a single correct statement from all possilble true statments + - and limits it to a toal of $max foils + +WARNING: this routine uses the random number generator, it should only +be called once per target, otherwise it can cause randomness changes in +homework problems. + +Arguments + $max - maximum number of foils to select (including the true one) + (so a max of 5 is: 1 true, 4 false) + + $randomize - whether to randomize the listing of foils, by default + will randomize, only if randomize is 'no' will it not + +Returns + $answer - location in the array of the correct answer + @foils - array of foil names in to display order + +=item displayfoils() + +=item displayallanswers() + +=item displayanswers() + +=item start_conceptgroup() + +=item end_conceptgroup() + +=item insert_conceptgroup() + +=item start_foil() + +=item end_foil() + +=item insert_foil() + +=back + +=cut