# The LearningOnline Network with CAPA
# Construct and maintain state and binary representation of course for user
#
# $Id: lonuserstate.pm,v 1.33 2002/07/07 17:52:20 www 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/
#
# (Server for RAT Maps
#
# (Edit Handler for RAT Maps
# (TeX Content Handler
#
# YEAR=2000
# 05/29/00,05/30 Gerd Kortemeyer)
# 7/1 Gerd Kortemeyer)
# 7/1,7/3,7/4,7/7,7/8,7/10 Gerd Kortemeyer)
#
# 7/15,7/17,7/18,8/1,8/2,8/4,8/5,8/21,8/22,8/23,8/30,
# 9/2,9/4,9/29,9/30,10/2,10/11,10/30,10/31,
# 11/1,11/2,11/14,11/16,11/22,12/28,
# YEAR=2001
# 07/05/01,08/30,08/31 Gerd Kortemeyer
# 12/16 Scott Harrison
#
###
package Apache::lonuserstate;
# ------------------------------------------------- modules used by this module
use strict;
use Apache::Constants qw(:common :http);
use Apache::File;
use HTML::TokeParser;
use Apache::lonnet();
use Apache::loncommon();
use GDBM_File;
use Apache::lonmsg;
use Safe;
use Safe::Hole;
use Opcode;
# ---------------------------------------------------- Globals for this package
my $pc; # Package counter
my %hash; # The big tied hash
my %parmhash;# The hash with the parameters
my @cond; # Array with all of the conditions
my $errtext; # variable with all errors
my $retfurl; # variable with the very first URL in the course
my %randompick; # randomly picked resources
# --------------------------------------------------------- Loads map from disk
sub loadmap {
my $uri=shift;
if ($hash{'map_pc_'.$uri}) { return OK; }
$pc++;
my $lpc=$pc;
$hash{'map_pc_'.$uri}=$lpc;
$hash{'map_id_'.$lpc}=$uri;
my $fn='/home/httpd/html'.$uri;
unless (($fn=~/\.sequence$/) ||
($fn=~/\.page$/)) {
$errtext.="Invalid map: $fn\n";
return OK;
}
my $ispage=($fn=~/\.page$/);
unless (-e $fn) {
my $returned=Apache::lonnet::repcopy($fn);
unless ($returned eq OK) {
$errtext.="Could not import: $fn - ";
if ($returned eq HTTP_SERVICE_UNAVAILABLE) {
$errtext.="Server unavailable\n";
}
if ($returned eq HTTP_NOT_FOUND) {
$errtext.="File not found\n";
}
if ($returned eq FORBIDDEN) {
$errtext.="Access forbidden\n";
}
return OK;
}
}
if (-e $fn) {
my @content;
{
my $fh=Apache::File->new($fn);
@content=<$fh>;
}
my $instr=join('',@content);
my $parser = HTML::TokeParser->new(\$instr);
my $token;
my $linkpc=0;
$fn=~/\.(\w+)$/;
$hash{'map_type_'.$lpc}=$1;
while ($token = $parser->get_token) {
if ($token->[0] eq 'S') {
if ($token->[1] eq 'resource') {
# -------------------------------------------------------------------- Resource
my $rid=$lpc.'.'.$token->[2]->{'id'};
$hash{'kind_'.$rid}='res';
$hash{'title_'.$rid}=$token->[2]->{'title'};
my $turi=$token->[2]->{'src'};
unless ($ispage) {
$turi=~/\.(\w+)$/;
my $embstyle=&Apache::loncommon::fileembstyle($1);
if ($token->[2]->{'external'} eq 'true') {
$turi=~s/^http\:\/\//\/adm\/wrapper\/ext\//;
} else {
my $embstyle=&Apache::loncommon::fileembstyle($1);
if (($embstyle eq 'img') || ($embstyle eq 'emb')) {
$turi='/adm/wrapper'.$turi;
}
}
}
$hash{'src_'.$rid}=$turi;
if (defined($hash{'ids_'.$turi})) {
$hash{'ids_'.$turi}.=','.$rid;
} else {
$hash{'ids_'.$turi}=''.$rid;
}
if ($token->[2]->{'external'} eq 'true') {
$hash{'ext_'.$rid}='true:';
} else {
$hash{'ext_'.$rid}='false:';
}
if ($token->[2]->{'type'}) {
$hash{'type_'.$rid}=$token->[2]->{'type'};
if ($token->[2]->{'type'} eq 'start') {
$hash{'map_start_'.$uri}="$rid";
}
if ($token->[2]->{'type'} eq 'finish') {
$hash{'map_finish_'.$uri}="$rid";
}
} else {
$hash{'type_'.$rid}='normal';
}
if (($turi=~/\.sequence$/) ||
($turi=~/\.page$/)) {
$hash{'is_map_'.$rid}=1;
&loadmap($turi);
}
} elsif ($token->[1] eq 'condition') {
# ------------------------------------------------------------------- Condition
my $rid=$lpc.'.'.$token->[2]->{'id'};
$hash{'kind_'.$rid}='cond';
$cond[$#cond+1]=$token->[2]->{'value'};
$hash{'condid_'.$rid}=$#cond;
if ($token->[2]->{'type'}) {
$cond[$#cond].=':'.$token->[2]->{'type'};
} else {
$cond[$#cond].=':normal';
}
} elsif ($token->[1] eq 'link') {
# ----------------------------------------------------------------------- Links
$linkpc++;
my $linkid=$lpc.'.'.$linkpc;
my $goesto=$lpc.'.'.$token->[2]->{'to'};
my $comesfrom=$lpc.'.'.$token->[2]->{'from'};
my $undercond=0;
if ($token->[2]->{'condition'}) {
$undercond=$lpc.'.'.$token->[2]->{'condition'};
}
$hash{'goesto_'.$linkid}=$goesto;
$hash{'comesfrom_'.$linkid}=$comesfrom;
$hash{'undercond_'.$linkid}=$undercond;
if (defined($hash{'to_'.$comesfrom})) {
$hash{'to_'.$comesfrom}.=','.$linkid;
} else {
$hash{'to_'.$comesfrom}=''.$linkid;
}
if (defined($hash{'from_'.$goesto})) {
$hash{'from_'.$goesto}.=','.$linkid;
} else {
$hash{'from_'.$goesto}=''.$linkid;
}
} elsif ($token->[1] eq 'param') {
# ------------------------------------------------------------------- Parameter
my $referid=$lpc.'.'.$token->[2]->{'to'};
my $part=$token->[2]->{'part'};
unless ($part) { $part=0; }
my $newparam=
&Apache::lonnet::escape($token->[2]->{'type'}).':'.
&Apache::lonnet::escape($part.'.'.
$token->[2]->{'name'}).'='.
&Apache::lonnet::escape($token->[2]->{'value'});
if (defined($hash{'param_'.$referid})) {
$hash{'param_'.$referid}.='&'.$newparam;
} else {
$hash{'param_'.$referid}=''.$newparam;
}
if ($token->[2]->{'name'} eq 'parameter_mapalias') {
$hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
}
if ($token->[2]->{'name'} eq 'parameter_randompick') {
$randompick{$referid}=$token->[2]->{'value'};
}
}
}
}
} else {
$errtext.='Map not loaded: The file does not exist. ';
}
}
# --------------------------------------------------------- Simplify expression
sub simplify {
my $expression=shift;
# (8)=8
$expression=~s/\((\d+)\)/$1/g;
# 8&8=8
$expression=~s/(\D)(\d+)\&\2(\D)/$1$2$3/g;
# 8|8=8
$expression=~s/(\D)(\d+)\|\2(\D)/$1$2$3/g;
# (5&3)&4=5&3&4
$expression=~s/\((\d+)((?:\&\d+)+)\)\&(\d+\D)/$1$2\&$3/g;
# (((5&3)|(4&6)))=((5&3)|(4&6))
$expression=~
s/\((\(\(\d+(?:\&\d+)*\)(?:\|\(\d+(?:\&\d+)*\))+\))\)/$1/g;
# ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
$expression=~
s/\((\(\d+(?:\&\d+)*\))((?:\|\(\d+(?:\&\d+)*\))+)\)\|(\(\d+(?:\&\d+)*\))/\($1$2\|$3\)/g;
return $expression;
}
# -------------------------------------------------------- Build condition hash
sub traceroute {
my ($sofar,$rid,$beenhere)=@_;
$sofar=simplify($sofar);
unless ($beenhere=~/\&$rid\&/) {
$beenhere.=$rid.'&';
if ($retfurl eq '') {
my ($mapid,$resid)=split(/\./,$rid);
$retfurl=$hash{'src_'.$rid}.'?symb='.
&Apache::lonnet::symbclean(
&Apache::lonnet::declutter($hash{'map_id_'.$mapid}).
'___'.$resid.'___'.
&Apache::lonnet::declutter($hash{'src_'.$rid}));
}
if (defined($hash{'conditions_'.$rid})) {
$hash{'conditions_'.$rid}=simplify(
'('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
} else {
$hash{'conditions_'.$rid}=$sofar;
}
if (defined($hash{'is_map_'.$rid})) {
if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
&traceroute($sofar,$hash{'map_start_'.$hash{'src_'.$rid}},'&');
if (defined($hash{'map_finish_'.$hash{'src_'.$rid}})) {
$sofar=
$hash{'conditions_'.$hash{'map_finish_'.$hash{'src_'.$rid}}};
}
}
}
if (defined($hash{'to_'.$rid})) {
foreach (split(/\,/,$hash{'to_'.$rid})) {
my $further=$sofar;
if ($hash{'undercond_'.$_}) {
if (defined($hash{'condid_'.$hash{'undercond_'.$_}})) {
$further=simplify('('.$further.')&('.
$hash{'condid_'.$hash{'undercond_'.$_}}.')');
} else {
$errtext.='Undefined condition ID: '
.$hash{'undercond_'.$_}.'. ';
}
}
&traceroute($further,$hash{'goesto_'.$_},$beenhere);
}
}
}
}
# ------------------------------ Cascading conditions, quick access, parameters
sub accinit {
my ($uri,$short,$fn)=@_;
my %acchash=();
my %captured=();
my $condcounter=0;
$acchash{'acc.cond.'.$short.'.0'}=0;
foreach (keys %hash) {
if ($_=~/^conditions/) {
my $expr=$hash{$_};
foreach ($expr=~m/(\(\(\d+(?:\&\d+)+\)(?:\|\(\d+(?:\&\d+)+\))+\))/g) {
my $sub=$_;
my $orig=$_;
$sub=~/\(\((\d+\&(:?\d+\&)*)(?:\d+\&*)+\)(?:\|\(\1(?:\d+\&*)+\))+\)/;
my $factor=$1;
$sub=~s/$factor//g;
$sub=~s/^\(/\($factor\(/;
$sub.=')';
$sub=simplify($sub);
$orig=~s/(\W)/\\$1/g;
$expr=~s/$orig/$sub/;
}
$hash{$_}=$expr;
unless (defined($captured{$expr})) {
$condcounter++;
$captured{$expr}=$condcounter;
$acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
}
} elsif ($_=~/^param_(\d+)\.(\d+)/) {
my $prefix=&Apache::lonnet::declutter($hash{'map_id_'.$1}).
'___'.$2.'___'.&Apache::lonnet::declutter($hash{'src_'.$1.'.'.$2});
foreach (split(/\&/,$hash{$_})) {
my ($typename,$value)=split(/\=/,$_);
my ($type,$name)=split(/\:/,$typename);
$parmhash{$prefix.'.'.&Apache::lonnet::unescape($name)}=
&Apache::lonnet::unescape($value);
$parmhash{$prefix.'.'.&Apache::lonnet::unescape($name).'.type'}=
&Apache::lonnet::unescape($type);
}
}
}
foreach (keys %hash) {
if ($_=~/^ids/) {
foreach (split(/\,/,$hash{$_})) {
my $resid=$_;
my $uri=$hash{'src_'.$resid};
$uri=~s/^\/adm\/wrapper//;
my @uriparts=split(/\//,$uri);
my $urifile=$uriparts[$#uriparts];
$#uriparts--;
my $uripath=join('/',@uriparts);
$uripath=~s/^\/res\///;
if ($uripath) {
my $uricond='0';
if (defined($hash{'conditions_'.$resid})) {
$uricond=$captured{$hash{'conditions_'.$resid}};
}
if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
/(\&$urifile\:[^\&]*)/) {
my $replace=$1;
my $regexp=$replace;
$regexp=~s/\|/\\\|/g;
$acchash{'acc.res.'.$short.'.'.$uripath}
=~s/$regexp/$replace\|$uricond/;
} else {
$acchash{'acc.res.'.$short.'.'.$uripath}.=
$urifile.':'.$uricond.'&';
}
} else {
$acchash{'acc.res.'.$short.'.'.$uripath}=
'&'.$urifile.':'.$uricond.'&';
}
}
}
}
}
$acchash{'acc.res.'.$short.'.'}='&:0&';
my $courseuri=$uri;
$courseuri=~s/^\/res\///;
&Apache::lonnet::delenv('(acc\.|httpref\.)');
&Apache::lonnet::appenv(%acchash,
"request.course.id" => $short,
"request.course.fn" => $fn,
"request.course.uri" => $courseuri);
}
# ------------------------------------- Selectively delete from randompick maps
sub pickrandom {
my $randomoutentry='';
foreach my $rid (keys %randompick) {
my $rndpick=$randompick{$rid};
my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
# ------------------------------------------- put existing resources into array
my @currentrids=();
foreach (keys %hash) {
if ($_=~/^src_($mpc\.\d+)/) {
if ($hash{'src_'.$1}) { push @currentrids, $1; }
}
}
next if ($#currentrids<$rndpick);
# -------------------------------- randomly eliminate the ones that should stay
srand(&Apache::lonnet::rndseed($rid)); # use rid instead of symb
for (my $i=1;$i<=$rndpick;$i++) {
while (1) {
my $randomidx=int(rand($#currentrids+1));
if ($currentrids[$randomidx]) {
$currentrids[$randomidx]='';
last;
}
}
}
# -------------------------------------------------------- delete the leftovers
for (my $k=0; $k<=$#currentrids; $k++) {
if ($currentrids[$k]) {
$hash{'randomout_'.$currentrids[$k]}=1;
my ($mapid,$resid)=split(/\./,$currentrids[$k]);
$randomoutentry.='&'.
&Apache::lonnet::symbclean(
&Apache::lonnet::declutter($hash{'map_id_'.$mapid}).
'___'.$resid.'___'.
&Apache::lonnet::declutter($hash{'src_'.$currentrids[$k]})
).'&';
}
}
}
if ($randomoutentry) {
&Apache::lonnet::appenv('acc.randomout' => $randomoutentry);
}
}
# ---------------------------------------------------- Read map and all submaps
sub readmap {
my $short=shift;
$short=~s/^\///;
my %cenv=&Apache::lonnet::coursedescription($short);
my $fn=$cenv{'fn'};
my $uri;
$short=~s/\//\_/g;
unless ($uri=$cenv{'url'}) {
&Apache::lonnet::logthis("<font color=blue>WARNING: ".
"Could not load course $short.</font>");
return 'No course data available.';
}
@cond=('true:normal');
unlink($fn.'.db');
unlink($fn.'_symb.db');
unlink($fn.'.state');
unlink($fn.'parms.db');
undef %randompick;
$retfurl='';
if ((tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT,0640)) &&
(tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT,0640))) {
%hash=();
%parmhash=();
$errtext='';
$pc=0;
my $furi='/res/'.&Apache::lonnet::declutter($uri);
$hash{'src_0.0'}=$furi;
$hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
$hash{'ids_'.$furi}='0.0';
$hash{'is_map_0.0'}=1;
loadmap($uri);
if (defined($hash{'map_start_'.$uri})) {
&traceroute('0',$hash{'map_start_'.$uri},'&');
&accinit($uri,$short,$fn);
&pickrandom();
}
unless ((untie(%hash)) && (untie(%parmhash))) {
&Apache::lonnet::logthis("<font color=blue>WARNING: ".
"Could not untie coursemap $fn for $uri.</font>");
}
{
my $cfh;
if ($cfh=Apache::File->new(">$fn.state")) {
print $cfh join("\n",@cond);
} else {
&Apache::lonnet::logthis("<font color=blue>WARNING: ".
"Could not write statemap $fn for $uri.</font>");
}
}
} else {
&Apache::lonnet::logthis("<font color=blue>WARNING: ".
"Could not tie coursemap $fn for $uri.</font>");
}
&Apache::lonmsg::author_res_msg($ENV{'request.course.uri'},$errtext);
return ($retfurl,$errtext);
}
# ------------------------------------------------------- Evaluate state string
sub evalstate {
my $fn=$ENV{'request.course.fn'}.'.state';
my $state='2';
if (-e $fn) {
my @conditions=();
{
my $fh=Apache::File->new($fn);
@conditions=<$fh>;
}
my $safeeval = new Safe;
my $safehole = new Safe::Hole;
$safeeval->permit("entereval");
$safeeval->permit(":base_math");
$safeeval->deny(":base_io");
$safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
foreach (@conditions) {
my $line=$_;
chomp($line);
my ($condition,$weight)=split(/\:/,$_);
if ($safeeval->reval($condition)) {
if ($weight eq 'force') {
$state.='3';
} else {
$state.='2';
}
} else {
if ($weight eq 'stop') {
$state.='0';
} else {
$state.='1';
}
}
}
}
&Apache::lonnet::appenv('user.state.'.$ENV{'request.course.id'} => $state);
return $state;
}
1;
__END__
=head1 NAME
Apache::lonuserstate - Construct and maintain state and binary representation
of course for user
=head1 SYNOPSIS
Invoked by lonroles.pm.
&Apache::lonuserstate::readmap($cdom.'/'.$cnum);
=head1 INTRODUCTION
This module constructs and maintains state and binary representation
of course for user.
This is part of the LearningOnline Network with CAPA project
described at http://www.lon-capa.org.
=head1 HANDLER SUBROUTINE
There is no handler subroutine.
=head1 OTHER SUBROUTINES
=over 4
=item *
loadmap() : Loads map from disk
=item *
simplify() : Simplify expression
=item *
traceroute() : Build condition hash
=item *
accinit() : Cascading conditions, quick access, parameters
=item *
readmap() : Read map and all submaps
=item *
evalstate() : Evaluate state string
=back
=cut
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