# The LearningOnline Network with CAPA
# Navigate Maps Handler
#
# (Page Handler
#
# (TeX Content Handler
#
# 05/29/00,05/30 Gerd Kortemeyer)
# 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
# 10/02,10/10,10/14,10/16,10/18,10/19,10/31,11/6,11/14,11/16 Gerd Kortemeyer)
#
# 3/1/1,6/1 Gerd Kortemeyer
package Apache::lonnavmaps;
use strict;
use Apache::Constants qw(:common :http);
use Apache::lonnet();
use HTML::TokeParser;
use GDBM_File;
# -------------------------------------------------------------- Module Globals
my %hash;
my @rows;
# ------------------------------------------------------------------ Euclid gcd
sub euclid {
my ($e,$f)=@_;
my $a; my $b; my $r;
if ($e>$f) { $b=$e; $r=$f; } else { $r=$e; $b=$f; }
while ($r!=0) {
$a=$b; $b=$r;
$r=$a%$b;
}
return $b;
}
# ------------------------------------------------------------ Build page table
sub tracetable {
my ($sofar,$rid,$beenhere)=@_;
my $further=$sofar;
unless ($beenhere=~/\&$rid\&/) {
$beenhere.=$rid.'&';
if (defined($hash{'is_map_'.$rid})) {
if ((defined($hash{'map_start_'.$hash{'src_'.$rid}})) &&
(defined($hash{'map_finish_'.$hash{'src_'.$rid}}))) {
my $frid=$hash{'map_finish_'.$hash{'src_'.$rid}};
$sofar=
&tracetable($sofar,$hash{'map_start_'.$hash{'src_'.$rid}},
'&'.$frid.'&');
$sofar++;
if ($hash{'src_'.$frid}) {
my $brepriv=&Apache::lonnet::allowed('bre',$hash{'src_'.$frid});
if (($brepriv eq '2') || ($brepriv eq 'F')) {
if (defined($rows[$sofar])) {
$rows[$sofar].='&'.$frid;
} else {
$rows[$sofar]=$frid;
}
}
}
}
} else {
$sofar++;
if ($hash{'src_'.$rid}) {
my $brepriv=&Apache::lonnet::allowed('bre',$hash{'src_'.$rid});
if (($brepriv eq '2') || ($brepriv eq 'F')) {
if (defined($rows[$sofar])) {
$rows[$sofar].='&'.$rid;
} else {
$rows[$sofar]=$rid;
}
}
}
}
if (defined($hash{'to_'.$rid})) {
my $mincond=1;
my $next='';
map {
my $thiscond=
&Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
if ($thiscond>=$mincond) {
if ($next) {
$next.=','.$_.':'.$thiscond;
} else {
$next=$_.':'.$thiscond;
}
if ($thiscond>$mincond) { $mincond=$thiscond; }
}
} split(/\,/,$hash{'to_'.$rid});
map {
my ($linkid,$condval)=split(/\:/,$_);
if ($condval>=$mincond) {
my $now=&tracetable($sofar,$hash{'goesto_'.$linkid},$beenhere);
if ($now>$further) { $further=$now; }
}
} split(/\,/,$next);
}
}
return $further;
}
# ================================================================ Main Handler
sub handler {
my $r=shift;
# ------------------------------------------- Set document type for header only
if ($r->header_only) {
if ($ENV{'browser.mathml'}) {
$r->content_type('text/xml');
} else {
$r->content_type('text/html');
}
$r->send_http_header;
return OK;
}
my $requrl=$r->uri;
# ----------------------------------------------------------------- Tie db file
if ($ENV{'request.course.fn'}) {
my $fn=$ENV{'request.course.fn'};
if (-e "$fn.db") {
if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
# ------------------------------------------------------------------- Hash tied
my $firstres=$hash{'map_start_/res/'.$ENV{'request.course.uri'}};
my $lastres=$hash{'map_finish_/res/'.$ENV{'request.course.uri'}};
if (($firstres) && ($lastres)) {
# ----------------------------------------------------------------- Render page
@rows=();
&tracetable(0,$firstres,'&'.$lastres.'&');
if ($hash{'src_'.$lastres}) {
my $brepriv=
&Apache::lonnet::allowed('bre',$hash{'src_'.$lastres});
if (($brepriv eq '2') || ($brepriv eq 'F')) {
$rows[$#rows+1]=''.$lastres;
}
}
# ------------------------------------------------------------------ Page parms
my $j;
my $lcm=1;
my $contents=0;
# ---------------------------------------------- Go through table to get layout
for ($i=0;$i<=$#rows;$i++) {
if ($rows[$i]) {
$contents++;
my @colcont=split(/\&/,$rows[$i]);
$lcm*=($#colcont+1)/euclid($lcm,($#colcont+1));
}
}
}
unless ($contents) {
$r->content_type('text/html');
$r->send_http_header;
$r->print('<html><body>Empty Map.</body></html>');
} else {
# ------------------------------------------------------------------ Build page
# ---------------------------------------------------------------- Send headers
$r->content_type('text/html');
$r->send_http_header;
$r->print(
'<html><head><title>Navigate LON-CAPA Maps</title></head>');
$r->print('<body bgcolor="#FFFFFF">'.
'<h1>Navigate Course Map</h1>');
$r->rflush();
# ----------------------------------------------------------------- Start table
$r->print('<table cols="'.$lcm.'" border="0">');
for ($i=0;$i<=$#rows;$i++) {
if ($rows[$i]) {
$r->print("\n<tr>");
my @colcont=split(/\&/,$rows[$i]);
my $avespan=$lcm/($#colcont+1);
for ($j=0;$j<=$#colcont;$j++) {
my $rid=$colcont[$j];
$r->print('<td><a href="'.
$hash{'src_'.$rid}.'">'.
$hash{'title_'.$rid}.'</a>');
$r->print('</td>');
}
$r->print('</tr>');
}
}
$r->print("\n</table>");
$r->print('</body></html>');
# -------------------------------------------------------------------- End page
}
# ------------------------------------------------------------- End render page
} else {
$r->content_type('text/html');
$r->send_http_header;
$r->print('<html><body>Coursemap undefined.</body></html>');
}
# ------------------------------------------------------------------ Untie hash
unless (untie(%hash)) {
&Apache::lonnet::logthis("<font color=blue>WARNING: ".
"Could not untie coursemap $fn (browse).</font>");
}
# -------------------------------------------------------------------- All done
return OK;
# ----------------------------------------------- Errors, hash could no be tied
}
}
}
$ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized";
return HTTP_NOT_ACCEPTABLE;
}
1;
__END__
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