Return to lonnavmaps.pm CVS log

Up to [LON-CAPA] / loncom / interface

Lists headings

# 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})) {
           $sofar++;      
           if (defined($rows[$sofar])) {
              $rows[$sofar].='&h'.$rid;
           } else {
              $rows[$sofar]='h'.$rid;
           }
           if ((defined($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 $i;
                  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">'.
                           '<img align=right src=/adm/lonIcons/lonlogos.gif>'.
                                    '<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];
                              my $add='<td>&nbsp;&nbsp;';
                              if ($rid=~/^h(.+)/) {
				  $rid=$1;
                                  $add='<th bgcolor="#AAFF55">';
                              }
                              $r->print($add.'<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__

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator at root@localhost to inform them of the time this error occurred, and the actions you performed just before this error.

More information about this error may be available in the server error log.