File:  [LON-CAPA] / loncom / interface / lonnavmaps.pm
Revision 1.2: download - view: text, annotated - select for diffs
Sat Jan 6 13:45:37 2001 UTC (23 years, 5 months ago) by www
Branches: MAIN
CVS tags: HEAD
First real "Navigate Maps" handler

    1: # The LearningOnline Network with CAPA
    2: # Navigate Maps Handler
    3: #
    4: # (Page Handler
    5: #
    6: # (TeX Content Handler
    7: #
    8: # 05/29/00,05/30 Gerd Kortemeyer)
    9: # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
   10: # 10/02,10/10,10/14,10/16,10/18,10/19,10/31,11/6,11/14,11/16 Gerd Kortemeyer)
   11: #
   12: # 3/1/1,6/1 Gerd Kortemeyer
   13: 
   14: package Apache::lonnavmaps;
   15: 
   16: use strict;
   17: use Apache::Constants qw(:common :http);
   18: use Apache::lonnet();
   19: use HTML::TokeParser;
   20: use GDBM_File;
   21: 
   22: # -------------------------------------------------------------- Module Globals
   23: my %hash;
   24: my @rows;
   25: 
   26: # ------------------------------------------------------------------ Euclid gcd
   27: 
   28: sub euclid {
   29:     my ($e,$f)=@_;
   30:     my $a; my $b; my $r;
   31:     if ($e>$f) { $b=$e; $r=$f; } else { $r=$e; $b=$f; }
   32:     while ($r!=0) {
   33: 	$a=$b; $b=$r;
   34:         $r=$a%$b;
   35:     }
   36:     return $b;
   37: }
   38: 
   39: # ------------------------------------------------------------ Build page table
   40: 
   41: sub tracetable {
   42:     my ($sofar,$rid,$beenhere)=@_;
   43:     my $further=$sofar;
   44:     unless ($beenhere=~/\&$rid\&/) {
   45:        $beenhere.=$rid.'&';  
   46: 
   47:        if (defined($hash{'is_map_'.$rid})) {
   48:            if ((defined($hash{'map_start_'.$hash{'src_'.$rid}})) &&
   49:                (defined($hash{'map_finish_'.$hash{'src_'.$rid}}))) {
   50:               my $frid=$hash{'map_finish_'.$hash{'src_'.$rid}};
   51: 	      $sofar=
   52:                 &tracetable($sofar,$hash{'map_start_'.$hash{'src_'.$rid}},
   53:                 '&'.$frid.'&');
   54:               $sofar++;
   55:               if ($hash{'src_'.$frid}) {
   56:                my $brepriv=&Apache::lonnet::allowed('bre',$hash{'src_'.$frid});
   57:                if (($brepriv eq '2') || ($brepriv eq 'F')) {
   58:                  if (defined($rows[$sofar])) {
   59:                    $rows[$sofar].='&'.$frid;
   60:                  } else {
   61:                    $rows[$sofar]=$frid;
   62:                  }
   63: 	       }
   64: 	      }
   65: 	   }
   66:        } else {
   67:           $sofar++;
   68:           if ($hash{'src_'.$rid}) {
   69:            my $brepriv=&Apache::lonnet::allowed('bre',$hash{'src_'.$rid});
   70:            if (($brepriv eq '2') || ($brepriv eq 'F')) {
   71:              if (defined($rows[$sofar])) {
   72:                $rows[$sofar].='&'.$rid;
   73:              } else {
   74:                $rows[$sofar]=$rid;
   75:              }
   76: 	   }
   77:           }
   78:        }
   79: 
   80:        if (defined($hash{'to_'.$rid})) {
   81: 	  my $mincond=1;
   82:           my $next='';
   83:           map {
   84:               my $thiscond=
   85:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
   86:               if ($thiscond>=$mincond) {
   87: 		  if ($next) {
   88: 		      $next.=','.$_.':'.$thiscond;
   89:                   } else {
   90:                       $next=$_.':'.$thiscond;
   91: 		  }
   92:                   if ($thiscond>$mincond) { $mincond=$thiscond; }
   93: 	      }
   94:           } split(/\,/,$hash{'to_'.$rid});
   95:           map {
   96:               my ($linkid,$condval)=split(/\:/,$_);
   97:               if ($condval>=$mincond) {
   98:                 my $now=&tracetable($sofar,$hash{'goesto_'.$linkid},$beenhere);
   99:                 if ($now>$further) { $further=$now; }
  100: 	      }
  101:           } split(/\,/,$next);
  102: 
  103:        }
  104:     }
  105:     return $further;
  106: }
  107: 
  108: # ================================================================ Main Handler
  109: 
  110: sub handler {
  111:   my $r=shift;
  112: 
  113: 
  114: # ------------------------------------------- Set document type for header only
  115: 
  116:   if ($r->header_only) {
  117:        if ($ENV{'browser.mathml'}) {
  118:            $r->content_type('text/xml');
  119:        } else {
  120:            $r->content_type('text/html');
  121:        }
  122:        $r->send_http_header;
  123:        return OK;
  124:    }
  125: 
  126:   my $requrl=$r->uri;
  127: # ----------------------------------------------------------------- Tie db file
  128:   if ($ENV{'request.course.fn'}) {
  129:       my $fn=$ENV{'request.course.fn'};
  130:       if (-e "$fn.db") {
  131:           if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
  132: # ------------------------------------------------------------------- Hash tied
  133:               my $firstres=$hash{'map_start_/res/'.$ENV{'request.course.uri'}};
  134:               my $lastres=$hash{'map_finish_/res/'.$ENV{'request.course.uri'}};
  135:               if (($firstres) && ($lastres)) {
  136: # ----------------------------------------------------------------- Render page
  137: 
  138:                   @rows=();
  139: 
  140:                   &tracetable(0,$firstres,'&'.$lastres.'&');
  141:                   if ($hash{'src_'.$lastres}) {
  142:                      my $brepriv=
  143:                         &Apache::lonnet::allowed('bre',$hash{'src_'.$lastres});
  144:                      if (($brepriv eq '2') || ($brepriv eq 'F')) {
  145:                         $rows[$#rows+1]=''.$lastres;
  146: 		     }
  147: 		  }
  148: 
  149: # ------------------------------------------------------------ Add to symb list
  150: 
  151:                   my $i;
  152:                   my %symbhash=();
  153:                   for ($i=0;$i<=$#rows;$i++) {
  154: 		     if ($rows[$i]) {
  155:                         my @colcont=split(/\&/,$rows[$i]);
  156:                         map {
  157:                            $symbhash{$hash{'src_'.$_}}='';
  158: 		        } @colcont;
  159: 		     }
  160: 		  }
  161:                   &Apache::lonnet::symblist($requrl,%symbhash);
  162: 
  163: # ------------------------------------------------------------------ Page parms
  164: 
  165:                   my $j;
  166:                   my $lcm=1;
  167:                   my $contents=0;
  168: 
  169: # ---------------------------------------------- Go through table to get layout
  170: 
  171:                   for ($i=0;$i<=$#rows;$i++) {
  172: 		     if ($rows[$i]) {
  173: 		      $contents++;
  174:                       my @colcont=split(/\&/,$rows[$i]);
  175:                       $lcm*=($#colcont+1)/euclid($lcm,($#colcont+1));
  176:                      } 
  177:                   }
  178: 
  179:                   unless ($contents) {
  180:                       $r->content_type('text/html');
  181:                       $r->send_http_header;
  182:                       $r->print('<html><body>Empty Map.</body></html>');
  183:                   } else {
  184: # ------------------------------------------------------------------ Build page
  185: 
  186: # ---------------------------------------------------------------- Send headers
  187: 
  188:                           $r->content_type('text/html');
  189:                           $r->send_http_header;
  190:                           $r->print(
  191:                    '<html><head><title>Navigate LON-CAPA Maps</title></head>');
  192: 
  193: 			  $r->print('<body bgcolor="#FFFFFF">'.
  194:                                     '<h1>Navigate Course Map</h1>');
  195: 
  196: # ----------------------------------------------------------------- Start table
  197:                       $r->print('<table cols="'.$lcm.'" border="0">');
  198:                       for ($i=0;$i<=$#rows;$i++) {
  199: 			if ($rows[$i]) {
  200:                           $r->print("\n<tr>");
  201:                           my @colcont=split(/\&/,$rows[$i]);
  202:                           my $avespan=$lcm/($#colcont+1);
  203:                           for ($j=0;$j<=$#colcont;$j++) {
  204:                               my $rid=$colcont[$j];
  205:                               $r->print('<td><a href="'.
  206:                                 $hash{'src_'.$rid}.'">'.
  207:                                 $hash{'title_'.$rid}.'</a>');
  208:                               $r->print('</td>');
  209:                           }
  210:                           $r->print('</tr>');
  211: 		        }
  212:                       }
  213:                       $r->print("\n</table>");
  214: 
  215:                       $r->print('</body></html>');
  216: # -------------------------------------------------------------------- End page
  217:                   }                  
  218: # ------------------------------------------------------------- End render page
  219:               } else {
  220:                   $r->content_type('text/html');
  221:                   $r->send_http_header;
  222: 		  $r->print('<html><body>Coursemap undefined.</body></html>');
  223:               }
  224: # ------------------------------------------------------------------ Untie hash
  225:               unless (untie(%hash)) {
  226:                    &Apache::lonnet::logthis("<font color=blue>WARNING: ".
  227:                        "Could not untie coursemap $fn (browse).</font>"); 
  228:               }
  229: # -------------------------------------------------------------------- All done
  230: 	      return OK;
  231: # ----------------------------------------------- Errors, hash could no be tied
  232:           }
  233:       } 
  234:   }
  235:   $ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized";
  236:   return HTTP_NOT_ACCEPTABLE; 
  237: }
  238: 
  239: 1;
  240: __END__
  241: 
  242: 
  243: 
  244: 
  245: 
  246: 
  247: 

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