Annotation of rat/lonpageflip.pm, revision 1.26

1.1       www         1: # The LearningOnline Network with CAPA
                      2: #
                      3: # Page flip handler
                      4: #
1.26    ! www         5: # $Id: lonpageflip.pm,v 1.25 2002/05/23 15:07:55 www Exp $
1.18      www         6: #
                      7: # Copyright Michigan State University Board of Trustees
                      8: #
                      9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
                     10: #
                     11: # LON-CAPA is free software; you can redistribute it and/or modify
                     12: # it under the terms of the GNU General Public License as published by
                     13: # the Free Software Foundation; either version 2 of the License, or
                     14: # (at your option) any later version.
                     15: #
                     16: # LON-CAPA is distributed in the hope that it will be useful,
                     17: # but WITHOUT ANY WARRANTY; without even the implied warranty of
                     18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     19: # GNU General Public License for more details.
                     20: #
                     21: # You should have received a copy of the GNU General Public License
                     22: # along with LON-CAPA; if not, write to the Free Software
                     23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
                     24: #
                     25: # /home/httpd/html/adm/gpl.txt
                     26: #
                     27: # http://www.lon-capa.org/
                     28: #
1.1       www        29: # (Page Handler
                     30: #
                     31: # (TeX Content Handler
                     32: #
                     33: # 05/29/00,05/30 Gerd Kortemeyer)
                     34: # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
                     35: # 10/02 Gerd Kortemeyer)
                     36: #
1.13      www        37: # 10/03,10/05,10/06,10/07,10/09,10/10,10/11,10/16,10/17,
1.14      www        38: # 11/14,11/16,
1.17      www        39: # 10/01/01,05/01,05/28,07/05 Gerd Kortemeyer
1.1       www        40: 
                     41: package Apache::lonpageflip;
                     42: 
                     43: use strict;
1.4       www        44: use Apache::Constants qw(:common :http REDIRECT);
1.1       www        45: use Apache::lonnet();
                     46: use HTML::TokeParser;
                     47: use GDBM_File;
                     48: 
1.3       www        49: # ========================================================== Module Global Hash
                     50:   
1.1       www        51: my %hash;
                     52: 
1.3       www        53: sub addrid {
1.4       www        54:     my ($current,$new,$condid)=@_;
                     55:     unless ($condid) { $condid=0; }
1.3       www        56:     if (&Apache::lonnet::allowed('bre',$hash{'src_'.$new})) {
                     57: 	if ($current) {
1.5       www        58: 	    $current.=','.$new;
1.3       www        59:         } else {
1.5       www        60:             $current=''.$new;
1.3       www        61:         }
1.1       www        62:     }
1.3       www        63:     return $current;
1.25      www        64: }
                     65: 
                     66: sub fullmove {
                     67:     my ($rid,$mapurl,$direction)=@_;
                     68:     if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                     69:                         &GDBM_READER,0640)) {
                     70: 	($rid,$mapurl)=&move($rid,$mapurl,$direction);
                     71:         untie(%hash);
                     72:     }
                     73:     return($rid,$mapurl);
1.1       www        74: }
                     75: 
1.15      www        76: sub move {
                     77:     my ($rid,$mapurl,$direction)=@_;
1.23      www        78:     my $startoutrid=$rid;
1.15      www        79: 
                     80:     my $next='';
                     81: 
                     82:               my $mincond=1;
                     83:               my $posnext='';
                     84:               if ($direction eq 'forward') {
                     85: # --------------------------------------------------------------------- Forward
                     86:                   if ($hash{'type_'.$rid} eq 'finish') {
                     87: 	             $rid=$hash{'ids_/res/'.$mapurl}; 
                     88:                   }
                     89:                   map {
                     90:                       my $thiscond=
                     91:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
                     92:                       if ($thiscond>=$mincond) {
                     93: 		          if ($posnext) {
                     94: 		             $posnext.=','.$_.':'.$thiscond;
                     95:                           } else {
                     96:                              $posnext=$_.':'.$thiscond;
                     97: 		          }
                     98:                           if ($thiscond>$mincond) { $mincond=$thiscond; }
                     99: 	              }
                    100:                   } split(/\,/,$hash{'to_'.$rid});
                    101:                   map {
                    102:                       my ($linkid,$condval)=split(/\:/,$_);
                    103:                       if ($condval>=$mincond) {
                    104: 		          $next=&addrid($next,$hash{'goesto_'.$linkid},
                    105:                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
                    106:                       }
                    107:                   } split(/\,/,$posnext);
                    108:                   if ($hash{'is_map_'.$next}) {
1.23      www       109: # This jumps to the beginning of a new map (going down level)
1.15      www       110:                       if (
                    111:       $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
                    112: 			  $mapurl=$hash{'src_'.$next};
                    113: 			  $next=$hash{'map_start_'.$hash{'src_'.$next}};
                    114:                      }
1.23      www       115:                   } elsif 
                    116:                     ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
                    117: # This comes up from a map (coming up one level);
                    118: 		      $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
1.15      www       119:                   }
                    120:               } elsif ($direction eq 'back') {
                    121: # ------------------------------------------------------------------- Backwards
                    122:                   if ($hash{'type_'.$rid} eq 'start') {
                    123: 	             $rid=$hash{'ids_/res/'.$mapurl};
                    124:                   }
                    125:                   map {
                    126:                       my $thiscond=
                    127:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
                    128:                       if ($thiscond>=$mincond) {
                    129: 		          if ($posnext) {
                    130: 		             $posnext.=','.$_.':'.$thiscond;
                    131:                           } else {
                    132:                              $posnext=$_.':'.$thiscond;
                    133: 		          }
                    134:                           if ($thiscond>$mincond) { $mincond=$thiscond; }
                    135: 	              }
                    136:                   } split(/\,/,$hash{'from_'.$rid});
                    137:                   map {
                    138:                       my ($linkid,$condval)=split(/\:/,$_);
                    139:                       if ($condval>=$mincond) {
                    140: 		          $next=&addrid($next,$hash{'comesfrom_'.$linkid},
                    141:                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
                    142:                       }
                    143:                   } split(/\,/,$posnext);
                    144:                   if ($hash{'is_map_'.$next}) {
1.24      www       145: # This jumps to the end of a new map (going down one level)
1.15      www       146:                       if (
                    147:       $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
                    148: 			  $mapurl=$hash{'src_'.$next};
                    149: 			  $next=$hash{'map_finish_'.$hash{'src_'.$next}};
                    150:                      }
1.24      www       151:                   } elsif 
                    152:                     ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
                    153: # This comes back up from a map (going up one level);
                    154: 		      $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
1.15      www       155:                   }
                    156: 	      }
                    157:               return ($next,$mapurl);
                    158: }
                    159: 
1.1       www       160: # ================================================================ Main Handler
                    161: 
                    162: sub handler {
1.2       www       163:    my $r=shift;
1.1       www       164: 
                    165: # ------------------------------------------- Set document type for header only
                    166: 
1.2       www       167:   if ($r->header_only) {
1.1       www       168:      $r->content_type('text/html');
                    169:      $r->send_http_header;
1.2       www       170:      return OK;
                    171:   }
                    172: 
1.5       www       173:   my %cachehash=(); 
                    174:   my $multichoice=0;
                    175:   my %multichoicehash=();
1.4       www       176:   my $redirecturl='';
                    177:   my $next='';
                    178:   my @possibilities=();
1.2       www       179:   if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
                    180:       $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
                    181:       my $direction=$1;
                    182:       my $currenturl=$2;
1.10      www       183:       if ($direction eq 'return') {
                    184: # -------------------------------------------------------- Return to last known
                    185:          my $last;
                    186:          if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
                    187:                     &GDBM_READER,0640)) {
                    188: 	     $last=$hash{'last_known'};
                    189:              untie(%hash);
                    190:          }
                    191:          my $newloc;
                    192:          if ($last) {
                    193:             $newloc='/res/'.(split(/\_\_\_/,$last))[1];
                    194:          } else {
                    195: 	    $newloc='/adm/noidea.html';
                    196:          }  
                    197: 	 $r->content_type('text/html');
                    198:          $r->header_out(Location => 
                    199: 			'http://'.$ENV{'HTTP_HOST'}.$newloc);
                    200:                                
                    201:          return REDIRECT;
                    202:       }
1.2       www       203:       $currenturl=~s/^http\:\/\///;
                    204:       $currenturl=~s/^[^\/]+//;
1.17      www       205:       unless (($currenturl=~/^\/res\//) || 
                    206:               ($currenturl=~/^\/adm\/wrapper\//))  {
1.7       www       207: 	 my $last;
                    208:          if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
                    209:                     &GDBM_READER,0640)) {
                    210: 	     $last=$hash{'last_known'};
                    211:              untie(%hash);
                    212:          }
                    213:          if ($last) {
                    214: 	     $currenturl='/res/'.(split(/\_\_\_/,$last))[1];
                    215: 	 } else {
                    216: 	     $r->content_type('text/html');
                    217:              $r->header_out(Location => 
                    218:                                'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
1.9       www       219:              return REDIRECT;
1.7       www       220:          }
                    221:       }
1.3       www       222: # ------------------------------------------- Do we have any idea where we are?
                    223:       my $position;
                    224:       if ($position=Apache::lonnet::symbread($currenturl)) {
                    225: # ------------------------------------------------------------------------- Yes
1.22      www       226: 	  my ($startoutmap,$mapnum,$thisurl)=split(/\_\_\_/,$position);
                    227:           $cachehash{$startoutmap}{$thisurl}=$mapnum;
1.23      www       228:           $cachehash{$startoutmap}{'last_known'}=
                    229:                                        &Apache::lonnet::declutter($currenturl);
1.20      albertel  230: 
1.5       www       231: # ============================================================ Tie the big hash
1.3       www       232:           if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                    233:                         &GDBM_READER,0640)) {
1.22      www       234:               my $rid=$hash{'map_pc_/res/'.$startoutmap}.'.'.$mapnum;
1.14      www       235: 
1.15      www       236: # ------------------------------------------------- Move forward, backward, etc
1.22      www       237:               my $endupmap;
                    238:               ($next,$endupmap)=&move($rid,$startoutmap,$direction);
1.15      www       239: # -------------------------------------- Do we have one and only one empty URL?
                    240:               my $safecount=0;
1.26    ! www       241:               while (($next) && ($next!~/\,/) && 
        !           242:                      ((!$hash{'src_'.$next}) || ($hash{'randomout_'.$next}))
        !           243:                      && ($safecount<10000)) {
1.22      www       244:                   ($next,$endupmap)=&move($next,$endupmap,$direction);
1.15      www       245:                   $safecount++;
                    246:               }
1.22      www       247: # We are now at at least one non-empty URL
1.4       www       248: # ----------------------------------------------------- Check out possibilities
                    249:               if ($next) {
                    250:                   @possibilities=split(/\,/,$next);
                    251:                   if ($#possibilities==0) {
1.5       www       252: # ---------------------------------------------- Only one possibility, redirect
                    253: 	              $redirecturl=$hash{'src_'.$next};
1.22      www       254:                       $cachehash{$endupmap}
1.19      www       255:                                 {&Apache::lonnet::declutter($redirecturl)}
1.5       www       256: 		                                 =(split(/\./,$next))[1];
1.4       www       257:                   } else {
1.5       www       258: # ------------------------ There are multiple possibilities for a next resource
                    259:                       $multichoice=1;
                    260:                       map {
                    261: 			  $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
                    262:                           $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
1.6       www       263:                           $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
1.22      www       264:                           my ($choicemap,$choiceres)=split(/\./,$_);
                    265:                           $cachehash
                    266: 			 {&Apache::lonnet::declutter($hash{'src_'.$choicemap})}
                    267:                          {&Apache::lonnet::declutter(
1.5       www       268: 						      $multichoicehash
                    269:                                                          {'src_'.$_}
                    270:                                                        )}
1.22      www       271: 		                                 =$choiceres;
1.5       www       272:                       } @possibilities;
1.4       www       273:                   }
1.5       www       274: 	      } else {
                    275: # -------------------------------------------------------------- No place to go
                    276:                   $multichoice=-1;
1.4       www       277:               }
1.5       www       278: # ----------------- The program must come past this point to untie the big hash
1.3       www       279: 	      untie(%hash);
1.5       www       280: # --------------------------------------------------------- Store position info
1.22      www       281:               $cachehash{$startoutmap}{'last_direction'}=$direction;
1.19      www       282:               foreach my $thismap (keys %cachehash) {
1.20      albertel  283:                  &Apache::lonnet::symblist($thismap,%{$cachehash{$thismap}});
1.19      www       284: 	      }
1.5       www       285: # ============================================== Do not return before this line
1.4       www       286:               if ($redirecturl) {
1.5       www       287: # ----------------------------------------------------- There is a URL to go to
1.4       www       288: 		  $r->content_type('text/html');
                    289:                   $r->header_out(Location => 
                    290:                                 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
                    291:                   return REDIRECT;
1.5       www       292: 	      } else {
                    293: # --------------------------------------------------------- There was a problem
1.8       www       294:                   $r->content_type('text/html');
                    295:                   $r->send_http_header;
                    296:                   if ($#possibilities>0) {
                    297:                      $r->print(<<ENDSTART);
                    298: <head><title>Choose Next Location</title></head>
                    299: <body bgcolor="#FFFFFF">
                    300: <h1>LON-CAPA</h1>
                    301: There are several possibilities of where to go next.
                    302: <p>
                    303: Please click on the the resource you intend to access:
                    304: <p>
                    305: <table border=2>
                    306: <tr><th>Title</th><th>Type</th></tr>
                    307: ENDSTART
1.26    ! www       308:                      foreach (@possibilities) {
1.8       www       309:                         $r->print(
                    310:                               '<tr><td><a href="'.
                    311:                               $multichoicehash{'src_'.$_}.'">'.
                    312:                               $multichoicehash{'title_'.$_}.
                    313:                               '</a></td><td>'.$multichoicehash{'type_'.$_}.
                    314: 			      '</td></tr>');
1.26    ! www       315:                      }
1.8       www       316:                      $r->print('</table></body></html>');
                    317: 		     return OK;
                    318:                   } else {
                    319:                      $r->print(<<ENDNONE);
                    320: <head><title>Choose Next Location</title></head>
                    321: <body bgcolor="#FFFFFF">
1.17      www       322: <img src="/adm/lonIcons/lonlogos.gif" align=right>
1.8       www       323: <h1>Sorry!</h1>
                    324: <h2>Next resource could not be identified.</h2>
1.17      www       325: <h3>You probably are at the beginning or the end of the course.</h3>
1.8       www       326: </body>
                    327: </html>
                    328: ENDNONE
                    329:                      return OK;
                    330: 	         }
                    331: 	     }
1.5       www       332: 	  } else {
                    333: # ------------------------------------------------- Problem, could not tie hash
                    334:               $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
                    335:               return HTTP_NOT_ACCEPTABLE; 
1.3       www       336:           }
1.5       www       337:       } else {
                    338: # ---------------------------------------- No, could not determine where we are
1.6       www       339:          $r->internal_redirect('/adm/ambiguous');
1.2       www       340:       }
1.5       www       341:   } else {
1.2       www       342: # -------------------------- Class was not initialized or page fliped strangely
                    343:       $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
                    344:       return HTTP_NOT_ACCEPTABLE; 
                    345:   } 
1.1       www       346: }
                    347: 
                    348: 1;
                    349: __END__
                    350: 
                    351: 
                    352: 
                    353: 
                    354: 
                    355: 
                    356: 

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>