Annotation of rat/lonpageflip.pm, revision 1.19

1.1       www         1: # The LearningOnline Network with CAPA
                      2: #
                      3: # Page flip handler
                      4: #
1.19    ! www         5: # $Id: lonpageflip.pm,v 1.18 2001/11/29 19:23:49 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 $current;
1.1       www        64: }
                     65: 
1.15      www        66: sub move {
                     67:     my ($rid,$mapurl,$direction)=@_;
                     68: 
                     69:     my $next='';
                     70: 
                     71:               my $mincond=1;
                     72:               my $posnext='';
                     73:               if ($direction eq 'forward') {
                     74: # --------------------------------------------------------------------- Forward
                     75:                   if ($hash{'type_'.$rid} eq 'finish') {
                     76: 	             $rid=$hash{'ids_/res/'.$mapurl}; 
                     77:                   }
                     78:                   map {
                     79:                       my $thiscond=
                     80:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
                     81:                       if ($thiscond>=$mincond) {
                     82: 		          if ($posnext) {
                     83: 		             $posnext.=','.$_.':'.$thiscond;
                     84:                           } else {
                     85:                              $posnext=$_.':'.$thiscond;
                     86: 		          }
                     87:                           if ($thiscond>$mincond) { $mincond=$thiscond; }
                     88: 	              }
                     89:                   } split(/\,/,$hash{'to_'.$rid});
                     90:                   map {
                     91:                       my ($linkid,$condval)=split(/\:/,$_);
                     92:                       if ($condval>=$mincond) {
                     93: 		          $next=&addrid($next,$hash{'goesto_'.$linkid},
                     94:                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
                     95:                       }
                     96:                   } split(/\,/,$posnext);
                     97:                   if ($hash{'is_map_'.$next}) {
                     98:                       if (
                     99:       $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
                    100: 			  $mapurl=$hash{'src_'.$next};
                    101: 			  $next=$hash{'map_start_'.$hash{'src_'.$next}};
                    102:                      }
                    103:                   }
                    104:               } elsif ($direction eq 'back') {
                    105: # ------------------------------------------------------------------- Backwards
                    106:                   if ($hash{'type_'.$rid} eq 'start') {
                    107: 	             $rid=$hash{'ids_/res/'.$mapurl};
                    108:                   }
                    109:                   map {
                    110:                       my $thiscond=
                    111:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
                    112:                       if ($thiscond>=$mincond) {
                    113: 		          if ($posnext) {
                    114: 		             $posnext.=','.$_.':'.$thiscond;
                    115:                           } else {
                    116:                              $posnext=$_.':'.$thiscond;
                    117: 		          }
                    118:                           if ($thiscond>$mincond) { $mincond=$thiscond; }
                    119: 	              }
                    120:                   } split(/\,/,$hash{'from_'.$rid});
                    121:                   map {
                    122:                       my ($linkid,$condval)=split(/\:/,$_);
                    123:                       if ($condval>=$mincond) {
                    124: 		          $next=&addrid($next,$hash{'comesfrom_'.$linkid},
                    125:                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
                    126:                       }
                    127:                   } split(/\,/,$posnext);
                    128:                   if ($hash{'is_map_'.$next}) {
                    129:                       if (
                    130:       $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
                    131: 			  $mapurl=$hash{'src_'.$next};
                    132: 			  $next=$hash{'map_finish_'.$hash{'src_'.$next}};
                    133:                      }
                    134:                   }
                    135: 	      }
                    136: 
                    137:               return ($next,$mapurl);
                    138: }
                    139: 
1.1       www       140: # ================================================================ Main Handler
                    141: 
                    142: sub handler {
1.2       www       143:    my $r=shift;
1.1       www       144: 
                    145: # ------------------------------------------- Set document type for header only
                    146: 
1.2       www       147:   if ($r->header_only) {
1.1       www       148:      $r->content_type('text/html');
                    149:      $r->send_http_header;
1.2       www       150:      return OK;
                    151:   }
                    152: 
1.5       www       153:   my %cachehash=(); 
                    154:   my $multichoice=0;
                    155:   my %multichoicehash=();
1.4       www       156:   my $redirecturl='';
                    157:   my $next='';
                    158:   my @possibilities=();
1.2       www       159: 
                    160:   if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
                    161:       $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
                    162:       my $direction=$1;
                    163:       my $currenturl=$2;
1.10      www       164:       if ($direction eq 'return') {
                    165: # -------------------------------------------------------- Return to last known
                    166:          my $last;
                    167:          if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
                    168:                     &GDBM_READER,0640)) {
                    169: 	     $last=$hash{'last_known'};
                    170:              untie(%hash);
                    171:          }
                    172:          my $newloc;
                    173:          if ($last) {
                    174:             $newloc='/res/'.(split(/\_\_\_/,$last))[1];
                    175:          } else {
                    176: 	    $newloc='/adm/noidea.html';
                    177:          }  
                    178: 	 $r->content_type('text/html');
                    179:          $r->header_out(Location => 
                    180: 			'http://'.$ENV{'HTTP_HOST'}.$newloc);
                    181:                                
                    182:          return REDIRECT;
                    183:       }
1.2       www       184:       $currenturl=~s/^http\:\/\///;
                    185:       $currenturl=~s/^[^\/]+//;
1.17      www       186:       unless (($currenturl=~/^\/res\//) || 
                    187:               ($currenturl=~/^\/adm\/wrapper\//))  {
1.7       www       188: 	 my $last;
                    189:          if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
                    190:                     &GDBM_READER,0640)) {
                    191: 	     $last=$hash{'last_known'};
                    192:              untie(%hash);
                    193:          }
                    194:          if ($last) {
                    195: 	     $currenturl='/res/'.(split(/\_\_\_/,$last))[1];
                    196: 	 } else {
                    197: 	     $r->content_type('text/html');
                    198:              $r->header_out(Location => 
                    199:                                'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
1.9       www       200:              return REDIRECT;
1.7       www       201:          }
                    202:       }
1.3       www       203: # ------------------------------------------- Do we have any idea where we are?
                    204:       my $position;
                    205:       if ($position=Apache::lonnet::symbread($currenturl)) {
                    206: # ------------------------------------------------------------------------- Yes
                    207: 	  my ($mapurl,$mapnum,$thisurl)=split(/\_\_\_/,$position);
1.19    ! www       208:           $cachehash{$mapurl}{$thisurl}=$mapnum;
1.5       www       209: # ============================================================ Tie the big hash
1.3       www       210:           if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                    211:                         &GDBM_READER,0640)) {
                    212:               my $rid=$hash{'map_pc_/res/'.$mapurl}.'.'.$mapnum;
1.14      www       213: 
1.15      www       214: # ------------------------------------------------- Move forward, backward, etc
                    215: 
                    216:               ($next,$mapurl)=&move($rid,$mapurl,$direction);
                    217: # -------------------------------------- Do we have one and only one empty URL?
                    218:               my $safecount=0;
                    219:               while (($next) && ($next!~/\,/) && (!$hash{'src_'.$next})
                    220:                      && ($safecount<25)) {
                    221:                   ($next,$mapurl)=&move($next,$mapurl,$direction);
                    222:                   $safecount++;
                    223:               }
1.4       www       224: # ----------------------------------------------------- Check out possibilities
                    225:               if ($next) {
                    226:                   @possibilities=split(/\,/,$next);
                    227:                   if ($#possibilities==0) {
1.5       www       228: # ---------------------------------------------- Only one possibility, redirect
                    229: 	              $redirecturl=$hash{'src_'.$next};
1.19    ! www       230:                       $cachehash{$mapurl}
        !           231:                                 {&Apache::lonnet::declutter($redirecturl)}
1.5       www       232: 		                                 =(split(/\./,$next))[1];
1.4       www       233:                   } else {
1.5       www       234: # ------------------------ There are multiple possibilities for a next resource
                    235:                       $multichoice=1;
                    236:                       map {
                    237: 			  $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
                    238:                           $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
1.6       www       239:                           $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
1.19    ! www       240:                           $cachehash{$mapurl}
1.5       www       241:                             {&Apache::lonnet::declutter(
                    242: 						      $multichoicehash
                    243:                                                          {'src_'.$_}
                    244:                                                        )}
                    245: 		                                 =(split(/\./,$_))[1];
                    246:                       } @possibilities;
1.4       www       247:                   }
1.5       www       248: 	      } else {
                    249: # -------------------------------------------------------------- No place to go
                    250:                   $multichoice=-1;
1.4       www       251:               }
1.5       www       252: # ----------------- The program must come past this point to untie the big hash
1.3       www       253: 	      untie(%hash);
1.5       www       254: # --------------------------------------------------------- Store position info
1.19    ! www       255:               $cachehash{$mapurl}{'last_direction'}=$direction;
        !           256:               $cachehash{$mapurl}{'last_known'}=
        !           257:                                        &Apache::lonnet::declutter($currenturl);
        !           258:               foreach my $thismap (keys %cachehash) {
        !           259:                  &Apache::lonnet::symblist($thismap,%{$cachehash{$thisurl}});
        !           260: 	      }
1.5       www       261: # ============================================== Do not return before this line
1.4       www       262:               if ($redirecturl) {
1.5       www       263: # ----------------------------------------------------- There is a URL to go to
1.4       www       264: 		  $r->content_type('text/html');
                    265:                   $r->header_out(Location => 
                    266:                                 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
                    267:                   return REDIRECT;
1.5       www       268: 	      } else {
                    269: # --------------------------------------------------------- There was a problem
1.8       www       270:                   $r->content_type('text/html');
                    271:                   $r->send_http_header;
                    272:                   if ($#possibilities>0) {
                    273:                      $r->print(<<ENDSTART);
                    274: <head><title>Choose Next Location</title></head>
                    275: <body bgcolor="#FFFFFF">
                    276: <h1>LON-CAPA</h1>
                    277: There are several possibilities of where to go next.
                    278: <p>
                    279: Please click on the the resource you intend to access:
                    280: <p>
                    281: <table border=2>
                    282: <tr><th>Title</th><th>Type</th></tr>
                    283: ENDSTART
                    284:                      map {
                    285:                         $r->print(
                    286:                               '<tr><td><a href="'.
                    287:                               $multichoicehash{'src_'.$_}.'">'.
                    288:                               $multichoicehash{'title_'.$_}.
                    289:                               '</a></td><td>'.$multichoicehash{'type_'.$_}.
                    290: 			      '</td></tr>');
                    291:                      } @possibilities;
                    292:                      $r->print('</table></body></html>');
                    293: 		     return OK;
                    294:                   } else {
                    295:                      $r->print(<<ENDNONE);
                    296: <head><title>Choose Next Location</title></head>
                    297: <body bgcolor="#FFFFFF">
1.17      www       298: <img src="/adm/lonIcons/lonlogos.gif" align=right>
1.8       www       299: <h1>Sorry!</h1>
                    300: <h2>Next resource could not be identified.</h2>
1.17      www       301: <h3>You probably are at the beginning or the end of the course.</h3>
1.8       www       302: </body>
                    303: </html>
                    304: ENDNONE
                    305:                      return OK;
                    306: 	         }
                    307: 	     }
1.5       www       308: 	  } else {
                    309: # ------------------------------------------------- Problem, could not tie hash
                    310:               $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
                    311:               return HTTP_NOT_ACCEPTABLE; 
1.3       www       312:           }
1.5       www       313:       } else {
                    314: # ---------------------------------------- No, could not determine where we are
1.6       www       315:          $r->internal_redirect('/adm/ambiguous');
1.2       www       316:       }
1.5       www       317:   } else {
1.2       www       318: # -------------------------- Class was not initialized or page fliped strangely
                    319:       $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
                    320:       return HTTP_NOT_ACCEPTABLE; 
                    321:   } 
1.1       www       322: }
                    323: 
                    324: 1;
                    325: __END__
                    326: 
                    327: 
                    328: 
                    329: 
                    330: 
                    331: 
                    332: 

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