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Hopefully flips pages across chapters

    1: # The LearningOnline Network with CAPA
    2: #
    3: # Page flip handler
    4: #
    5: # (Page Handler
    6: #
    7: # (TeX Content Handler
    8: #
    9: # 05/29/00,05/30 Gerd Kortemeyer)
   10: # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
   11: # 10/02 Gerd Kortemeyer)
   12: #
   13: # 10/03,10/05,10/06,10/07,10/09,10/10,10/11,10/16,10/17,
   14: # 11/14,11/16,
   15: # 10/01/01 Gerd Kortemeyer
   16: 
   17: package Apache::lonpageflip;
   18: 
   19: use strict;
   20: use Apache::Constants qw(:common :http REDIRECT);
   21: use Apache::lonnet();
   22: use HTML::TokeParser;
   23: use GDBM_File;
   24: 
   25: # ========================================================== Module Global Hash
   26:   
   27: my %hash;
   28: 
   29: sub addrid {
   30:     my ($current,$new,$condid)=@_;
   31:     unless ($condid) { $condid=0; }
   32:     if (&Apache::lonnet::allowed('bre',$hash{'src_'.$new})) {
   33: 	if ($current) {
   34: 	    $current.=','.$new;
   35:         } else {
   36:             $current=''.$new;
   37:         }
   38:     }
   39:     return $current;
   40: }
   41: 
   42: # ================================================================ Main Handler
   43: 
   44: sub handler {
   45:    my $r=shift;
   46: 
   47: # ------------------------------------------- Set document type for header only
   48: 
   49:   if ($r->header_only) {
   50:      $r->content_type('text/html');
   51:      $r->send_http_header;
   52:      return OK;
   53:   }
   54: 
   55:   my %cachehash=(); 
   56:   my $multichoice=0;
   57:   my %multichoicehash=();
   58:   my $redirecturl='';
   59:   my $next='';
   60:   my @possibilities=();
   61: 
   62:   if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
   63:       $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
   64:       my $direction=$1;
   65:       my $currenturl=$2;
   66:       if ($direction eq 'return') {
   67: # -------------------------------------------------------- Return to last known
   68:          my $last;
   69:          if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
   70:                     &GDBM_READER,0640)) {
   71: 	     $last=$hash{'last_known'};
   72:              untie(%hash);
   73:          }
   74:          my $newloc;
   75:          if ($last) {
   76:             $newloc='/res/'.(split(/\_\_\_/,$last))[1];
   77:          } else {
   78: 	    $newloc='/adm/noidea.html';
   79:          }  
   80: 	 $r->content_type('text/html');
   81:          $r->header_out(Location => 
   82: 			'http://'.$ENV{'HTTP_HOST'}.$newloc);
   83:                                
   84:          return REDIRECT;
   85:       }
   86:       $currenturl=~s/^http\:\/\///;
   87:       $currenturl=~s/^[^\/]+//;
   88:       unless ($currenturl=~/\/res\//) {
   89: 	 my $last;
   90:          if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
   91:                     &GDBM_READER,0640)) {
   92: 	     $last=$hash{'last_known'};
   93:              untie(%hash);
   94:          }
   95:          if ($last) {
   96: 	     $currenturl='/res/'.(split(/\_\_\_/,$last))[1];
   97: 	 } else {
   98: 	     $r->content_type('text/html');
   99:              $r->header_out(Location => 
  100:                                'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
  101:              return REDIRECT;
  102:          }
  103:       }
  104: # ------------------------------------------- Do we have any idea where we are?
  105:       my $position;
  106:       if ($position=Apache::lonnet::symbread($currenturl)) {
  107: # ------------------------------------------------------------------------- Yes
  108: 	  my ($mapurl,$mapnum,$thisurl)=split(/\_\_\_/,$position);
  109:           $cachehash{$thisurl}=$mapnum;
  110: # ============================================================ Tie the big hash
  111:           if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
  112:                         &GDBM_READER,0640)) {
  113:               my $rid=$hash{'map_pc_/res/'.$mapurl}.'.'.$mapnum;
  114: 
  115:               my $next='';
  116:               my $mincond=1;
  117:               my $posnext='';
  118:               if ($direction eq 'forward') {
  119: # --------------------------------------------------------------------- Forward
  120:                   if ($hash{'type_'.$rid} eq 'finish') {
  121: 	             $rid=$hash{'ids_/res/'.$mapurl};
  122:                   }
  123:                   map {
  124:                       my $thiscond=
  125:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
  126:                       if ($thiscond>=$mincond) {
  127: 		          if ($posnext) {
  128: 		             $posnext.=','.$_.':'.$thiscond;
  129:                           } else {
  130:                              $posnext=$_.':'.$thiscond;
  131: 		          }
  132:                           if ($thiscond>$mincond) { $mincond=$thiscond; }
  133: 	              }
  134:                   } split(/\,/,$hash{'to_'.$rid});
  135:                   map {
  136:                       my ($linkid,$condval)=split(/\:/,$_);
  137:                       if ($condval>=$mincond) {
  138: 		          $next=&addrid($next,$hash{'goesto_'.$linkid},
  139:                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
  140:                       }
  141:                   } split(/\,/,$posnext);
  142:                   if ($hash{'is_map_'.$next}) {
  143:                       if (
  144:       $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
  145: 			  $mapurl=$hash{'src_'.$next};
  146: 			  $next=$hash{'map_start_'.$hash{'src_'.$next}};
  147:                      }
  148:                   }
  149:               } elsif ($direction eq 'back') {
  150: # ------------------------------------------------------------------- Backwards
  151:                   if ($hash{'type_'.$rid} eq 'start') {
  152: 	             $rid=$hash{'ids_/res/'.$mapurl};
  153:                   }
  154:                   map {
  155:                       my $thiscond=
  156:       &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
  157:                       if ($thiscond>=$mincond) {
  158: 		          if ($posnext) {
  159: 		             $posnext.=','.$_.':'.$thiscond;
  160:                           } else {
  161:                              $posnext=$_.':'.$thiscond;
  162: 		          }
  163:                           if ($thiscond>$mincond) { $mincond=$thiscond; }
  164: 	              }
  165:                   } split(/\,/,$hash{'from_'.$rid});
  166:                   map {
  167:                       my ($linkid,$condval)=split(/\:/,$_);
  168:                       if ($condval>=$mincond) {
  169: 		          $next=&addrid($next,$hash{'comesfrom_'.$linkid},
  170:                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
  171:                       }
  172:                   } split(/\,/,$posnext);
  173:                   if ($hash{'is_map_'.$next}) {
  174:                       if (
  175:       $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
  176: 			  $mapurl=$hash{'src_'.$next};
  177: 			  $next=$hash{'map_finish_'.$hash{'src_'.$next}};
  178:                      }
  179:                   }
  180:  	      } elsif ($direction eq 'up') {
  181: # -------------------------------------------------------------------------- Up
  182:               } elsif ($direction eq 'down') {
  183: # ------------------------------------------------------------------------ Down
  184: 	      }
  185: # ----------------------------------------------------- Check out possibilities
  186:               if ($next) {
  187:                   @possibilities=split(/\,/,$next);
  188:                   if ($#possibilities==0) {
  189: # ---------------------------------------------- Only one possibility, redirect
  190: 	              $redirecturl=$hash{'src_'.$next};
  191:                       $cachehash{&Apache::lonnet::declutter($redirecturl)}
  192: 		                                 =(split(/\./,$next))[1];
  193:                   } else {
  194: # ------------------------ There are multiple possibilities for a next resource
  195:                       $multichoice=1;
  196:                       map {
  197: 			  $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
  198:                           $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
  199:                           $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
  200:                           $cachehash
  201:                             {&Apache::lonnet::declutter(
  202: 						      $multichoicehash
  203:                                                          {'src_'.$_}
  204:                                                        )}
  205: 		                                 =(split(/\./,$_))[1];
  206:                       } @possibilities;
  207:                   }
  208: 	      } else {
  209: # -------------------------------------------------------------- No place to go
  210:                   $multichoice=-1;
  211:               }
  212: # ----------------- The program must come past this point to untie the big hash
  213: 	      untie(%hash);
  214: # --------------------------------------------------------- Store position info
  215:               $cachehash{'last_direction'}=$direction;
  216:               $cachehash{'last_known'}=&Apache::lonnet::declutter($currenturl);
  217:               &Apache::lonnet::symblist($mapurl,%cachehash);
  218: # ============================================== Do not return before this line
  219:               if ($redirecturl) {
  220: # ----------------------------------------------------- There is a URL to go to
  221: 		  $r->content_type('text/html');
  222:                   $r->header_out(Location => 
  223:                                 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
  224:                   return REDIRECT;
  225: 	      } else {
  226: # --------------------------------------------------------- There was a problem
  227:                   $r->content_type('text/html');
  228:                   $r->send_http_header;
  229:                   if ($#possibilities>0) {
  230:                      $r->print(<<ENDSTART);
  231: <head><title>Choose Next Location</title></head>
  232: <body bgcolor="#FFFFFF">
  233: <h1>LON-CAPA</h1>
  234: There are several possibilities of where to go next.
  235: <p>
  236: Please click on the the resource you intend to access:
  237: <p>
  238: <table border=2>
  239: <tr><th>Title</th><th>Type</th></tr>
  240: ENDSTART
  241:                      map {
  242:                         $r->print(
  243:                               '<tr><td><a href="'.
  244:                               $multichoicehash{'src_'.$_}.'">'.
  245:                               $multichoicehash{'title_'.$_}.
  246:                               '</a></td><td>'.$multichoicehash{'type_'.$_}.
  247: 			      '</td></tr>');
  248:                      } @possibilities;
  249:                      $r->print('</table></body></html>');
  250: 		     return OK;
  251:                   } else {
  252:                      $r->print(<<ENDNONE);
  253: <head><title>Choose Next Location</title></head>
  254: <body bgcolor="#FFFFFF">
  255: <img src="/adm/lonKaputt/lonlogo_broken.gif" align=left>
  256: <h1>Sorry!</h1>
  257: <h2>Next resource could not be identified.</h2>
  258: </body>
  259: </html>
  260: ENDNONE
  261:                      return OK;
  262: 	         }
  263: 	     }
  264: 	  } else {
  265: # ------------------------------------------------- Problem, could not tie hash
  266:               $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
  267:               return HTTP_NOT_ACCEPTABLE; 
  268:           }
  269:       } else {
  270: # ---------------------------------------- No, could not determine where we are
  271:          $r->internal_redirect('/adm/ambiguous');
  272:       }
  273:   } else {
  274: # -------------------------- Class was not initialized or page fliped strangely
  275:       $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
  276:       return HTTP_NOT_ACCEPTABLE; 
  277:   } 
  278: }
  279: 
  280: 1;
  281: __END__
  282: 
  283: 
  284: 
  285: 
  286: 
  287: 
  288: