Annotation of rat/lonambiguous.pm, revision 1.12

1.1       www         1: # The LearningOnline Network with CAPA
                      2: # Handler to resolve ambiguous file locations
                      3: #
1.12    ! albertel    4: # $Id: lonambiguous.pm,v 1.11 2004/12/17 22:40:24 albertel Exp $
1.4       www         5: #
                      6: # Copyright Michigan State University Board of Trustees
                      7: #
                      8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
                      9: #
                     10: # LON-CAPA is free software; you can redistribute it and/or modify
                     11: # it under the terms of the GNU General Public License as published by
                     12: # the Free Software Foundation; either version 2 of the License, or
                     13: # (at your option) any later version.
                     14: #
                     15: # LON-CAPA is distributed in the hope that it will be useful,
                     16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
                     17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     18: # GNU General Public License for more details.
                     19: #
                     20: # You should have received a copy of the GNU General Public License
                     21: # along with LON-CAPA; if not, write to the Free Software
                     22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
                     23: #
                     24: # /home/httpd/html/adm/gpl.txt
                     25: #
                     26: # http://www.lon-capa.org/
                     27: #
1.1       www        28: # (TeX Content Handler
                     29: #
                     30: # 05/29/00,05/30,10/11 Gerd Kortemeyer)
                     31: #
1.3       www        32: # 10/11,10/12,10/16 Gerd Kortemeyer
1.1       www        33: 
                     34: package Apache::lonambiguous;
                     35: 
                     36: use strict;
                     37: use Apache::lonnet;
                     38: use Apache::Constants qw(:common REDIRECT);
                     39: use GDBM_File;
1.9       www        40: use Apache::loncommon;
1.10      www        41: use Apache::lonlocal;
1.1       www        42: 
1.8       www        43: my %bighash;
                     44: 
                     45: sub cleanup {
                     46:     if (tied(%bighash)){
                     47: 	&Apache::lonnet::logthis('Cleanup ambiguous: bighash');
                     48:         unless (untie(%bighash)) {
                     49: 	    &Apache::lonnet::logthis('Failed cleanup ambiguous: bighash');
                     50:         }
                     51:     }
                     52: }
1.1       www        53: 
                     54: # ----------------------------------------------------------- Could not resolve
                     55: 
                     56: sub getlost {
1.2       www        57:     my ($r,$errmsg)=@_;
1.10      www        58:     $errmsg=&mt($errmsg);
1.1       www        59:     $r->content_type('text/html');
                     60:     $r->send_http_header;
1.2       www        61:     $r->print(
1.9       www        62:  '<head><title>Unknown Error</title></head>'.
                     63:   &Apache::loncommon::bodytag('Could not handle ambiguous resource reference').
                     64:   $errmsg.
1.2       www        65:  '</body></html>');
1.1       www        66: }
                     67: 
                     68: # ================================================================ Main Handler
                     69: 
1.11      albertel   70: sub make_symb {
                     71:     my ($id)=@_;
                     72:     my ($mapid,$resid)=split(/\./,$id);
                     73:     my $map=$bighash{'map_id_'.$mapid};
                     74:     my $res=$bighash{'src_'.$id};
                     75:     my $symb=&Apache::lonnet::encode_symb($map,$resid,$res);
                     76:     return $symb;
                     77: }
                     78: 
1.1       www        79: sub handler {
                     80:    my $r=shift;
                     81: 
                     82:    if ($r->header_only) {
1.10      www        83:       &Apache::loncommon::content_type($r,'text/html');
1.1       www        84:       $r->send_http_header;
                     85:       return OK;
                     86:    }
                     87: 
1.2       www        88: # ---------------------------------------------------------- Is this selecting?
1.8       www        89:  
1.2       www        90:    if ($ENV{'form.selecturl'}) {
                     91:        my $envkey;
                     92:        if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
1.5       albertel   93:                     &GDBM_READER(),0640)) {
1.2       www        94:           foreach $envkey (keys %ENV) {
                     95:              if ($envkey=~/^form\.(\d+)\.(\d+)$/) {
1.3       www        96: # ---------------------------------------------------- Update symb and redirect
1.2       www        97: 	         my $mapid=$1;
                     98:                  my $resid=$2;
                     99:                  my $resurl=$bighash{'src_'.$mapid.'.'.$resid};
                    100:                  &Apache::lonnet::symblist($bighash{'map_id_'.$mapid},
                    101: 				           $resurl => $resid);
1.3       www       102:                  untie(%bighash);
1.2       www       103:                  $r->header_out(Location => 
                    104:                                 'http://'.$ENV{'HTTP_HOST'}.$resurl);
                    105:                  return REDIRECT;
                    106:              }
                    107: 	  }
                    108:           untie(%bighash);
                    109:        } else {
                    110:           &getlost($r,'Could not access course structure.');
                    111:           return OK;
                    112:        }
                    113:    }
                    114: 
1.1       www       115: # ---------------------------------------------------------- Do we have a case?
                    116: 
                    117:    my $thisfn;
                    118:    unless (($thisfn=$ENV{'request.ambiguous'})&&($ENV{'request.course.fn'})) {
1.2       www       119:        &getlost($r,'Could not find information on resource.');
1.1       www       120:        return OK;
                    121:    }
                    122:       
                    123: # ---------------------------------- Should this file have been part of a page?
                    124: 
                    125:     $thisfn=&Apache::lonnet::declutter($thisfn);
                    126:     my %hash;
                    127:     my $syval='';
                    128:     
                    129:     if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
1.5       albertel  130:                   &GDBM_READER(),0640)) {
1.1       www       131:        $syval=$hash{$thisfn};
                    132:        untie(%hash);
                    133:     }
1.2       www       134: 
1.1       www       135: # ---------------------------------------------------------- There was an entry
1.2       www       136: 
1.1       www       137:     if ($syval) {
1.2       www       138: 
1.1       www       139:        if ($syval=~/\_$/) {
                    140: # ----------------------------------- Okay, this should have appeared on a page
                    141: 	   $syval=~s/\_\_\_$//;
                    142:  	   $r->content_type('text/html');
                    143:            $r->header_out(Location => 
                    144:                 'http://'.$ENV{'HTTP_HOST'}.'/res/'.$syval);
                    145:            return REDIRECT;
                    146:        } else {
                    147: #  There is not really a problem (???), but cannot go back without endless loop
1.2       www       148:            &getlost($r,'The nature of the problem is unclear');
1.1       www       149:            return OK;
                    150:        }
                    151:     }
                    152: # ------------------------------------------------ Would be standalone resource
                    153: 
                    154:    if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
1.5       albertel  155:                     &GDBM_READER(),0640)) {
1.1       www       156: # ---------------------------------------------- Get ID(s) for current resource
1.7       albertel  157:       my $ids=$bighash{'ids_'.&Apache::lonnet::clutter($thisfn)};
1.1       www       158:       if ($ids) {
                    159: # ------------------------------------------------------------------- Has ID(s)
                    160:          my @possibilities=split(/\,/,$ids);
                    161:          my $couldbe='';
1.11      albertel  162:          foreach (@possibilities) {
                    163:              if ($bighash{'encrypted_'.$_}) { next; }
                    164: 	     my $symb=&make_symb($_);
                    165:              if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_},$symb)) {
1.1       www       166: 	         if ($couldbe) {
                    167: 		     $couldbe.=','.$_;
                    168:                  } else {
                    169:                      $couldbe=$_;
                    170:                  }
                    171:              }
1.11      albertel  172: 	 }
1.1       www       173:          if ($couldbe) {
                    174:             @possibilities=split(/\,/,$couldbe);
1.12    ! albertel  175: 	    if ($#possibilities==0) {
        !           176: 		my $id=$possibilities[0];
        !           177: 		my $resurl=$bighash{'src_'.$id};
        !           178: 		my $mapurl=$bighash{'map_id_'.(split(/\./,$id))[0]};
        !           179: 		my $symb=&make_symb($id);
        !           180: 		$r->content_type('text/html');
        !           181: 		&Apache::lonnet::logthis('http://'.$ENV{'HTTP_HOST'}.$resurl.'?symb='.$symb);
        !           182: 		$r->header_out(Location => 
        !           183: 			   'http://'.$ENV{'HTTP_HOST'}.$resurl.'?symb='.$symb);
        !           184: 		return REDIRECT;
        !           185: 	    }
1.1       www       186:             if ($#possibilities>0) {
                    187: # ----------------------------------------------- Okay, really multiple choices
                    188:                $r->content_type('text/html');
                    189:                $r->send_http_header;
1.9       www       190:                my $bodytag=
                    191:                       &Apache::loncommon::bodytag('Pick Instance of Resource');
1.2       www       192:                $r->print(<<ENDSTART);
                    193: <head><title>Choose Location</title></head>
1.9       www       194: $bodytag
1.2       www       195: The resource you had been accessing appears more than once in this course,
                    196: and LON-CAPA has insufficient session information to determine which instance
                    197: of the resource you meant.
                    198: <p>
                    199: Please click on the instance of the resource you intended to access:
1.11      albertel  200: </p>
                    201: <table border="2">
                    202: <tr><th>Title</th><th>Part of ...</th></tr>
1.2       www       203: ENDSTART
                    204:                map {
1.11      albertel  205: 		   my $resurl=$bighash{'src_'.$_};
1.2       www       206:                    my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
1.11      albertel  207: 		   my $symb=&make_symb($_);
                    208: 		   $r->print('<tr><td><a href="'.$resurl.'?symb='.$symb.'">'.
                    209: 			     &Apache::lonnet::gettitle($symb).
                    210: 			     '</a></td><td>'.
                    211: 			     &Apache::lonnet::gettitle($mapurl).'&nbsp;'.
                    212: 			     '</td></tr>');
1.2       www       213:                } @possibilities;
1.11      albertel  214:                $r->print('</table></body></html>');
1.1       www       215: 	       untie(%bighash);
                    216:                return OK;
                    217:             }
                    218:          }
                    219:       }
                    220:       untie(%bighash);
                    221:   }
                    222: 
                    223: # ------------------------------------ This handler should not have been called
1.2       www       224:    &getlost($r,'Invalid call of handler');
1.1       www       225:    return OK;
                    226: }
                    227: 
                    228: 1;
                    229: __END__
                    230: 
                    231: 
                    232: 
                    233: 
                    234: 
                    235: 
                    236: 

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