Annotation of rat/lonambiguous.pm, revision 1.14

1.1       www         1: # The LearningOnline Network with CAPA
                      2: # Handler to resolve ambiguous file locations
                      3: #
1.14    ! albertel    4: # $Id: lonambiguous.pm,v 1.13 2004/12/20 20:13:52 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: 
                     29: package Apache::lonambiguous;
                     30: 
                     31: use strict;
                     32: use Apache::lonnet;
                     33: use Apache::Constants qw(:common REDIRECT);
                     34: use GDBM_File;
1.9       www        35: use Apache::loncommon;
1.10      www        36: use Apache::lonlocal;
1.1       www        37: 
1.8       www        38: my %bighash;
                     39: 
                     40: sub cleanup {
                     41:     if (tied(%bighash)){
                     42: 	&Apache::lonnet::logthis('Cleanup ambiguous: bighash');
                     43:         unless (untie(%bighash)) {
                     44: 	    &Apache::lonnet::logthis('Failed cleanup ambiguous: bighash');
                     45:         }
                     46:     }
                     47: }
1.1       www        48: 
                     49: # ----------------------------------------------------------- Could not resolve
                     50: 
                     51: sub getlost {
1.2       www        52:     my ($r,$errmsg)=@_;
1.10      www        53:     $errmsg=&mt($errmsg);
1.14    ! albertel   54:     &Apache::loncommon::content_type($r,'text/html');
1.1       www        55:     $r->send_http_header;
1.2       www        56:     $r->print(
1.9       www        57:  '<head><title>Unknown Error</title></head>'.
                     58:   &Apache::loncommon::bodytag('Could not handle ambiguous resource reference').
                     59:   $errmsg.
1.2       www        60:  '</body></html>');
1.1       www        61: }
                     62: 
                     63: # ================================================================ Main Handler
                     64: 
1.11      albertel   65: sub make_symb {
                     66:     my ($id)=@_;
                     67:     my ($mapid,$resid)=split(/\./,$id);
                     68:     my $map=$bighash{'map_id_'.$mapid};
                     69:     my $res=$bighash{'src_'.$id};
                     70:     my $symb=&Apache::lonnet::encode_symb($map,$resid,$res);
                     71:     return $symb;
                     72: }
                     73: 
1.1       www        74: sub handler {
                     75:    my $r=shift;
                     76: 
                     77:    if ($r->header_only) {
1.10      www        78:       &Apache::loncommon::content_type($r,'text/html');
1.1       www        79:       $r->send_http_header;
                     80:       return OK;
                     81:    }
                     82: 
1.2       www        83: # ---------------------------------------------------------- Is this selecting?
1.8       www        84:  
1.2       www        85:    if ($ENV{'form.selecturl'}) {
                     86:        my $envkey;
                     87:        if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
1.5       albertel   88:                     &GDBM_READER(),0640)) {
1.2       www        89:           foreach $envkey (keys %ENV) {
                     90:              if ($envkey=~/^form\.(\d+)\.(\d+)$/) {
1.3       www        91: # ---------------------------------------------------- Update symb and redirect
1.2       www        92: 	         my $mapid=$1;
                     93:                  my $resid=$2;
                     94:                  my $resurl=$bighash{'src_'.$mapid.'.'.$resid};
                     95:                  &Apache::lonnet::symblist($bighash{'map_id_'.$mapid},
                     96: 				           $resurl => $resid);
1.3       www        97:                  untie(%bighash);
1.2       www        98:                  $r->header_out(Location => 
                     99:                                 'http://'.$ENV{'HTTP_HOST'}.$resurl);
                    100:                  return REDIRECT;
                    101:              }
                    102: 	  }
                    103:           untie(%bighash);
                    104:        } else {
                    105:           &getlost($r,'Could not access course structure.');
                    106:           return OK;
                    107:        }
                    108:    }
                    109: 
1.1       www       110: # ---------------------------------------------------------- Do we have a case?
                    111: 
                    112:    my $thisfn;
                    113:    unless (($thisfn=$ENV{'request.ambiguous'})&&($ENV{'request.course.fn'})) {
1.2       www       114:        &getlost($r,'Could not find information on resource.');
1.1       www       115:        return OK;
                    116:    }
                    117:       
                    118: # ---------------------------------- Should this file have been part of a page?
                    119: 
                    120:     $thisfn=&Apache::lonnet::declutter($thisfn);
                    121:     my %hash;
                    122:     my $syval='';
                    123:     
                    124:     if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
1.5       albertel  125:                   &GDBM_READER(),0640)) {
1.1       www       126:        $syval=$hash{$thisfn};
                    127:        untie(%hash);
                    128:     }
1.2       www       129: 
1.1       www       130: # ---------------------------------------------------------- There was an entry
1.2       www       131: 
1.1       www       132:     if ($syval) {
1.2       www       133: 
1.1       www       134:        if ($syval=~/\_$/) {
                    135: # ----------------------------------- Okay, this should have appeared on a page
                    136: 	   $syval=~s/\_\_\_$//;
1.14    ! albertel  137: 	   &Apache::loncommon::content_type($r,'text/html');
1.1       www       138:            $r->header_out(Location => 
                    139:                 'http://'.$ENV{'HTTP_HOST'}.'/res/'.$syval);
                    140:            return REDIRECT;
                    141:        } else {
                    142: #  There is not really a problem (???), but cannot go back without endless loop
1.2       www       143:            &getlost($r,'The nature of the problem is unclear');
1.1       www       144:            return OK;
                    145:        }
                    146:     }
1.13      albertel  147: # ------------------------------------Encrypted requests go straight to navmaps
                    148:    if ($ENV{'request.enc'}) {
1.14    ! albertel  149:        &Apache::loncommon::content_type($r,'text/html');
1.13      albertel  150:        $r->header_out(Location => 'http://'.$ENV{'HTTP_HOST'}.'/adm/navmaps');
                    151:        return REDIRECT;
                    152:    }
1.1       www       153: # ------------------------------------------------ Would be standalone resource
                    154: 
                    155:    if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
1.5       albertel  156:                     &GDBM_READER(),0640)) {
1.1       www       157: # ---------------------------------------------- Get ID(s) for current resource
1.7       albertel  158:       my $ids=$bighash{'ids_'.&Apache::lonnet::clutter($thisfn)};
1.1       www       159:       if ($ids) {
                    160: # ------------------------------------------------------------------- Has ID(s)
                    161:          my @possibilities=split(/\,/,$ids);
                    162:          my $couldbe='';
1.11      albertel  163:          foreach (@possibilities) {
                    164:              if ($bighash{'encrypted_'.$_}) { next; }
                    165: 	     my $symb=&make_symb($_);
                    166:              if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_},$symb)) {
1.1       www       167: 	         if ($couldbe) {
                    168: 		     $couldbe.=','.$_;
                    169:                  } else {
                    170:                      $couldbe=$_;
                    171:                  }
                    172:              }
1.11      albertel  173: 	 }
1.1       www       174:          if ($couldbe) {
                    175:             @possibilities=split(/\,/,$couldbe);
1.12      albertel  176: 	    if ($#possibilities==0) {
                    177: 		my $id=$possibilities[0];
                    178: 		my $resurl=$bighash{'src_'.$id};
                    179: 		my $mapurl=$bighash{'map_id_'.(split(/\./,$id))[0]};
                    180: 		my $symb=&make_symb($id);
1.14    ! albertel  181: 		&Apache::loncommon::content_type($r,'text/html');
1.12      albertel  182: 		&Apache::lonnet::logthis('http://'.$ENV{'HTTP_HOST'}.$resurl.'?symb='.$symb);
                    183: 		$r->header_out(Location => 
                    184: 			   'http://'.$ENV{'HTTP_HOST'}.$resurl.'?symb='.$symb);
                    185: 		return REDIRECT;
                    186: 	    }
1.1       www       187:             if ($#possibilities>0) {
                    188: # ----------------------------------------------- Okay, really multiple choices
1.14    ! albertel  189: 	       &Apache::loncommon::content_type($r,'text/html');
1.1       www       190:                $r->send_http_header;
1.9       www       191:                my $bodytag=
                    192:                       &Apache::loncommon::bodytag('Pick Instance of Resource');
1.2       www       193:                $r->print(<<ENDSTART);
                    194: <head><title>Choose Location</title></head>
1.9       www       195: $bodytag
1.2       www       196: The resource you had been accessing appears more than once in this course,
                    197: and LON-CAPA has insufficient session information to determine which instance
                    198: of the resource you meant.
                    199: <p>
                    200: Please click on the instance of the resource you intended to access:
1.11      albertel  201: </p>
                    202: <table border="2">
                    203: <tr><th>Title</th><th>Part of ...</th></tr>
1.2       www       204: ENDSTART
                    205:                map {
1.11      albertel  206: 		   my $resurl=$bighash{'src_'.$_};
1.2       www       207:                    my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
1.11      albertel  208: 		   my $symb=&make_symb($_);
                    209: 		   $r->print('<tr><td><a href="'.$resurl.'?symb='.$symb.'">'.
                    210: 			     &Apache::lonnet::gettitle($symb).
                    211: 			     '</a></td><td>'.
                    212: 			     &Apache::lonnet::gettitle($mapurl).'&nbsp;'.
                    213: 			     '</td></tr>');
1.2       www       214:                } @possibilities;
1.11      albertel  215:                $r->print('</table></body></html>');
1.1       www       216: 	       untie(%bighash);
                    217:                return OK;
                    218:             }
                    219:          }
                    220:       }
                    221:       untie(%bighash);
                    222:   }
                    223: 
                    224: # ------------------------------------ This handler should not have been called
1.2       www       225:    &getlost($r,'Invalid call of handler');
1.1       www       226:    return OK;
                    227: }
                    228: 
                    229: 1;
                    230: __END__
                    231: 
                    232: 
                    233: 
                    234: 
                    235: 
                    236: 
                    237: 

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