Annotation of rat/lonambiguous.pm, revision 1.7

1.1       www         1: # The LearningOnline Network with CAPA
                      2: # Handler to resolve ambiguous file locations
                      3: #
1.7     ! albertel    4: # $Id: lonambiguous.pm,v 1.6 2002/09/14 18:57:59 www 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;
                     40: 
                     41: 
                     42: # ----------------------------------------------------------- Could not resolve
                     43: 
                     44: sub getlost {
1.2       www        45:     my ($r,$errmsg)=@_;
1.1       www        46:     $r->content_type('text/html');
                     47:     $r->send_http_header;
1.2       www        48:     $r->print(
                     49:  '<head><title>Unknown Error</title></head><body bgcolor="#FFFFFF"><h1>'.
                     50:  'LON-CAPA</h1>Could not handle ambiguous resource reference.<p>'.$errmsg.
                     51:  '</body></html>');
1.1       www        52: }
                     53: 
                     54: # ================================================================ Main Handler
                     55: 
                     56: sub handler {
                     57:    my $r=shift;
                     58: 
                     59:    if ($r->header_only) {
                     60:       $r->content_type('text/html');
                     61:       $r->send_http_header;
                     62:       return OK;
                     63:    }
                     64: 
1.2       www        65: # ---------------------------------------------------------- Is this selecting?
                     66:    
                     67:    my %bighash;
                     68: 
                     69:    if ($ENV{'form.selecturl'}) {
                     70:        my $envkey;
                     71:        if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
1.5       albertel   72:                     &GDBM_READER(),0640)) {
1.2       www        73:           foreach $envkey (keys %ENV) {
                     74:              if ($envkey=~/^form\.(\d+)\.(\d+)$/) {
1.3       www        75: # ---------------------------------------------------- Update symb and redirect
1.2       www        76: 	         my $mapid=$1;
                     77:                  my $resid=$2;
                     78:                  my $resurl=$bighash{'src_'.$mapid.'.'.$resid};
                     79:                  &Apache::lonnet::symblist($bighash{'map_id_'.$mapid},
                     80: 				           $resurl => $resid);
1.3       www        81:                  untie(%bighash);
1.2       www        82:                  $r->header_out(Location => 
                     83:                                 'http://'.$ENV{'HTTP_HOST'}.$resurl);
                     84:                  return REDIRECT;
                     85:              }
                     86: 	  }
                     87:           untie(%bighash);
                     88:        } else {
                     89:           &getlost($r,'Could not access course structure.');
                     90:           return OK;
                     91:        }
                     92:    }
                     93: 
1.1       www        94: # ---------------------------------------------------------- Do we have a case?
                     95: 
                     96:    my $thisfn;
                     97:    unless (($thisfn=$ENV{'request.ambiguous'})&&($ENV{'request.course.fn'})) {
1.2       www        98:        &getlost($r,'Could not find information on resource.');
1.1       www        99:        return OK;
                    100:    }
                    101:       
                    102: # ---------------------------------- Should this file have been part of a page?
                    103: 
                    104:     $thisfn=&Apache::lonnet::declutter($thisfn);
                    105:     my %hash;
                    106:     my $syval='';
                    107:     
                    108:     if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
1.5       albertel  109:                   &GDBM_READER(),0640)) {
1.1       www       110:        $syval=$hash{$thisfn};
                    111:        untie(%hash);
                    112:     }
1.2       www       113: 
1.1       www       114: # ---------------------------------------------------------- There was an entry
1.2       www       115: 
1.1       www       116:     if ($syval) {
1.2       www       117: 
1.1       www       118:        if ($syval=~/\_$/) {
                    119: # ----------------------------------- Okay, this should have appeared on a page
                    120: 	   $syval=~s/\_\_\_$//;
                    121:  	   $r->content_type('text/html');
                    122:            $r->header_out(Location => 
                    123:                 'http://'.$ENV{'HTTP_HOST'}.'/res/'.$syval);
                    124:            return REDIRECT;
                    125:        } else {
                    126: #  There is not really a problem (???), but cannot go back without endless loop
1.2       www       127:            &getlost($r,'The nature of the problem is unclear');
1.1       www       128:            return OK;
                    129:        }
                    130:     }
                    131: 
                    132: # ------------------------------------------------ Would be standalone resource
                    133: 
                    134:    if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
1.5       albertel  135:                     &GDBM_READER(),0640)) {
1.1       www       136: # ---------------------------------------------- Get ID(s) for current resource
1.7     ! albertel  137:       my $ids=$bighash{'ids_'.&Apache::lonnet::clutter($thisfn)};
1.1       www       138:       if ($ids) {
                    139: # ------------------------------------------------------------------- Has ID(s)
                    140:          my @possibilities=split(/\,/,$ids);
                    141:          my $couldbe='';
                    142:          map {
1.2       www       143:              if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_})) {
1.1       www       144: 	         if ($couldbe) {
                    145: 		     $couldbe.=','.$_;
                    146:                  } else {
                    147:                      $couldbe=$_;
                    148:                  }
                    149:              }
                    150: 	 } @possibilities;
                    151:          if ($couldbe) {
                    152:             @possibilities=split(/\,/,$couldbe);
                    153:             if ($#possibilities>0) {
                    154: # ----------------------------------------------- Okay, really multiple choices
                    155:                $r->content_type('text/html');
                    156:                $r->send_http_header;
1.2       www       157:                $r->print(<<ENDSTART);
                    158: <head><title>Choose Location</title></head>
                    159: <body bgcolor="#FFFFFF">
                    160: <h1>LON-CAPA</h1>
                    161: The resource you had been accessing appears more than once in this course,
                    162: and LON-CAPA has insufficient session information to determine which instance
                    163: of the resource you meant.
                    164: <p>
                    165: Please click on the instance of the resource you intended to access:
                    166: <p>
                    167: <form action="/adm/ambiguous" method=post>
                    168: <input type=hidden name=orgurl value="$thisfn">
                    169: <input type=hidden name=selecturl value=1>
                    170: <table border=2>
                    171: <tr><th>&nbsp;</th><th>Title</th><th>Type</th><th>Part of ...</th></tr>
                    172: ENDSTART
                    173:                map {
                    174:                    my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
                    175:                    $r->print('<tr><td><input type=submit value=Select name="'.
                    176:                               $_.'"></td><td>'.$bighash{'title_'.$_}.
                    177:                               '</td><td>'.$bighash{'type_'.$_}.
                    178:                               '</td><td><a href="'.$mapurl.'">'.$mapurl.
                    179: 			      '</a></td></tr>');
                    180:                } @possibilities;
                    181:                $r->print('</table></form></body></html>');
1.1       www       182: 	       untie(%bighash);
                    183:                return OK;
                    184:             }
                    185:          }
                    186:       }
                    187:       untie(%bighash);
                    188:   }
                    189: 
                    190: # ------------------------------------ This handler should not have been called
1.2       www       191:    &getlost($r,'Invalid call of handler');
1.1       www       192:    return OK;
                    193: }
                    194: 
                    195: 1;
                    196: __END__
                    197: 
                    198: 
                    199: 
                    200: 
                    201: 
                    202: 
                    203: 

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