File:  [LON-CAPA] / rat / lonambiguous.pm
Revision 1.21: download - view: text, annotated - select for diffs
Tue Sep 19 19:03:27 2006 UTC (17 years, 6 months ago) by albertel
Branches: MAIN
CVS tags: version_2_8_X, version_2_8_2, version_2_8_1, version_2_8_0, version_2_7_X, version_2_7_99_1, version_2_7_99_0, version_2_7_1, version_2_7_0, version_2_6_X, version_2_6_99_1, version_2_6_99_0, version_2_6_3, version_2_6_2, version_2_6_1, version_2_6_0, version_2_5_X, version_2_5_99_1, version_2_5_99_0, version_2_5_2, version_2_5_1, version_2_5_0, version_2_4_X, version_2_4_99_0, version_2_4_2, version_2_4_1, version_2_4_0, version_2_3_X, version_2_3_99_0, version_2_3_2, version_2_3_1, version_2_3_0, version_2_2_X, version_2_2_99_1, version_2_2_99_0, version_2_2_2, HEAD, GCI_1
- move absoltue_url to lonnet,
- use absolute_url in lonnet::ssi

    1: # The LearningOnline Network with CAPA
    2: # Handler to resolve ambiguous file locations
    3: #
    4: # $Id: lonambiguous.pm,v 1.21 2006/09/19 19:03:27 albertel Exp $
    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: #
   28: 
   29: package Apache::lonambiguous;
   30: 
   31: use strict;
   32: use Apache::lonnet;
   33: use Apache::Constants qw(:common REDIRECT);
   34: use GDBM_File;
   35: use Apache::loncommon;
   36: use Apache::lonlocal;
   37: 
   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:     return OK;
   48: }
   49: 
   50: # ----------------------------------------------------------- Could not resolve
   51: 
   52: sub getlost {
   53:     my ($r,$errmsg)=@_;
   54:     $errmsg=&mt($errmsg);
   55:     &Apache::loncommon::content_type($r,'text/html');
   56:     $r->send_http_header;
   57:     $r->print(&Apache::loncommon::start_page('Could not handle ambiguous resource reference').
   58: 	      $errmsg.
   59: 	      &Apache::loncommon::end_page());
   60: }
   61: 
   62: # ================================================================ Main Handler
   63: 
   64: sub make_symb {
   65:     my ($id)=@_;
   66:     my ($mapid,$resid)=split(/\./,$id);
   67:     my $map=$bighash{'map_id_'.$mapid};
   68:     my $res=$bighash{'src_'.$id};
   69:     my $symb=&Apache::lonnet::encode_symb($map,$resid,$res);
   70:     return $symb;
   71: }
   72: 
   73: sub handler {
   74:    my $r=shift;
   75: 
   76:    if ($r->header_only) {
   77:       &Apache::loncommon::content_type($r,'text/html');
   78:       $r->send_http_header;
   79:       return OK;
   80:    }
   81: 
   82: # ---------------------------------------------------------- Is this selecting?
   83:  
   84:    if ($env{'form.selecturl'}) {
   85:        my $envkey;
   86:        if (tie(%bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
   87:                     &GDBM_READER(),0640)) {
   88:           foreach $envkey (keys %env) {
   89:              if ($envkey=~/^form\.(\d+)\.(\d+)$/) {
   90: # ---------------------------------------------------- Update symb and redirect
   91: 	         my $mapid=$1;
   92:                  my $resid=$2;
   93:                  my $resurl=$bighash{'src_'.$mapid.'.'.$resid};
   94:                  &Apache::lonnet::symblist($bighash{'map_id_'.$mapid},
   95: 				           $resurl => [$resurl,$resid]);
   96:                  untie(%bighash);
   97:                  $r->header_out(Location => 
   98: 				&Apache::lonnet::absolute_url().$resurl);
   99:                  return REDIRECT;
  100:              }
  101: 	  }
  102:           untie(%bighash);
  103:        } else {
  104:           &getlost($r,'Could not access course structure.');
  105:           return OK;
  106:        }
  107:    }
  108: 
  109: # ---------------------------------------------------------- Do we have a case?
  110: 
  111:    my $thisfn;
  112:    unless (($thisfn=$env{'request.ambiguous'})&&($env{'request.course.fn'})) {
  113:        &getlost($r,'Could not find information on resource.');
  114:        return OK;
  115:    }
  116:       
  117: # ---------------------------------- Should this file have been part of a page?
  118: 
  119:     $thisfn=&Apache::lonnet::declutter($thisfn);
  120:     my %hash;
  121:     my $syval='';
  122:     
  123:     if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
  124:                   &GDBM_READER(),0640)) {
  125:        $syval=$hash{$thisfn};
  126:        untie(%hash);
  127:     }
  128: 
  129: # ---------------------------------------------------------- There was an entry
  130: 
  131:     if ($syval) {
  132: 	my ($page,undef,$res)=&Apache::lonnet::decode_symb($syval);
  133: 	if ($res eq 'page') {
  134: # ----------------------------------- Okay, this should have appeared on a page
  135: 	   &Apache::loncommon::content_type($r,'text/html');
  136:            $r->header_out(Location => 
  137: 			  &Apache::lonnet::absolute_url().
  138: 			  &Apache::lonnet::clutter($page));
  139:            return REDIRECT;
  140:        } else {
  141: #  There is not really a problem (???), but cannot go back without endless loop
  142:            &getlost($r,'The nature of the problem is unclear');
  143:            return OK;
  144:        }
  145:     }
  146: # ------------------------------------Encrypted requests go straight to navmaps
  147:    if ($env{'request.enc'}) {
  148:        &Apache::loncommon::content_type($r,'text/html');
  149:        $r->header_out(Location => 
  150: 		      &Apache::lonnet::absolute_url().'/adm/navmaps');
  151:        return REDIRECT;
  152:    }
  153: # ------------------------------------------------ Would be standalone resource
  154: 
  155:    if (tie(%bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
  156:                     &GDBM_READER(),0640)) {
  157: # ---------------------------------------------- Get ID(s) for current resource
  158:       my $ids=$bighash{'ids_'.&Apache::lonnet::clutter($thisfn)};
  159:       if ($ids) {
  160: # ------------------------------------------------------------------- Has ID(s)
  161:          my @possibilities=split(/\,/,$ids);
  162:          my $couldbe='';
  163:          foreach (@possibilities) {
  164:              if ($bighash{'encrypted_'.$_}) { next; }
  165: 	     my $symb=&make_symb($_);
  166:              if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_},$symb)) {
  167: 	         if ($couldbe) {
  168: 		     $couldbe.=','.$_;
  169:                  } else {
  170:                      $couldbe=$_;
  171:                  }
  172:              }
  173: 	 }
  174:          if ($couldbe) {
  175:             @possibilities=split(/\,/,$couldbe);
  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);
  181: 		&Apache::loncommon::content_type($r,'text/html');
  182: 		$r->header_out(Location => 
  183: 			       &Apache::lonnet::absolute_url().
  184: 			       $resurl.'?symb='.$symb);
  185: 		return REDIRECT;
  186: 	    }
  187:             if ($#possibilities>0) {
  188: # ----------------------------------------------- Okay, really multiple choices
  189: 	       &Apache::loncommon::content_type($r,'text/html');
  190:                $r->send_http_header;
  191:                my $start_page=
  192: 		   &Apache::loncommon::start_page('Pick Instance of Resource');
  193:                $r->print(<<ENDSTART);
  194: $start_page
  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:
  200: </p>
  201: <table border="2">
  202: <tr><th>Title</th><th>Part of ...</th></tr>
  203: ENDSTART
  204:                map {
  205: 		   my $resurl=$bighash{'src_'.$_};
  206:                    my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
  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>');
  213:                } @possibilities;
  214:                $r->print('</table>'.&Apache::loncommon::end_page());
  215: 	       untie(%bighash);
  216:                return OK;
  217:             }
  218:          }
  219:       }
  220:       untie(%bighash);
  221:   }
  222: 
  223: # ------------------------------------ This handler should not have been called
  224:    &getlost($r,'Invalid call of handler');
  225:    return OK;
  226: }
  227: 
  228: 1;
  229: __END__
  230: 
  231: 
  232: 
  233: 
  234: 
  235: 
  236: 

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