Return to lonambiguous.pm CVS log

Up to [LON-CAPA] / rat

- Coding style: keys()

    1: # The LearningOnline Network with CAPA
    2: # Handler to resolve ambiguous file locations
    3: #
    4: # $Id: lonambiguous.pm,v 1.26 2014/12/11 01:13:24 raeburn 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: 
   30: 
   31: package Apache::lonambiguous;
   32: 
   33: use strict;
   34: use Apache::lonnet;
   35: use Apache::Constants qw(:common REDIRECT);
   36: use GDBM_File;
   37: use Apache::loncommon;
   38: use Apache::lonlocal;
   39: 
   40: my %bighash;
   41: 
   42: sub cleanup {
   43:     if (tied(%bighash)){
   44: 	&Apache::lonnet::logthis('Cleanup ambiguous: bighash');
   45:         unless (untie(%bighash)) {
   46: 	    &Apache::lonnet::logthis('Failed cleanup ambiguous: bighash');
   47:         }
   48:     }
   49:     return OK;
   50: }
   51: 
   52: # ----------------------------------------------------------- Could not resolve
   53: 
   54: sub getlost {
   55:     my ($r,$errmsg)=@_;
   56:     $errmsg=&mt($errmsg);
   57:     &Apache::loncommon::content_type($r,'text/html');
   58:     $r->send_http_header;
   59:     $r->print(&Apache::loncommon::start_page('Could not handle ambiguous resource reference').
   60: 	      '<div class="LC_warning">'.$errmsg.'</div>'.
   61: 	      &Apache::loncommon::end_page());
   62: }
   63: 
   64: # ================================================================ Main Handler
   65: 
   66: sub make_symb {
   67:     my ($id)=@_;
   68:     my ($mapid,$resid)=split(/\./,$id);
   69:     my $map=$bighash{'map_id_'.$mapid};
   70:     my $res=$bighash{'src_'.$id};
   71:     my $symb=&Apache::lonnet::encode_symb($map,$resid,$res);
   72:     return $symb;
   73: }
   74: 
   75: sub handler {
   76:    my $r=shift;
   77: 
   78:    if ($r->header_only) {
   79:       &Apache::loncommon::content_type($r,'text/html');
   80:       $r->send_http_header;
   81:       return OK;
   82:    }
   83: 
   84: # ---------------------------------------------------------- Is this selecting?
   85:  
   86:    if ($env{'form.selecturl'}) {
   87:        my $envkey;
   88:        if (tie(%bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
   89:                     &GDBM_READER(),0640)) {
   90:           foreach $envkey (keys(%env)) {
   91:              if ($envkey=~/^form\.(\d+)\.(\d+)$/) {
   92: # ---------------------------------------------------- Update symb and redirect
   93: 	         my $mapid=$1;
   94:                  my $resid=$2;
   95:                  my $resurl=$bighash{'src_'.$mapid.'.'.$resid};
   96:                  &Apache::lonnet::symblist($bighash{'map_id_'.$mapid},
   97: 				           $resurl => [$resurl,$resid]);
   98:                  untie(%bighash);
   99:                  $r->header_out(Location => 
  100: 				&Apache::lonnet::absolute_url().$resurl);
  101:                  return REDIRECT;
  102:              }
  103: 	  }
  104:           untie(%bighash);
  105:        } else {
  106:           &getlost($r,'Could not access course structure.');
  107:           return OK;
  108:        }
  109:    }
  110: 
  111: # ---------------------------------------------------------- Do we have a case?
  112: 
  113:    my $thisfn;
  114:    unless (($thisfn=$env{'request.ambiguous'})&&($env{'request.course.fn'})) {
  115:        &getlost($r,'Could not find information on resource.');
  116:        return OK;
  117:    }
  118:       
  119: # ---------------------------------- Should this file have been part of a page?
  120: 
  121:     $thisfn=&Apache::lonnet::declutter($thisfn);
  122:     my %hash;
  123:     my $syval='';
  124:     
  125:     if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
  126:                   &GDBM_READER(),0640)) {
  127:        $syval=$hash{$thisfn};
  128:        untie(%hash);
  129:     }
  130: 
  131: # ---------------------------------------------------------- There was an entry
  132: 
  133:     if ($syval) {
  134: 	my ($page,undef,$res)=&Apache::lonnet::decode_symb($syval);
  135: 	if ($res eq 'page') {
  136: # ----------------------------------- Okay, this should have appeared on a page
  137: 	   &Apache::loncommon::content_type($r,'text/html');
  138:            $r->header_out(Location => 
  139: 			  &Apache::lonnet::absolute_url().
  140: 			  &Apache::lonnet::clutter($page));
  141:            return REDIRECT;
  142:        } else {
  143: #  There is not really a problem (???), but cannot go back without endless loop
  144:            &getlost($r,'The nature of the problem is unclear');
  145:            return OK;
  146:        }
  147:     }
  148: # ------------------------------------Encrypted requests go straight to navmaps
  149:    if ($env{'request.enc'}) {
  150:        &Apache::loncommon::content_type($r,'text/html');
  151:        $r->header_out(Location => 
  152: 		      &Apache::lonnet::absolute_url().'/adm/navmaps');
  153:        return REDIRECT;
  154:    }
  155: # ------------------------------------------------ Would be standalone resource
  156: 
  157:    if (tie(%bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
  158:                     &GDBM_READER(),0640)) {
  159: # ---------------------------------------------- Get ID(s) for current resource
  160:       my $ids=$bighash{'ids_'.&Apache::lonnet::clutter($thisfn)};
  161:       if ($ids) {
  162: # ------------------------------------------------------------------- Has ID(s)
  163:          my @possibilities=split(/\,/,$ids);
  164:          my $couldbe='';
  165:          foreach (@possibilities) {
  166:              if ($bighash{'encrypted_'.$_}) { next; }
  167: 	     my $symb=&make_symb($_);
  168:              if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_},$symb)) {
  169: 	         if ($couldbe) {
  170: 		     $couldbe.=','.$_;
  171:                  } else {
  172:                      $couldbe=$_;
  173:                  }
  174:              }
  175: 	 }
  176:          if ($couldbe) {
  177:             @possibilities=split(/\,/,$couldbe);
  178: 	    if ($#possibilities==0) {
  179: 		my $id=$possibilities[0];
  180: 		my $resurl=$bighash{'src_'.$id};
  181: 		my $mapurl=$bighash{'map_id_'.(split(/\./,$id))[0]};
  182: 		my $symb=&make_symb($id);
  183: 		&Apache::loncommon::content_type($r,'text/html');
  184: 		$r->header_out(Location => 
  185: 			       &Apache::lonnet::absolute_url().
  186: 			       $resurl.'?symb='.$symb);
  187: 		return REDIRECT;
  188: 	    }
  189:             if ($#possibilities>0) {
  190: # ----------------------------------------------- Okay, really multiple choices
  191: 	       &Apache::loncommon::content_type($r,'text/html');
  192:                $r->send_http_header;
  193:                my $start_page=
  194: 		   &Apache::loncommon::start_page('Pick Instance of Resource');
  195:                $r->print(
  196:                    $start_page
  197:                   .'<p class="LC_warning">'
  198:                   .&mt('The resource you had been accessing appears more than'
  199:                       .' once in this course, and LON-CAPA has insufficient'
  200:                       .' session information to determine which instance'
  201:                       .' of the resource you meant.')
  202:                   .'</p>'
  203:                   .'<p>'
  204:                   .&mt('Please click on the instance of the resource you'
  205:                       .' intended to access:')
  206:                   .'</p>'
  207:                );
  208:                $r->print(
  209:                    &Apache::loncommon::start_data_table()
  210:                   .&Apache::loncommon::start_data_table_header_row()
  211:                   .'<th>'.&mt('Title').'</th>'
  212:                   .'<th>'.&mt('Part of ...').'</th>'
  213:                   .&Apache::loncommon::end_data_table_header_row()
  214:                   .&Apache::loncommon::start_data_table_row()
  215:                );
  216:                map {
  217:                    my $resurl=$bighash{'src_'.$_};
  218:                    my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
  219:                    my $symb=&make_symb($_);
  220:                    $r->print(
  221:                        &Apache::loncommon::start_data_table_row()
  222:                       .'<td><a href="'.$resurl.'?symb='.$symb.'">'
  223:                       .&Apache::lonnet::gettitle($symb)
  224:                       .'</a></td>'
  225:                       .'<td>'.&Apache::lonnet::gettitle($mapurl).'&nbsp;</td>'
  226:                       .&Apache::loncommon::end_data_table_row()
  227:                    );
  228:                } @possibilities;
  229:                $r->print(
  230:                    &Apache::loncommon::end_data_table()
  231:                   .&Apache::loncommon::end_page()
  232:                );
  233:                untie(%bighash);
  234:                return OK;
  235:             }
  236:          }
  237:       }
  238:       untie(%bighash);
  239:   }
  240: 
  241: # ------------------------------------ This handler should not have been called
  242:    &getlost($r,'Invalid call of handler');
  243:    return OK;
  244: }
  245: 
  246: 1;
  247: __END__
  248: 
  249: 
  250: 
  251: =head1 NAME
  252: 
  253: Apache::lonambiguous
  254: 
  255: =head1 SYNOPSIS
  256: 
  257: Handler to resolve ambiguous file locations.
  258: 
  259: This is part of the LearningOnline Network with CAPA project
  260: described at http://www.lon-capa.org.
  261: 
  262: =head1 HANDLER SUBROUTINE
  263: 
  264: make_symb()
  265: 
  266: and
  267: 
  268: handler()
  269: 
  270: =head1 OTHER SUBROUTINES
  271: 
  272: =over
  273: 
  274: =item *
  275: 
  276: cleanup()
  277: 
  278: =item *
  279: 
  280: getlost()
  281: 
  282: =back
  283: 
  284: =cut
  285: 
  286: 
  287: 
  288: