# The LearningOnline Network with CAPA # Handler to resolve ambiguous file locations # # $Id: lonambiguous.pm,v 1.6 2002/09/14 18:57:59 www Exp $ # # Copyright Michigan State University Board of Trustees # # This file is part of the LearningOnline Network with CAPA (LON-CAPA). # # LON-CAPA is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # LON-CAPA is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with LON-CAPA; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # # /home/httpd/html/adm/gpl.txt # # http://www.lon-capa.org/ # # (TeX Content Handler # # 05/29/00,05/30,10/11 Gerd Kortemeyer) # # 10/11,10/12,10/16 Gerd Kortemeyer package Apache::lonambiguous; use strict; use Apache::lonnet; use Apache::Constants qw(:common REDIRECT); use GDBM_File; # ----------------------------------------------------------- Could not resolve sub getlost { my ($r,$errmsg)=@_; $r->content_type('text/html'); $r->send_http_header; $r->print( 'Unknown Error

'. 'LON-CAPA

Could not handle ambiguous resource reference.

'.$errmsg. ''); } # ================================================================ Main Handler sub handler { my $r=shift; if ($r->header_only) { $r->content_type('text/html'); $r->send_http_header; return OK; } # ---------------------------------------------------------- Is this selecting? my %bighash; if ($ENV{'form.selecturl'}) { my $envkey; if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db', &GDBM_READER(),0640)) { foreach $envkey (keys %ENV) { if ($envkey=~/^form\.(\d+)\.(\d+)$/) { # ---------------------------------------------------- Update symb and redirect my $mapid=$1; my $resid=$2; my $resurl=$bighash{'src_'.$mapid.'.'.$resid}; &Apache::lonnet::symblist($bighash{'map_id_'.$mapid}, $resurl => $resid); untie(%bighash); $r->header_out(Location => 'http://'.$ENV{'HTTP_HOST'}.$resurl); return REDIRECT; } } untie(%bighash); } else { &getlost($r,'Could not access course structure.'); return OK; } } # ---------------------------------------------------------- Do we have a case? my $thisfn; unless (($thisfn=$ENV{'request.ambiguous'})&&($ENV{'request.course.fn'})) { &getlost($r,'Could not find information on resource.'); return OK; } # ---------------------------------- Should this file have been part of a page? $thisfn=&Apache::lonnet::declutter($thisfn); my %hash; my $syval=''; if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db', &GDBM_READER(),0640)) { $syval=$hash{$thisfn}; untie(%hash); } # ---------------------------------------------------------- There was an entry if ($syval) { if ($syval=~/\_$/) { # ----------------------------------- Okay, this should have appeared on a page $syval=~s/\_\_\_$//; $r->content_type('text/html'); $r->header_out(Location => 'http://'.$ENV{'HTTP_HOST'}.'/res/'.$syval); return REDIRECT; } else { # There is not really a problem (???), but cannot go back without endless loop &getlost($r,'The nature of the problem is unclear'); return OK; } } # ------------------------------------------------ Would be standalone resource if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db', &GDBM_READER(),0640)) { # ---------------------------------------------- Get ID(s) for current resource my $ids=$bighash{'ids_'.&clutter($thisfn)}; if ($ids) { # ------------------------------------------------------------------- Has ID(s) my @possibilities=split(/\,/,$ids); my $couldbe=''; map { if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_})) { if ($couldbe) { $couldbe.=','.$_; } else { $couldbe=$_; } } } @possibilities; if ($couldbe) { @possibilities=split(/\,/,$couldbe); if ($#possibilities>0) { # ----------------------------------------------- Okay, really multiple choices $r->content_type('text/html'); $r->send_http_header; $r->print(<Choose Location

LON-CAPA

The resource you had been accessing appears more than once in this course, and LON-CAPA has insufficient session information to determine which instance of the resource you meant.

Please click on the instance of the resource you intended to access:

ENDSTART map { my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]}; $r->print(''); } @possibilities; $r->print('
 TitleTypePart of ...
'.$bighash{'title_'.$_}. ''.$bighash{'type_'.$_}. ''.$mapurl. '
'); untie(%bighash); return OK; } } } untie(%bighash); } # ------------------------------------ This handler should not have been called &getlost($r,'Invalid call of handler'); return OK; } 1; __END__ 500 Internal Server Error

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator at root@localhost to inform them of the time this error occurred, and the actions you performed just before this error.

More information about this error may be available in the server error log.