rat/lonambiguous.pm - view

File: [LON-CAPA] / rat / lonambiguous.pm
Revision 1.11: download - view: text, annotated - select for diffs
Fri Dec 17 22:40:24 2004 UTC (19 years, 4 months ago) by albertel
Branches: MAIN
CVS tags: HEAD

 BUG# 3714

1: # The LearningOnline Network with CAPA 2: # Handler to resolve ambiguous file locations 3: # 4: # $Id: lonambiguous.pm,v 1.11 2004/12/17 22:40:24 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: # (TeX Content Handler 29: # 30: # 05/29/00,05/30,10/11 Gerd Kortemeyer) 31: # 32: # 10/11,10/12,10/16 Gerd Kortemeyer 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: use Apache::loncommon; 41: use Apache::lonlocal; 42: 43: my %bighash; 44: 45: sub cleanup { 46: if (tied(%bighash)){ 47: &Apache::lonnet::logthis('Cleanup ambiguous: bighash'); 48: unless (untie(%bighash)) { 49: &Apache::lonnet::logthis('Failed cleanup ambiguous: bighash'); 50: } 51: } 52: } 53: 54: # ----------------------------------------------------------- Could not resolve 55: 56: sub getlost { 57: my ($r,$errmsg)=@_; 58: $errmsg=&mt($errmsg); 59: $r->content_type('text/html'); 60: $r->send_http_header; 61: $r->print( 62: '<head><title>Unknown Error</title></head>'. 63: &Apache::loncommon::bodytag('Could not handle ambiguous resource reference'). 64: $errmsg. 65: '</body></html>'); 66: } 67: 68: # ================================================================ Main Handler 69: 70: sub make_symb { 71: my ($id)=@_; 72: my ($mapid,$resid)=split(/\./,$id); 73: my $map=$bighash{'map_id_'.$mapid}; 74: my $res=$bighash{'src_'.$id}; 75: my $symb=&Apache::lonnet::encode_symb($map,$resid,$res); 76: return $symb; 77: } 78: 79: sub handler { 80: my $r=shift; 81: 82: if ($r->header_only) { 83: &Apache::loncommon::content_type($r,'text/html'); 84: $r->send_http_header; 85: return OK; 86: } 87: 88: # ---------------------------------------------------------- Is this selecting? 89: 90: if ($ENV{'form.selecturl'}) { 91: my $envkey; 92: if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db', 93: &GDBM_READER(),0640)) { 94: foreach $envkey (keys %ENV) { 95: if ($envkey=~/^form\.(\d+)\.(\d+)$/) { 96: # ---------------------------------------------------- Update symb and redirect 97: my $mapid=$1; 98: my $resid=$2; 99: my $resurl=$bighash{'src_'.$mapid.'.'.$resid}; 100: &Apache::lonnet::symblist($bighash{'map_id_'.$mapid}, 101: $resurl => $resid); 102: untie(%bighash); 103: $r->header_out(Location => 104: 'http://'.$ENV{'HTTP_HOST'}.$resurl); 105: return REDIRECT; 106: } 107: } 108: untie(%bighash); 109: } else { 110: &getlost($r,'Could not access course structure.'); 111: return OK; 112: } 113: } 114: 115: # ---------------------------------------------------------- Do we have a case? 116: 117: my $thisfn; 118: unless (($thisfn=$ENV{'request.ambiguous'})&&($ENV{'request.course.fn'})) { 119: &getlost($r,'Could not find information on resource.'); 120: return OK; 121: } 122: 123: # ---------------------------------- Should this file have been part of a page? 124: 125: $thisfn=&Apache::lonnet::declutter($thisfn); 126: my %hash; 127: my $syval=''; 128: 129: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db', 130: &GDBM_READER(),0640)) { 131: $syval=$hash{$thisfn}; 132: untie(%hash); 133: } 134: 135: # ---------------------------------------------------------- There was an entry 136: 137: if ($syval) { 138: 139: if ($syval=~/\_$/) { 140: # ----------------------------------- Okay, this should have appeared on a page 141: $syval=~s/\_\_\_$//; 142: $r->content_type('text/html'); 143: $r->header_out(Location => 144: 'http://'.$ENV{'HTTP_HOST'}.'/res/'.$syval); 145: return REDIRECT; 146: } else { 147: # There is not really a problem (???), but cannot go back without endless loop 148: &getlost($r,'The nature of the problem is unclear'); 149: return OK; 150: } 151: } 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: # ----------------------------------------------- Okay, really multiple choices 178: $r->content_type('text/html'); 179: $r->send_http_header; 180: my $bodytag= 181: &Apache::loncommon::bodytag('Pick Instance of Resource'); 182: $r->print(<<ENDSTART); 183: <head><title>Choose Location</title></head> 184: $bodytag 185: The resource you had been accessing appears more than once in this course, 186: and LON-CAPA has insufficient session information to determine which instance 187: of the resource you meant. 188: <p> 189: Please click on the instance of the resource you intended to access: 190: </p> 191: <table border="2"> 192: <tr><th>Title</th><th>Part of ...</th></tr> 193: ENDSTART 194: map { 195: my $resurl=$bighash{'src_'.$_}; 196: my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]}; 197: my $symb=&make_symb($_); 198: $r->print('<tr><td><a href="'.$resurl.'?symb='.$symb.'">'. 199: &Apache::lonnet::gettitle($symb). 200: '</a></td><td>'. 201: &Apache::lonnet::gettitle($mapurl).' '. 202: '</td></tr>'); 203: } @possibilities; 204: $r->print('</table></body></html>'); 205: untie(%bighash); 206: return OK; 207: } 208: } 209: } 210: untie(%bighash); 211: } 212: 213: # ------------------------------------ This handler should not have been called 214: &getlost($r,'Invalid call of handler'); 215: return OK; 216: } 217: 218: 1; 219: __END__ 220: 221: 222: 223: 224: 225: 226: