Annotation of rat/lonambiguous.pm, revision 1.23
1.1 www 1: # The LearningOnline Network with CAPA
2: # Handler to resolve ambiguous file locations
3: #
1.23 ! jms 4: # $Id: lonambiguous.pm,v 1.22 2008/11/11 16:06:46 jms 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:
1.22 jms 29:
30:
1.1 www 31: package Apache::lonambiguous;
32:
33: use strict;
34: use Apache::lonnet;
35: use Apache::Constants qw(:common REDIRECT);
36: use GDBM_File;
1.9 www 37: use Apache::loncommon;
1.10 www 38: use Apache::lonlocal;
1.1 www 39:
1.8 www 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: }
1.17 albertel 49: return OK;
1.8 www 50: }
1.1 www 51:
52: # ----------------------------------------------------------- Could not resolve
53:
54: sub getlost {
1.2 www 55: my ($r,$errmsg)=@_;
1.10 www 56: $errmsg=&mt($errmsg);
1.14 albertel 57: &Apache::loncommon::content_type($r,'text/html');
1.1 www 58: $r->send_http_header;
1.18 albertel 59: $r->print(&Apache::loncommon::start_page('Could not handle ambiguous resource reference').
60: $errmsg.
1.19 albertel 61: &Apache::loncommon::end_page());
1.1 www 62: }
63:
64: # ================================================================ Main Handler
65:
1.11 albertel 66: sub make_symb {
67: my ($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:
1.1 www 75: sub handler {
76: my $r=shift;
77:
78: if ($r->header_only) {
1.10 www 79: &Apache::loncommon::content_type($r,'text/html');
1.1 www 80: $r->send_http_header;
81: return OK;
82: }
83:
1.2 www 84: # ---------------------------------------------------------- Is this selecting?
1.8 www 85:
1.16 albertel 86: if ($env{'form.selecturl'}) {
1.2 www 87: my $envkey;
1.16 albertel 88: if (tie(%bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
1.5 albertel 89: &GDBM_READER(),0640)) {
1.16 albertel 90: foreach $envkey (keys %env) {
1.2 www 91: if ($envkey=~/^form\.(\d+)\.(\d+)$/) {
1.3 www 92: # ---------------------------------------------------- Update symb and redirect
1.2 www 93: my $mapid=$1;
94: my $resid=$2;
95: my $resurl=$bighash{'src_'.$mapid.'.'.$resid};
96: &Apache::lonnet::symblist($bighash{'map_id_'.$mapid},
1.15 albertel 97: $resurl => [$resurl,$resid]);
1.3 www 98: untie(%bighash);
1.2 www 99: $r->header_out(Location =>
1.21 albertel 100: &Apache::lonnet::absolute_url().$resurl);
1.2 www 101: return REDIRECT;
102: }
103: }
104: untie(%bighash);
105: } else {
106: &getlost($r,'Could not access course structure.');
107: return OK;
108: }
109: }
110:
1.1 www 111: # ---------------------------------------------------------- Do we have a case?
112:
113: my $thisfn;
1.16 albertel 114: unless (($thisfn=$env{'request.ambiguous'})&&($env{'request.course.fn'})) {
1.2 www 115: &getlost($r,'Could not find information on resource.');
1.1 www 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 $syval='';
124:
1.16 albertel 125: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
1.5 albertel 126: &GDBM_READER(),0640)) {
1.1 www 127: $syval=$hash{$thisfn};
128: untie(%hash);
129: }
1.2 www 130:
1.1 www 131: # ---------------------------------------------------------- There was an entry
1.2 www 132:
1.1 www 133: if ($syval) {
1.15 albertel 134: my ($page,undef,$res)=&Apache::lonnet::decode_symb($syval);
135: if ($res eq 'page') {
1.1 www 136: # ----------------------------------- Okay, this should have appeared on a page
1.14 albertel 137: &Apache::loncommon::content_type($r,'text/html');
1.1 www 138: $r->header_out(Location =>
1.21 albertel 139: &Apache::lonnet::absolute_url().
1.15 albertel 140: &Apache::lonnet::clutter($page));
1.1 www 141: return REDIRECT;
142: } else {
143: # There is not really a problem (???), but cannot go back without endless loop
1.2 www 144: &getlost($r,'The nature of the problem is unclear');
1.1 www 145: return OK;
146: }
147: }
1.13 albertel 148: # ------------------------------------Encrypted requests go straight to navmaps
1.16 albertel 149: if ($env{'request.enc'}) {
1.14 albertel 150: &Apache::loncommon::content_type($r,'text/html');
1.20 albertel 151: $r->header_out(Location =>
1.21 albertel 152: &Apache::lonnet::absolute_url().'/adm/navmaps');
1.13 albertel 153: return REDIRECT;
154: }
1.1 www 155: # ------------------------------------------------ Would be standalone resource
156:
1.16 albertel 157: if (tie(%bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
1.5 albertel 158: &GDBM_READER(),0640)) {
1.1 www 159: # ---------------------------------------------- Get ID(s) for current resource
1.7 albertel 160: my $ids=$bighash{'ids_'.&Apache::lonnet::clutter($thisfn)};
1.1 www 161: if ($ids) {
162: # ------------------------------------------------------------------- Has ID(s)
163: my @possibilities=split(/\,/,$ids);
164: my $couldbe='';
1.11 albertel 165: foreach (@possibilities) {
166: if ($bighash{'encrypted_'.$_}) { next; }
167: my $symb=&make_symb($_);
168: if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_},$symb)) {
1.1 www 169: if ($couldbe) {
170: $couldbe.=','.$_;
171: } else {
172: $couldbe=$_;
173: }
174: }
1.11 albertel 175: }
1.1 www 176: if ($couldbe) {
177: @possibilities=split(/\,/,$couldbe);
1.12 albertel 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);
1.14 albertel 183: &Apache::loncommon::content_type($r,'text/html');
1.12 albertel 184: $r->header_out(Location =>
1.21 albertel 185: &Apache::lonnet::absolute_url().
1.20 albertel 186: $resurl.'?symb='.$symb);
1.12 albertel 187: return REDIRECT;
188: }
1.1 www 189: if ($#possibilities>0) {
190: # ----------------------------------------------- Okay, really multiple choices
1.14 albertel 191: &Apache::loncommon::content_type($r,'text/html');
1.1 www 192: $r->send_http_header;
1.18 albertel 193: my $start_page=
194: &Apache::loncommon::start_page('Pick Instance of Resource');
1.2 www 195: $r->print(<<ENDSTART);
1.18 albertel 196: $start_page
1.2 www 197: The resource you had been accessing appears more than once in this course,
198: and LON-CAPA has insufficient session information to determine which instance
199: of the resource you meant.
200: <p>
201: Please click on the instance of the resource you intended to access:
1.11 albertel 202: </p>
203: <table border="2">
204: <tr><th>Title</th><th>Part of ...</th></tr>
1.2 www 205: ENDSTART
206: map {
1.11 albertel 207: my $resurl=$bighash{'src_'.$_};
1.2 www 208: my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
1.11 albertel 209: my $symb=&make_symb($_);
210: $r->print('<tr><td><a href="'.$resurl.'?symb='.$symb.'">'.
211: &Apache::lonnet::gettitle($symb).
212: '</a></td><td>'.
213: &Apache::lonnet::gettitle($mapurl).' '.
214: '</td></tr>');
1.2 www 215: } @possibilities;
1.18 albertel 216: $r->print('</table>'.&Apache::loncommon::end_page());
1.1 www 217: untie(%bighash);
218: return OK;
219: }
220: }
221: }
222: untie(%bighash);
223: }
224:
225: # ------------------------------------ This handler should not have been called
1.2 www 226: &getlost($r,'Invalid call of handler');
1.1 www 227: return OK;
228: }
229:
230: 1;
231: __END__
232:
233:
234:
1.23 ! jms 235: =head1 NAME
! 236:
! 237: Apache::lonambiguous
! 238:
! 239: =head1 SYNOPSIS
! 240:
! 241: Handler to resolve ambiguous file locations.
! 242:
! 243: This is part of the LearningOnline Network with CAPA project
! 244: described at http://www.lon-capa.org.
! 245:
! 246: =head1 HANDLER SUBROUTINE
! 247:
! 248: make_symb()
! 249:
! 250: and
! 251:
! 252: handler()
! 253:
! 254: =head1 OTHER SUBROUTINES
! 255:
! 256: =over
! 257:
! 258: =item *
! 259:
! 260: cleanup()
! 261:
! 262: =item *
! 263:
! 264: getlost()
! 265:
! 266: =back
! 267:
! 268: =cut
1.1 www 269:
270:
271:
272:
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