File:
[LON-CAPA] /
rat /
lonambiguous.pm
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1.23:
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Thu Nov 20 15:19:05 2008 UTC (15 years, 10 months ago) by
jms
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CVS tags:
version_2_9_X,
version_2_9_99_0,
version_2_9_1,
version_2_9_0,
version_2_8_99_1,
version_2_8_99_0,
version_2_10_X,
version_2_10_1,
version_2_10_0_RC2,
version_2_10_0_RC1,
version_2_10_0,
loncapaMITrelate_1,
language_hyphenation_merge,
language_hyphenation,
bz6209-base,
bz6209,
bz5969,
bz2851,
HEAD,
GCI_3,
GCI_2,
BZ4492-merge,
BZ4492-feature_horizontal_radioresponse,
BZ4492-feature_Support_horizontal_radioresponse
Moved POD comments to bottom of file
1: # The LearningOnline Network with CAPA
2: # Handler to resolve ambiguous file locations
3: #
4: # $Id: lonambiguous.pm,v 1.23 2008/11/20 15:19:05 jms 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: $errmsg.
61: &Apache::loncommon::end_page());
62: }
63:
64: # ================================================================ Main Handler
65:
66: sub make_symb {
67: my ($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(<<ENDSTART);
196: $start_page
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:
202: </p>
203: <table border="2">
204: <tr><th>Title</th><th>Part of ...</th></tr>
205: ENDSTART
206: map {
207: my $resurl=$bighash{'src_'.$_};
208: my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]};
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>');
215: } @possibilities;
216: $r->print('</table>'.&Apache::loncommon::end_page());
217: untie(%bighash);
218: return OK;
219: }
220: }
221: }
222: untie(%bighash);
223: }
224:
225: # ------------------------------------ This handler should not have been called
226: &getlost($r,'Invalid call of handler');
227: return OK;
228: }
229:
230: 1;
231: __END__
232:
233:
234:
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
269:
270:
271:
272:
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