1: # The LearningOnline Network with CAPA
2: #
3: # Page flip handler
4: #
5: # $Id: lonpageflip.pm,v 1.31 2002/10/10 19:05:32 www Exp $
6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
10: #
11: # LON-CAPA is free software; you can redistribute it and/or modify
12: # it under the terms of the GNU General Public License as published by
13: # the Free Software Foundation; either version 2 of the License, or
14: # (at your option) any later version.
15: #
16: # LON-CAPA is distributed in the hope that it will be useful,
17: # but WITHOUT ANY WARRANTY; without even the implied warranty of
18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19: # GNU General Public License for more details.
20: #
21: # You should have received a copy of the GNU General Public License
22: # along with LON-CAPA; if not, write to the Free Software
23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24: #
25: # /home/httpd/html/adm/gpl.txt
26: #
27: # http://www.lon-capa.org/
28: #
29: # (Page Handler
30: #
31: # (TeX Content Handler
32: #
33: # 05/29/00,05/30 Gerd Kortemeyer)
34: # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
35: # 10/02 Gerd Kortemeyer)
36: #
37: # 10/03,10/05,10/06,10/07,10/09,10/10,10/11,10/16,10/17,
38: # 11/14,11/16,
39: # 10/01/01,05/01,05/28,07/05 Gerd Kortemeyer
40:
41: package Apache::lonpageflip;
42:
43: use strict;
44: use Apache::Constants qw(:common :http REDIRECT);
45: use Apache::lonnet();
46: use HTML::TokeParser;
47: use GDBM_File;
48:
49: # ========================================================== Module Global Hash
50:
51: my %hash;
52:
53: sub addrid {
54: my ($current,$new,$condid)=@_;
55: unless ($condid) { $condid=0; }
56:
57: if ($current) {
58: $current.=','.$new;
59: } else {
60: $current=''.$new;
61: }
62:
63: return $current;
64: }
65:
66: sub fullmove {
67: my ($rid,$mapurl,$direction)=@_;
68: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
69: &GDBM_READER(),0640)) {
70: ($rid,$mapurl)=&move($rid,$mapurl,$direction);
71: untie(%hash);
72: }
73: return($rid,$mapurl);
74: }
75:
76: sub move {
77: my ($rid,$mapurl,$direction)=@_;
78: my $startoutrid=$rid;
79:
80: my $next='';
81:
82: my $mincond=1;
83: my $posnext='';
84: if ($direction eq 'forward') {
85: # --------------------------------------------------------------------- Forward
86: if ($hash{'type_'.$rid} eq 'finish') {
87: $rid=$hash{'ids_'.&Apache::lonnet::clutter($mapurl)};
88: }
89: map {
90: my $thiscond=
91: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
92: if ($thiscond>=$mincond) {
93: if ($posnext) {
94: $posnext.=','.$_.':'.$thiscond;
95: } else {
96: $posnext=$_.':'.$thiscond;
97: }
98: if ($thiscond>$mincond) { $mincond=$thiscond; }
99: }
100: } split(/\,/,$hash{'to_'.$rid});
101: map {
102: my ($linkid,$condval)=split(/\:/,$_);
103: if ($condval>=$mincond) {
104: $next=&addrid($next,$hash{'goesto_'.$linkid},
105: $hash{'condid_'.$hash{'undercond_'.$linkid}});
106: }
107: } split(/\,/,$posnext);
108: if ($hash{'is_map_'.$next}) {
109: # This jumps to the beginning of a new map (going down level)
110: if (
111: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
112: $mapurl=$hash{'src_'.$next};
113: $next=$hash{'map_start_'.$hash{'src_'.$next}};
114: }
115: } elsif
116: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
117: # This comes up from a map (coming up one level);
118: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
119: }
120: } elsif ($direction eq 'back') {
121: # ------------------------------------------------------------------- Backwards
122: if ($hash{'type_'.$rid} eq 'start') {
123: $rid=$hash{'ids_'.&Apache::lonnet::clutter($mapurl)};
124: }
125: map {
126: my $thiscond=
127: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
128: if ($thiscond>=$mincond) {
129: if ($posnext) {
130: $posnext.=','.$_.':'.$thiscond;
131: } else {
132: $posnext=$_.':'.$thiscond;
133: }
134: if ($thiscond>$mincond) { $mincond=$thiscond; }
135: }
136: } split(/\,/,$hash{'from_'.$rid});
137: map {
138: my ($linkid,$condval)=split(/\:/,$_);
139: if ($condval>=$mincond) {
140: $next=&addrid($next,$hash{'comesfrom_'.$linkid},
141: $hash{'condid_'.$hash{'undercond_'.$linkid}});
142: }
143: } split(/\,/,$posnext);
144: if ($hash{'is_map_'.$next}) {
145: # This jumps to the end of a new map (going down one level)
146: if (
147: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
148: $mapurl=$hash{'src_'.$next};
149: $next=$hash{'map_finish_'.$hash{'src_'.$next}};
150: }
151: } elsif
152: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
153: # This comes back up from a map (going up one level);
154: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
155: }
156: }
157: return ($next,$mapurl);
158: }
159:
160: # ================================================================ Main Handler
161:
162: sub handler {
163: my $r=shift;
164:
165: # ------------------------------------------- Set document type for header only
166:
167: if ($r->header_only) {
168: $r->content_type('text/html');
169: $r->send_http_header;
170: return OK;
171: }
172:
173: my %cachehash=();
174: my $multichoice=0;
175: my %multichoicehash=();
176: my $redirecturl='';
177: my $next='';
178: my @possibilities=();
179: if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
180: $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
181: my $direction=$1;
182: my $currenturl=$2;
183: if ($direction eq 'return') {
184: # -------------------------------------------------------- Return to last known
185: my $last;
186: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
187: &GDBM_READER(),0640)) {
188: $last=$hash{'last_known'};
189: untie(%hash);
190: }
191: my $newloc;
192: if ($last) {
193: $newloc=&Apache::lonnet::clutter((split(/\_\_\_/,$last))[1]);
194: } else {
195: $newloc='/adm/noidea.html';
196: }
197: $r->content_type('text/html');
198: $r->header_out(Location =>
199: 'http://'.$ENV{'HTTP_HOST'}.$newloc);
200:
201: return REDIRECT;
202: }
203: $currenturl=~s/^http\:\/\///;
204: $currenturl=~s/^[^\/]+//;
205: unless ($currenturl=~/^\/(res|adm\/wrapper|public|adm\/coursedocs)\//) {
206: my $last;
207: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
208: &GDBM_READER(),0640)) {
209: $last=$hash{'last_known'};
210: untie(%hash);
211: }
212: if ($last) {
213: $currenturl=&Apache::lonnet::clutter((split(/\_\_\_/,$last))[1]);
214: } else {
215: $r->content_type('text/html');
216: $r->header_out(Location =>
217: 'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
218: return REDIRECT;
219: }
220: }
221: # ------------------------------------------- Do we have any idea where we are?
222: my $position;
223: if ($position=Apache::lonnet::symbread($currenturl)) {
224: # ------------------------------------------------------------------------- Yes
225: my ($startoutmap,$mapnum,$thisurl)=split(/\_\_\_/,$position);
226: $cachehash{$startoutmap}{$thisurl}=$mapnum;
227: $cachehash{$startoutmap}{'last_known'}=
228: &Apache::lonnet::declutter($currenturl);
229:
230: # ============================================================ Tie the big hash
231: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
232: &GDBM_READER(),0640)) {
233: my $rid=$hash{'map_pc_'.&Apache::lonnet::clutter($startoutmap)}.
234: '.'.$mapnum;
235:
236: # ------------------------------------------------- Move forward, backward, etc
237: my $endupmap;
238: ($next,$endupmap)=&move($rid,$startoutmap,$direction);
239: # -------------------------------------- Do we have one and only one empty URL?
240: my $safecount=0;
241: while (($next) && ($next!~/\,/) &&
242: ((!$hash{'src_'.$next}) || ($hash{'randomout_'.$next}))
243: && ($safecount<10000)) {
244: ($next,$endupmap)=&move($next,$endupmap,$direction);
245: $safecount++;
246: }
247: # We are now at at least one non-empty URL
248: # ----------------------------------------------------- Check out possibilities
249: if ($next) {
250: @possibilities=split(/\,/,$next);
251: if ($#possibilities==0) {
252: # ---------------------------------------------- Only one possibility, redirect
253: $redirecturl=$hash{'src_'.$next};
254: $cachehash{$endupmap}
255: {&Apache::lonnet::declutter($redirecturl)}
256: =(split(/\./,$next))[1];
257: } else {
258: # ------------------------ There are multiple possibilities for a next resource
259: $multichoice=1;
260: map {
261: $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
262: $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
263: $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
264: my ($choicemap,$choiceres)=split(/\./,$_);
265: $cachehash
266: {&Apache::lonnet::declutter($hash{'src_'.$choicemap})}
267: {&Apache::lonnet::declutter(
268: $multichoicehash
269: {'src_'.$_}
270: )}
271: =$choiceres;
272: } @possibilities;
273: }
274: } else {
275: # -------------------------------------------------------------- No place to go
276: $multichoice=-1;
277: }
278: # ----------------- The program must come past this point to untie the big hash
279: untie(%hash);
280: # --------------------------------------------------------- Store position info
281: $cachehash{$startoutmap}{'last_direction'}=$direction;
282: foreach my $thismap (keys %cachehash) {
283: &Apache::lonnet::symblist($thismap,%{$cachehash{$thismap}});
284: }
285: # ============================================== Do not return before this line
286: if ($redirecturl) {
287: # ----------------------------------------------------- There is a URL to go to
288: # ------------------------------------------------- Check for critical messages
289: if ((time-$ENV{'user.criticalcheck.time'})>300) {
290: my @what=&Apache::lonnet::dump
291: ('critical',$ENV{'user.domain'},
292: $ENV{'user.name'});
293: if ($what[0]) {
294: if (($what[0] ne 'con_lost') &&
295: ($what[0]!~/^error\:/)) {
296: $redirecturl='/adm/email?critical=display';
297: }
298: }
299: &Apache::lonnet::appenv('user.criticalcheck.time'=>time);
300: }
301:
302: $r->content_type('text/html');
303: $r->header_out(Location =>
304: 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
305: return REDIRECT;
306: } else {
307: # --------------------------------------------------------- There was a problem
308: $r->content_type('text/html');
309: $r->send_http_header;
310: if ($#possibilities>0) {
311: $r->print(<<ENDSTART);
312: <head><title>Choose Next Location</title></head>
313: <body bgcolor="#FFFFFF">
314: <h1>LON-CAPA</h1>
315: There are several possibilities of where to go next.
316: <p>
317: Please click on the the resource you intend to access:
318: <p>
319: <table border=2>
320: <tr><th>Title</th><th>Type</th></tr>
321: ENDSTART
322: foreach (@possibilities) {
323: $r->print(
324: '<tr><td><a href="'.
325: $multichoicehash{'src_'.$_}.'">'.
326: $multichoicehash{'title_'.$_}.
327: '</a></td><td>'.$multichoicehash{'type_'.$_}.
328: '</td></tr>');
329: }
330: $r->print('</table></body></html>');
331: return OK;
332: } else {
333: $r->print(<<ENDNONE);
334: <head><title>Choose Next Location</title></head>
335: <body bgcolor="#FFFFFF">
336: <img src="/adm/lonIcons/lonlogos.gif" align=right>
337: <h1>Sorry!</h1>
338: <h2>Next resource could not be identified.</h2>
339: <h3>You probably are at the beginning or the end of the course.</h3>
340: </body>
341: </html>
342: ENDNONE
343: return OK;
344: }
345: }
346: } else {
347: # ------------------------------------------------- Problem, could not tie hash
348: $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
349: return HTTP_NOT_ACCEPTABLE;
350: }
351: } else {
352: # ---------------------------------------- No, could not determine where we are
353: $r->internal_redirect('/adm/ambiguous');
354: }
355: } else {
356: # -------------------------- Class was not initialized or page fliped strangely
357: $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
358: return HTTP_NOT_ACCEPTABLE;
359: }
360: }
361:
362: 1;
363: __END__
364:
365:
366:
367:
368:
369:
370:
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