1: # The LearningOnline Network with CAPA
2: #
3: # Page flip handler
4: #
5: # $Id: lonpageflip.pm,v 1.36 2003/03/03 20:24:25 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 cleanup {
54: if (tied(%hash)){
55: &Apache::lonnet::logthis('Cleanup pageflip: hash');
56: unless (untie(%hash)) {
57: &Apache::lonnet::logthis('Failed cleanup pageflip: hash');
58: }
59: }
60: }
61:
62: sub addrid {
63: my ($current,$new,$condid)=@_;
64: unless ($condid) { $condid=0; }
65:
66: if ($current) {
67: $current.=','.$new;
68: } else {
69: $current=''.$new;
70: }
71:
72: return $current;
73: }
74:
75: sub fullmove {
76: my ($rid,$mapurl,$direction)=@_;
77: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
78: &GDBM_READER(),0640)) {
79: ($rid,$mapurl)=&move($rid,$mapurl,$direction);
80: untie(%hash);
81: }
82: return($rid,$mapurl);
83: }
84:
85: sub move {
86: my ($rid,$mapurl,$direction)=@_;
87: my $startoutrid=$rid;
88:
89: my $next='';
90:
91: my $mincond=1;
92: my $posnext='';
93: if ($direction eq 'forward') {
94: # --------------------------------------------------------------------- Forward
95: while ($hash{'type_'.$rid} eq 'finish') {
96: $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}};
97: }
98: map {
99: my $thiscond=
100: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
101: if ($thiscond>=$mincond) {
102: if ($posnext) {
103: $posnext.=','.$_.':'.$thiscond;
104: } else {
105: $posnext=$_.':'.$thiscond;
106: }
107: if ($thiscond>$mincond) { $mincond=$thiscond; }
108: }
109: } split(/\,/,$hash{'to_'.$rid});
110: map {
111: my ($linkid,$condval)=split(/\:/,$_);
112: if ($condval>=$mincond) {
113: $next=&addrid($next,$hash{'goesto_'.$linkid},
114: $hash{'condid_'.$hash{'undercond_'.$linkid}});
115: }
116: } split(/\,/,$posnext);
117: if ($hash{'is_map_'.$next}) {
118: # This jumps to the beginning of a new map (going down level)
119: if (
120: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
121: $mapurl=$hash{'src_'.$next};
122: $next=$hash{'map_start_'.$hash{'src_'.$next}};
123: }
124: } elsif
125: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
126: # This comes up from a map (coming up one level);
127: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
128: }
129: } elsif ($direction eq 'back') {
130: # ------------------------------------------------------------------- Backwards
131: while ($hash{'type_'.$rid} eq 'start') {
132: $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}};
133: }
134: map {
135: my $thiscond=
136: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
137: if ($thiscond>=$mincond) {
138: if ($posnext) {
139: $posnext.=','.$_.':'.$thiscond;
140: } else {
141: $posnext=$_.':'.$thiscond;
142: }
143: if ($thiscond>$mincond) { $mincond=$thiscond; }
144: }
145: } split(/\,/,$hash{'from_'.$rid});
146: map {
147: my ($linkid,$condval)=split(/\:/,$_);
148: if ($condval>=$mincond) {
149: $next=&addrid($next,$hash{'comesfrom_'.$linkid},
150: $hash{'condid_'.$hash{'undercond_'.$linkid}});
151: }
152: } split(/\,/,$posnext);
153: if ($hash{'is_map_'.$next}) {
154: # This jumps to the end of a new map (going down one level)
155: if (
156: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
157: $mapurl=$hash{'src_'.$next};
158: $next=$hash{'map_finish_'.$hash{'src_'.$next}};
159: }
160: } elsif
161: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
162: # This comes back up from a map (going up one level);
163: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
164: }
165: }
166: return ($next,$mapurl);
167: }
168:
169: # ================================================================ Main Handler
170:
171: sub handler {
172: my $r=shift;
173:
174: # ------------------------------------------- Set document type for header only
175:
176: if ($r->header_only) {
177: $r->content_type('text/html');
178: $r->send_http_header;
179: return OK;
180: }
181:
182: my %cachehash=();
183: my $multichoice=0;
184: my %multichoicehash=();
185: my $redirecturl='';
186: my $next='';
187: my @possibilities=();
188: if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
189: $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
190: my $direction=$1;
191: my $currenturl=$2;
192: if ($direction eq 'return') {
193: # -------------------------------------------------------- Return to last known
194: my $last;
195: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
196: &GDBM_READER(),0640)) {
197: $last=$hash{'last_known'};
198: untie(%hash);
199: }
200: my $newloc;
201: if (($last) && (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
202: &GDBM_READER(),0640))) {
203: my ($murl,$mid,$fn)=split(/\_\_\_/,$last);
204: $newloc=$hash{'src_'.
205: $hash{'map_pc_'.&Apache::lonnet::clutter($murl)}.
206: '.'.$mid};
207: untie %hash;
208: } else {
209: $newloc='/adm/noidea.html';
210: }
211: $r->content_type('text/html');
212: $r->header_out(Location =>
213: 'http://'.$ENV{'HTTP_HOST'}.$newloc);
214:
215: return REDIRECT;
216: }
217: $currenturl=~s/^http\:\/\///;
218: $currenturl=~s/^[^\/]+//;
219: #
220: # Is the current URL on the map? If not, start with last known URL
221: #
222: unless (&Apache::lonnet::is_on_map($currenturl)) {
223: my $last;
224: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
225: &GDBM_READER(),0640)) {
226: $last=$hash{'last_known'};
227: untie(%hash);
228: }
229: if ($last) {
230: $currenturl=&Apache::lonnet::clutter((split(/\_\_\_/,$last))[1]);
231: } else {
232: $r->content_type('text/html');
233: $r->header_out(Location =>
234: 'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
235: return REDIRECT;
236: }
237: }
238: # ------------------------------------------- Do we have any idea where we are?
239: my $position;
240: if ($position=Apache::lonnet::symbread($currenturl)) {
241: # ------------------------------------------------------------------------- Yes
242: my ($startoutmap,$mapnum,$thisurl)=split(/\_\_\_/,$position);
243: $cachehash{$startoutmap}{$thisurl}=$mapnum;
244: $cachehash{$startoutmap}{'last_known'}=
245: &Apache::lonnet::declutter($currenturl);
246:
247: # ============================================================ Tie the big hash
248: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
249: &GDBM_READER(),0640)) {
250: my $rid=$hash{'map_pc_'.&Apache::lonnet::clutter($startoutmap)}.
251: '.'.$mapnum;
252:
253: # ------------------------------------------------- Move forward, backward, etc
254: my $endupmap;
255: ($next,$endupmap)=&move($rid,$startoutmap,$direction);
256: # -------------------------------------- Do we have one and only one empty URL?
257: my $safecount=0;
258: while (($next) && ($next!~/\,/) &&
259: ((!$hash{'src_'.$next}) || ($hash{'randomout_'.$next}))
260: && ($safecount<10000)) {
261: ($next,$endupmap)=&move($next,$endupmap,$direction);
262: $safecount++;
263: }
264: # We are now at at least one non-empty URL
265: # ----------------------------------------------------- Check out possibilities
266: if ($next) {
267: @possibilities=split(/\,/,$next);
268: if ($#possibilities==0) {
269: # ---------------------------------------------- Only one possibility, redirect
270: $redirecturl=$hash{'src_'.$next};
271: $cachehash{$endupmap}
272: {&Apache::lonnet::declutter($redirecturl)}
273: =(split(/\./,$next))[1];
274: } else {
275: # ------------------------ There are multiple possibilities for a next resource
276: $multichoice=1;
277: map {
278: $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
279: $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
280: $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
281: (my $first, my $second) = $_ =~ /(\d+).(\d+)/;
282: my $symbSrc = Apache::lonnet::declutter($hash{'src_'.$_});
283: $multichoicehash{'symb_'.$_} =
284: Apache::lonnet::declutter($hash{'map_id_'.$first}.'___'.
285: $second.'___'.$symbSrc);
286:
287: my ($choicemap,$choiceres)=split(/\./,$_);
288: $cachehash
289: {&Apache::lonnet::declutter($hash{'src_'.$choicemap})}
290: {&Apache::lonnet::declutter(
291: $multichoicehash
292: {'src_'.$_}
293: )}
294: =$choiceres;
295: } @possibilities;
296: }
297: } else {
298: # -------------------------------------------------------------- No place to go
299: $multichoice=-1;
300: }
301: # ----------------- The program must come past this point to untie the big hash
302: untie(%hash);
303: # --------------------------------------------------------- Store position info
304: $cachehash{$startoutmap}{'last_direction'}=$direction;
305: foreach my $thismap (keys %cachehash) {
306: &Apache::lonnet::symblist($thismap,%{$cachehash{$thismap}});
307: }
308: # ============================================== Do not return before this line
309: if ($redirecturl) {
310: # ----------------------------------------------------- There is a URL to go to
311: # ------------------------------------------------- Check for critical messages
312: if ((time-$ENV{'user.criticalcheck.time'})>300) {
313: my @what=&Apache::lonnet::dump
314: ('critical',$ENV{'user.domain'},
315: $ENV{'user.name'});
316: if ($what[0]) {
317: if (($what[0] ne 'con_lost') &&
318: ($what[0]!~/^error\:/)) {
319: $redirecturl='/adm/email?critical=display';
320: }
321: }
322: &Apache::lonnet::appenv('user.criticalcheck.time'=>time);
323: }
324:
325: $r->content_type('text/html');
326: $r->header_out(Location =>
327: 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
328: return REDIRECT;
329: } else {
330: # --------------------------------------------------------- There was a problem
331: $r->content_type('text/html');
332: $r->send_http_header;
333: if ($#possibilities>0) {
334: $r->print(<<ENDSTART);
335: <head><title>Choose Next Location</title></head>
336: <body bgcolor="#FFFFFF">
337: <h1>LON-CAPA</h1>
338: There are several possibilities of where to go next.
339: <p>
340: Please click on the the resource you intend to access:
341: <p>
342: <table border=2>
343: <tr><th>Title</th><th>Type</th></tr>
344: ENDSTART
345: foreach (@possibilities) {
346: $r->print(
347: '<tr><td><a href="'.
348: $multichoicehash{'src_'.$_}.'?symb=' .
349: Apache::lonnet::escape($multichoicehash{'symb_'.$_}).'">'.
350: $multichoicehash{'title_'.$_}.
351: '</a></td><td>'.$multichoicehash{'type_'.$_}.
352: '</td></tr>');
353: }
354: $r->print('</table></body></html>');
355: return OK;
356: } else {
357: $r->print(<<ENDNONE);
358: <head><title>Choose Next Location</title></head>
359: <body bgcolor="#FFFFFF">
360: <img src="/adm/lonIcons/lonlogos.gif" align=right>
361: <h1>Sorry!</h1>
362: <h2>Next resource could not be identified.</h2>
363: <h3>You probably are at the beginning or the end of the course.</h3>
364: </body>
365: </html>
366: ENDNONE
367: return OK;
368: }
369: }
370: } else {
371: # ------------------------------------------------- Problem, could not tie hash
372: $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
373: return HTTP_NOT_ACCEPTABLE;
374: }
375: } else {
376: # ---------------------------------------- No, could not determine where we are
377: $r->internal_redirect('/adm/ambiguous');
378: }
379: } else {
380: # -------------------------- Class was not initialized or page fliped strangely
381: $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
382: return HTTP_NOT_ACCEPTABLE;
383: }
384: }
385:
386: 1;
387: __END__
388:
389:
390:
391:
392:
393:
394:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to lonpageflip.pm CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / rat