1: # The LearningOnline Network with CAPA
2: #
3: # Page flip handler
4: #
5: # $Id: lonpageflip.pm,v 1.70 2006/08/18 20:24:53 albertel 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:
30: package Apache::lonpageflip;
31:
32: use strict;
33: use LONCAPA;
34: use Apache::Constants qw(:common :http REDIRECT);
35: use Apache::lonnet;
36: use Apache::loncommon();
37: use HTML::TokeParser;
38: use GDBM_File;
39:
40: # ========================================================== Module Global Hash
41:
42: my %hash;
43:
44: sub cleanup {
45: if (tied(%hash)){
46: &Apache::lonnet::logthis('Cleanup pageflip: hash');
47: unless (untie(%hash)) {
48: &Apache::lonnet::logthis('Failed cleanup pageflip: hash');
49: }
50: }
51: return OK;
52: }
53:
54: sub addrid {
55: my ($current,$new,$condid)=@_;
56: unless ($condid) { $condid=0; }
57:
58: if ($current) {
59: $current.=','.$new;
60: } else {
61: $current=''.$new;
62: }
63:
64: return $current;
65: }
66:
67: sub fullmove {
68: my ($rid,$mapurl,$direction)=@_;
69: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db',
70: &GDBM_READER(),0640)) {
71: ($rid,$mapurl)=&move($rid,$mapurl,$direction);
72: untie(%hash);
73: }
74: return($rid,$mapurl);
75: }
76:
77: sub hash_src {
78: my ($id)=@_;
79: my ($mapid,$resid)=split(/\./,$id);
80: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
81: $resid,$hash{'src_'.$id});
82: if ($hash{'encrypted_'.$id}) {
83: return (&Apache::lonenc::encrypted($hash{'src_'.$id}),
84: &Apache::lonenc::encrypted($symb));
85: }
86: return ($hash{'src_'.$id},$symb);
87: }
88:
89: sub move {
90: my ($rid,$mapurl,$direction)=@_;
91: my $startoutrid=$rid;
92:
93: my $next='';
94:
95: my $mincond=1;
96: my $posnext='';
97: if ($direction eq 'forward') {
98: # --------------------------------------------------------------------- Forward
99: while ($hash{'type_'.$rid} eq 'finish') {
100: $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}};
101: }
102: foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
103: my $condition= $hash{'conditions_'.$hash{'goesto_'.$id}};
104: my $rescond = &Apache::lonnet::docondval($condition);
105: my $linkcond = &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$id}});
106: my $thiscond = ($rescond<$linkcond)?$rescond:$linkcond;
107: if ($thiscond>=$mincond) {
108: if ($posnext) {
109: $posnext.=','.$id.':'.$thiscond;
110: } else {
111: $posnext=$id.':'.$thiscond;
112: }
113: if ($thiscond>$mincond) { $mincond=$thiscond; }
114: }
115: }
116: foreach my $id (split(/\,/,$posnext)) {
117: my ($linkid,$condval)=split(/\:/,$id);
118: if ($condval>=$mincond) {
119: $next=&addrid($next,$hash{'goesto_'.$linkid},
120: $hash{'condid_'.$hash{'undercond_'.$linkid}});
121: }
122: }
123: if ($hash{'is_map_'.$next}) {
124: # This jumps to the beginning of a new map (going down level)
125: if (
126: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
127: $mapurl=$hash{'src_'.$next};
128: $next=$hash{'map_start_'.$hash{'src_'.$next}};
129: } elsif (
130: # This jumps back up from an empty sequence, to a page up one level
131: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'page') {
132: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
133: }
134: } elsif
135: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
136: # This comes up from a map (coming up one level);
137: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
138: }
139: } elsif ($direction eq 'back') {
140: # ------------------------------------------------------------------- Backwards
141: while ($hash{'type_'.$rid} eq 'start') {
142: $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}};
143: }
144: foreach my $id (split(/\,/,$hash{'from_'.$rid})) {
145: my $condition= $hash{'conditions_'.$hash{'comesfrom_'.$id}};
146: my $rescond = &Apache::lonnet::docondval($condition);
147: my $linkcond = &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$id}});
148: my $thiscond = ($rescond<$linkcond)?$rescond:$linkcond;
149: if ($thiscond>=$mincond) {
150: if ($posnext) {
151: $posnext.=','.$id.':'.$thiscond;
152: } else {
153: $posnext=$id.':'.$thiscond;
154: }
155: if ($thiscond>$mincond) { $mincond=$thiscond; }
156: }
157: }
158: foreach my $id (split(/\,/,$posnext)) {
159: my ($linkid,$condval)=split(/\:/,$id);
160: if ($condval>=$mincond) {
161: $next=&addrid($next,$hash{'comesfrom_'.$linkid},
162: $hash{'condid_'.$hash{'undercond_'.$linkid}});
163: }
164: }
165: if ($hash{'is_map_'.$next}) {
166: # This jumps to the end of a new map (going down one level)
167: if (
168: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
169: $mapurl=$hash{'src_'.$next};
170: $next=$hash{'map_finish_'.$hash{'src_'.$next}};
171: } elsif (
172: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'page') {
173: # This jumps back up from an empty sequence, to a page up one level
174: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
175: }
176: } elsif
177: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
178: # This comes back up from a map (going up one level);
179: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
180: }
181: }
182: return ($next,$mapurl);
183: }
184:
185: sub navlaunch {
186: my ($r)=@_;
187: &Apache::loncommon::content_type($r,'text/html');
188: &Apache::loncommon::no_cache($r);
189: $r->send_http_header;
190: $r->print(&Apache::loncommon::start_page('Launched'));
191: $r->print(<<ENDNAV);
192: <p><a href="/adm/flip?postdata=firstres%3a">Goto first resource</a></p>
193: <script type="text/javascript">
194: function collapse() {
195: menu=window.open("/adm/navmaps?collapseExternal","loncapanav",
196: "height=600,width=400,scrollbars=1");
197: this.document.location='/adm/navmaps?turningOffExternal';
198: }
199: </script>
200: <p><a href="javascript:collapse();">Collapse external navigation window</a></p>
201: ENDNAV
202: $r->print(&Apache::loncommon::end_page());
203: }
204:
205: sub first_accessible_resource {
206: my $furl;
207: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db',
208: &GDBM_READER(),0640)) {
209: $furl=$hash{'first_url'};
210: if (!&Apache::lonnet::allowed('bre',$furl)) {
211: # Wow, we cannot see this ... move forward to the next one that we can see
212: my ($newrid,$newmap)=&move($hash{'first_rid'},$hash{'first_mapurl'},'forward');
213: # Build the new URL
214: my ($newresid,$newmapid)=split(/\./,$newrid);
215: my $symb=&Apache::lonnet::encode_symb($newmap,$newresid,$hash{'src_'.$newrid});
216: $furl=&add_get_param($hash{'src_'.$newrid},{ 'symb' => $symb });
217: if ($hash{'encrypted_'.$newrid}) {
218: $furl=&Apache::lonenc::encrypted($furl);
219: }
220: }
221: untie(%hash);
222: return $furl;
223: } else {
224: return '/adm/navmaps';
225: }
226: }
227:
228: # ================================================================ Main Handler
229:
230: sub handler {
231: my $r=shift;
232:
233: # ------------------------------------------- Set document type for header only
234:
235: if ($r->header_only) {
236: &Apache::loncommon::content_type($r,'text/html');
237: $r->send_http_header;
238: return OK;
239: }
240:
241: my %cachehash=();
242: my $multichoice=0;
243: my %multichoicehash=();
244: my ($redirecturl,$redirectsymb);
245: my $next='';
246: my @possibilities=();
247: &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},['postdata']);
248: if (($env{'form.postdata'})&&($env{'request.course.fn'})) {
249: $env{'form.postdata'}=~/(\w+)\:(.*)/;
250: my $direction=$1;
251: my $currenturl=$2;
252: if ($currenturl=~m|^/enc/|) {
253: $currenturl=&Apache::lonenc::unencrypted($currenturl);
254: }
255: $currenturl=~s/\.\d+\.(\w+)$/\.$1/;
256: if ($direction eq 'firstres') {
257: my $furl=&first_accessible_resource();
258: &Apache::loncommon::content_type($r,'text/html');
259: $r->header_out(Location =>
260: &Apache::loncommon::absolute_url().$furl);
261:
262: return REDIRECT;
263: }
264: if ($direction eq 'return' || $direction eq 'navlaunch') {
265: # -------------------------------------------------------- Return to last known
266: my $last;
267: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
268: &GDBM_READER(),0640)) {
269: $last=$hash{'last_known'};
270: untie(%hash);
271: }
272: my $newloc;
273: if (($last) && (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db',
274: &GDBM_READER(),0640))) {
275: my ($murl,$id,$fn)=&Apache::lonnet::decode_symb($last);
276: $id=$hash{'map_pc_'.&Apache::lonnet::clutter($murl)}.'.'.$id;
277: $newloc=$hash{'src_'.$id};
278: if ($newloc) {
279: if ($hash{'encrypted_'.$id}) { $newloc=&Apache::lonenc::encrypted($newloc); }
280:
281: } else {
282: $newloc='/adm/navmaps';
283: }
284: untie %hash;
285: } else {
286: $newloc='/adm/navmaps';
287: }
288: if ($newloc eq '/adm/navmaps' && $direction eq 'navlaunch') {
289: &navlaunch($r);
290: return OK;
291: } else {
292: &Apache::loncommon::content_type($r,'text/html');
293: $r->header_out(Location =>
294: &Apache::loncommon::absolute_url().$newloc);
295:
296: return REDIRECT;
297: }
298: }
299: $currenturl=~s/^http\:\/\///;
300: $currenturl=~s/^[^\/]+//;
301: #
302: # Is the current URL on the map? If not, start with last known URL
303: #
304: unless (&Apache::lonnet::is_on_map($currenturl)) {
305: my $last;
306: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
307: &GDBM_READER(),0640)) {
308: $last=$hash{'last_known'};
309: untie(%hash);
310: }
311: if ($last) {
312: $currenturl=&Apache::lonnet::clutter((&Apache::lonnet::decode_symb($last))[2]);
313: } else {
314: if ($direction eq 'return') {
315: &Apache::loncommon::content_type($r,'text/html');
316: $r->header_out(Location =>
317: &Apache::loncommon::absolute_url().
318: '/adm/noidea.html');
319: return REDIRECT;
320: } else {
321: &navlaunch($r);
322: return OK;
323: }
324: }
325: }
326: # ------------------------------------------- Do we have any idea where we are?
327: my $position;
328: if ($position=Apache::lonnet::symbread($currenturl)) {
329: # ------------------------------------------------------------------------- Yes
330: my ($startoutmap,$mapnum,$thisurl)=&Apache::lonnet::decode_symb($position);
331: $cachehash{$startoutmap}{$thisurl}=[$thisurl,$mapnum];
332: $cachehash{$startoutmap}{'last_known'}=
333: [&Apache::lonnet::declutter($currenturl),$mapnum];
334:
335: # ============================================================ Tie the big hash
336: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db',
337: &GDBM_READER(),0640)) {
338: my $rid=$hash{'map_pc_'.&Apache::lonnet::clutter($startoutmap)}.
339: '.'.$mapnum;
340:
341: # ------------------------------------------------- Move forward, backward, etc
342: my $endupmap;
343: ($next,$endupmap)=&move($rid,$startoutmap,$direction);
344: # -------------------------------------- Do we have one and only one empty URL?
345: my $safecount=0;
346: while (($next) && ($next!~/\,/) &&
347: ((!$hash{'src_'.$next}) ||
348: ((!$env{'request.role.adv'}) && $hash{'randomout_'.$next}))
349: && ($safecount<10000)) {
350: ($next,$endupmap)=&move($next,$endupmap,$direction);
351: $safecount++;
352: }
353: # We are now at at least one non-empty URL
354: # ----------------------------------------------------- Check out possibilities
355: if ($next) {
356: @possibilities=split(/\,/,$next);
357: if ($#possibilities==0) {
358: # ---------------------------------------------- Only one possibility, redirect
359: ($redirecturl,$redirectsymb)=&hash_src($next);
360: $cachehash{$endupmap}{$redirecturl}=
361: [$redirecturl,(split(/\./,$next))[1]];
362: } else {
363: # ------------------------ There are multiple possibilities for a next resource
364: $multichoice=1;
365: foreach my $id (@possibilities) {
366: $multichoicehash{'src_'.$id}=$hash{'src_'.$id};
367: $multichoicehash{'title_'.$id}=$hash{'title_'.$id};
368: $multichoicehash{'type_'.$id}=$hash{'type_'.$id};
369: (my $first, my $second) = $id =~ /(\d+).(\d+)/;
370: my $symbSrc = Apache::lonnet::declutter($hash{'src_'.$id});
371: $multichoicehash{'symb_'.$id} =
372: Apache::lonnet::declutter($hash{'map_id_'.$first}.'___'.
373: $second.'___'.$symbSrc);
374:
375: my ($choicemap,$choiceres)=split(/\./,$id);
376: my $map=&Apache::lonnet::declutter($hash{'src_'.$choicemap});
377: my $url=$multichoicehash{'src_'.$id};
378: $cachehash{$map}{$url}=[$url,$choiceres];
379: }
380: }
381: } else {
382: # -------------------------------------------------------------- No place to go
383: $multichoice=-1;
384: }
385: # ----------------- The program must come past this point to untie the big hash
386: untie(%hash);
387: # --------------------------------------------------------- Store position info
388: $cachehash{$startoutmap}{'last_direction'}=[$direction,'notasymb'];
389: foreach my $thismap (keys %cachehash) {
390: my $mapnum=$cachehash{$thismap}->{'mapnum'};
391: delete($cachehash{$thismap}->{'mapnum'});
392: &Apache::lonnet::symblist($thismap,
393: %{$cachehash{$thismap}});
394: }
395: # ============================================== Do not return before this line
396: if ($redirecturl) {
397: # ----------------------------------------------------- There is a URL to go to
398: if ($direction eq 'forward') {
399: &Apache::lonnet::linklog($currenturl,$redirecturl);
400: }
401: if ($direction eq 'back') {
402: &Apache::lonnet::linklog($redirecturl,$currenturl);
403: }
404: # ------------------------------------------------- Check for critical messages
405: if ((time-$env{'user.criticalcheck.time'})>300) {
406: my @what=&Apache::lonnet::dump
407: ('critical',$env{'user.domain'},
408: $env{'user.name'});
409: if ($what[0]) {
410: if (($what[0] ne 'con_lost') &&
411: ($what[0]!~/^error\:/)) {
412: $redirecturl='/adm/email?critical=display';
413: $redirectsymb='';
414: }
415: }
416: &Apache::lonnet::appenv('user.criticalcheck.time'=>time);
417: }
418:
419: &Apache::loncommon::content_type($r,'text/html');
420: my $url=&Apache::loncommon::absolute_url().$redirecturl;
421: $url = &add_get_param($url, { 'symb' => $redirectsymb});
422: $r->header_out(Location => $url);
423: return REDIRECT;
424: } else {
425: # --------------------------------------------------------- There was a problem
426: &Apache::loncommon::content_type($r,'text/html');
427: $r->send_http_header;
428: my %lt=&Apache::lonlocal::texthash('title' => 'End of Sequence',
429: 'explain' =>
430: 'You have reached the end of the sequence of materials.',
431: 'back' => 'Go Back',
432: 'nav' => 'Navigate Course Content',
433: 'wherenext' =>
434: 'There are several possibilities of where to go next',
435: 'pick' =>
436: 'Please click on the the resource you intend to access',
437: 'titleheader' => 'Title',
438: 'type' => 'Type');
439: if ($#possibilities>0) {
440: my $start_page=
441: &Apache::loncommon::start_page('Multiple Resources');
442: $r->print(<<ENDSTART);
443: $start_page
444: <h3>$lt{'wherenext'}</h3>
445: <p>
446: $lt{'pick'}:
447: <p>
448: <table border=2>
449: <tr><th>$lt{'titleheader'}</th><th>$lt{'type'}</th></tr>
450: ENDSTART
451: foreach my $id (@possibilities) {
452: $r->print(
453: '<tr><td><a href="'.
454: &add_get_param($multichoicehash{'src_'.$id},
455: {'symb' =>
456: $multichoicehash{'symb_'.$id},
457: }).'">'.
458: $multichoicehash{'title_'.$id}.
459: '</a></td><td>'.$multichoicehash{'type_'.$id}.
460: '</td></tr>');
461: }
462: $r->print('</table>');
463: } else {
464: my $start_page=
465: &Apache::loncommon::start_page('No Resource');
466: $r->print(<<ENDNONE);
467: $start_page
468: <h3>$lt{'title'}</h3>
469: <p>$lt{'explain'}</p>
470: ENDNONE
471: }
472: $r->print(<<ENDMENU);
473: <ul>
474: <li><a href="/adm/flip?postdata=return:">$lt{'back'}</a></li>
475: <li><a href="/adm/navmaps">$lt{'nav'}</a></li>
476: </ul>
477: ENDMENU
478: $r->print(&Apache::loncommon::end_page());
479: return OK;
480: }
481: } else {
482: # ------------------------------------------------- Problem, could not tie hash
483: $env{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
484: return HTTP_NOT_ACCEPTABLE;
485: }
486: } else {
487: # ---------------------------------------- No, could not determine where we are
488: $r->internal_redirect('/adm/ambiguous');
489: }
490: } else {
491: # -------------------------- Class was not initialized or page fliped strangely
492: $env{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
493: return HTTP_NOT_ACCEPTABLE;
494: }
495: }
496:
497: 1;
498: __END__
499:
500:
501:
502:
503:
504:
505:
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