1: # The LearningOnline Network with CAPA
2: #
3: # Page flip handler
4: #
5: # $Id: lonpageflip.pm,v 1.23 2002/04/12 13:47:21 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) { $condid=0; }
56: if (&Apache::lonnet::allowed('bre',$hash{'src_'.$new})) {
57: if ($current) {
58: $current.=','.$new;
59: } else {
60: $current=''.$new;
61: }
62: }
63: return $current;
64: }
65:
66: sub move {
67: my ($rid,$mapurl,$direction)=@_;
68: my $startoutrid=$rid;
69:
70: my $next='';
71:
72: my $mincond=1;
73: my $posnext='';
74: if ($direction eq 'forward') {
75: # --------------------------------------------------------------------- Forward
76: if ($hash{'type_'.$rid} eq 'finish') {
77: $rid=$hash{'ids_/res/'.$mapurl};
78: }
79: map {
80: my $thiscond=
81: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
82: if ($thiscond>=$mincond) {
83: if ($posnext) {
84: $posnext.=','.$_.':'.$thiscond;
85: } else {
86: $posnext=$_.':'.$thiscond;
87: }
88: if ($thiscond>$mincond) { $mincond=$thiscond; }
89: }
90: } split(/\,/,$hash{'to_'.$rid});
91: map {
92: my ($linkid,$condval)=split(/\:/,$_);
93: if ($condval>=$mincond) {
94: $next=&addrid($next,$hash{'goesto_'.$linkid},
95: $hash{'condid_'.$hash{'undercond_'.$linkid}});
96: }
97: } split(/\,/,$posnext);
98: if ($hash{'is_map_'.$next}) {
99: # This jumps to the beginning of a new map (going down level)
100: if (
101: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
102: $mapurl=$hash{'src_'.$next};
103: $next=$hash{'map_start_'.$hash{'src_'.$next}};
104: }
105: } elsif
106: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
107: # This comes up from a map (coming up one level);
108: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
109: }
110: } elsif ($direction eq 'back') {
111: # ------------------------------------------------------------------- Backwards
112: if ($hash{'type_'.$rid} eq 'start') {
113: $rid=$hash{'ids_/res/'.$mapurl};
114: }
115: map {
116: my $thiscond=
117: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
118: if ($thiscond>=$mincond) {
119: if ($posnext) {
120: $posnext.=','.$_.':'.$thiscond;
121: } else {
122: $posnext=$_.':'.$thiscond;
123: }
124: if ($thiscond>$mincond) { $mincond=$thiscond; }
125: }
126: } split(/\,/,$hash{'from_'.$rid});
127: map {
128: my ($linkid,$condval)=split(/\:/,$_);
129: if ($condval>=$mincond) {
130: $next=&addrid($next,$hash{'comesfrom_'.$linkid},
131: $hash{'condid_'.$hash{'undercond_'.$linkid}});
132: }
133: } split(/\,/,$posnext);
134: if ($hash{'is_map_'.$next}) {
135: if (
136: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
137: $mapurl=$hash{'src_'.$next};
138: $next=$hash{'map_finish_'.$hash{'src_'.$next}};
139: }
140: }
141: }
142: return ($next,$mapurl);
143: }
144:
145: # ================================================================ Main Handler
146:
147: sub handler {
148: my $r=shift;
149:
150: # ------------------------------------------- Set document type for header only
151:
152: if ($r->header_only) {
153: $r->content_type('text/html');
154: $r->send_http_header;
155: return OK;
156: }
157:
158: my %cachehash=();
159: my $multichoice=0;
160: my %multichoicehash=();
161: my $redirecturl='';
162: my $next='';
163: my @possibilities=();
164: if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
165: $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
166: my $direction=$1;
167: my $currenturl=$2;
168: if ($direction eq 'return') {
169: # -------------------------------------------------------- Return to last known
170: my $last;
171: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
172: &GDBM_READER,0640)) {
173: $last=$hash{'last_known'};
174: untie(%hash);
175: }
176: my $newloc;
177: if ($last) {
178: $newloc='/res/'.(split(/\_\_\_/,$last))[1];
179: } else {
180: $newloc='/adm/noidea.html';
181: }
182: $r->content_type('text/html');
183: $r->header_out(Location =>
184: 'http://'.$ENV{'HTTP_HOST'}.$newloc);
185:
186: return REDIRECT;
187: }
188: $currenturl=~s/^http\:\/\///;
189: $currenturl=~s/^[^\/]+//;
190: unless (($currenturl=~/^\/res\//) ||
191: ($currenturl=~/^\/adm\/wrapper\//)) {
192: my $last;
193: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
194: &GDBM_READER,0640)) {
195: $last=$hash{'last_known'};
196: untie(%hash);
197: }
198: if ($last) {
199: $currenturl='/res/'.(split(/\_\_\_/,$last))[1];
200: } else {
201: $r->content_type('text/html');
202: $r->header_out(Location =>
203: 'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
204: return REDIRECT;
205: }
206: }
207: # ------------------------------------------- Do we have any idea where we are?
208: my $position;
209: if ($position=Apache::lonnet::symbread($currenturl)) {
210: # ------------------------------------------------------------------------- Yes
211: my ($startoutmap,$mapnum,$thisurl)=split(/\_\_\_/,$position);
212: $cachehash{$startoutmap}{$thisurl}=$mapnum;
213: $cachehash{$startoutmap}{'last_known'}=
214: &Apache::lonnet::declutter($currenturl);
215:
216: # ============================================================ Tie the big hash
217: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
218: &GDBM_READER,0640)) {
219: my $rid=$hash{'map_pc_/res/'.$startoutmap}.'.'.$mapnum;
220:
221: # ------------------------------------------------- Move forward, backward, etc
222: my $endupmap;
223: ($next,$endupmap)=&move($rid,$startoutmap,$direction);
224: # -------------------------------------- Do we have one and only one empty URL?
225: my $safecount=0;
226: while (($next) && ($next!~/\,/) && (!$hash{'src_'.$next})
227: && ($safecount<25)) {
228: ($next,$endupmap)=&move($next,$endupmap,$direction);
229: $safecount++;
230: }
231: # We are now at at least one non-empty URL
232: # ----------------------------------------------------- Check out possibilities
233: if ($next) {
234: @possibilities=split(/\,/,$next);
235: if ($#possibilities==0) {
236: # ---------------------------------------------- Only one possibility, redirect
237: $redirecturl=$hash{'src_'.$next};
238: $cachehash{$endupmap}
239: {&Apache::lonnet::declutter($redirecturl)}
240: =(split(/\./,$next))[1];
241: } else {
242: # ------------------------ There are multiple possibilities for a next resource
243: $multichoice=1;
244: map {
245: $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
246: $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
247: $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
248: my ($choicemap,$choiceres)=split(/\./,$_);
249: $cachehash
250: {&Apache::lonnet::declutter($hash{'src_'.$choicemap})}
251: {&Apache::lonnet::declutter(
252: $multichoicehash
253: {'src_'.$_}
254: )}
255: =$choiceres;
256: } @possibilities;
257: }
258: } else {
259: # -------------------------------------------------------------- No place to go
260: $multichoice=-1;
261: }
262: # ----------------- The program must come past this point to untie the big hash
263: untie(%hash);
264: # --------------------------------------------------------- Store position info
265: $cachehash{$startoutmap}{'last_direction'}=$direction;
266: foreach my $thismap (keys %cachehash) {
267: &Apache::lonnet::symblist($thismap,%{$cachehash{$thismap}});
268: }
269: # ============================================== Do not return before this line
270: if ($redirecturl) {
271: # ----------------------------------------------------- There is a URL to go to
272: $r->content_type('text/html');
273: $r->header_out(Location =>
274: 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
275: return REDIRECT;
276: } else {
277: # --------------------------------------------------------- There was a problem
278: $r->content_type('text/html');
279: $r->send_http_header;
280: if ($#possibilities>0) {
281: $r->print(<<ENDSTART);
282: <head><title>Choose Next Location</title></head>
283: <body bgcolor="#FFFFFF">
284: <h1>LON-CAPA</h1>
285: There are several possibilities of where to go next.
286: <p>
287: Please click on the the resource you intend to access:
288: <p>
289: <table border=2>
290: <tr><th>Title</th><th>Type</th></tr>
291: ENDSTART
292: map {
293: $r->print(
294: '<tr><td><a href="'.
295: $multichoicehash{'src_'.$_}.'">'.
296: $multichoicehash{'title_'.$_}.
297: '</a></td><td>'.$multichoicehash{'type_'.$_}.
298: '</td></tr>');
299: } @possibilities;
300: $r->print('</table></body></html>');
301: return OK;
302: } else {
303: $r->print(<<ENDNONE);
304: <head><title>Choose Next Location</title></head>
305: <body bgcolor="#FFFFFF">
306: <img src="/adm/lonIcons/lonlogos.gif" align=right>
307: <h1>Sorry!</h1>
308: <h2>Next resource could not be identified.</h2>
309: <h3>You probably are at the beginning or the end of the course.</h3>
310: </body>
311: </html>
312: ENDNONE
313: return OK;
314: }
315: }
316: } else {
317: # ------------------------------------------------- Problem, could not tie hash
318: $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
319: return HTTP_NOT_ACCEPTABLE;
320: }
321: } else {
322: # ---------------------------------------- No, could not determine where we are
323: $r->internal_redirect('/adm/ambiguous');
324: }
325: } else {
326: # -------------------------- Class was not initialized or page fliped strangely
327: $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
328: return HTTP_NOT_ACCEPTABLE;
329: }
330: }
331:
332: 1;
333: __END__
334:
335:
336:
337:
338:
339:
340:
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