Annotation of rat/lonpageflip.pm, revision 1.27
1.1 www 1: # The LearningOnline Network with CAPA
2: #
3: # Page flip handler
4: #
1.27 ! www 5: # $Id: lonpageflip.pm,v 1.26 2002/07/07 21:04:47 www Exp $
1.18 www 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: #
1.1 www 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: #
1.13 www 37: # 10/03,10/05,10/06,10/07,10/09,10/10,10/11,10/16,10/17,
1.14 www 38: # 11/14,11/16,
1.17 www 39: # 10/01/01,05/01,05/28,07/05 Gerd Kortemeyer
1.1 www 40:
41: package Apache::lonpageflip;
42:
43: use strict;
1.4 www 44: use Apache::Constants qw(:common :http REDIRECT);
1.1 www 45: use Apache::lonnet();
46: use HTML::TokeParser;
47: use GDBM_File;
48:
1.3 www 49: # ========================================================== Module Global Hash
50:
1.1 www 51: my %hash;
52:
1.3 www 53: sub addrid {
1.4 www 54: my ($current,$new,$condid)=@_;
55: unless ($condid) { $condid=0; }
1.27 ! www 56:
1.3 www 57: if ($current) {
1.5 www 58: $current.=','.$new;
1.3 www 59: } else {
1.5 www 60: $current=''.$new;
1.3 www 61: }
1.27 ! www 62:
1.3 www 63: return $current;
1.25 www 64: }
65:
66: sub fullmove {
67: my ($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);
1.1 www 74: }
75:
1.15 www 76: sub move {
77: my ($rid,$mapurl,$direction)=@_;
1.23 www 78: my $startoutrid=$rid;
1.15 www 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_/res/'.$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}) {
1.23 www 109: # This jumps to the beginning of a new map (going down level)
1.15 www 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: }
1.23 www 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(/\./,$next))[0]};
1.15 www 119: }
120: } elsif ($direction eq 'back') {
121: # ------------------------------------------------------------------- Backwards
122: if ($hash{'type_'.$rid} eq 'start') {
123: $rid=$hash{'ids_/res/'.$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}) {
1.24 www 145: # This jumps to the end of a new map (going down one level)
1.15 www 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: }
1.24 www 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(/\./,$next))[0]};
1.15 www 155: }
156: }
157: return ($next,$mapurl);
158: }
159:
1.1 www 160: # ================================================================ Main Handler
161:
162: sub handler {
1.2 www 163: my $r=shift;
1.1 www 164:
165: # ------------------------------------------- Set document type for header only
166:
1.2 www 167: if ($r->header_only) {
1.1 www 168: $r->content_type('text/html');
169: $r->send_http_header;
1.2 www 170: return OK;
171: }
172:
1.5 www 173: my %cachehash=();
174: my $multichoice=0;
175: my %multichoicehash=();
1.4 www 176: my $redirecturl='';
177: my $next='';
178: my @possibilities=();
1.2 www 179: if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
180: $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
181: my $direction=$1;
182: my $currenturl=$2;
1.10 www 183: if ($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: $newloc='/res/'.(split(/\_\_\_/,$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: }
1.2 www 203: $currenturl=~s/^http\:\/\///;
204: $currenturl=~s/^[^\/]+//;
1.17 www 205: unless (($currenturl=~/^\/res\//) ||
206: ($currenturl=~/^\/adm\/wrapper\//)) {
1.7 www 207: my $last;
208: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
209: &GDBM_READER,0640)) {
210: $last=$hash{'last_known'};
211: untie(%hash);
212: }
213: if ($last) {
214: $currenturl='/res/'.(split(/\_\_\_/,$last))[1];
215: } else {
216: $r->content_type('text/html');
217: $r->header_out(Location =>
218: 'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
1.9 www 219: return REDIRECT;
1.7 www 220: }
221: }
1.3 www 222: # ------------------------------------------- Do we have any idea where we are?
223: my $position;
224: if ($position=Apache::lonnet::symbread($currenturl)) {
225: # ------------------------------------------------------------------------- Yes
1.22 www 226: my ($startoutmap,$mapnum,$thisurl)=split(/\_\_\_/,$position);
227: $cachehash{$startoutmap}{$thisurl}=$mapnum;
1.23 www 228: $cachehash{$startoutmap}{'last_known'}=
229: &Apache::lonnet::declutter($currenturl);
1.20 albertel 230:
1.5 www 231: # ============================================================ Tie the big hash
1.3 www 232: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
233: &GDBM_READER,0640)) {
1.22 www 234: my $rid=$hash{'map_pc_/res/'.$startoutmap}.'.'.$mapnum;
1.14 www 235:
1.15 www 236: # ------------------------------------------------- Move forward, backward, etc
1.22 www 237: my $endupmap;
238: ($next,$endupmap)=&move($rid,$startoutmap,$direction);
1.15 www 239: # -------------------------------------- Do we have one and only one empty URL?
240: my $safecount=0;
1.26 www 241: while (($next) && ($next!~/\,/) &&
242: ((!$hash{'src_'.$next}) || ($hash{'randomout_'.$next}))
243: && ($safecount<10000)) {
1.22 www 244: ($next,$endupmap)=&move($next,$endupmap,$direction);
1.15 www 245: $safecount++;
246: }
1.22 www 247: # We are now at at least one non-empty URL
1.4 www 248: # ----------------------------------------------------- Check out possibilities
249: if ($next) {
250: @possibilities=split(/\,/,$next);
251: if ($#possibilities==0) {
1.5 www 252: # ---------------------------------------------- Only one possibility, redirect
253: $redirecturl=$hash{'src_'.$next};
1.22 www 254: $cachehash{$endupmap}
1.19 www 255: {&Apache::lonnet::declutter($redirecturl)}
1.5 www 256: =(split(/\./,$next))[1];
1.4 www 257: } else {
1.5 www 258: # ------------------------ There are multiple possibilities for a next resource
259: $multichoice=1;
260: map {
261: $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
262: $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
1.6 www 263: $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
1.22 www 264: my ($choicemap,$choiceres)=split(/\./,$_);
265: $cachehash
266: {&Apache::lonnet::declutter($hash{'src_'.$choicemap})}
267: {&Apache::lonnet::declutter(
1.5 www 268: $multichoicehash
269: {'src_'.$_}
270: )}
1.22 www 271: =$choiceres;
1.5 www 272: } @possibilities;
1.4 www 273: }
1.5 www 274: } else {
275: # -------------------------------------------------------------- No place to go
276: $multichoice=-1;
1.4 www 277: }
1.5 www 278: # ----------------- The program must come past this point to untie the big hash
1.3 www 279: untie(%hash);
1.5 www 280: # --------------------------------------------------------- Store position info
1.22 www 281: $cachehash{$startoutmap}{'last_direction'}=$direction;
1.19 www 282: foreach my $thismap (keys %cachehash) {
1.20 albertel 283: &Apache::lonnet::symblist($thismap,%{$cachehash{$thismap}});
1.19 www 284: }
1.5 www 285: # ============================================== Do not return before this line
1.4 www 286: if ($redirecturl) {
1.5 www 287: # ----------------------------------------------------- There is a URL to go to
1.4 www 288: $r->content_type('text/html');
289: $r->header_out(Location =>
290: 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
291: return REDIRECT;
1.5 www 292: } else {
293: # --------------------------------------------------------- There was a problem
1.8 www 294: $r->content_type('text/html');
295: $r->send_http_header;
296: if ($#possibilities>0) {
297: $r->print(<<ENDSTART);
298: <head><title>Choose Next Location</title></head>
299: <body bgcolor="#FFFFFF">
300: <h1>LON-CAPA</h1>
301: There are several possibilities of where to go next.
302: <p>
303: Please click on the the resource you intend to access:
304: <p>
305: <table border=2>
306: <tr><th>Title</th><th>Type</th></tr>
307: ENDSTART
1.26 www 308: foreach (@possibilities) {
1.8 www 309: $r->print(
310: '<tr><td><a href="'.
311: $multichoicehash{'src_'.$_}.'">'.
312: $multichoicehash{'title_'.$_}.
313: '</a></td><td>'.$multichoicehash{'type_'.$_}.
314: '</td></tr>');
1.26 www 315: }
1.8 www 316: $r->print('</table></body></html>');
317: return OK;
318: } else {
319: $r->print(<<ENDNONE);
320: <head><title>Choose Next Location</title></head>
321: <body bgcolor="#FFFFFF">
1.17 www 322: <img src="/adm/lonIcons/lonlogos.gif" align=right>
1.8 www 323: <h1>Sorry!</h1>
324: <h2>Next resource could not be identified.</h2>
1.17 www 325: <h3>You probably are at the beginning or the end of the course.</h3>
1.8 www 326: </body>
327: </html>
328: ENDNONE
329: return OK;
330: }
331: }
1.5 www 332: } else {
333: # ------------------------------------------------- Problem, could not tie hash
334: $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
335: return HTTP_NOT_ACCEPTABLE;
1.3 www 336: }
1.5 www 337: } else {
338: # ---------------------------------------- No, could not determine where we are
1.6 www 339: $r->internal_redirect('/adm/ambiguous');
1.2 www 340: }
1.5 www 341: } else {
1.2 www 342: # -------------------------- Class was not initialized or page fliped strangely
343: $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
344: return HTTP_NOT_ACCEPTABLE;
345: }
1.1 www 346: }
347:
348: 1;
349: __END__
350:
351:
352:
353:
354:
355:
356:
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