1: # The LearningOnline Network with CAPA
2: #
3: # Page flip handler
4: #
5: # (Page Handler
6: #
7: # (TeX Content Handler
8: #
9: # 05/29/00,05/30 Gerd Kortemeyer)
10: # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
11: # 10/02 Gerd Kortemeyer)
12: #
13: # 10/03,10/05,10/06,10/07,10/09,10/10,10/11,10/16,10/17,
14: # 11/14,11/16,
15: # 10/01/01,05/01,05/28 Gerd Kortemeyer
16:
17: package Apache::lonpageflip;
18:
19: use strict;
20: use Apache::Constants qw(:common :http REDIRECT);
21: use Apache::lonnet();
22: use HTML::TokeParser;
23: use GDBM_File;
24:
25: # ========================================================== Module Global Hash
26:
27: my %hash;
28:
29: sub addrid {
30: my ($current,$new,$condid)=@_;
31: unless ($condid) { $condid=0; }
32: if (&Apache::lonnet::allowed('bre',$hash{'src_'.$new})) {
33: if ($current) {
34: $current.=','.$new;
35: } else {
36: $current=''.$new;
37: }
38: }
39: return $current;
40: }
41:
42: sub move {
43: my ($rid,$mapurl,$direction)=@_;
44:
45: my $next='';
46:
47: my $mincond=1;
48: my $posnext='';
49: if ($direction eq 'forward') {
50: # --------------------------------------------------------------------- Forward
51: if ($hash{'type_'.$rid} eq 'finish') {
52: $rid=$hash{'ids_/res/'.$mapurl};
53: }
54: map {
55: my $thiscond=
56: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
57: if ($thiscond>=$mincond) {
58: if ($posnext) {
59: $posnext.=','.$_.':'.$thiscond;
60: } else {
61: $posnext=$_.':'.$thiscond;
62: }
63: if ($thiscond>$mincond) { $mincond=$thiscond; }
64: }
65: } split(/\,/,$hash{'to_'.$rid});
66: map {
67: my ($linkid,$condval)=split(/\:/,$_);
68: if ($condval>=$mincond) {
69: $next=&addrid($next,$hash{'goesto_'.$linkid},
70: $hash{'condid_'.$hash{'undercond_'.$linkid}});
71: }
72: } split(/\,/,$posnext);
73: if ($hash{'is_map_'.$next}) {
74: if (
75: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
76: $mapurl=$hash{'src_'.$next};
77: $next=$hash{'map_start_'.$hash{'src_'.$next}};
78: }
79: }
80: } elsif ($direction eq 'back') {
81: # ------------------------------------------------------------------- Backwards
82: if ($hash{'type_'.$rid} eq 'start') {
83: $rid=$hash{'ids_/res/'.$mapurl};
84: }
85: map {
86: my $thiscond=
87: &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
88: if ($thiscond>=$mincond) {
89: if ($posnext) {
90: $posnext.=','.$_.':'.$thiscond;
91: } else {
92: $posnext=$_.':'.$thiscond;
93: }
94: if ($thiscond>$mincond) { $mincond=$thiscond; }
95: }
96: } split(/\,/,$hash{'from_'.$rid});
97: map {
98: my ($linkid,$condval)=split(/\:/,$_);
99: if ($condval>=$mincond) {
100: $next=&addrid($next,$hash{'comesfrom_'.$linkid},
101: $hash{'condid_'.$hash{'undercond_'.$linkid}});
102: }
103: } split(/\,/,$posnext);
104: if ($hash{'is_map_'.$next}) {
105: if (
106: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') {
107: $mapurl=$hash{'src_'.$next};
108: $next=$hash{'map_finish_'.$hash{'src_'.$next}};
109: }
110: }
111: }
112:
113: return ($next,$mapurl);
114: }
115:
116: # ================================================================ Main Handler
117:
118: sub handler {
119: my $r=shift;
120:
121: # ------------------------------------------- Set document type for header only
122:
123: if ($r->header_only) {
124: $r->content_type('text/html');
125: $r->send_http_header;
126: return OK;
127: }
128:
129: my %cachehash=();
130: my $multichoice=0;
131: my %multichoicehash=();
132: my $redirecturl='';
133: my $next='';
134: my @possibilities=();
135:
136: if (($ENV{'form.postdata'})&&($ENV{'request.course.fn'})) {
137: $ENV{'form.postdata'}=~/(\w+)\:(.*)/;
138: my $direction=$1;
139: my $currenturl=$2;
140: if ($direction eq 'return') {
141: # -------------------------------------------------------- Return to last known
142: my $last;
143: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
144: &GDBM_READER,0640)) {
145: $last=$hash{'last_known'};
146: untie(%hash);
147: }
148: my $newloc;
149: if ($last) {
150: $newloc='/res/'.(split(/\_\_\_/,$last))[1];
151: } else {
152: $newloc='/adm/noidea.html';
153: }
154: $r->content_type('text/html');
155: $r->header_out(Location =>
156: 'http://'.$ENV{'HTTP_HOST'}.$newloc);
157:
158: return REDIRECT;
159: }
160: $currenturl=~s/^http\:\/\///;
161: $currenturl=~s/^[^\/]+//;
162: unless ($currenturl=~/\/res\//) {
163: my $last;
164: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
165: &GDBM_READER,0640)) {
166: $last=$hash{'last_known'};
167: untie(%hash);
168: }
169: if ($last) {
170: $currenturl='/res/'.(split(/\_\_\_/,$last))[1];
171: } else {
172: $r->content_type('text/html');
173: $r->header_out(Location =>
174: 'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
175: return REDIRECT;
176: }
177: }
178: # ------------------------------------------- Do we have any idea where we are?
179: my $position;
180: if ($position=Apache::lonnet::symbread($currenturl)) {
181: # ------------------------------------------------------------------------- Yes
182: my ($mapurl,$mapnum,$thisurl)=split(/\_\_\_/,$position);
183: $cachehash{$thisurl}=$mapnum;
184: # ============================================================ Tie the big hash
185: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
186: &GDBM_READER,0640)) {
187: my $rid=$hash{'map_pc_/res/'.$mapurl}.'.'.$mapnum;
188:
189: # ------------------------------------------------- Move forward, backward, etc
190:
191: ($next,$mapurl)=&move($rid,$mapurl,$direction);
192: # -------------------------------------- Do we have one and only one empty URL?
193: my $safecount=0;
194: while (($next) && ($next!~/\,/) && (!$hash{'src_'.$next})
195: && ($safecount<25)) {
196: ($next,$mapurl)=&move($next,$mapurl,$direction);
197: $safecount++;
198: }
199: # ----------------------------------------------------- Check out possibilities
200: if ($next) {
201: @possibilities=split(/\,/,$next);
202: if ($#possibilities==0) {
203: # ---------------------------------------------- Only one possibility, redirect
204: $redirecturl=$hash{'src_'.$next};
205: $cachehash{&Apache::lonnet::declutter($redirecturl)}
206: =(split(/\./,$next))[1];
207: } else {
208: # ------------------------ There are multiple possibilities for a next resource
209: $multichoice=1;
210: map {
211: $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
212: $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
213: $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
214: $cachehash
215: {&Apache::lonnet::declutter(
216: $multichoicehash
217: {'src_'.$_}
218: )}
219: =(split(/\./,$_))[1];
220: } @possibilities;
221: }
222: } else {
223: # -------------------------------------------------------------- No place to go
224: $multichoice=-1;
225: }
226: # ----------------- The program must come past this point to untie the big hash
227: untie(%hash);
228: # --------------------------------------------------------- Store position info
229: $cachehash{'last_direction'}=$direction;
230: $cachehash{'last_known'}=&Apache::lonnet::declutter($currenturl);
231: &Apache::lonnet::symblist($mapurl,%cachehash);
232: # ============================================== Do not return before this line
233: if ($redirecturl) {
234: # ----------------------------------------------------- There is a URL to go to
235: $r->content_type('text/html');
236: $r->header_out(Location =>
237: 'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
238: return REDIRECT;
239: } else {
240: # --------------------------------------------------------- There was a problem
241: $r->content_type('text/html');
242: $r->send_http_header;
243: if ($#possibilities>0) {
244: $r->print(<<ENDSTART);
245: <head><title>Choose Next Location</title></head>
246: <body bgcolor="#FFFFFF">
247: <h1>LON-CAPA</h1>
248: There are several possibilities of where to go next.
249: <p>
250: Please click on the the resource you intend to access:
251: <p>
252: <table border=2>
253: <tr><th>Title</th><th>Type</th></tr>
254: ENDSTART
255: map {
256: $r->print(
257: '<tr><td><a href="'.
258: $multichoicehash{'src_'.$_}.'">'.
259: $multichoicehash{'title_'.$_}.
260: '</a></td><td>'.$multichoicehash{'type_'.$_}.
261: '</td></tr>');
262: } @possibilities;
263: $r->print('</table></body></html>');
264: return OK;
265: } else {
266: $r->print(<<ENDNONE);
267: <head><title>Choose Next Location</title></head>
268: <body bgcolor="#FFFFFF">
269: <img src="/adm/lonKaputt/lonlogo_broken.gif" align=left>
270: <h1>Sorry!</h1>
271: <h2>Next resource could not be identified.</h2>
272: </body>
273: </html>
274: ENDNONE
275: return OK;
276: }
277: }
278: } else {
279: # ------------------------------------------------- Problem, could not tie hash
280: $ENV{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
281: return HTTP_NOT_ACCEPTABLE;
282: }
283: } else {
284: # ---------------------------------------- No, could not determine where we are
285: $r->internal_redirect('/adm/ambiguous');
286: }
287: } else {
288: # -------------------------- Class was not initialized or page fliped strangely
289: $ENV{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course";
290: return HTTP_NOT_ACCEPTABLE;
291: }
292: }
293:
294: 1;
295: __END__
296:
297:
298:
299:
300:
301:
302:
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