1: # The LearningOnline Network
2: #
3: # Read maps into a 'big hash'.
4: #
5: # $Id: lonmap.pm,v 1.3 2011/10/06 10:56:49 foxr 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:
31: package Apache::lonmap;
32: use strict;
33:
34: #------------- Required external modules.
35:
36: use Error qw(:try);
37:
38: use HTML::TokeParser;
39:
40:
41: use LONCAPA;
42: use Apache::lonnet;
43: use Data::Dumper;
44:
45:
46: #------------- File scoped variables:
47:
48: my $map_number = 0; # keep track of maps within the course.
49: my $course_id; # Will be the id of the course being read in.
50:
51: #
52: # The variables below are auxiliary hashes. They will be tacked onto the
53: # big hash though currently not used by clients.. you never know about later.
54: #
55:
56: my %randompick;
57: my %randompickseed;
58: my %randomorder;
59: my %encurl;
60: my %hiddenurl;
61: my %parmhash;
62: my @cond; # Array of conditions.
63: my $retfrid;
64: #
65: # Other stuff we make global (sigh) so that it does not need
66: # to be passed around all the time:
67: #
68:
69: my $username; # User for whom the map is being read.
70: my $userdomain; # Domain the user lives in.
71: my %mapalias_cache; # Keeps track of map aliases -> resources detects duplicates.
72: my %cenv; # Course environment.
73:
74: #------------- Executable code:
75:
76:
77: #----------------------------------------------------------------
78: #
79: # General utilities:
80:
81:
82: #
83: # I _think_ this does common sub-expression simplification and
84: # optimization for condition strings...based on common pattern matching.
85: # Parameters:
86: # expression - the condition expression string.
87: # Returns:
88: # The optimized expression if an optimization could be found.
89: #
90: # NOTE:
91: # Added repetetive optimization..it's possible that an
92: # optimization results in an expression that can be recognized further in
93: # a subsequent optimization pass:
94: #
95:
96: sub simplify {
97: my $expression=shift;
98: my $prior = ''; # This is safe as a null expression is pretty optimal.
99:
100: while ($prior ne $expression) {
101: $prior = $expression; # Stop when the substitutions below do nothing.
102: # (0&1) = 1
103: $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
104: # (8)=8
105: $expression=~s/\(([_\.\d]+)\)/$1/g;
106: # 8&8=8
107: $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
108: # 8|8=8
109: $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g;
110: # (5&3)&4=5&3&4
111: $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
112: # (((5&3)|(4&6)))=((5&3)|(4&6))
113: $expression=~
114: s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
115: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
116: $expression=~
117: s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
118: }
119: return $expression;
120: }
121:
122:
123: #
124: # Merge the conditions into the big hash
125: # these will result in hash entries of the form:
126: # 'condition.n' where 'n' is the array index of the condition in the
127: # @cond array above.
128: #
129: # Parameters:
130: # $hash - big hashthat's being built up.
131: #
132: sub merge_conditions {
133: my $hash = shift;
134:
135: for (my $i = 0; $i < scalar(@cond); $i++) {
136: $hash->{'condition' . '.' . $i} = $cond[$i];
137: }
138: }
139:
140: # Merge the contents of a 'child hash' into a parent hash hanging it off another key.
141: # This is _not_ done by hanging a reference to the child hash as the parent may be
142: # bound to a GDBM file e.g. and shared by more than one process ..and references are
143: # pretty clearly not going to work across process boundaries.
144: #
145: # Parameters:
146: # $parent - The hash to which the child will be merged (reference)
147: # $key - The key in the parent hash on which the child elements will be hung.
148: # given a key named $childkey the final parent hash entry will be
149: # $parent . '.' $childkey
150: # $child - The hash whose contents we merge into the parent (reference)
151: #
152: sub merge_hash {
153: my ($parent, $key, $child) = @_;
154:
155: if ($key ne '') {
156: $key .= '.'; # If we are prefixing, prefix then .
157: }
158:
159: foreach my $childkey (keys (%$child)) {
160: $parent->{$key . $childkey} = $child->{$childkey};
161: }
162: }
163:
164: #----------------------------------------------------------------------------------
165: #
166: # Code to keep track of map aliases and to determine if there are doubly
167: # defined aliases.
168: #
169:
170: #
171: # Maintains the mapalias hash. This is a hash of arrays. Each array
172: # is indexed by the alias and contains the set of resource ids pointed to by that
173: # alias. In an ideal world, there will only be one element in each array.
174: # The point of this, however is to determine which aliases might be doubley defined
175: # due to map nesting e.g.
176: #
177: # Parameters:
178: # $value - Alias name.
179: # $resid - Resource id pointed to by the alias.
180: #
181: #
182: sub count_mapalias {
183: my ($value,$resid) = @_;
184: push(@{ $mapalias_cache{$value} }, $resid);
185: }
186: #
187: # Looks at each key in the mapalias hash and, for each case where an
188: # alias points to more than one value adds an error text to the
189: # result string.'
190: #
191: # Parameters:
192: # hash - Reference to the hash we are trying t build up.
193: # Implicit inputs
194: # %mapalias - a hash that is indexed by map aliases and contains for each key
195: # an array of the resource id's the alias 'points to'.
196: # Returns:
197: # A hopefully empty string of messages that descsribe the aliases that have more
198: # than one value. This string is formatted like an html list.
199: #
200: #
201: sub get_mapalias_errors {
202: my $hash = shift;
203: my $error_text;
204: foreach my $mapalias (sort(keys(%mapalias_cache))) {
205: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
206: my $count;
207: my $which =
208: join('</li><li>',
209: map {
210: my $id = $_;
211: if (exists($hash->{'src_'.$id})) {
212: $count++;
213: }
214: my ($mapid) = split(/\./,$id);
215: &mt('Resource "[_1]" <br /> in Map "[_2]"',
216: $hash->{'title_'.$id},
217: $hash->{'title_'.$hash->{'ids_'.$hash->{'map_id_'.$mapid}}});
218: } (@{ $mapalias_cache{$mapalias} }));
219: next if ($count < 2);
220: $error_text .= '<div class="LC_error">'.
221: &mt('Error: Found the mapalias "[_1]" defined multiple times.',
222: $mapalias).
223: '</div><ul><li>'.$which.'</li></ul>';
224: }
225: &clear_mapalias_count();
226: return $error_text;
227: }
228: #
229: # Clears the map aliase hash.
230: #
231: sub clear_mapalias_count {
232: undef(%mapalias_cache);
233: }
234:
235: #----------------------------------------------------------------
236: #
237: # Code dealing with resource versions.
238: #
239:
240: #
241: # Put a version into a src element of a hash or url:
242: #
243: # Parameters:
244: # uri - URI into which the version must be added.
245: # hash - Reference to the hash being built up.
246: # short- Short coursename.
247: #
248:
249: sub putinversion {
250: my ($uri, $hash, $short) = @_;
251: my $key=$short.'_'.&Apache::lonnet::clutter($uri);
252: if ($hash->{'version_'.$uri}) {
253: my $version=$hash->{'version_'.$uri};
254: if ($version eq 'mostrecent') { return $uri; }
255: if ($version eq &Apache::lonnet::getversion(
256: &Apache::lonnet::filelocation('',$uri)))
257: { return $uri; }
258: $uri=~s/\.(\w+)$/\.$version\.$1/;
259: }
260: &Apache::lonnet::do_cache_new('courseresversion',$key,&Apache::lonnet::declutter($uri),600);
261: return $uri;
262: }
263:
264:
265: #
266: # Create hash entries for each version of the course.
267: # Parameters:
268: # $cenv - Reference to a course environment from lonnet::coursedescription.
269: # $hash - Reference to a hash that will be populated.
270:
271: #
272: sub process_versions {
273: my ($cenv, $hash) = @_;
274:
275:
276: my %versions = &Apache::lonnet::dump('resourceversions',
277: $cenv->{'domain'},
278: $cenv->{'num'});
279:
280: foreach my $ver (keys (%versions)) {
281: if ($ver =~/^error\:/) { # lonc/lond transaction failed.
282: throw Error::Simple('lonc/lond returned error: ' . $ver);
283: }
284: $hash->{'version_'.$ver} = $versions{$ver};
285: }
286: }
287:
288: #
289: # Generate text for a version discrepancy error:
290: # Parameters:
291: # $uri - URI of the resource.
292: # $used - Version used.
293: # $unused - Veresion of duplicate.
294: #
295: sub versionerror {
296: my ($uri, $used, $unused) = @_;
297: my ($uri,$usedversion,$unusedversion)=@_;
298: return '<br />'.
299: &mt('Version discrepancy: resource [_1] included in both version [_2] and version [_3]. Using version [_2].',
300: $uri,$used,$unused).'<br />';
301:
302: }
303:
304: # Removes the version number from a URI and returns the resulting
305: # URI (e.g. mumbly.version.stuff => mumbly.stuff).
306: #
307: # If the URI has not been seen with a version before the
308: # hash{'version_'.resultingURI} is set to the version number.
309: # If the hash has already been seen, but differs then
310: # an error is raised.
311: #
312: # Parameters:
313: # $uri - potentially with a version.
314: # $hash - reference to a hash to fill in.
315: # Returns:
316: # URI with the version cut out.
317: #
318: sub versiontrack {
319: my ($uri, $hash) = @_;
320:
321:
322: if ($uri=~/\.(\d+)\.\w+$/) { # URI like *.n.text it's version 'n'
323: my $version=$1;
324: $uri=~s/\.\d+\.(\w+)$/\.$1/; # elide the version.
325: unless ($hash->{'version_'.$uri}) {
326: $hash->{'version_'.$uri}=$version;
327: } elsif ($version!=$hash->{'version_'.$uri}) {
328: throw Error::Simple(&versionerror($uri, $hash->{'version_'.$uri}, $version));
329: }
330: }
331: return $uri;
332: }
333: #
334: # Appends the version of a resource to its uri and also caches the
335: # URI (contents?) on the local server
336: #
337: # Parameters:
338: # $uri - URI of the course (without version informatino.
339: # $hash - What we have of the big hash.
340: #
341: # Side-Effects:
342: # The URI is cached by memcached.
343: #
344: # Returns:
345: # The version appended URI.
346: #
347: sub append_version {
348: my ($uri, $hash) = @_;
349:
350: # Create the key for the cache entry.
351:
352: my $key = $course_id . '_' . &Apache::lonnet::clutter($uri);
353:
354: # If there is a version it will already be in the hash:
355:
356: if ($hash->{'version_' . $uri}) {
357: my $version = $hash->{'version_' . $uri};
358: if ($version eq 'mostrecent') {
359: return $uri; # Most recent version does not require decoration (or caching?).
360: }
361: if ($version eq
362: &Apache::lonnet::getversion(&Apache::lonnet::filelocation('', $uri))) {
363: return $uri; # version matches the most recent file version?
364: }
365: $uri =~ s/\.(\w+)$/\.$version\.$1/; # insert the versino prior to the last .word.
366: }
367:
368: # cache the version:
369:
370: &Apache::lonnet::do_cache_new('courseresversion', $key,
371: &Apache::lonnet::declutter($uri), 600);
372:
373: return $uri;
374:
375: }
376: #--------------------------------------------------------------------------------
377: # Post processing subs:
378: sub hiddenurls {
379: my $hash = shift;
380:
381: my $uname = $hash->{'context.username'};
382: my $udom = $hash->{'context.userdom'};
383: my $courseid = $hash->{'context.courseid'};
384:
385: my $randomoutentry='';
386: foreach my $rid (keys %randompick) {
387: my $rndpick=$randompick{$rid};
388: my $mpc=$hash->{'map_pc_'.$hash->{'src_'.$rid}};
389: # ------------------------------------------- put existing resources into array
390: my @currentrids=();
391: foreach my $key (sort(keys(%$hash))) {
392: if ($key=~/^src_($mpc\.\d+)/) {
393: if ($hash->{'src_'.$1}) { push @currentrids, $1; }
394: }
395: }
396: # rids are number.number and we want to numercially sort on
397: # the second number
398: @currentrids=sort {
399: my (undef,$aid)=split(/\./,$a);
400: my (undef,$bid)=split(/\./,$b);
401: $aid <=> $bid;
402: } @currentrids;
403: next if ($#currentrids<$rndpick);
404: # -------------------------------- randomly eliminate the ones that should stay
405: my (undef,$id)=split(/\./,$rid);
406: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
407: my $rndseed=&Apache::lonnet::rndseed($id, $courseid, $udom, $uname, \%cenv); # use id instead of symb
408: &Apache::lonnet::logthis("lonmap random seed: $rndseed");
409: &Apache::lonnet::setup_random_from_rndseed($rndseed);
410: my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
411: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
412:
413: # -------------------------------------------------------- delete the leftovers
414: for (my $k=0; $k<=$#currentrids; $k++) {
415: if ($currentrids[$k]) {
416: $hash->{'randomout_'.$currentrids[$k]}='1';
417: my ($mapid,$resid)=split(/\./,$currentrids[$k]);
418: $randomoutentry.='&'.
419: &Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},
420: $resid,
421: $hash->{'src_'.$currentrids[$k]}
422: ).'&';
423: }
424: }
425: }
426: # ------------------------------ take care of explicitly hidden urls or folders
427: foreach my $rid (keys %hiddenurl) {
428: $hash->{'randomout_'.$rid}='1';
429: my ($mapid,$resid)=split(/\./,$rid);
430: $randomoutentry.='&'.
431: &Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},$resid,
432: $hash->{'src_'.$rid}).'&';
433: }
434: # --------------------------------------- add randomout to the hash.
435: if ($randomoutentry) {
436: $hash->{'acc.randomout'} = $randomoutentry;
437:
438: }
439: }
440:
441: #
442: # It's not so clear to me what this sub does.
443: #
444: # Parameters
445: # uri - URI from the course description hash.
446: # short - Course short name.
447: # fn - Course filename.
448: # hash - Reference to the big hash as filled in so far
449: #
450:
451: sub accinit {
452: my ($uri, $short, $hash)=@_;
453: my %acchash=();
454: my %captured=();
455: my $condcounter=0;
456: $acchash{'acc.cond.'.$short.'.0'}=0;
457:
458: # This loop is only interested in conditions and
459: # parameters in the big hash:
460:
461: foreach my $key (keys(%$hash)) {
462:
463: # conditions:
464:
465: if ($key=~/^conditions/) {
466: my $expr=$hash->{$key};
467:
468: # try to find and factor out common sub-expressions
469: # Any subexpression that is found is simplified, removed from
470: # the original condition expression and the simplified sub-expression
471: # substituted back in to the epxression..I'm not actually convinced this
472: # factors anything out...but instead maybe simplifies common factors(?)
473:
474: foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
475: my $orig=$sub;
476:
477: my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
478: next if (!defined($factor));
479:
480: $sub=~s/\Q$factor\E//g;
481: $sub=~s/^\(/\($factor\(/;
482: $sub.=')';
483: $sub=simplify($sub);
484: $expr=~s/\Q$orig\E/$sub/;
485: }
486: $hash->{$key}=$expr;
487:
488: # If not yet seen, record in acchash and that we've seen it.
489:
490: unless (defined($captured{$expr})) {
491: $condcounter++;
492: $captured{$expr}=$condcounter;
493: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
494: }
495: # Parameters:
496:
497: } elsif ($key=~/^param_(\d+)\.(\d+)/) {
498: my $prefix=&Apache::lonnet::encode_symb($hash->{'map_id_'.$1},$2,
499: $hash->{'src_'.$1.'.'.$2});
500: foreach my $param (split(/\&/,$hash->{$key})) {
501: my ($typename,$value)=split(/\=/,$param);
502: my ($type,$name)=split(/\:/,$typename);
503: $parmhash{$prefix.'.'.&unescape($name)}=
504: &unescape($value);
505: $parmhash{$prefix.'.'.&unescape($name).'.type'}=
506: &unescape($type);
507: }
508: }
509: }
510: # This loop only processes id entries in the big hash.
511:
512: foreach my $key (keys(%$hash)) {
513: if ($key=~/^ids/) {
514: foreach my $resid (split(/\,/,$hash->{$key})) {
515: my $uri=$hash->{'src_'.$resid};
516: my ($uripath,$urifile) =
517: &Apache::lonnet::split_uri_for_cond($uri);
518: if ($uripath) {
519: my $uricond='0';
520: if (defined($hash->{'conditions_'.$resid})) {
521: $uricond=$captured{$hash->{'conditions_'.$resid}};
522: }
523: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
524: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
525: /(\&\Q$urifile\E\:[^\&]*)/) {
526: my $replace=$1;
527: my $regexp=$replace;
528: #$regexp=~s/\|/\\\|/g;
529: $acchash{'acc.res.'.$short.'.'.$uripath} =~
530: s/\Q$regexp\E/$replace\|$uricond/;
531: } else {
532: $acchash{'acc.res.'.$short.'.'.$uripath}.=
533: $urifile.':'.$uricond.'&';
534: }
535: } else {
536: $acchash{'acc.res.'.$short.'.'.$uripath}=
537: '&'.$urifile.':'.$uricond.'&';
538: }
539: }
540: }
541: }
542: }
543: $acchash{'acc.res.'.$short.'.'}='&:0&';
544: my $courseuri=$uri;
545: $courseuri=~s/^\/res\///;
546: my $regexp = 1;
547:
548: &merge_hash($hash, '', \%acchash); # there's already an acc prefix in the hash keys.
549:
550:
551: }
552:
553:
554: #
555: # Traces a route recursively through the map after it has been loaded
556: # (I believe this really visits each resource that is reachable fromt he
557: # start top node.
558: #
559: # - Marks hidden resources as hidden.
560: # - Marks which resource URL's must be encrypted.
561: # - Figures out (if necessary) the first resource in the map.
562: # - Further builds the chunks of the big hash that define how
563: # conditions work
564: #
565: # Note that the tracing strategy won't visit resources that are not linked to
566: # anything or islands in the map (groups of resources that form a path but are not
567: # linked in to the path that can be traced from the start resource...but that's ok
568: # because by definition, those resources are not reachable by users of the course.
569: #
570: # Parameters:
571: # sofar - _URI of the prior entry or 0 if this is the top.
572: # rid - URI of the resource to visit.
573: # beenhere - list of resources (each resource enclosed by &'s) that have
574: # already been visited.
575: # encflag - If true the resource that resulted in a recursive call to us
576: # has an encoded URL (which means contained resources should too).
577: # hdnflag - If true,the resource that resulted in a recursive call to us
578: # was hidden (which means contained resources should be hidden too).
579: # hash - Reference to the hash we are traversing.
580: # Returns
581: # new value indicating how far the map has been traversed (the sofar).
582: #
583: sub traceroute {
584: my ($sofar, $rid, $beenhere, $encflag, $hdnflag, $hash)=@_;
585: my $newsofar=$sofar=simplify($sofar);
586:
587: unless ($beenhere=~/\&\Q$rid\E\&/) {
588: $beenhere.=$rid.'&';
589: my ($mapid,$resid)=split(/\./,$rid);
590: my $symb=&Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},$resid,
591: $hash->{'src_'.$rid});
592: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
593:
594: if ($hdnflag || lc($hidden) eq 'yes') {
595: $hiddenurl{$rid}=1;
596: }
597: if (!$hdnflag && lc($hidden) eq 'no') {
598: delete($hiddenurl{$rid});
599: }
600:
601: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
602: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
603:
604: if (($retfrid eq '') && ($hash->{'src_'.$rid})
605: && ($hash->{'src_'.$rid}!~/\.sequence$/)) {
606: $retfrid=$rid;
607: }
608:
609: if (defined($hash->{'conditions_'.$rid})) {
610: $hash->{'conditions_'.$rid}=simplify(
611: '('.$hash->{'conditions_'.$rid}.')|('.$sofar.')');
612: } else {
613: $hash->{'conditions_'.$rid}=$sofar;
614: }
615:
616: # if the expression is just the 0th condition keep it
617: # otherwise leave a pointer to this condition expression
618:
619: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
620:
621: # Recurse if the resource is a map:
622:
623: if (defined($hash->{'is_map_'.$rid})) {
624: if (defined($hash->{'map_start_'.$hash->{'src_'.$rid}})) {
625: $sofar=$newsofar=
626: &traceroute($sofar,
627: $hash->{'map_start_'.$hash->{'src_'.$rid}},
628: $beenhere,
629: $encflag || $encurl{$rid},
630: $hdnflag || $hiddenurl{$rid}, $hash);
631: }
632: }
633:
634: # Processes links to this resource:
635: # - verify the existence of any conditionals on the link to here.
636: # - Recurse to any resources linked to us.
637: #
638: if (defined($hash->{'to_'.$rid})) {
639: foreach my $id (split(/\,/,$hash->{'to_'.$rid})) {
640: my $further=$sofar;
641: #
642: # If there's a condition associated with this link be sure
643: # it's been defined else that's an error:
644: #
645: if ($hash->{'undercond_'.$id}) {
646: if (defined($hash->{'condid_'.$hash->{'undercond_'.$id}})) {
647: $further=simplify('('.'_'.$rid.')&('.
648: $hash->{'condid_'.$hash->{'undercond_'.$id}}.')');
649: } else {
650: my $errtext.=&mt('<br />Undefined condition ID: [_1]',$hash->{'undercond_'.$id});
651: throw Error::Simple($errtext);
652: }
653: }
654: # Recurse to resoruces that have to's to us.
655: $newsofar=&traceroute($further,$hash->{'goesto_'.$id},$beenhere,
656: $encflag,$hdnflag, $hash);
657: }
658: }
659: }
660: return $newsofar;
661: }
662:
663:
664: #---------------------------------------------------------------------------------
665: #
666: # Map parsing code:
667: #
668:
669: #
670: # Parse the <param> tag. for most parameters, the only action is to define/extend
671: # a has entry for {'param_{refid}'} where refid is the resource the parameter is
672: # attached to and the value built up is an & separated list of parameters of the form:
673: # type:part.name=value
674: #
675: # In addition there is special case code for:
676: # - randompick
677: # - randompickseed
678: # - randomorder
679: #
680: # - encrypturl
681: # - hiddenresource
682: #
683: # Parameters:
684: # token - The token array from HTML::TokeParse we mostly care about element [2]
685: # which is a hash of attribute => values supplied in the tag
686: # (remember this sub is only processing start tag tokens).
687: # mno - Map number. This is used to qualify resource ids within a map
688: # to make them unique course wide (a process known as uniquifaction).
689: # hash - Reference to the hash we are building.
690: #
691: sub parse_param {
692: my ($token, $mno, $hash) = @_;
693:
694: # Qualify the reference and name by the map number and part number.
695: # if no explicit part number is supplied, 0 is the implicit part num.
696:
697: my $referid=$mno.'.'.$token->[2]->{'to'}; # Resource param applies to.
698: my $name=$token->[2]->{'name'}; # Name of parameter
699: my $part;
700:
701:
702: if ($name=~/^parameter_(.*)_/) {
703: $part=$1;
704: } else {
705: $part=0;
706: }
707:
708: # Peel the parameter_ off the parameter name.
709:
710: $name=~s/^.*_([^_]*)$/$1/;
711:
712: # The value is:
713: # type.part.name.value
714:
715: my $newparam=
716: &escape($token->[2]->{'type'}).':'.
717: &escape($part.'.'.$name).'='.
718: &escape($token->[2]->{'value'});
719:
720: # The hash key is param_resourceid.
721: # Multiple parameters for a single resource are & separated in the hash.
722:
723:
724: if (defined($hash->{'param_'.$referid})) {
725: $hash->{'param_'.$referid}.='&'.$newparam;
726: } else {
727: $hash->{'param_'.$referid}=''.$newparam;
728: }
729: #
730: # These parameters have to do with randomly selecting
731: # resources, therefore a separate hash is also created to
732: # make it easy to locate them when actually computing the resource set later on
733: # See the code conditionalized by ($randomize) in read_map().
734:
735: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
736: $randompick{$referid}=$token->[2]->{'value'};
737: }
738: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
739: $randompickseed{$referid}=$token->[2]->{'value'};
740: }
741: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
742: $randomorder{$referid}=$token->[2]->{'value'};
743: }
744:
745: # These parameters have to do with how the URLs of resources are presented to
746: # course members(?). encrypturl presents encypted url's while
747: # hiddenresource hides the URL.
748: #
749:
750: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
751: if ($token->[2]->{'value'}=~/^yes$/i) {
752: $encurl{$referid}=1;
753: }
754: }
755: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
756: if ($token->[2]->{'value'}=~/^yes$/i) {
757: $hiddenurl{$referid}=1;
758: }
759: }
760:
761: }
762:
763:
764: #
765: # Parses a resource tag to produce the value to push into the
766: # map_ids array.
767: #
768: #
769: # Information about the actual type of resource is provided by the file extension
770: # of the uri (e.g. .problem, .sequence etc. etc.).
771: #
772: # Parameters:
773: # $token - A token from HTML::TokeParser
774: # This is an array that describes the most recently parsed HTML item.
775: # $lpc - Map nesting level (?)
776: # $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
777: # $uri - URI of the enclosing resource.
778: # $hash - Reference to the hash we are building.
779: #
780: # Returns:
781: # Value of the id attribute of the tag.
782: #
783: # Note:
784: # The token is an array that contains the following elements:
785: # [0] => 'S' indicating this is a start token
786: # [1] => 'resource' indicating this tag is a <resource> tag.
787: # [2] => Hash of attribute =>value pairs.
788: # [3] => @(keys [2]).
789: # [4] => unused.
790: #
791: # The attributes of the resourcde tag include:
792: #
793: # id - The resource id.
794: # src - The URI of the resource.
795: # type - The resource type (e.g. start and finish).
796: # title - The resource title.
797: #
798:
799: sub parse_resource {
800: my ($token,$lpc,$ispage,$uri, $hash) = @_;
801:
802: # I refuse to countenance code like this that has
803: # such a dirty side effect (and forcing this sub to be called within a loop).
804: #
805: # if ($token->[2]->{'type'} eq 'zombie') { next; }
806: #
807: # The original code both returns _and_ skips to the next pass of the >caller's<
808: # loop, that's just dirty.
809: #
810:
811: # Zombie resources don't produce anything useful.
812:
813: if ($token->[2]->{'type'} eq 'zombie') {
814: return undef;
815: }
816:
817: my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
818:
819: # Save the hash element type and title:
820:
821: $hash->{'kind_'.$rid}='res';
822: $hash->{'title_'.$rid}=$token->[2]->{'title'};
823:
824: # Get the version free URI for the resource.
825: # If a 'version' attribute was supplied, and this resource's version
826: # information has not yet been stored, store it.
827: #
828:
829:
830: my $turi=&versiontrack($token->[2]->{'src'});
831: if ($token->[2]->{'version'}) {
832: unless ($hash->{'version_'.$turi}) {
833:
834: #Where does the value of $1 below come from?
835: #$1 for the regexps in versiontrack should have gone out of scope.
836: #
837: # I think this may be dead code since versiontrack ought to set
838: # this hash element(?).
839: #
840: $hash->{'version_'.$turi}=$1;
841: }
842: }
843: # Pull out the title and do entity substitution on &colon
844: # Q: Why no other entity substitutions?
845:
846: my $title=$token->[2]->{'title'};
847: $title=~s/\&colon\;/\:/gs;
848:
849:
850:
851: # I think the point of all this code is to construct a final
852: # URI that apache and its rewrite rules can use to
853: # fetch the resource. Thi s sonly necessary if the resource
854: # is not a page. If the resource is a page then it must be
855: # assembled (at fetch time?).
856:
857: unless ($ispage) {
858: $turi=~/\.(\w+)$/;
859: my $embstyle=&Apache::loncommon::fileembstyle($1);
860: if ($token->[2]->{'external'} eq 'true') { # external
861: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
862: } elsif ($turi=~/^\/*uploaded\//) { # uploaded
863: if (($embstyle eq 'img')
864: || ($embstyle eq 'emb')
865: || ($embstyle eq 'wrp')) {
866: $turi='/adm/wrapper'.$turi;
867: } elsif ($embstyle eq 'ssi') {
868: #do nothing with these
869: } elsif ($turi!~/\.(sequence|page)$/) {
870: $turi='/adm/coursedocs/showdoc'.$turi;
871: }
872: } elsif ($turi=~/\S/) { # normal non-empty internal resource
873: my $mapdir=$uri;
874: $mapdir=~s/[^\/]+$//;
875: $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
876: if (($embstyle eq 'img')
877: || ($embstyle eq 'emb')
878: || ($embstyle eq 'wrp')) {
879: $turi='/adm/wrapper'.$turi;
880: }
881: }
882: }
883: # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
884: # If the URI appears more than one time in the sequence, it's resourcde
885: # id's are constructed as a comma spearated list.
886:
887: my $idsuri=$turi;
888: $idsuri=~s/\?.+$//;
889: if (defined($hash->{'ids_'.$idsuri})) {
890: $hash->{'ids_'.$idsuri}.=','.$rid;
891: } else {
892: $hash->{'ids_'.$idsuri}=''.$rid;
893: }
894:
895:
896:
897: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
898: $turi.='?register=1';
899: }
900:
901:
902: # resource id lookup: 'src'_resourc-di => URI decorated with a query
903: # parameter as above if necessary due to the resource type.
904:
905: $hash->{'src_'.$rid}=$turi;
906:
907: # Mark the external-ness of the resource:
908:
909: if ($token->[2]->{'external'} eq 'true') {
910: $hash->{'ext_'.$rid}='true:';
911: } else {
912: $hash->{'ext_'.$rid}='false:';
913: }
914:
915: # If the resource is a start/finish resource set those
916: # entries in the has so that navigation knows where everything starts.
917: # If there is a malformed sequence that has no start or no finish
918: # resource, should this be detected and errors thrown? How would such a
919: # resource come into being other than being manually constructed by a person
920: # and then uploaded? Could that happen if an author decided a sequence was almost
921: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
922: # start or finish resources?
923: #
924: # All resourcess also get a type_id => (start | finish | normal) hash entr.
925: #
926: if ($token->[2]->{'type'}) {
927: $hash->{'type_'.$rid}=$token->[2]->{'type'};
928: if ($token->[2]->{'type'} eq 'start') {
929: $hash->{'map_start_'.$uri}="$rid";
930: }
931: if ($token->[2]->{'type'} eq 'finish') {
932: $hash->{'map_finish_'.$uri}="$rid";
933: }
934: } else {
935: $hash->{'type_'.$rid}='normal';
936: }
937:
938: # Sequences end pages are constructed entities. They require that the
939: # map that defines _them_ be loaded as well into the hash...with this resourcde
940: # as the base of the nesting.
941: # Resources like that are also marked with is_map_id => 1 entries.
942: #
943:
944: if (($turi=~/\.sequence$/) ||
945: ($turi=~/\.page$/)) {
946: $hash->{'is_map_'.$rid}='1'; # String in lonuserstate.
947: &read_map($turi,$rid, $hash);
948: }
949: return $token->[2]->{'id'};
950: }
951:
952: # Links define how you are allowed to move from one resource to another.
953: # They are the transition edges in the directed graph that a map is.
954: # This sub takes informatino from a <link> tag and constructs the
955: # navigation bits and pieces of a map. There is no requirement that the
956: # resources that are linke are already defined, however clearly the map is
957: # badly broken if they are not _eventually_ defined.
958: #
959: # Note that links can be unconditional or conditional.
960: #
961: # Parameters:
962: # linkpc - The link counter for this level of map nesting (this is
963: # reset to zero by read_map prior to starting to process
964: # links for map).
965: # lpc - The map level ocounter (how deeply nested this map is in
966: # the hierarchy of maps that are recursively read in.
967: # to - resource id (within the XML) of the target of the edge.
968: # from - resource id (within the XML) of the source of the edge.
969: # condition- id of condition associated with the edge (also within the XML).
970: # hash - reference to the hash we are building.
971:
972: #
973:
974: sub make_link {
975: my ($linkpc,$lpc,$to,$from,$condition, $hash) = @_;
976:
977: # Compute fully qualified ids for the link, the
978: # and from/to by prepending lpc.
979: #
980:
981: my $linkid=$lpc.'.'.$linkpc;
982: my $goesto=$lpc.'.'.$to;
983: my $comesfrom=$lpc.'.'.$from;
984: my $undercond='0';
985:
986:
987: # If there is a condition, qualify it with the level counter.
988:
989: if ($condition) {
990: $undercond=$lpc.'.'.$condition;
991: }
992:
993: # Links are represnted by:
994: # goesto_.fuullyqualifedlinkid => fully qualified to
995: # comesfrom.fullyqualifiedlinkid => fully qualified from
996: # undercond_.fullyqualifiedlinkid => fully qualified condition id.
997:
998: $hash->{'goesto_'.$linkid}=$goesto;
999: $hash->{'comesfrom_'.$linkid}=$comesfrom;
1000: $hash->{'undercond_'.$linkid}=$undercond;
1001:
1002: # In addition:
1003: # to_.fully qualified from => comma separated list of
1004: # link ids with that from.
1005: # Similarly:
1006: # from_.fully qualified to => comma separated list of link ids`
1007: # with that to.
1008: # That allows us given a resource id to know all edges that go to it
1009: # and leave from it.
1010: #
1011:
1012: if (defined($hash->{'to_'.$comesfrom})) {
1013: $hash->{'to_'.$comesfrom}.=','.$linkid;
1014: } else {
1015: $hash->{'to_'.$comesfrom}=''.$linkid;
1016: }
1017: if (defined($hash->{'from_'.$goesto})) {
1018: $hash->{'from_'.$goesto}.=','.$linkid;
1019: } else {
1020: $hash->{'from_'.$goesto}=''.$linkid;
1021: }
1022: }
1023:
1024: # ------------------------------------------------------------------- Condition
1025: #
1026: # Processes <condition> tags, storing sufficient information about them
1027: # in the hash so that they can be evaluated and used to conditionalize
1028: # what is presented to the student.
1029: #
1030: # these can have the following attributes
1031: #
1032: # id = A unique identifier of the condition within the map.
1033: #
1034: # value = Is a perl script-let that, when evaluated in safe space
1035: # determines whether or not the condition is true.
1036: # Normally this takes the form of a test on an Apache::lonnet::EXT call
1037: # to find the value of variable associated with a resource in the
1038: # map identified by a mapalias.
1039: # Here's a fragment of XML code that illustrates this:
1040: #
1041: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
1042: # <resource src="" id="1" type="start" title="Start" />
1043: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" />
1044: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
1045: # <2 " id="61" type="stop" />
1046: # <link to="5" index="1" from="1" condition="61" />
1047: #
1048: # In this fragment:
1049: # - The param tag establishes an alias to resource id 5 of 'mainproblem'.
1050: # - The resource that is the start of the map is identified.
1051: # - The resource tag identifies the resource associated with this tag
1052: # and gives it the id 5.
1053: # - The condition is true if the tries variable associated with mainproblem
1054: # is less than 2 (that is the user has had more than 2 tries).
1055: # The condition type is a stop condition which inhibits(?) the associated
1056: # link if the condition is false.
1057: # - The link to resource 5 from resource 1 is affected by this condition.
1058: #
1059: # type = Type of the condition. The type determines how the condition affects the
1060: # link associated with it and is one of
1061: # - 'force'
1062: # - 'stop'
1063: # anything else including not supplied..which treated as:
1064: # - 'normal'.
1065: # Presumably maps get created by the resource assembly tool and therefore
1066: # illegal type values won't squirm their way into the XML.
1067: # hash - Reference to the hash we are trying to build up.
1068: #
1069: # Side effects:
1070: # - The kind_level-qualified-condition-id hash element is set to 'cond'.
1071: # - The condition text is pushed into the cond array and its element number is
1072: # set in the condid_level-qualified-condition-id element of the hash.
1073: # - The condition type is colon appneded to the cond array element for this condition.
1074: sub parse_condition {
1075: my ($token, $lpc, $hash) = @_;
1076: my $rid=$lpc.'.'.$token->[2]->{'id'};
1077:
1078: $hash->{'kind_'.$rid}='cond';
1079:
1080: my $condition = $token->[2]->{'value'};
1081: $condition =~ s/[\n\r]+/ /gs;
1082: push(@cond, $condition);
1083: $hash->{'condid_'.$rid}=$#cond;
1084: if ($token->[2]->{'type'}) {
1085: $cond[$#cond].=':'.$token->[2]->{'type'};
1086: } else {
1087: $cond[$#cond].=':normal';
1088: }
1089: }
1090:
1091: #
1092: # Parse mapalias parameters.
1093: # these are tags of the form:
1094: # <param to="nn"
1095: # value="some-alias-for-resourceid-nn"
1096: # name="parameter_0_mapalias"
1097: # type="string" />
1098: # A map alias is a textual name for a resource:
1099: # - The to attribute identifies the resource (this gets level qualified below)
1100: # - The value attributes provides the alias string.
1101: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/
1102: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings
1103: # terminating with the string 'mapalias'.
1104: # Examples:
1105: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
1106: # Invalid to ids are silently ignored.
1107: #
1108: # Parameters:
1109: # token - The token array fromthe HMTML::TokeParser
1110: # lpc - The current map level counter.
1111: # hash - Reference to the hash that we are building.
1112: #
1113: sub parse_mapalias_param {
1114: my ($token, $lpc, $hash) = @_;
1115:
1116: # Fully qualify the to value and ignore the alias if there is no
1117: # corresponding resource.
1118:
1119: my $referid=$lpc.'.'.$token->[2]->{'to'};
1120: return if (!exists($hash->{'src_'.$referid}));
1121:
1122: # If this is a valid mapalias parameter,
1123: # Append the target id to the count_mapalias element for that
1124: # alias so that we can detect doubly defined aliases
1125: # e.g.:
1126: # <param to="1" value="george" name="parameter_0_mapalias" type="string" />
1127: # <param to="2" value="george" name="parameter_0_mapalias" type="string" />
1128: #
1129: # The example above is trivial but the case that's important has to do with
1130: # constructing a map that includes a nested map where the nested map may have
1131: # aliases that conflict with aliases established in the enclosing map.
1132: #
1133: # ...and create/update the hash mapalias entry to actually store the alias.
1134: #
1135:
1136: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
1137: &count_mapalias($token->[2]->{'value'},$referid);
1138: $hash->{'mapalias_'.$token->[2]->{'value'}}=$referid;
1139: }
1140: }
1141:
1142:
1143: #---------------------------------------------------------------------------------
1144: #
1145: # Code to process the map file.
1146:
1147: # read a map file and add it to the hash. Since a course map can contain resources
1148: # that are themselves maps, read_map might be recursively called.
1149: #
1150: # Parameters:
1151: # $uri - URI of the course itself (not the map file).
1152: # $parent_rid - map number qualified id of the parent of the map being read.
1153: # For the top level course map this is 0.0. For the first nested
1154: # map 1.n where n is the id of the resource within the
1155: # top level map and so on.
1156: # $hash - Reference to a hash that will become the big hash for the course
1157: # This hash is modified as per the map description.
1158: # Side-effects:
1159: # $map_number - Will be incremented. This keeps track of the number of the map
1160: # we are currently working on (see parent_rid above, the number to the
1161: # left of the . in $parent_rid is the map number).
1162: #
1163: #
1164: sub read_map {
1165: my ($uri, $parent_rid, $hash) = @_;
1166:
1167:
1168: # Check for duplication: A map may only be included once.
1169:
1170: if($hash->{'map_pc_' . $uri}) {
1171: throw Error::Simple('Duplicate map: ', $uri);
1172: }
1173: # count the map number and save it locally so that we don't lose it
1174: # when we recurse.
1175:
1176: $map_number++;
1177: my $lmap_no = $map_number;
1178:
1179: # save the map_pc and map_id elements of the hash for this map:
1180: # map_pc_uri is the map number of the map with that URI.
1181: # map_id_$lmap_no is the URI for this map level.
1182: #
1183: $hash->{'map_pc_' . $uri} = "$lmap_no"; # string form in lonuserstate.
1184: $hash->{'map_id_' . $lmap_no} = "$uri";
1185:
1186: # Create the path up to the top of the course.
1187: # this is in 'map_hierarchy_mapno' that's a comma separated path down to us
1188: # in the hierarchy:
1189:
1190: if ($parent_rid =~/^(\d+).\d+$/) {
1191: my $parent_no = $1; # Parent's map number.
1192: if (defined($hash->{'map_hierarchy_' . $parent_no})) {
1193: $hash->{'map_hierarchy_' . $lmap_no} =
1194: $hash->{'map_hierarchy_' . $parent_no} . ',' . $parent_no;
1195: } else {
1196: # Only 1 level deep ..nothing to append to:
1197:
1198: $hash->{'map_hierarchy_' . $lmap_no} = $parent_no;
1199: }
1200: }
1201:
1202: # figure out the name of the map file we need to read.
1203: # ensure that it is a .page or a .sequence as those are the only
1204: # sorts of files that make sense for this sub
1205:
1206: my $filename = &Apache::lonnet::filelocation('', &append_version($uri, $hash));
1207:
1208:
1209: my $ispage = ($filename =~/\.page$/);
1210: unless ($ispage || ($filename =~ /\.sequence$/)) {
1211: throw Error::Simple(&mt("<br />Invalid map: <tt>[_1]</tt>", $filename));
1212: }
1213:
1214: $filename =~ /\.(\w+)$/;
1215:
1216: $hash->{'map_type_'.$lmap_no}=$1;
1217:
1218: # Repcopy the file and get its contents...report errors if we can't
1219:
1220: my $contents = &Apache::lonnet::getfile($filename);
1221: if($contents eq -1) {
1222: throw Error::Simple(&mt('<br />Map not loaded: The file <tt>[_1]</tt> does not exist.',
1223: $filename));
1224: }
1225: # Now that we succesfully retrieved the file we can make our parsing passes over it:
1226: # parsing is done in passes:
1227: # 1. Parameters are parsed.
1228: # 2. Resource, links and conditions are parsed.
1229: #
1230: # post processing takes care of the case where the sequence is random ordered
1231: # or randomselected.
1232:
1233: # Parse the parameters, This pass only cares about start tags for <param>
1234: # tags.. this is because there is no body to a <param> tag.
1235: #
1236:
1237: my $parser = HTML::TokeParser->new(\$contents);
1238: $parser->attr_encoded(1); # Don't interpret entities in attributes (leave &xyz; alone).
1239:
1240: while (my $token = $parser->get_token()) {
1241: if (($token->[0] eq 'S') && ($token->[1] eq 'param')) {
1242: &parse_param($token, $map_number, $hash);
1243: }
1244: }
1245:
1246: # ready for pass 2: Resource links and conditions.
1247: # Note that if the map is random-ordered link tags are computed by randomizing
1248: # resource order. Furthermore, since conditions are set on links rather than
1249: # resources, they are also not processed if random order is turned on.
1250: #
1251:
1252: $parser = HTML::TokeParser->new(\$contents); # no way to reset the existing parser
1253: $parser->attr_encoded(1);
1254:
1255: my $linkpc=0;
1256: my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i);
1257:
1258: my @map_ids;
1259: while (my $token = $parser->get_token) {
1260: next if ($token->[0] ne 'S');
1261:
1262: # Resource
1263:
1264: if ($token->[1] eq 'resource') {
1265: my $resource_id = &parse_resource($token,$lmap_no,$ispage,$uri, $hash);
1266: if (defined $resource_id) {
1267: push(@map_ids, $resource_id);
1268: }
1269:
1270: # Link
1271:
1272: } elsif ($token->[1] eq 'link' && !$randomize) {
1273: &make_link(++$linkpc,$lmap_no,$token->[2]->{'to'},
1274: $token->[2]->{'from'},
1275: $token->[2]->{'condition'}, $hash); # note ..condition may be undefined.
1276:
1277: # condition
1278:
1279: } elsif ($token->[1] eq 'condition' && !$randomize) {
1280: &parse_condition($token,$lmap_no, $hash);
1281: }
1282: }
1283:
1284: # This section handles random ordering by permuting the
1285: # IDs of the map according to the user's random seed.
1286: #
1287:
1288: if ($randomize) {
1289: if (!$env{'request.role.adv'}) {
1290: my $seed;
1291:
1292: # In the advanced role, the map's random seed
1293: # parameter is used as the basis for computing the
1294: # seed ... if it has been specified:
1295:
1296: if (defined($randompickseed{$parent_rid})) {
1297: $seed = $randompickseed{$parent_rid};
1298: } else {
1299:
1300: # Otherwise the parent's fully encoded symb is used.
1301:
1302: my ($mapid,$resid)=split(/\./,$parent_rid);
1303: my $symb=
1304: &Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},
1305: $resid,$hash->{'src_'.$parent_rid});
1306:
1307: $seed = $symb;
1308: }
1309:
1310:
1311: my $rndseed=&Apache::lonnet::rndseed($seed, $username, $userdomain);
1312: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1313:
1314: # Take the set of map ids we have decoded and permute them to a
1315: # random order based on the seed set above. All of this is
1316: # processing the randomorder parameter if it is set, not
1317: # randompick.
1318:
1319: @map_ids=&math::Random::random_permutation(@map_ids);
1320: }
1321:
1322:
1323: my $from = shift(@map_ids);
1324: my $from_rid = $lmap_no.'.'.$from;
1325: $hash->{'map_start_'.$uri} = $from_rid;
1326: $hash->{'type_'.$from_rid}='start';
1327:
1328: # Create links to reflect the random re-ordering done above.
1329: # In the code to process the map XML, we did not process links or conditions
1330: # if randomorder was set. This means that for an instructor to choose
1331:
1332: while (my $to = shift(@map_ids)) {
1333: &make_link(++$linkpc,$lmap_no,$to,$from, 0, $hash);
1334: my $to_rid = $lmap_no.'.'.$to;
1335: $hash->{'type_'.$to_rid}='normal';
1336: $from = $to;
1337: $from_rid = $to_rid;
1338: }
1339:
1340: $hash->{'map_finish_'.$uri}= $from_rid;
1341: $hash->{'type_'.$from_rid}='finish';
1342: }
1343:
1344: # The last parsing pass parses the <mapalias> tags that associate a name
1345: # with resource ids.
1346:
1347: $parser = HTML::TokeParser->new(\$contents);
1348: $parser->attr_encoded(1);
1349:
1350: while (my $token = $parser->get_token) {
1351: next if ($token->[0] ne 'S');
1352: if ($token->[1] eq 'param') {
1353: &parse_mapalias_param($token,$lmap_no, $hash);
1354: }
1355: }
1356:
1357: }
1358:
1359:
1360: #
1361: # Load a map from file into a target hash. This is done by first parsing the
1362: # map file into local hashes and then unrolling those hashes into the big hash.
1363: #
1364: # Parameters:
1365: #
1366: # $cnum - number of course being read.
1367: # $cdom - Domain in which the course is evaluated.
1368: # $uname - Name of the user for whom the course is being read
1369: # $udom - Name of the domain of the user for whom the course is being read.
1370: # $target_hash- Reference to the target hash into which all of this is read.
1371: # Note tht some of the hash entries we need to build require knowledge of the
1372: # course URI.. these are expected to be filled in by the caller.
1373: #
1374: # Errors are logged to lonnet and are managed via the Perl structured exception package.
1375: #
1376: #
1377: sub loadmap {
1378: my ($cnum, $cdom, $uname, $udom, $target_hash) = @_;
1379:
1380:
1381:
1382: # Clear the auxillary hashes and the cond array.
1383:
1384:
1385: %randompick = ();
1386: %randompickseed = ();
1387: %encurl = ();
1388: %hiddenurl = ();
1389: %parmhash = ();
1390: @cond = ();
1391: $retfrid = '';
1392: $username = '';
1393: $userdomain = '';
1394: %mapalias_cache = ();
1395: %cenv = ();
1396:
1397:
1398: #
1399:
1400: $username = $uname;
1401: $userdomain = $udom;
1402:
1403: my $short_name = $cdom .'/' . $cnum;
1404: my $retfurl;
1405:
1406: try {
1407:
1408:
1409: # Get the information we need about the course.
1410: # Return without filling in anything if we can't get any info:
1411:
1412: %cenv = &Apache::lonnet::coursedescription($short_name,
1413: {'freshen_cache' => 1,
1414: 'user' => $uname});
1415:
1416: unless ($cenv{'url'}) {
1417: &Apache::lonnet::logthis("lonmap::loadmap failed: $cnum/$cdom - did not get url");
1418: return;
1419: }
1420: &Apache::lonnet::logthis("Course environment: \n" . Dumper(\%cenv));
1421:
1422: $course_id = $cdom . '_' . $cnum; # Long course id.
1423:
1424: # Load the version information into the hash
1425:
1426:
1427: &process_versions(\%cenv, $target_hash);
1428:
1429:
1430: # Figure out the map filename's URI, and set up some starting points for the map.
1431:
1432: my $course_uri = $cenv{'url'};
1433: my $map_uri = &Apache::lonnet::clutter($course_uri);
1434:
1435: $target_hash->{'src_0.0'} = &versiontrack($map_uri, $target_hash);
1436: $target_hash->{'title_0.0'} = &Apache::lonnet::metadata($course_uri, 'title');
1437: if(!defined $target_hash->{'title_0.0'}) {
1438: $target_hash->{'title_0.0'} = '';
1439: }
1440: $target_hash->{'ids_'.$map_uri} = '0.0';
1441: $target_hash->{'is_map_0.0'} = '1';
1442:
1443: # In some places we need a username a domain and the courseid...store that
1444: # in the target hash in the context.xxxx keys:
1445:
1446: $target_hash->{'context.username'} = $username;
1447: $target_hash->{'context.userdom'} = $userdomain;
1448: $target_hash->{'context.courseid'} = $course_id;
1449:
1450: &read_map($course_uri, '0.0', $target_hash);
1451:
1452: #
1453:
1454: if (defined($target_hash->{'map_start_'.$map_uri})) {
1455:
1456: &traceroute('0',$target_hash->{'map_start_'.$course_uri},'&', 0, 0, $target_hash);
1457: &accinit($course_uri, $short_name, $target_hash);
1458: &hiddenurls($target_hash);
1459: }
1460: my $errors = &get_mapalias_errors($target_hash);
1461: if ($errors ne "") {
1462: throw Error::Simple("Map alias errors: ", $errors);
1463: }
1464:
1465: # Put the versions in to src:
1466:
1467: foreach my $key (keys(%$target_hash)) {
1468: if ($key =~ /^src_/) {
1469: $target_hash->{$key} =
1470: &putinversion($target_hash->{$key}, $target_hash, $short_name);
1471: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
1472: my ($type, $url) = ($1,$2);
1473: my $value = $target_hash->{$key};
1474: $target_hash->{$type.&putinversion($url, $target_hash, $short_name)}=$value;
1475: }
1476: }
1477: # Mark necrypted URLS.
1478:
1479: foreach my $id (keys(%encurl)) {
1480: $target_hash->{'encrypted_'.$id}=1;
1481: }
1482:
1483: # Store first keys.
1484:
1485: $target_hash->{'first_rid'}=$retfrid;
1486: my ($mapid,$resid)=split(/\./,$retfrid);
1487: $target_hash->{'first_mapurl'}=$target_hash->{'map_id_'.$mapid};
1488: my $symb=&Apache::lonnet::encode_symb($target_hash->{'map_id_'.$mapid},
1489: $resid,
1490: $target_hash->{'src_'.$retfrid});
1491: $retfurl=&add_get_param($target_hash->{'src_'.$retfrid},{ 'symb' => $symb });
1492: if ($target_hash->{'encrypted_'.$retfrid}) {
1493: $retfurl=&Apache::lonenc::encrypted($retfurl,
1494: (&Apache::lonnet::allowed('adv') ne 'F'));
1495: }
1496: $target_hash->{'first_url'}=$retfurl;
1497:
1498: # Merge in the child hashes in case the caller wants that information as well.
1499:
1500:
1501: &merge_hash($target_hash, 'randompick', \%randompick);
1502: &merge_hash($target_hash, 'randompickseed', \%randompick);
1503: &merge_hash($target_hash, 'randomorder', \%randomorder);
1504: &merge_hash($target_hash, 'encurl', \%encurl);
1505: &merge_hash($target_hash, 'hiddenurl', \%hiddenurl);
1506: &merge_hash($target_hash, 'param', \%parmhash);
1507: &merge_conditions($target_hash);
1508: }
1509: otherwise {
1510: my $e = shift;
1511: &Apache::lonnet::logthis("lonmap::loadmap failed: " . $e->stringify());
1512: }
1513:
1514: }
1515:
1516:
1517: 1;
1518:
1519: #
1520: # Module initialization code:
1521: # TODO: Fix the pod docs below.
1522:
1523: 1;
1524: __END__
1525:
1526: =head1 NAME
1527:
1528: Apache::lonmap - Construct a hash that represents a course (Big Hash).
1529:
1530: =head1 SYNOPSIS
1531:
1532: &Apache::lonmap::loadmap($filepath, \%target_hash);
1533:
1534: =head1 INTRODUCTION
1535:
1536: This module reads a course filename into a hash reference. It's up to the caller
1537: to to things like decide the has should be tied to some external file and handle the locking
1538: if this file should be shared amongst several Apache children.
1539:
1540: =head1 SUBROUTINES
1541:
1542: =over
1543:
1544: =item loadmap($filepath, $targethash)
1545:
1546:
1547: Reads the map file into a target hash.
1548:
1549: =over
1550:
1551: =item $filepath - The path to the map file to read.
1552:
1553: =item $targethash - A reference to hash into which the course is read.
1554:
1555: =back
1556:
1557: =item process_versions($cenv, $hash)
1558:
1559: Makes hash entries for each version of a course described by a course environment
1560: returned from Apache::lonnet::coursedescription.
1561:
1562: =over
1563:
1564: =item $cenv - Reference to the environment hash returned by Apache::lonnet::coursedescription
1565:
1566: =item $hash - Hash to be filled in with 'version_xxx' entries as per the big hash.
1567:
1568: =back
1569:
1570: =back
1571:
1572:
1573: =cut
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