1: # The LearningOnline Network
2: #
3: # Read maps into a 'big hash'.
4: #
5: # $Id: lonmap.pm,v 1.6 2011/11/29 11:50:53 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 Apache::lonlocal;
44:
45: use Data::Dumper;
46:
47:
48: #------------- File scoped variables:
49:
50: my $map_number = 0; # keep track of maps within the course.
51: my $course_id; # Will be the id of the course being read in.
52:
53: #
54: # The variables below are auxiliary hashes. They will be tacked onto the
55: # big hash though currently not used by clients.. you never know about later.
56: #
57:
58: my %randompick;
59: my %randompickseed;
60: my %randomorder;
61: my %encurl;
62: my %hiddenurl;
63: my %parmhash;
64: my @cond; # Array of conditions.
65: my $retfrid;
66: #
67: # Other stuff we make global (sigh) so that it does not need
68: # to be passed around all the time:
69: #
70:
71: my $username; # User for whom the map is being read.
72: my $userdomain; # Domain the user lives in.
73: my $short_name; # Course shortname.
74: my %mapalias_cache; # Keeps track of map aliases -> resources detects duplicates.
75: my %cenv; # Course environment.
76:
77: #------------- Executable code:
78:
79:
80: #----------------------------------------------------------------
81: #
82: # General utilities:
83:
84:
85: #
86: # I _think_ this does common sub-expression simplification and
87: # optimization for condition strings...based on common pattern matching.
88: # Parameters:
89: # expression - the condition expression string.
90: # Returns:
91: # The optimized expression if an optimization could be found.
92: #
93: # NOTE:
94: # Added repetetive optimization..it's possible that an
95: # optimization results in an expression that can be recognized further in
96: # a subsequent optimization pass:
97: #
98:
99: sub simplify {
100: my $expression=shift;
101:
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:
120: return $expression;
121: }
122:
123:
124: #
125: # Merge the conditions into the big hash
126: # these will result in hash entries of the form:
127: # 'condition.n' where 'n' is the array index of the condition in the
128: # @cond array above.
129: #
130: # Parameters:
131: # $hash - big hashthat's being built up.
132: #
133: sub merge_conditions {
134: my $hash = shift;
135:
136: for (my $i = 0; $i < scalar(@cond); $i++) {
137: $hash->{'condition' . '.' . $i} = $cond[$i];
138: }
139: }
140:
141: # Merge the contents of a 'child hash' into a parent hash hanging it off another key.
142: # This is _not_ done by hanging a reference to the child hash as the parent may be
143: # bound to a GDBM file e.g. and shared by more than one process ..and references are
144: # pretty clearly not going to work across process boundaries.
145: #
146: # Parameters:
147: # $parent - The hash to which the child will be merged (reference)
148: # $key - The key in the parent hash on which the child elements will be hung.
149: # given a key named $childkey the final parent hash entry will be
150: # $parent . '.' $childkey
151: # $child - The hash whose contents we merge into the parent (reference)
152: #
153: sub merge_hash {
154: my ($parent, $key, $child) = @_;
155:
156: if ($key ne '') {
157: $key .= '.'; # If we are prefixing, prefix then .
158: }
159:
160: foreach my $childkey (keys (%$child)) {
161: $parent->{$key . $childkey} = $child->{$childkey};
162: }
163: }
164:
165: #----------------------------------------------------------------------------------
166: #
167: # Code to keep track of map aliases and to determine if there are doubly
168: # defined aliases.
169: #
170:
171: #
172: # Maintains the mapalias hash. This is a hash of arrays. Each array
173: # is indexed by the alias and contains the set of resource ids pointed to by that
174: # alias. In an ideal world, there will only be one element in each array.
175: # The point of this, however is to determine which aliases might be doubley defined
176: # due to map nesting e.g.
177: #
178: # Parameters:
179: # $value - Alias name.
180: # $resid - Resource id pointed to by the alias.
181: #
182: #
183: sub count_mapalias {
184: my ($value,$resid) = @_;
185: push(@{ $mapalias_cache{$value} }, $resid);
186: }
187: #
188: # Looks at each key in the mapalias hash and, for each case where an
189: # alias points to more than one value adds an error text to the
190: # result string.'
191: #
192: # Parameters:
193: # hash - Reference to the hash we are trying t build up.
194: # Implicit inputs
195: # %mapalias - a hash that is indexed by map aliases and contains for each key
196: # an array of the resource id's the alias 'points to'.
197: # Returns:
198: # A hopefully empty string of messages that descsribe the aliases that have more
199: # than one value. This string is formatted like an html list.
200: #
201: #
202: sub get_mapalias_errors {
203: my $hash = shift;
204: my $error_text;
205: foreach my $mapalias (sort(keys(%mapalias_cache))) {
206: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
207: my $count;
208: my $which =
209: join('</li><li>',
210: map {
211: my $id = $_;
212: if (exists($hash->{'src_'.$id})) {
213: $count++;
214: }
215: my ($mapid) = split(/\./,$id);
216: &mt('Resource "[_1]" <br /> in Map "[_2]"',
217: $hash->{'title_'.$id},
218: $hash->{'title_'.$hash->{'ids_'.$hash->{'map_id_'.$mapid}}});
219: } (@{ $mapalias_cache{$mapalias} }));
220: next if ($count < 2);
221: $error_text .= '<div class="LC_error">'.
222: &mt('Error: Found the mapalias "[_1]" defined multiple times.',
223: $mapalias).
224: '</div><ul><li>'.$which.'</li></ul>';
225: }
226: &clear_mapalias_count();
227: return $error_text;
228: }
229: #
230: # Clears the map aliase hash.
231: #
232: sub clear_mapalias_count {
233: undef(%mapalias_cache);
234: }
235:
236: #----------------------------------------------------------------
237: #
238: # Code dealing with resource versions.
239: #
240:
241: #
242: # Put a version into a src element of a hash or url:
243: #
244: # Parameters:
245: # uri - URI into which the version must be added.
246: # hash - Reference to the hash being built up.
247: # short- Short coursename.
248: #
249:
250: sub putinversion {
251: my ($uri, $hash, $short) = @_;
252: my $key=$short.'_'.&Apache::lonnet::clutter($uri);
253: if ($hash->{'version_'.$uri}) {
254: my $version=$hash->{'version_'.$uri};
255: if ($version eq 'mostrecent') { return $uri; }
256: if ($version eq &Apache::lonnet::getversion(
257: &Apache::lonnet::filelocation('',$uri)))
258: { return $uri; }
259: $uri=~s/\.(\w+)$/\.$version\.$1/;
260: }
261: &Apache::lonnet::do_cache_new('courseresversion',$key,&Apache::lonnet::declutter($uri),600);
262: return $uri;
263: }
264:
265:
266: #
267: # Create hash entries for each version of the course.
268: # Parameters:
269: # $cenv - Reference to a course environment from lonnet::coursedescription.
270: # $hash - Reference to a hash that will be populated.
271:
272: #
273: sub process_versions {
274: my ($cenv, $hash) = @_;
275:
276:
277: my %versions = &Apache::lonnet::dump('resourceversions',
278: $cenv->{'domain'},
279: $cenv->{'num'});
280:
281: foreach my $ver (keys (%versions)) {
282: if ($ver =~/^error\:/) { # lonc/lond transaction failed.
283: throw Error::Simple('lonc/lond returned error: ' . $ver);
284: }
285: $hash->{'version_'.$ver} = $versions{$ver};
286: }
287: }
288:
289: #
290: # Generate text for a version discrepancy error:
291: # Parameters:
292: # $uri - URI of the resource.
293: # $used - Version used.
294: # $unused - Veresion of duplicate.
295: #
296: sub versionerror {
297: my ($uri, $used, $unused) = @_;
298: my ($uri,$usedversion,$unusedversion)=@_;
299: return '<br />'.
300: &mt('Version discrepancy: resource [_1] included in both version [_2] and version [_3]. Using version [_2].',
301: $uri,$used,$unused).'<br />';
302:
303: }
304:
305: # Removes the version number from a URI and returns the resulting
306: # URI (e.g. mumbly.version.stuff => mumbly.stuff).
307: #
308: # If the URI has not been seen with a version before the
309: # hash{'version_'.resultingURI} is set to the version number.
310: # If the hash has already been seen, but differs then
311: # an error is raised.
312: #
313: # Parameters:
314: # $uri - potentially with a version.
315: # $hash - reference to a hash to fill in.
316: # Returns:
317: # URI with the version cut out.
318: #
319: sub versiontrack {
320: my ($uri, $hash) = @_;
321:
322:
323: if ($uri=~/\.(\d+)\.\w+$/) { # URI like *.n.text it's version 'n'
324: my $version=$1;
325: $uri=~s/\.\d+\.(\w+)$/\.$1/; # elide the version.
326: unless ($hash->{'version_'.$uri}) {
327: $hash->{'version_'.$uri}=$version;
328: } elsif ($version!=$hash->{'version_'.$uri}) {
329: throw Error::Simple(&versionerror($uri, $hash->{'version_'.$uri}, $version));
330: }
331: }
332: return $uri;
333: }
334: #
335: # Appends the version of a resource to its uri and also caches the
336: # URI (contents?) on the local server
337: #
338: # Parameters:
339: # $uri - URI of the course (without version informatino.
340: # $hash - What we have of the big hash.
341: #
342: # Side-Effects:
343: # The URI is cached by memcached.
344: #
345: # Returns:
346: # The version appended URI.
347: #
348: sub append_version {
349: my ($uri, $hash) = @_;
350:
351: # Create the key for the cache entry.
352:
353: my $key = $course_id . '_' . &Apache::lonnet::clutter($uri);
354:
355: # If there is a version it will already be in the hash:
356:
357: if ($hash->{'version_' . $uri}) {
358: my $version = $hash->{'version_' . $uri};
359: if ($version eq 'mostrecent') {
360: return $uri; # Most recent version does not require decoration (or caching?).
361: }
362: if ($version eq
363: &Apache::lonnet::getversion(&Apache::lonnet::filelocation('', $uri))) {
364: return $uri; # version matches the most recent file version?
365: }
366: $uri =~ s/\.(\w+)$/\.$version\.$1/; # insert the versino prior to the last .word.
367: }
368:
369: # cache the version:
370:
371: &Apache::lonnet::do_cache_new('courseresversion', $key,
372: &Apache::lonnet::declutter($uri), 600);
373:
374: return $uri;
375:
376: }
377: #------------------------------------------------------------------------------
378: #
379: # Misc. utilities that don't fit into the other classifications.
380:
381: # Determine if the specified user has an 'advanced' role in a course.
382: # Parameters:
383: # cenv - reference to a course environment.
384: # username - Name of the user we care about.
385: # domain - Domain in which the user is defined.
386: # Returns:
387: # 0 - User does not have an advanced role in the course.
388: # 1 - User does have an advanced role in the course.
389: #
390: sub has_advanced_role {
391: my ($username, $domain) = @_;
392:
393: my %adv_roles = &Apache::lonnet::get_course_adv_roles($short_name);
394: my $merged_username = $username . ':' . $domain;
395: foreach my $user (values %adv_roles) {
396: if ($merged_username eq $user) {
397: return 1;
398: }
399: }
400: return 0;
401: }
402:
403: #--------------------------------------------------------------------------------
404: # Post processing subs:
405: sub hiddenurls {
406: my $hash = shift;
407:
408: my $uname = $hash->{'context.username'};
409: my $udom = $hash->{'context.userdom'};
410: my $courseid = $hash->{'context.courseid'};
411:
412: my $randomoutentry='';
413: foreach my $rid (keys %randompick) {
414: my $rndpick=$randompick{$rid};
415: my $mpc=$hash->{'map_pc_'.$hash->{'src_'.$rid}};
416: # ------------------------------------------- put existing resources into array
417: my @currentrids=();
418: foreach my $key (sort(keys(%$hash))) {
419: if ($key=~/^src_($mpc\.\d+)/) {
420: if ($hash->{'src_'.$1}) { push @currentrids, $1; }
421: }
422: }
423: # rids are number.number and we want to numercially sort on
424: # the second number
425: @currentrids=sort {
426: my (undef,$aid)=split(/\./,$a);
427: my (undef,$bid)=split(/\./,$b);
428: $aid <=> $bid;
429: } @currentrids;
430: next if ($#currentrids<$rndpick);
431: # -------------------------------- randomly eliminate the ones that should stay
432: my (undef,$id)=split(/\./,$rid);
433: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
434: my $rndseed=&Apache::lonnet::rndseed($id, $courseid, $udom, $uname, \%cenv); # use id instead of symb
435: &Apache::lonnet::setup_random_from_rndseed($rndseed);
436: my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
437: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
438:
439: # -------------------------------------------------------- delete the leftovers
440: for (my $k=0; $k<=$#currentrids; $k++) {
441: if ($currentrids[$k]) {
442: $hash->{'randomout_'.$currentrids[$k]}='1';
443: my ($mapid,$resid)=split(/\./,$currentrids[$k]);
444: $randomoutentry.='&'.
445: &Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},
446: $resid,
447: $hash->{'src_'.$currentrids[$k]}
448: ).'&';
449: }
450: }
451: }
452: # ------------------------------ take care of explicitly hidden urls or folders
453: foreach my $rid (keys %hiddenurl) {
454: $hash->{'randomout_'.$rid}='1';
455: my ($mapid,$resid)=split(/\./,$rid);
456: $randomoutentry.='&'.
457: &Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},$resid,
458: $hash->{'src_'.$rid}).'&';
459: }
460: # --------------------------------------- add randomout to the hash.
461: if ($randomoutentry) {
462: $hash->{'acc.randomout'} = $randomoutentry;
463:
464: }
465: }
466:
467: #
468: # It's not so clear to me what this sub does.
469: #
470: # Parameters
471: # uri - URI from the course description hash.
472: # short - Course short name.
473: # fn - Course filename.
474: # hash - Reference to the big hash as filled in so far
475: #
476:
477: sub accinit {
478: my ($uri, $short, $hash)=@_;
479: my %acchash=();
480: my %captured=();
481: my $condcounter=0;
482: $acchash{'acc.cond.'.$short.'.0'}=0;
483:
484: # This loop is only interested in conditions and
485: # parameters in the big hash:
486:
487: foreach my $key (keys(%$hash)) {
488:
489: # conditions:
490:
491: if ($key=~/^conditions/) {
492: my $expr=$hash->{$key};
493:
494: # try to find and factor out common sub-expressions
495: # Any subexpression that is found is simplified, removed from
496: # the original condition expression and the simplified sub-expression
497: # substituted back in to the epxression..I'm not actually convinced this
498: # factors anything out...but instead maybe simplifies common factors(?)
499:
500: foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
501: my $orig=$sub;
502:
503: my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
504: next if (!defined($factor));
505:
506: $sub=~s/\Q$factor\E//g;
507: $sub=~s/^\(/\($factor\(/;
508: $sub.=')';
509: $sub=simplify($sub);
510: $expr=~s/\Q$orig\E/$sub/;
511: }
512: $hash->{$key}=$expr;
513:
514: # If not yet seen, record in acchash and that we've seen it.
515:
516: unless (defined($captured{$expr})) {
517: $condcounter++;
518: $captured{$expr}=$condcounter;
519: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
520: }
521: # Parameters:
522:
523: } elsif ($key=~/^param_(\d+)\.(\d+)/) {
524: my $prefix=&Apache::lonnet::encode_symb($hash->{'map_id_'.$1},$2,
525: $hash->{'src_'.$1.'.'.$2});
526: foreach my $param (split(/\&/,$hash->{$key})) {
527: my ($typename,$value)=split(/\=/,$param);
528: my ($type,$name)=split(/\:/,$typename);
529: $parmhash{$prefix.'.'.&unescape($name)}=
530: &unescape($value);
531: $parmhash{$prefix.'.'.&unescape($name).'.type'}=
532: &unescape($type);
533: }
534: }
535: }
536: # This loop only processes id entries in the big hash.
537:
538: foreach my $key (keys(%$hash)) {
539: if ($key=~/^ids/) {
540: foreach my $resid (split(/\,/,$hash->{$key})) {
541: my $uri=$hash->{'src_'.$resid};
542: my ($uripath,$urifile) =
543: &Apache::lonnet::split_uri_for_cond($uri);
544: if ($uripath) {
545: my $uricond='0';
546: if (defined($hash->{'conditions_'.$resid})) {
547: $uricond=$captured{$hash->{'conditions_'.$resid}};
548: }
549: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
550: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
551: /(\&\Q$urifile\E\:[^\&]*)/) {
552: my $replace=$1;
553: my $regexp=$replace;
554: #$regexp=~s/\|/\\\|/g;
555: $acchash{'acc.res.'.$short.'.'.$uripath} =~
556: s/\Q$regexp\E/$replace\|$uricond/;
557: } else {
558: $acchash{'acc.res.'.$short.'.'.$uripath}.=
559: $urifile.':'.$uricond.'&';
560: }
561: } else {
562: $acchash{'acc.res.'.$short.'.'.$uripath}=
563: '&'.$urifile.':'.$uricond.'&';
564: }
565: }
566: }
567: }
568: }
569: $acchash{'acc.res.'.$short.'.'}='&:0&';
570: my $courseuri=$uri;
571: $courseuri=~s/^\/res\///;
572: my $regexp = 1;
573:
574: &merge_hash($hash, '', \%acchash); # there's already an acc prefix in the hash keys.
575:
576:
577: }
578:
579:
580: #
581: # Traces a route recursively through the map after it has been loaded
582: # (I believe this really visits each resource that is reachable fromt he
583: # start top node.
584: #
585: # - Marks hidden resources as hidden.
586: # - Marks which resource URL's must be encrypted.
587: # - Figures out (if necessary) the first resource in the map.
588: # - Further builds the chunks of the big hash that define how
589: # conditions work
590: #
591: # Note that the tracing strategy won't visit resources that are not linked to
592: # anything or islands in the map (groups of resources that form a path but are not
593: # linked in to the path that can be traced from the start resource...but that's ok
594: # because by definition, those resources are not reachable by users of the course.
595: #
596: # Parameters:
597: # sofar - _URI of the prior entry or 0 if this is the top.
598: # rid - URI of the resource to visit.
599: # beenhere - list of resources (each resource enclosed by &'s) that have
600: # already been visited.
601: # encflag - If true the resource that resulted in a recursive call to us
602: # has an encoded URL (which means contained resources should too).
603: # hdnflag - If true,the resource that resulted in a recursive call to us
604: # was hidden (which means contained resources should be hidden too).
605: # hash - Reference to the hash we are traversing.
606: # Returns
607: # new value indicating how far the map has been traversed (the sofar).
608: #
609: sub traceroute {
610: my ($sofar, $rid, $beenhere, $encflag, $hdnflag, $hash)=@_;
611: my $newsofar=$sofar=simplify($sofar);
612:
613: unless ($beenhere=~/\&\Q$rid\E\&/) {
614: $beenhere.=$rid.'&';
615: my ($mapid,$resid)=split(/\./,$rid);
616: my $symb=&Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},$resid,
617: $hash->{'src_'.$rid});
618: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
619:
620: if ($hdnflag || lc($hidden) eq 'yes') {
621: $hiddenurl{$rid}=1;
622: }
623: if (!$hdnflag && lc($hidden) eq 'no') {
624: delete($hiddenurl{$rid});
625: }
626:
627: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
628: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
629:
630: if (($retfrid eq '') && ($hash->{'src_'.$rid})
631: && ($hash->{'src_'.$rid}!~/\.sequence$/)) {
632: $retfrid=$rid;
633: }
634:
635: if (defined($hash->{'conditions_'.$rid})) {
636: $hash->{'conditions_'.$rid}=simplify(
637: '('.$hash->{'conditions_'.$rid}.')|('.$sofar.')');
638: } else {
639: $hash->{'conditions_'.$rid}=$sofar;
640: }
641:
642: # if the expression is just the 0th condition keep it
643: # otherwise leave a pointer to this condition expression
644:
645: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
646:
647: # Recurse if the resource is a map:
648:
649: if (defined($hash->{'is_map_'.$rid})) {
650: if (defined($hash->{'map_start_'.$hash->{'src_'.$rid}})) {
651: $sofar=$newsofar=
652: &traceroute($sofar,
653: $hash->{'map_start_'.$hash->{'src_'.$rid}},
654: $beenhere,
655: $encflag || $encurl{$rid},
656: $hdnflag || $hiddenurl{$rid}, $hash);
657: }
658: }
659:
660: # Processes links to this resource:
661: # - verify the existence of any conditionals on the link to here.
662: # - Recurse to any resources linked to us.
663: #
664: if (defined($hash->{'to_'.$rid})) {
665: foreach my $id (split(/\,/,$hash->{'to_'.$rid})) {
666: my $further=$sofar;
667: #
668: # If there's a condition associated with this link be sure
669: # it's been defined else that's an error:
670: #
671: if ($hash->{'undercond_'.$id}) {
672: if (defined($hash->{'condid_'.$hash->{'undercond_'.$id}})) {
673: $further=simplify('('.'_'.$rid.')&('.
674: $hash->{'condid_'.$hash->{'undercond_'.$id}}.')');
675: } else {
676: my $errtext.=&mt('<br />Undefined condition ID: [_1]',$hash->{'undercond_'.$id});
677: throw Error::Simple($errtext);
678: }
679: }
680: # Recurse to resoruces that have to's to us.
681: $newsofar=&traceroute($further,$hash->{'goesto_'.$id},$beenhere,
682: $encflag,$hdnflag, $hash);
683: }
684: }
685: }
686: return $newsofar;
687: }
688:
689:
690: #---------------------------------------------------------------------------------
691: #
692: # Map parsing code:
693: #
694:
695: #
696: # Parse the <param> tag. for most parameters, the only action is to define/extend
697: # a has entry for {'param_{refid}'} where refid is the resource the parameter is
698: # attached to and the value built up is an & separated list of parameters of the form:
699: # type:part.name=value
700: #
701: # In addition there is special case code for:
702: # - randompick
703: # - randompickseed
704: # - randomorder
705: #
706: # - encrypturl
707: # - hiddenresource
708: #
709: # Parameters:
710: # token - The token array from HTML::TokeParse we mostly care about element [2]
711: # which is a hash of attribute => values supplied in the tag
712: # (remember this sub is only processing start tag tokens).
713: # mno - Map number. This is used to qualify resource ids within a map
714: # to make them unique course wide (a process known as uniquifaction).
715: # hash - Reference to the hash we are building.
716: #
717: sub parse_param {
718: my ($token, $mno, $hash) = @_;
719:
720: # Qualify the reference and name by the map number and part number.
721: # if no explicit part number is supplied, 0 is the implicit part num.
722:
723: my $referid=$mno.'.'.$token->[2]->{'to'}; # Resource param applies to.
724: my $name=$token->[2]->{'name'}; # Name of parameter
725: my $part;
726:
727:
728: if ($name=~/^parameter_(.*)_/) {
729: $part=$1;
730: } else {
731: $part=0;
732: }
733:
734: # Peel the parameter_ off the parameter name.
735:
736: $name=~s/^.*_([^_]*)$/$1/;
737:
738: # The value is:
739: # type.part.name.value
740:
741: my $newparam=
742: &escape($token->[2]->{'type'}).':'.
743: &escape($part.'.'.$name).'='.
744: &escape($token->[2]->{'value'});
745:
746: # The hash key is param_resourceid.
747: # Multiple parameters for a single resource are & separated in the hash.
748:
749:
750: if (defined($hash->{'param_'.$referid})) {
751: $hash->{'param_'.$referid}.='&'.$newparam;
752: } else {
753: $hash->{'param_'.$referid}=''.$newparam;
754: }
755: #
756: # These parameters have to do with randomly selecting
757: # resources, therefore a separate hash is also created to
758: # make it easy to locate them when actually computing the resource set later on
759: # See the code conditionalized by ($randomize) in read_map().
760:
761: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
762: $randompick{$referid}=$token->[2]->{'value'};
763: }
764: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
765: $randompickseed{$referid}=$token->[2]->{'value'};
766: }
767: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
768: $randomorder{$referid}=$token->[2]->{'value'};
769: }
770:
771: # These parameters have to do with how the URLs of resources are presented to
772: # course members(?). encrypturl presents encypted url's while
773: # hiddenresource hides the URL.
774: #
775:
776: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
777: if ($token->[2]->{'value'}=~/^yes$/i) {
778: $encurl{$referid}=1;
779: }
780: }
781: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
782: if ($token->[2]->{'value'}=~/^yes$/i) {
783: $hiddenurl{$referid}=1;
784: }
785: }
786:
787: }
788:
789:
790: #
791: # Parses a resource tag to produce the value to push into the
792: # map_ids array.
793: #
794: #
795: # Information about the actual type of resource is provided by the file extension
796: # of the uri (e.g. .problem, .sequence etc. etc.).
797: #
798: # Parameters:
799: # $token - A token from HTML::TokeParser
800: # This is an array that describes the most recently parsed HTML item.
801: # $lpc - Map nesting level (?)
802: # $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
803: # $uri - URI of the enclosing resource.
804: # $hash - Reference to the hash we are building.
805: #
806: # Returns:
807: # Value of the id attribute of the tag.
808: #
809: # Note:
810: # The token is an array that contains the following elements:
811: # [0] => 'S' indicating this is a start token
812: # [1] => 'resource' indicating this tag is a <resource> tag.
813: # [2] => Hash of attribute =>value pairs.
814: # [3] => @(keys [2]).
815: # [4] => unused.
816: #
817: # The attributes of the resourcde tag include:
818: #
819: # id - The resource id.
820: # src - The URI of the resource.
821: # type - The resource type (e.g. start and finish).
822: # title - The resource title.
823: #
824:
825: sub parse_resource {
826: my ($token,$lpc,$ispage,$uri, $hash) = @_;
827:
828: # I refuse to countenance code like this that has
829: # such a dirty side effect (and forcing this sub to be called within a loop).
830: #
831: # if ($token->[2]->{'type'} eq 'zombie') { next; }
832: #
833: # The original code both returns _and_ skips to the next pass of the >caller's<
834: # loop, that's just dirty.
835: #
836:
837: # Zombie resources don't produce anything useful.
838:
839: if ($token->[2]->{'type'} eq 'zombie') {
840: return undef;
841: }
842:
843: my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
844:
845: # Save the hash element type and title:
846:
847: $hash->{'kind_'.$rid}='res';
848: $hash->{'title_'.$rid}=$token->[2]->{'title'};
849:
850: # Get the version free URI for the resource.
851: # If a 'version' attribute was supplied, and this resource's version
852: # information has not yet been stored, store it.
853: #
854:
855:
856: my $turi=&versiontrack($token->[2]->{'src'});
857: if ($token->[2]->{'version'}) {
858: unless ($hash->{'version_'.$turi}) {
859:
860: #Where does the value of $1 below come from?
861: #$1 for the regexps in versiontrack should have gone out of scope.
862: #
863: # I think this may be dead code since versiontrack ought to set
864: # this hash element(?).
865: #
866: $hash->{'version_'.$turi}=$1;
867: }
868: }
869: # Pull out the title and do entity substitution on &colon
870: # Q: Why no other entity substitutions?
871:
872: my $title=$token->[2]->{'title'};
873: $title=~s/\&colon\;/\:/gs;
874:
875:
876:
877: # I think the point of all this code is to construct a final
878: # URI that apache and its rewrite rules can use to
879: # fetch the resource. Thi s sonly necessary if the resource
880: # is not a page. If the resource is a page then it must be
881: # assembled (at fetch time?).
882:
883: unless ($ispage) {
884: $turi=~/\.(\w+)$/;
885: my $embstyle=&Apache::loncommon::fileembstyle($1);
886: if ($token->[2]->{'external'} eq 'true') { # external
887: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
888: } elsif ($turi=~/^\/*uploaded\//) { # uploaded
889: if (($embstyle eq 'img')
890: || ($embstyle eq 'emb')
891: || ($embstyle eq 'wrp')) {
892: $turi='/adm/wrapper'.$turi;
893: } elsif ($embstyle eq 'ssi') {
894: #do nothing with these
895: } elsif ($turi!~/\.(sequence|page)$/) {
896: $turi='/adm/coursedocs/showdoc'.$turi;
897: }
898: } elsif ($turi=~/\S/) { # normal non-empty internal resource
899: my $mapdir=$uri;
900: $mapdir=~s/[^\/]+$//;
901: $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
902: if (($embstyle eq 'img')
903: || ($embstyle eq 'emb')
904: || ($embstyle eq 'wrp')) {
905: $turi='/adm/wrapper'.$turi;
906: }
907: }
908: }
909: # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
910: # If the URI appears more than one time in the sequence, it's resourcde
911: # id's are constructed as a comma spearated list.
912:
913: my $idsuri=$turi;
914: $idsuri=~s/\?.+$//;
915: if (defined($hash->{'ids_'.$idsuri})) {
916: $hash->{'ids_'.$idsuri}.=','.$rid;
917: } else {
918: $hash->{'ids_'.$idsuri}=''.$rid;
919: }
920:
921:
922:
923: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
924: $turi.='?register=1';
925: }
926:
927:
928: # resource id lookup: 'src'_resourc-di => URI decorated with a query
929: # parameter as above if necessary due to the resource type.
930:
931: $hash->{'src_'.$rid}=$turi;
932:
933: # Mark the external-ness of the resource:
934:
935: if ($token->[2]->{'external'} eq 'true') {
936: $hash->{'ext_'.$rid}='true:';
937: } else {
938: $hash->{'ext_'.$rid}='false:';
939: }
940:
941: # If the resource is a start/finish resource set those
942: # entries in the has so that navigation knows where everything starts.
943: # If there is a malformed sequence that has no start or no finish
944: # resource, should this be detected and errors thrown? How would such a
945: # resource come into being other than being manually constructed by a person
946: # and then uploaded? Could that happen if an author decided a sequence was almost
947: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
948: # start or finish resources?
949: #
950: # All resourcess also get a type_id => (start | finish | normal) hash entr.
951: #
952: if ($token->[2]->{'type'}) {
953: $hash->{'type_'.$rid}=$token->[2]->{'type'};
954: if ($token->[2]->{'type'} eq 'start') {
955: $hash->{'map_start_'.$uri}="$rid";
956: }
957: if ($token->[2]->{'type'} eq 'finish') {
958: $hash->{'map_finish_'.$uri}="$rid";
959: }
960: } else {
961: $hash->{'type_'.$rid}='normal';
962: }
963:
964: # Sequences end pages are constructed entities. They require that the
965: # map that defines _them_ be loaded as well into the hash...with this resourcde
966: # as the base of the nesting.
967: # Resources like that are also marked with is_map_id => 1 entries.
968: #
969:
970: if (($turi=~/\.sequence$/) ||
971: ($turi=~/\.page$/)) {
972: $hash->{'is_map_'.$rid}='1'; # String in lonuserstate.
973: &read_map($turi,$rid, $hash);
974: }
975: return $token->[2]->{'id'};
976: }
977:
978: # Links define how you are allowed to move from one resource to another.
979: # They are the transition edges in the directed graph that a map is.
980: # This sub takes informatino from a <link> tag and constructs the
981: # navigation bits and pieces of a map. There is no requirement that the
982: # resources that are linke are already defined, however clearly the map is
983: # badly broken if they are not _eventually_ defined.
984: #
985: # Note that links can be unconditional or conditional.
986: #
987: # Parameters:
988: # linkpc - The link counter for this level of map nesting (this is
989: # reset to zero by read_map prior to starting to process
990: # links for map).
991: # lpc - The map level ocounter (how deeply nested this map is in
992: # the hierarchy of maps that are recursively read in.
993: # to - resource id (within the XML) of the target of the edge.
994: # from - resource id (within the XML) of the source of the edge.
995: # condition- id of condition associated with the edge (also within the XML).
996: # hash - reference to the hash we are building.
997:
998: #
999:
1000: sub make_link {
1001: my ($linkpc,$lpc,$to,$from,$condition, $hash) = @_;
1002:
1003: # Compute fully qualified ids for the link, the
1004: # and from/to by prepending lpc.
1005: #
1006:
1007: my $linkid=$lpc.'.'.$linkpc;
1008: my $goesto=$lpc.'.'.$to;
1009: my $comesfrom=$lpc.'.'.$from;
1010: my $undercond='0';
1011:
1012:
1013: # If there is a condition, qualify it with the level counter.
1014:
1015: if ($condition) {
1016: $undercond=$lpc.'.'.$condition;
1017: }
1018:
1019: # Links are represnted by:
1020: # goesto_.fuullyqualifedlinkid => fully qualified to
1021: # comesfrom.fullyqualifiedlinkid => fully qualified from
1022: # undercond_.fullyqualifiedlinkid => fully qualified condition id.
1023:
1024: $hash->{'goesto_'.$linkid}=$goesto;
1025: $hash->{'comesfrom_'.$linkid}=$comesfrom;
1026: $hash->{'undercond_'.$linkid}=$undercond;
1027:
1028: # In addition:
1029: # to_.fully qualified from => comma separated list of
1030: # link ids with that from.
1031: # Similarly:
1032: # from_.fully qualified to => comma separated list of link ids`
1033: # with that to.
1034: # That allows us given a resource id to know all edges that go to it
1035: # and leave from it.
1036: #
1037:
1038: if (defined($hash->{'to_'.$comesfrom})) {
1039: $hash->{'to_'.$comesfrom}.=','.$linkid;
1040: } else {
1041: $hash->{'to_'.$comesfrom}=''.$linkid;
1042: }
1043: if (defined($hash->{'from_'.$goesto})) {
1044: $hash->{'from_'.$goesto}.=','.$linkid;
1045: } else {
1046: $hash->{'from_'.$goesto}=''.$linkid;
1047: }
1048: }
1049:
1050: # ------------------------------------------------------------------- Condition
1051: #
1052: # Processes <condition> tags, storing sufficient information about them
1053: # in the hash so that they can be evaluated and used to conditionalize
1054: # what is presented to the student.
1055: #
1056: # these can have the following attributes
1057: #
1058: # id = A unique identifier of the condition within the map.
1059: #
1060: # value = Is a perl script-let that, when evaluated in safe space
1061: # determines whether or not the condition is true.
1062: # Normally this takes the form of a test on an Apache::lonnet::EXT call
1063: # to find the value of variable associated with a resource in the
1064: # map identified by a mapalias.
1065: # Here's a fragment of XML code that illustrates this:
1066: #
1067: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
1068: # <resource src="" id="1" type="start" title="Start" />
1069: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" />
1070: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
1071: # <2 " id="61" type="stop" />
1072: # <link to="5" index="1" from="1" condition="61" />
1073: #
1074: # In this fragment:
1075: # - The param tag establishes an alias to resource id 5 of 'mainproblem'.
1076: # - The resource that is the start of the map is identified.
1077: # - The resource tag identifies the resource associated with this tag
1078: # and gives it the id 5.
1079: # - The condition is true if the tries variable associated with mainproblem
1080: # is less than 2 (that is the user has had more than 2 tries).
1081: # The condition type is a stop condition which inhibits(?) the associated
1082: # link if the condition is false.
1083: # - The link to resource 5 from resource 1 is affected by this condition.
1084: #
1085: # type = Type of the condition. The type determines how the condition affects the
1086: # link associated with it and is one of
1087: # - 'force'
1088: # - 'stop'
1089: # anything else including not supplied..which treated as:
1090: # - 'normal'.
1091: # Presumably maps get created by the resource assembly tool and therefore
1092: # illegal type values won't squirm their way into the XML.
1093: # hash - Reference to the hash we are trying to build up.
1094: #
1095: # Side effects:
1096: # - The kind_level-qualified-condition-id hash element is set to 'cond'.
1097: # - The condition text is pushed into the cond array and its element number is
1098: # set in the condid_level-qualified-condition-id element of the hash.
1099: # - The condition type is colon appneded to the cond array element for this condition.
1100: sub parse_condition {
1101: my ($token, $lpc, $hash) = @_;
1102: my $rid=$lpc.'.'.$token->[2]->{'id'};
1103:
1104: $hash->{'kind_'.$rid}='cond';
1105:
1106: my $condition = $token->[2]->{'value'};
1107: $condition =~ s/[\n\r]+/ /gs;
1108: push(@cond, $condition);
1109: $hash->{'condid_'.$rid}=$#cond;
1110: if ($token->[2]->{'type'}) {
1111: $cond[$#cond].=':'.$token->[2]->{'type'};
1112: } else {
1113: $cond[$#cond].=':normal';
1114: }
1115: }
1116:
1117: #
1118: # Parse mapalias parameters.
1119: # these are tags of the form:
1120: # <param to="nn"
1121: # value="some-alias-for-resourceid-nn"
1122: # name="parameter_0_mapalias"
1123: # type="string" />
1124: # A map alias is a textual name for a resource:
1125: # - The to attribute identifies the resource (this gets level qualified below)
1126: # - The value attributes provides the alias string.
1127: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/
1128: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings
1129: # terminating with the string 'mapalias'.
1130: # Examples:
1131: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
1132: # Invalid to ids are silently ignored.
1133: #
1134: # Parameters:
1135: # token - The token array fromthe HMTML::TokeParser
1136: # lpc - The current map level counter.
1137: # hash - Reference to the hash that we are building.
1138: #
1139: sub parse_mapalias_param {
1140: my ($token, $lpc, $hash) = @_;
1141:
1142: # Fully qualify the to value and ignore the alias if there is no
1143: # corresponding resource.
1144:
1145: my $referid=$lpc.'.'.$token->[2]->{'to'};
1146: return if (!exists($hash->{'src_'.$referid}));
1147:
1148: # If this is a valid mapalias parameter,
1149: # Append the target id to the count_mapalias element for that
1150: # alias so that we can detect doubly defined aliases
1151: # e.g.:
1152: # <param to="1" value="george" name="parameter_0_mapalias" type="string" />
1153: # <param to="2" value="george" name="parameter_0_mapalias" type="string" />
1154: #
1155: # The example above is trivial but the case that's important has to do with
1156: # constructing a map that includes a nested map where the nested map may have
1157: # aliases that conflict with aliases established in the enclosing map.
1158: #
1159: # ...and create/update the hash mapalias entry to actually store the alias.
1160: #
1161:
1162: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
1163: &count_mapalias($token->[2]->{'value'},$referid);
1164: $hash->{'mapalias_'.$token->[2]->{'value'}}=$referid;
1165: }
1166: }
1167:
1168:
1169: #---------------------------------------------------------------------------------
1170: #
1171: # Code to process the map file.
1172:
1173: # read a map file and add it to the hash. Since a course map can contain resources
1174: # that are themselves maps, read_map might be recursively called.
1175: #
1176: # Parameters:
1177: # $uri - URI of the course itself (not the map file).
1178: # $parent_rid - map number qualified id of the parent of the map being read.
1179: # For the top level course map this is 0.0. For the first nested
1180: # map 1.n where n is the id of the resource within the
1181: # top level map and so on.
1182: # $hash - Reference to a hash that will become the big hash for the course
1183: # This hash is modified as per the map description.
1184: # Side-effects:
1185: # $map_number - Will be incremented. This keeps track of the number of the map
1186: # we are currently working on (see parent_rid above, the number to the
1187: # left of the . in $parent_rid is the map number).
1188: #
1189: #
1190: sub read_map {
1191: my ($uri, $parent_rid, $hash) = @_;
1192:
1193:
1194: # Check for duplication: A map may only be included once.
1195:
1196: if($hash->{'map_pc_' . $uri}) {
1197: throw Error::Simple('Duplicate map: ', $uri);
1198: }
1199: # count the map number and save it locally so that we don't lose it
1200: # when we recurse.
1201:
1202: $map_number++;
1203: my $lmap_no = $map_number;
1204:
1205: # save the map_pc and map_id elements of the hash for this map:
1206: # map_pc_uri is the map number of the map with that URI.
1207: # map_id_$lmap_no is the URI for this map level.
1208: #
1209: $hash->{'map_pc_' . $uri} = "$lmap_no"; # string form in lonuserstate.
1210: $hash->{'map_id_' . $lmap_no} = "$uri";
1211:
1212: # Create the path up to the top of the course.
1213: # this is in 'map_hierarchy_mapno' that's a comma separated path down to us
1214: # in the hierarchy:
1215:
1216: if ($parent_rid =~/^(\d+).\d+$/) {
1217: my $parent_no = $1; # Parent's map number.
1218: if (defined($hash->{'map_hierarchy_' . $parent_no})) {
1219: $hash->{'map_hierarchy_' . $lmap_no} =
1220: $hash->{'map_hierarchy_' . $parent_no} . ',' . $parent_no;
1221: } else {
1222: # Only 1 level deep ..nothing to append to:
1223:
1224: $hash->{'map_hierarchy_' . $lmap_no} = $parent_no;
1225: }
1226: }
1227:
1228: # figure out the name of the map file we need to read.
1229: # ensure that it is a .page or a .sequence as those are the only
1230: # sorts of files that make sense for this sub
1231:
1232: my $filename = &Apache::lonnet::filelocation('', &append_version($uri, $hash));
1233:
1234:
1235: my $ispage = ($filename =~/\.page$/);
1236: unless ($ispage || ($filename =~ /\.sequence$/)) {
1237: &Apache::lonnet::logthis("invalid: $filename : $uri");
1238: throw Error::Simple(&mt("<br />Invalid map: <tt>[_1]</tt>", $filename));
1239: }
1240:
1241: $filename =~ /\.(\w+)$/;
1242:
1243: $hash->{'map_type_'.$lmap_no}=$1;
1244:
1245: # Repcopy the file and get its contents...report errors if we can't
1246:
1247: my $contents = &Apache::lonnet::getfile($filename);
1248: if($contents eq -1) {
1249: throw Error::Simple(&mt('<br />Map not loaded: The file <tt>[_1]</tt> does not exist.',
1250: $filename));
1251: }
1252: # Now that we succesfully retrieved the file we can make our parsing passes over it:
1253: # parsing is done in passes:
1254: # 1. Parameters are parsed.
1255: # 2. Resource, links and conditions are parsed.
1256: #
1257: # post processing takes care of the case where the sequence is random ordered
1258: # or randomselected.
1259:
1260: # Parse the parameters, This pass only cares about start tags for <param>
1261: # tags.. this is because there is no body to a <param> tag.
1262: #
1263:
1264: my $parser = HTML::TokeParser->new(\$contents);
1265: $parser->attr_encoded(1); # Don't interpret entities in attributes (leave &xyz; alone).
1266:
1267: while (my $token = $parser->get_token()) {
1268: if (($token->[0] eq 'S') && ($token->[1] eq 'param')) {
1269: &parse_param($token, $map_number, $hash);
1270: }
1271: }
1272:
1273: # ready for pass 2: Resource links and conditions.
1274: # Note that if the map is random-ordered link tags are computed by randomizing
1275: # resource order. Furthermore, since conditions are set on links rather than
1276: # resources, they are also not processed if random order is turned on.
1277: #
1278:
1279: $parser = HTML::TokeParser->new(\$contents); # no way to reset the existing parser
1280: $parser->attr_encoded(1);
1281:
1282: my $linkpc=0;
1283: my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i);
1284:
1285: my @map_ids;
1286: while (my $token = $parser->get_token) {
1287: next if ($token->[0] ne 'S');
1288:
1289: # Resource
1290:
1291: if ($token->[1] eq 'resource') {
1292: my $resource_id = &parse_resource($token,$lmap_no,$ispage,$uri, $hash);
1293: if (defined $resource_id) {
1294: push(@map_ids, $resource_id);
1295: }
1296:
1297: # Link
1298:
1299: } elsif ($token->[1] eq 'link' && !$randomize) {
1300: &make_link(++$linkpc,$lmap_no,$token->[2]->{'to'},
1301: $token->[2]->{'from'},
1302: $token->[2]->{'condition'}, $hash); # note ..condition may be undefined.
1303:
1304: # condition
1305:
1306: } elsif ($token->[1] eq 'condition' && !$randomize) {
1307: &parse_condition($token,$lmap_no, $hash);
1308: }
1309: }
1310:
1311: # This section handles random ordering by permuting the
1312: # IDs of the map according to the user's random seed.
1313: #
1314:
1315: if ($randomize) {
1316: if (!&has_advanced_role($username, $userdomain) ) {
1317: my $seed;
1318:
1319: # In the advanced role, the map's random seed
1320: # parameter is used as the basis for computing the
1321: # seed ... if it has been specified:
1322:
1323: if (defined($randompickseed{$parent_rid})) {
1324: $seed = $randompickseed{$parent_rid};
1325: } else {
1326:
1327: # Otherwise the parent's fully encoded symb is used.
1328:
1329: my ($mapid,$resid)=split(/\./,$parent_rid);
1330: my $symb=
1331: &Apache::lonnet::encode_symb($hash->{'map_id_'.$mapid},
1332: $resid,$hash->{'src_'.$parent_rid});
1333:
1334: $seed = $symb;
1335: }
1336:
1337:
1338: my $rndseed=&Apache::lonnet::rndseed($seed, '',
1339: $userdomain, $username,
1340: \%cenv);
1341:
1342:
1343: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1344:
1345: # Take the set of map ids we have decoded and permute them to a
1346: # random order based on the seed set above. All of this is
1347: # processing the randomorder parameter if it is set, not
1348: # randompick.
1349:
1350: @map_ids=&Math::Random::random_permutation(@map_ids);
1351: }
1352: my $from = shift(@map_ids);
1353: my $from_rid = $lmap_no.'.'.$from;
1354: $hash->{'map_start_'.$uri} = $from_rid;
1355: $hash->{'type_'.$from_rid}='start';
1356:
1357: # Create links to reflect the random re-ordering done above.
1358: # In the code to process the map XML, we did not process links or conditions
1359: # if randomorder was set. This means that for an instructor to choose
1360:
1361: while (my $to = shift(@map_ids)) {
1362: &make_link(++$linkpc,$lmap_no,$to,$from, 0, $hash);
1363: my $to_rid = $lmap_no.'.'.$to;
1364: $hash->{'type_'.$to_rid}='normal';
1365: $from = $to;
1366: $from_rid = $to_rid;
1367: }
1368:
1369: $hash->{'map_finish_'.$uri}= $from_rid;
1370: $hash->{'type_'.$from_rid}='finish';
1371: }
1372:
1373:
1374: # The last parsing pass parses the <mapalias> tags that associate a name
1375: # with resource ids.
1376:
1377: $parser = HTML::TokeParser->new(\$contents);
1378: $parser->attr_encoded(1);
1379:
1380: while (my $token = $parser->get_token) {
1381: next if ($token->[0] ne 'S');
1382: if ($token->[1] eq 'param') {
1383: &parse_mapalias_param($token,$lmap_no, $hash);
1384: }
1385: }
1386:
1387: }
1388:
1389:
1390: #
1391: # Load a map from file into a target hash. This is done by first parsing the
1392: # map file into local hashes and then unrolling those hashes into the big hash.
1393: #
1394: # Parameters:
1395: #
1396: # $cnum - number of course being read.
1397: # $cdom - Domain in which the course is evaluated.
1398: # $uname - Name of the user for whom the course is being read
1399: # $udom - Name of the domain of the user for whom the course is being read.
1400: # $target_hash- Reference to the target hash into which all of this is read.
1401: # Note tht some of the hash entries we need to build require knowledge of the
1402: # course URI.. these are expected to be filled in by the caller.
1403: #
1404: # Errors are logged to lonnet and are managed via the Perl structured exception package.
1405: #
1406: #
1407: sub loadmap {
1408: my ($cnum, $cdom, $uname, $udom, $target_hash) = @_;
1409:
1410:
1411:
1412: # Clear the auxillary hashes and the cond array.
1413:
1414:
1415: %randompick = ();
1416: %randompickseed = ();
1417: %encurl = ();
1418: %hiddenurl = ();
1419: %parmhash = ();
1420: @cond = ('true:normal'); # Initial value for cond 0.
1421: $retfrid = '';
1422: $username = '';
1423: $userdomain = '';
1424: %mapalias_cache = ();
1425: %cenv = ();
1426:
1427:
1428: #
1429:
1430: $username = $uname;
1431: $userdomain = $udom;
1432:
1433: $short_name = $cdom .'/' . $cnum;
1434: my $retfurl;
1435:
1436: try {
1437:
1438:
1439: # Get the information we need about the course.
1440: # Return without filling in anything if we can't get any info:
1441:
1442: %cenv = &Apache::lonnet::coursedescription($short_name,
1443: {'freshen_cache' => 1,
1444: 'user' => $uname});
1445:
1446: unless ($cenv{'url'}) {
1447: &Apache::lonnet::logthis("lonmap::loadmap failed: $cnum/$cdom - did not get url");
1448: return;
1449: }
1450:
1451: $course_id = $cdom . '_' . $cnum; # Long course id.
1452:
1453: # Load the version information into the hash
1454:
1455:
1456: &process_versions(\%cenv, $target_hash);
1457:
1458:
1459: # Figure out the map filename's URI, and set up some starting points for the map.
1460:
1461: my $course_uri = $cenv{'url'};
1462: my $map_uri = &Apache::lonnet::clutter($course_uri);
1463:
1464: $target_hash->{'src_0.0'} = &versiontrack($map_uri, $target_hash);
1465: $target_hash->{'title_0.0'} = &Apache::lonnet::metadata($course_uri, 'title');
1466: if(!defined $target_hash->{'title_0.0'}) {
1467: $target_hash->{'title_0.0'} = '';
1468: }
1469: $target_hash->{'ids_'.$map_uri} = '0.0';
1470: $target_hash->{'is_map_0.0'} = '1';
1471:
1472: # In some places we need a username a domain and the courseid...store that
1473: # in the target hash in the context.xxxx keys:
1474:
1475: $target_hash->{'context.username'} = $username;
1476: $target_hash->{'context.userdom'} = $userdomain;
1477: $target_hash->{'context.courseid'} = $course_id;
1478:
1479:
1480: &read_map($course_uri, '0.0', $target_hash);
1481:
1482: #
1483:
1484: if (defined($target_hash->{'map_start_'.$map_uri})) {
1485:
1486: &traceroute('0',$target_hash->{'map_start_'.$course_uri},'&', 0, 0, $target_hash);
1487: &accinit($course_uri, $short_name, $target_hash);
1488: &hiddenurls($target_hash);
1489: }
1490: my $errors = &get_mapalias_errors($target_hash);
1491: if ($errors ne "") {
1492: throw Error::Simple("Map alias errors: ", $errors);
1493: }
1494:
1495: # Put the versions in to src:
1496:
1497: foreach my $key (keys(%$target_hash)) {
1498: if ($key =~ /^src_/) {
1499: $target_hash->{$key} =
1500: &putinversion($target_hash->{$key}, $target_hash, $short_name);
1501: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
1502: my ($type, $url) = ($1,$2);
1503: my $value = $target_hash->{$key};
1504: $target_hash->{$type.&putinversion($url, $target_hash, $short_name)}=$value;
1505: }
1506: }
1507: # Mark necrypted URLS.
1508:
1509: foreach my $id (keys(%encurl)) {
1510: $target_hash->{'encrypted_'.$id}=1;
1511: }
1512:
1513: # Store first keys.
1514:
1515: $target_hash->{'first_rid'}=$retfrid;
1516: my ($mapid,$resid)=split(/\./,$retfrid);
1517: $target_hash->{'first_mapurl'}=$target_hash->{'map_id_'.$mapid};
1518: my $symb=&Apache::lonnet::encode_symb($target_hash->{'map_id_'.$mapid},
1519: $resid,
1520: $target_hash->{'src_'.$retfrid});
1521: $retfurl=&add_get_param($target_hash->{'src_'.$retfrid},{ 'symb' => $symb });
1522: if ($target_hash->{'encrypted_'.$retfrid}) {
1523: $retfurl=&Apache::lonenc::encrypted($retfurl,
1524: (&Apache::lonnet::allowed('adv') ne 'F'));
1525: }
1526: $target_hash->{'first_url'}=$retfurl;
1527:
1528: # Merge in the child hashes in case the caller wants that information as well.
1529:
1530:
1531: &merge_hash($target_hash, 'randompick', \%randompick);
1532: &merge_hash($target_hash, 'randompickseed', \%randompick);
1533: &merge_hash($target_hash, 'randomorder', \%randomorder);
1534: &merge_hash($target_hash, 'encurl', \%encurl);
1535: &merge_hash($target_hash, 'hiddenurl', \%hiddenurl);
1536: &merge_hash($target_hash, 'param', \%parmhash);
1537: &merge_conditions($target_hash);
1538: }
1539: otherwise {
1540: my $e = shift;
1541: &Apache::lonnet::logthis("lonmap::loadmap failed: " . $e->stringify());
1542: }
1543:
1544: }
1545:
1546:
1547: 1;
1548:
1549: #
1550: # Module initialization code:
1551: # TODO: Fix the pod docs below.
1552:
1553: 1;
1554: __END__
1555:
1556: =head1 NAME
1557:
1558: Apache::lonmap - Construct a hash that represents a course (Big Hash).
1559:
1560: =head1 SYNOPSIS
1561:
1562: &Apache::lonmap::loadmap($filepath, \%target_hash);
1563:
1564: =head1 INTRODUCTION
1565:
1566: This module reads a course filename into a hash reference. It's up to the caller
1567: to to things like decide the has should be tied to some external file and handle the locking
1568: if this file should be shared amongst several Apache children.
1569:
1570: =head1 SUBROUTINES
1571:
1572: =over
1573:
1574: =item loadmap($filepath, $targethash)
1575:
1576:
1577: Reads the map file into a target hash.
1578:
1579: =over
1580:
1581: =item $filepath - The path to the map file to read.
1582:
1583: =item $targethash - A reference to hash into which the course is read.
1584:
1585: =back
1586:
1587: =item process_versions($cenv, $hash)
1588:
1589: Makes hash entries for each version of a course described by a course environment
1590: returned from Apache::lonnet::coursedescription.
1591:
1592: =over
1593:
1594: =item $cenv - Reference to the environment hash returned by Apache::lonnet::coursedescription
1595:
1596: =item $hash - Hash to be filled in with 'version_xxx' entries as per the big hash.
1597:
1598: =back
1599:
1600: =back
1601:
1602:
1603: =cut
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