1: # The LearningOnline Network with CAPA
2: # Construct and maintain state and binary representation of course for user
3: #
4: # $Id: lonuserstate.pm,v 1.162 2021/04/19 21:12:53 raeburn Exp $
5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28: ###
29:
30: package Apache::lonuserstate;
31:
32: # ------------------------------------------------- modules used by this module
33: use strict;
34: use HTML::TokeParser;
35: use Apache::lonnet;
36: use Apache::lonlocal;
37: use Apache::loncommon();
38: use GDBM_File;
39: use Apache::lonmsg;
40: use Safe;
41: use Safe::Hole;
42: use Opcode;
43: use Apache::lonenc;
44: use Fcntl qw(:flock);
45: use LONCAPA qw(:DEFAULT :match);
46: use File::Basename;
47:
48:
49:
50: # ---------------------------------------------------- Globals for this package
51:
52: my $pc; # Package counter is this what 'Guts' calls the map counter?
53: my %hash; # The big tied hash
54: my %parmhash;# The hash with the parameters
55: my @cond; # Array with all of the conditions
56: my $errtext; # variable with all errors
57: my $retfrid; # variable with the very first RID in the course
58: my $retfurl; # first URL
59: my %randompick; # randomly picked resources
60: my %randompickseed; # optional seed for randomly picking resources
61: my %randomorder; # maps to order contents randomly
62: my %randomizationcode; # code used to grade folder for bubblesheet exam
63: my %encurl; # URLs in this folder are supposed to be encrypted
64: my %hiddenurl; # this URL (or complete folder) is supposed to be hidden
65: my %deeplinkonly; # this URL (or complete folder) is deep-link only
66: my %rescount; # count of unhidden items in each map
67: my %mapcount; # count of unhidden maps in each map
68:
69: # ----------------------------------- Remove version from URL and store in hash
70:
71: sub versionerror {
72: my ($uri,$usedversion,$unusedversion)=@_;
73: return '<br />'.&mt('Version discrepancy: resource [_1] included in both version [_2] and version [_3]. Using version [_2].',
74: $uri,$usedversion,$unusedversion).'<br />';
75: }
76:
77: # Removes the version number from a URI and returns the resulting
78: # URI (e.g. mumbly.version.stuff => mumbly.stuff).
79: #
80: # If the URI has not been seen with a versio before the
81: # hash{'version_'.resultingURI} is set to the version number.
82: # If the URI has been seen and the version does not match and error
83: # is added to the error string.
84: #
85: # Parameters:
86: # URI potentially with a version.
87: # Returns:
88: # URI with the version cut out.
89: # See above for side effects.
90: #
91:
92: sub versiontrack {
93: my $uri=shift;
94: if ($uri=~/\.(\d+)\.\w+$/) {
95: my $version=$1;
96: $uri=~s/\.\d+\.(\w+)$/\.$1/;
97: unless ($hash{'version_'.$uri}) {
98: $hash{'version_'.$uri}=$version;
99: } elsif ($version!=$hash{'version_'.$uri}) {
100: $errtext.=&versionerror($uri,$hash{'version_'.$uri},$version);
101: }
102: }
103: return $uri;
104: }
105:
106: # -------------------------------------------------------------- Put in version
107:
108: sub putinversion {
109: my $uri=shift;
110: my $key=$env{'request.course.id'}.'_'.&Apache::lonnet::clutter($uri);
111: if ($hash{'version_'.$uri}) {
112: my $version=$hash{'version_'.$uri};
113: if ($version eq 'mostrecent') { return $uri; }
114: if ($version eq &Apache::lonnet::getversion(
115: &Apache::lonnet::filelocation('',$uri)))
116: { return $uri; }
117: $uri=~s/\.(\w+)$/\.$version\.$1/;
118: }
119: &Apache::lonnet::do_cache_new('courseresversion',$key,&Apache::lonnet::declutter($uri),600);
120: return $uri;
121: }
122:
123: # ----------------------------------------- Processing versions file for course
124:
125: sub processversionfile {
126: my %cenv=@_;
127: my %versions=&Apache::lonnet::dump('resourceversions',
128: $cenv{'domain'},
129: $cenv{'num'});
130: foreach my $ver (keys(%versions)) {
131: if ($ver=~/^error\:/) { return; }
132: $hash{'version_'.$ver}=$versions{$ver};
133: }
134: }
135:
136: # --------------------------------------------------------- Loads from disk
137:
138:
139: #
140: # Loads a map file.
141: # Note that this may implicitly recurse via parse_resource if one of the resources
142: # is itself composed.
143: #
144: # Parameters:
145: # uri - URI of the map file.
146: # parent_rid - Resource id in the map of the parent resource (0.0 for the top level map)
147: # courseid - Course id for the course for which the map is being loaded
148: #
149: sub loadmap {
150: my ($uri,$parent_rid,$courseid)=@_;
151:
152: # Is the map already included?
153:
154: if ($hash{'map_pc_'.$uri}) {
155: $errtext.='<p class="LC_error">'.
156: &mt('Multiple use of sequence/page [_1]! The course will not function properly.','<tt>'.$uri.'</tt>').
157: '</p>';
158: return;
159: }
160: # Register the resource in it's map_pc_ [for the URL]
161: # map_id.nnn is the nesting level -> to the URI.
162:
163: $pc++;
164: my $lpc=$pc;
165: $hash{'map_pc_'.$uri}=$lpc;
166: $hash{'map_id_'.$lpc}=$uri;
167:
168: # If the parent is of the form n.m hang this map underneath it in the
169: # map hierarchy.
170:
171: if ($parent_rid =~ /^(\d+)\.\d+$/) {
172: my $parent_pc = $1;
173: if (defined($hash{'map_hierarchy_'.$parent_pc})) {
174: $hash{'map_hierarchy_'.$lpc}=$hash{'map_hierarchy_'.$parent_pc}.','.
175: $parent_pc;
176: } else {
177: $hash{'map_hierarchy_'.$lpc}=$parent_pc;
178: }
179: }
180:
181: # Determine and check filename of the sequence we need to read:
182:
183: my $fn=&Apache::lonnet::filelocation('',&putinversion($uri));
184:
185: my $ispage=($fn=~/\.page$/);
186:
187: # We can only nest sequences or pages. Anything else is an illegal nest.
188:
189: unless (($fn=~/\.sequence$/) || $ispage) {
190: $errtext.='<br />'.&mt('Invalid map: [_1]',"<tt>$fn</tt>");
191: return;
192: }
193:
194: # Read the XML that constitutes the file.
195:
196: my $instr=&Apache::lonnet::getfile($fn);
197:
198: if ($instr eq -1) {
199: $errtext.= '<br />'
200: .&mt('Map not loaded: The file [_1] does not exist.',
201: "<tt>$fn</tt>");
202: return;
203: }
204:
205: # Successfully got file, parse it
206:
207: # parse for parameter processing.
208: # Note that these are <param... / > tags
209: # so we only care about 'S' (tag start) nodes.
210:
211:
212: my $parser = HTML::TokeParser->new(\$instr);
213: $parser->attr_encoded(1);
214:
215: # first get all parameters
216:
217:
218: while (my $token = $parser->get_token) {
219: next if ($token->[0] ne 'S');
220: if ($token->[1] eq 'param') {
221: &parse_param($token,$lpc);
222: }
223: }
224:
225: # Get set to take another pass through the XML:
226: # for resources and links.
227:
228: $parser = HTML::TokeParser->new(\$instr);
229: $parser->attr_encoded(1);
230:
231: my $linkpc=0;
232:
233: $fn=~/\.(\w+)$/;
234:
235: $hash{'map_type_'.$lpc}=$1;
236:
237: my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i);
238:
239: # Parse the resources, link and condition tags.
240: # Note that if randomorder or random select is chosen the links and
241: # conditions are meaningless but are determined by the randomization.
242: # This is handled in the next chunk of code.
243:
244: my @map_ids;
245: my $codechecked;
246: $rescount{$lpc} = 0;
247: $mapcount{$lpc} = 0;
248: while (my $token = $parser->get_token) {
249: next if ($token->[0] ne 'S');
250:
251: # Resource
252:
253: if ($token->[1] eq 'resource') {
254: my $resource_id = &parse_resource($token,$lpc,$ispage,$uri,$courseid);
255: if (defined $resource_id) {
256: push(@map_ids, $resource_id);
257: if ($hash{'src_'.$lpc.'.'.$resource_id}) {
258: $rescount{$lpc} ++;
259: if (($hash{'src_'.$lpc.'.'.$resource_id}=~/\.sequence$/) ||
260: ($hash{'src_'.$lpc.'.'.$resource_id}=~/\.page$/)) {
261: $mapcount{$lpc} ++;
262: }
263: }
264: unless ($codechecked) {
265: my $startsymb =
266: &Apache::lonnet::encode_symb($hash{'map_id_'.$lpc},$resource_id,
267: $hash{'src_'."$lpc.$resource_id"});
268: my $code =
269: &Apache::lonnet::EXT('resource.0.examcode',$startsymb,undef,undef,
270: undef,undef,$courseid);
271: if ($code) {
272: $randomizationcode{$parent_rid} = $code;
273: }
274: $codechecked = 1;
275: }
276: }
277:
278: # Link
279:
280: } elsif ($token->[1] eq 'link' && !$randomize) {
281: &make_link(++$linkpc,$lpc,$token->[2]->{'to'},
282: $token->[2]->{'from'},
283: $token->[2]->{'condition'}); # note ..condition may be undefined.
284:
285: # condition
286:
287: } elsif ($token->[1] eq 'condition' && !$randomize) {
288: &parse_condition($token,$lpc);
289: }
290: }
291: undef($codechecked);
292:
293: # Handle randomization and random selection
294:
295: if ($randomize) {
296: unless (&is_advanced($courseid)) {
297: # Order of resources is not randomized if user has and advanced role in the course.
298: my $seed;
299:
300: # If the map's random seed parameter has been specified
301: # it is used as the basis for computing the seed ...
302:
303: if (defined($randompickseed{$parent_rid})) {
304: $seed = $randompickseed{$parent_rid};
305: } else {
306:
307: # Otherwise the parent's fully encoded symb is used.
308:
309: my ($mapid,$resid)=split(/\./,$parent_rid);
310: my $symb=
311: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
312: $resid,$hash{'src_'.$parent_rid});
313:
314: $seed = $symb;
315: }
316:
317: # TODO: Here for sure we need to pass along the username/domain
318: # so that we can impersonate users in lonprintout e.g.
319:
320: my $setcode;
321: if (defined($randomizationcode{$parent_rid})) {
322: if ($env{'form.CODE'} eq '') {
323: $env{'form.CODE'} = $randomizationcode{$parent_rid};
324: $setcode = 1;
325: }
326: }
327:
328: my $rndseed=&Apache::lonnet::rndseed($seed);
329: &Apache::lonnet::setup_random_from_rndseed($rndseed);
330:
331: if ($setcode) {
332: undef($env{'form.CODE'});
333: undef($setcode);
334: }
335:
336: # Take the set of map ids we have decoded and permute them to a
337: # random order based on the seed set above. All of this is
338: # processing the randomorder parameter if it is set, not
339: # randompick.
340:
341: @map_ids=&Math::Random::random_permutation(@map_ids);
342: }
343:
344: my $from = shift(@map_ids);
345: my $from_rid = $lpc.'.'.$from;
346: $hash{'map_start_'.$uri} = $from_rid;
347: $hash{'type_'.$from_rid}='start';
348:
349: # Create links to reflect the random re-ordering done above.
350: # In the code to process the map XML, we did not process links or conditions
351: # if randomorder was set. This means that for an instructor to choose
352:
353: while (my $to = shift(@map_ids)) {
354: &make_link(++$linkpc,$lpc,$to,$from);
355: my $to_rid = $lpc.'.'.$to;
356: $hash{'type_'.$to_rid}='normal';
357: $from = $to;
358: $from_rid = $to_rid;
359: }
360:
361: $hash{'map_finish_'.$uri}= $from_rid;
362: $hash{'type_'.$from_rid}='finish';
363: }
364:
365: $parser = HTML::TokeParser->new(\$instr);
366: $parser->attr_encoded(1);
367:
368: # last parse out the mapalias params. These provide mnemonic
369: # tags to resources that can be used in conditions
370:
371: while (my $token = $parser->get_token) {
372: next if ($token->[0] ne 'S');
373: if ($token->[1] eq 'param') {
374: &parse_mapalias_param($token,$lpc);
375: }
376: }
377: }
378:
379: sub is_advanced {
380: my ($courseid) = @_;
381: my $advanced;
382: if ($env{'request.course.id'}) {
383: $advanced = (&Apache::lonnet::allowed('adv') eq 'F');
384: } else {
385: $env{'request.course.id'} = $courseid;
386: $advanced = (&Apache::lonnet::allowed('adv') eq 'F');
387: $env{'request.course.id'} = '';
388: }
389: return $advanced;
390: }
391:
392: # -------------------------------------------------------------------- Resource
393: #
394: # Parses a resource tag to produce the value to push into the
395: # map_ids array.
396: #
397: #
398: # Information about the actual type of resource is provided by the file extension
399: # of the uri (e.g. .problem, .sequence etc. etc.).
400: #
401: # Parameters:
402: # $token - A token from HTML::TokeParser
403: # This is an array that describes the most recently parsed HTML item.
404: # $lpc - Map nesting level (?)
405: # $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
406: # $uri - URI of the enclosing resource.
407: # $courseid - Course id of the course containing the resource being parsed.
408: # Returns:
409: # Value of the id attribute of the tag.
410: #
411: # Note:
412: # The token is an array that contains the following elements:
413: # [0] => 'S' indicating this is a start token
414: # [1] => 'resource' indicating this tag is a <resource> tag.
415: # [2] => Hash of attribute =>value pairs.
416: # [3] => @(keys [2]).
417: # [4] => unused.
418: #
419: # The attributes of the resourcde tag include:
420: #
421: # id - The resource id.
422: # src - The URI of the resource.
423: # type - The resource type (e.g. start and finish).
424: # title - The resource title.
425:
426:
427: sub parse_resource {
428: my ($token,$lpc,$ispage,$uri,$courseid) = @_;
429:
430: # I refuse to countenance code like this that has
431: # such a dirty side effect (and forcing this sub to be called within a loop).
432: #
433: # if ($token->[2]->{'type'} eq 'zombie') { next; }
434: #
435: # The original code both returns _and_ skips to the next pass of the >caller's<
436: # loop, that's just dirty.
437: #
438:
439: # Zombie resources don't produce anything useful.
440:
441: if ($token->[2]->{'type'} eq 'zombie') {
442: return undef;
443: }
444:
445: my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
446:
447: # Save the hash element type and title:
448:
449: $hash{'kind_'.$rid}='res';
450: $hash{'title_'.$rid}=$token->[2]->{'title'};
451:
452: # Get the version free URI for the resource.
453: # If a 'version' attribute was supplied, and this resource's version
454: # information has not yet been stored, store it.
455: #
456:
457: my $turi=&versiontrack($token->[2]->{'src'});
458: if ($token->[2]->{'version'}) {
459: unless ($hash{'version_'.$turi}) {
460: $hash{'version_'.$turi}=$1;
461: }
462: }
463: # Pull out the title and do entity substitution on &colon
464: # Q: Why no other entity substitutions?
465:
466: my $title=$token->[2]->{'title'};
467: $title=~s/\&colon\;/\:/gs;
468:
469:
470:
471: # I think the point of all this code is to construct a final
472: # URI that apache and its rewrite rules can use to
473: # fetch the resource. Thi s sonly necessary if the resource
474: # is not a page. If the resource is a page then it must be
475: # assembled (at fetch time?).
476:
477: if ($ispage) {
478: if ($token->[2]->{'external'} eq 'true') { # external
479: $turi=~s{^http\://}{/ext/};
480: }
481: } else {
482: $turi=~/\.(\w+)$/;
483: my $embstyle=&Apache::loncommon::fileembstyle($1);
484: if ($token->[2]->{'external'} eq 'true') { # external
485: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
486: } elsif ($turi=~/^\/*uploaded\//) { # uploaded
487: if (($embstyle eq 'img')
488: || ($embstyle eq 'emb')
489: || ($embstyle eq 'wrp')) {
490: $turi='/adm/wrapper'.$turi;
491: } elsif ($embstyle eq 'ssi') {
492: #do nothing with these
493: } elsif ($turi!~/\.(sequence|page)$/) {
494: $turi='/adm/coursedocs/showdoc'.$turi;
495: }
496: } elsif ($turi=~ m{^/adm/$match_domain/$match_courseid/\d+/ext\.tool$}) {
497: $turi='/adm/wrapper'.$turi;
498: } elsif ($turi=~/\S/) { # normal non-empty internal resource
499: my $mapdir=$uri;
500: $mapdir=~s/[^\/]+$//;
501: $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
502: if (($embstyle eq 'img')
503: || ($embstyle eq 'emb')
504: || ($embstyle eq 'wrp')) {
505: $turi='/adm/wrapper'.$turi;
506: }
507: }
508: }
509: # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
510: # If the URI appears more than one time in the sequence, it's resourcde
511: # id's are constructed as a comma spearated list.
512:
513: my $idsuri=$turi;
514: $idsuri=~s/\?.+$//;
515: if (defined($hash{'ids_'.$idsuri})) {
516: $hash{'ids_'.$idsuri}.=','.$rid;
517: } else {
518: $hash{'ids_'.$idsuri}=''.$rid;
519: }
520:
521:
522:
523: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
524: $turi.='?register=1';
525: }
526:
527:
528: # resource id lookup: 'src'_resourc-di => URI decorated with a query
529: # parameter as above if necessary due to the resource type.
530:
531: $hash{'src_'.$rid}=$turi;
532:
533: # Mark the external-ness of the resource:
534:
535: if ($token->[2]->{'external'} eq 'true') {
536: $hash{'ext_'.$rid}='true:';
537: } else {
538: $hash{'ext_'.$rid}='false:';
539: }
540:
541: # If the resource is a start/finish resource set those
542: # entries in the has so that navigation knows where everything starts.
543: # TODO? If there is a malformed sequence that has no start or no finish
544: # resource, should this be detected and errors thrown? How would such a
545: # resource come into being other than being manually constructed by a person
546: # and then uploaded? Could that happen if an author decided a sequence was almost
547: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
548: # start or finish resources?
549: #
550: # All resourcess also get a type_id => (start | finish | normal) hash entr.
551: #
552: if ($token->[2]->{'type'}) {
553: $hash{'type_'.$rid}=$token->[2]->{'type'};
554: if ($token->[2]->{'type'} eq 'start') {
555: $hash{'map_start_'.$uri}="$rid";
556: }
557: if ($token->[2]->{'type'} eq 'finish') {
558: $hash{'map_finish_'.$uri}="$rid";
559: }
560: } else {
561: $hash{'type_'.$rid}='normal';
562: }
563:
564: # Sequences end pages are constructed entities. They require that the
565: # map that defines _them_ be loaded as well into the hash...with this resourcde
566: # as the base of the nesting.
567: # Resources like that are also marked with is_map_id => 1 entries.
568: #
569:
570: if (($turi=~/\.sequence$/) ||
571: ($turi=~/\.page$/)) {
572: $hash{'is_map_'.$rid}=1;
573: if ((!$hiddenurl{$rid}) || (&is_advanced($courseid))) {
574: &loadmap($turi,$rid,$courseid);
575: }
576: }
577: return $token->[2]->{'id'};
578: }
579:
580: #-------------------------------------------------------------------- link
581: # Links define how you are allowed to move from one resource to another.
582: # They are the transition edges in the directed graph that a map is.
583: # This sub takes informatino from a <link> tag and constructs the
584: # navigation bits and pieces of a map. There is no requirement that the
585: # resources that are linke are already defined, however clearly the map is
586: # badly broken if they are not _eventually_ defined.
587: #
588: # Note that links can be unconditional or conditional.
589: #
590: # Parameters:
591: # linkpc - The link counter for this level of map nesting (this is
592: # reset to zero by loadmap prior to starting to process
593: # links for map).
594: # lpc - The map level ocounter (how deeply nested this map is in
595: # the hierarchy of maps that are recursively read in.
596: # to - resource id (within the XML) of the target of the edge.
597: # from - resource id (within the XML) of the source of the edge.
598: # condition- id of condition associated with the edge (also within the XML).
599: #
600:
601: sub make_link {
602: my ($linkpc,$lpc,$to,$from,$condition) = @_;
603:
604: # Compute fully qualified ids for the link, the
605: # and from/to by prepending lpc.
606: #
607:
608: my $linkid=$lpc.'.'.$linkpc;
609: my $goesto=$lpc.'.'.$to;
610: my $comesfrom=$lpc.'.'.$from;
611: my $undercond=0;
612:
613:
614: # If there is a condition, qualify it with the level counter.
615:
616: if ($condition) {
617: $undercond=$lpc.'.'.$condition;
618: }
619:
620: # Links are represnted by:
621: # goesto_.fuullyqualifedlinkid => fully qualified to
622: # comesfrom.fullyqualifiedlinkid => fully qualified from
623: # undercond_.fullyqualifiedlinkid => fully qualified condition id.
624:
625: $hash{'goesto_'.$linkid}=$goesto;
626: $hash{'comesfrom_'.$linkid}=$comesfrom;
627: $hash{'undercond_'.$linkid}=$undercond;
628:
629: # In addition:
630: # to_.fully qualified from => comma separated list of
631: # link ids with that from.
632: # Similarly:
633: # from_.fully qualified to => comma separated list of link ids`
634: # with that to.
635: # That allows us given a resource id to know all edges that go to it
636: # and leave from it.
637: #
638:
639: if (defined($hash{'to_'.$comesfrom})) {
640: $hash{'to_'.$comesfrom}.=','.$linkid;
641: } else {
642: $hash{'to_'.$comesfrom}=''.$linkid;
643: }
644: if (defined($hash{'from_'.$goesto})) {
645: $hash{'from_'.$goesto}.=','.$linkid;
646: } else {
647: $hash{'from_'.$goesto}=''.$linkid;
648: }
649: }
650:
651: # ------------------------------------------------------------------- Condition
652: #
653: # Processes <condition> tags, storing sufficient information about them
654: # in the hash so that they can be evaluated and used to conditionalize
655: # what is presented to the student.
656: #
657: # these can have the following attributes
658: #
659: # id = A unique identifier of the condition within the map.
660: #
661: # value = Is a perl script-let that, when evaluated in safe space
662: # determines whether or not the condition is true.
663: # Normally this takes the form of a test on an Apache::lonnet::EXT call
664: # to find the value of variable associated with a resource in the
665: # map identified by a mapalias.
666: # Here's a fragment of XML code that illustrates this:
667: #
668: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
669: # <resource src="" id="1" type="start" title="Start" />
670: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" />
671: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
672: # <2 " id="61" type="stop" />
673: # <link to="5" index="1" from="1" condition="61" />
674: #
675: # In this fragment:
676: # - The param tag establishes an alias to resource id 5 of 'mainproblem'.
677: # - The resource that is the start of the map is identified.
678: # - The resource tag identifies the resource associated with this tag
679: # and gives it the id 5.
680: # - The condition is true if the tries variable associated with mainproblem
681: # is less than 2 (that is the user has had more than 2 tries).
682: # The condition type is a stop condition which inhibits(?) the associated
683: # link if the condition is false.
684: # - The link to resource 5 from resource 1 is affected by this condition.
685: #
686: # type = Type of the condition. The type determines how the condition affects the
687: # link associated with it and is one of
688: # - 'force'
689: # - 'stop'
690: # anything else including not supplied..which treated as:
691: # - 'normal'.
692: # Presumably maps get created by the resource assembly tool and therefore
693: # illegal type values won't squirm their way into the XML.
694: #
695: # Side effects:
696: # - The kind_level-qualified-condition-id hash element is set to 'cond'.
697: # - The condition text is pushed into the cond array and its element number is
698: # set in the condid_level-qualified-condition-id element of the hash.
699: # - The condition type is colon appneded to the cond array element for this condition.
700: sub parse_condition {
701: my ($token,$lpc) = @_;
702: my $rid=$lpc.'.'.$token->[2]->{'id'};
703:
704: $hash{'kind_'.$rid}='cond';
705:
706: my $condition = $token->[2]->{'value'};
707: $condition =~ s/[\n\r]+/ /gs;
708: push(@cond, $condition);
709: $hash{'condid_'.$rid}=$#cond;
710: if ($token->[2]->{'type'}) {
711: $cond[$#cond].=':'.$token->[2]->{'type'};
712: } else {
713: $cond[$#cond].=':normal';
714: }
715: }
716:
717: # ------------------------------------------------------------------- Parameter
718: # Parse a <parameter> tag in the map.
719: # Parmameters:
720: # $token Token array for a start tag from HTML::TokeParser
721: # [0] = 'S'
722: # [1] = tagname ("param")
723: # [2] = Hash of {attribute} = values.
724: # [3] = Array of the keys in [2].
725: # [4] = unused.
726: # $lpc Current map nesting level.a
727: #
728: # Typical attributes:
729: # to=n - Number of the resource the parameter applies to.
730: # type=xx - Type of parameter value (e.g. string_yesno or int_pos).
731: # name=xxx - Name of parameter (e.g. parameter_randompick or parameter_randomorder).
732: # value=xxx - value of the parameter.
733:
734: sub parse_param {
735: my ($token,$lpc) = @_;
736: my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to.
737: my $name=$token->[2]->{'name'}; # Name of parameter
738: my $part;
739:
740:
741: if ($name=~/^parameter_(.*)_/) {
742: $part=$1;
743: } else {
744: $part=0;
745: }
746:
747: # Peel the parameter_ off the parameter name.
748:
749: $name=~s/^.*_([^_]*)$/$1/;
750:
751: # The value is:
752: # type.part.name.value
753:
754: my $newparam=
755: &escape($token->[2]->{'type'}).':'.
756: &escape($part.'.'.$name).'='.
757: &escape($token->[2]->{'value'});
758:
759: # The hash key is param_resourceid.
760: # Multiple parameters for a single resource are & separated in the hash.
761:
762:
763: if (defined($hash{'param_'.$referid})) {
764: $hash{'param_'.$referid}.='&'.$newparam;
765: } else {
766: $hash{'param_'.$referid}=''.$newparam;
767: }
768: #
769: # These parameters have to do with randomly selecting
770: # resources, therefore a separate hash is also created to
771: # make it easy to locate them when actually computing the resource set later on
772: # See the code conditionalized by ($randomize) in loadmap().
773:
774: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
775: $randompick{$referid}=$token->[2]->{'value'};
776: }
777: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
778: $randompickseed{$referid}=$token->[2]->{'value'};
779: }
780: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
781: $randomorder{$referid}=$token->[2]->{'value'};
782: }
783:
784: # These parameters have to do with how the URLs of resources are presented to
785: # course members(?). encrypturl presents encypted url's while
786: # hiddenresource hides the URL.
787: #
788:
789: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
790: if ($token->[2]->{'value'}=~/^yes$/i) {
791: $encurl{$referid}=1;
792: }
793: }
794: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
795: if ($token->[2]->{'value'}=~/^yes$/i) {
796: $hiddenurl{$referid}=1;
797: }
798: }
799: }
800: #
801: # Parse mapalias parameters.
802: # these are tags of the form:
803: # <param to="nn"
804: # value="some-alias-for-resourceid-nn"
805: # name="parameter_0_mapalias"
806: # type="string" />
807: # A map alias is a textual name for a resource:
808: # - The to attribute identifies the resource (this gets level qualified below)
809: # - The value attributes provides the alias string.
810: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/
811: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings
812: # terminating with the string 'mapalias'.
813: # Examples:
814: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
815: # Invalid to ids are silently ignored.
816: #
817: # Parameters:
818: # token - The token array fromthe HMTML::TokeParser
819: # lpc - The current map level counter.
820: #
821: sub parse_mapalias_param {
822: my ($token,$lpc) = @_;
823:
824: # Fully qualify the to value and ignore the alias if there is no
825: # corresponding resource.
826:
827: my $referid=$lpc.'.'.$token->[2]->{'to'};
828: return if (!exists($hash{'src_'.$referid}));
829:
830: # If this is a valid mapalias parameter,
831: # Append the target id to the count_mapalias element for that
832: # alias so that we can detect doubly defined aliases
833: # e.g.:
834: # <param to="1" value="george" name="parameter_0_mapalias" type="string" />
835: # <param to="2" value="george" name="parameter_0_mapalias" type="string" />
836: #
837: # The example above is trivial but the case that's important has to do with
838: # constructing a map that includes a nested map where the nested map may have
839: # aliases that conflict with aliases established in the enclosing map.
840: #
841: # ...and create/update the hash mapalias entry to actually store the alias.
842: #
843:
844: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
845: &count_mapalias($token->[2]->{'value'},$referid);
846: $hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
847: }
848: }
849:
850: # --------------------------------------------------------- Simplify expression
851:
852:
853: #
854: # Someone should really comment this to describe what it does to what and why.
855: #
856: sub simplify {
857: my $expression=shift;
858: # (0&1) = 1
859: $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
860: # (8)=8
861: $expression=~s/\(([_\.\d]+)\)/$1/g;
862: # 8&8=8
863: $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
864: # 8|8=8
865: $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g;
866: # (5&3)&4=5&3&4
867: $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
868: # (((5&3)|(4&6)))=((5&3)|(4&6))
869: $expression=~
870: s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
871: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
872: $expression=~
873: s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
874: return $expression;
875: }
876:
877: # -------------------------------------------------------- Build condition hash
878:
879: #
880: # Traces a route recursively through the map after it has been loaded
881: # (I believe this really visits each resourcde that is reachable fromt he
882: # start top node.
883: #
884: # - Marks hidden resources as hidden.
885: # - Marks which resource URL's must be encrypted.
886: # - Figures out (if necessary) the first resource in the map.
887: # - Further builds the chunks of the big hash that define how
888: # conditions work
889: #
890: # Note that the tracing strategy won't visit resources that are not linked to
891: # anything or islands in the map (groups of resources that form a path but are not
892: # linked in to the path that can be traced from the start resource...but that's ok
893: # because by definition, those resources are not reachable by users of the course.
894: #
895: # Parameters:
896: # sofar - _URI of the prior entry or 0 if this is the top.
897: # rid - URI of the resource to visit.
898: # beenhere - list of resources (each resource enclosed by &'s) that have
899: # already been visited.
900: # encflag - If true the resource that resulted in a recursive call to us
901: # has an encoded URL (which means contained resources should too).
902: # hdnflag - If true,the resource that resulted in a recursive call to us
903: # was hidden (which means contained resources should be hidden too).
904: # Returns
905: # new value indicating how far the map has been traversed (the sofar).
906: #
907: sub traceroute {
908: my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_;
909: my $newsofar=$sofar=simplify($sofar);
910:
911: unless ($beenhere=~/\&\Q$rid\E\&/) {
912: $beenhere.=$rid.'&';
913: my ($mapid,$resid)=split(/\./,$rid);
914: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
915: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
916:
917: if ($hdnflag || lc($hidden) eq 'yes') {
918: $hiddenurl{$rid}=1;
919: }
920: if (!$hdnflag && lc($hidden) eq 'no') {
921: delete($hiddenurl{$rid});
922: }
923:
924: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
925: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
926:
927: if (($retfrid eq '') && ($hash{'src_'.$rid})
928: && ($hash{'src_'.$rid}!~/\.sequence$/)) {
929: $retfrid=$rid;
930: }
931: my @deeplink=&Apache::lonnet::EXT('resource.0.deeplink',$symb);
932: unless ((@deeplink == 0) || ($deeplink[0] eq 'full')) {
933: $deeplinkonly{$rid}=join(':',@deeplink);
934: if ($deeplink[1] eq 'map') {
935: my $parent = (split(/\,/,$hash{'map_hierarchy_'.$mapid}))[-1];
936: $deeplinkonly{"$parent.$mapid"}=$deeplinkonly{$rid};
937: }
938: }
939:
940: if (defined($hash{'conditions_'.$rid})) {
941: $hash{'conditions_'.$rid}=simplify(
942: '('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
943: } else {
944: $hash{'conditions_'.$rid}=$sofar;
945: }
946:
947: # if the expression is just the 0th condition keep it
948: # otherwise leave a pointer to this condition expression
949:
950: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
951:
952: # Recurse if the resource is a map:
953:
954: if (defined($hash{'is_map_'.$rid})) {
955: if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
956: $sofar=$newsofar=
957: &traceroute($sofar,
958: $hash{'map_start_'.$hash{'src_'.$rid}},
959: $beenhere,
960: $encflag || $encurl{$rid},
961: $hdnflag || $hiddenurl{$rid});
962: }
963: }
964:
965: # Processes links to this resource:
966: # - verify the existence of any conditionals on the link to here.
967: # - Recurse to any resources linked to us.
968: #
969: if (defined($hash{'to_'.$rid})) {
970: foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
971: my $further=$sofar;
972: #
973: # If there's a condition associated with this link be sure
974: # it's been defined else that's an error:
975: #
976: if ($hash{'undercond_'.$id}) {
977: if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) {
978: $further=simplify('('.'_'.$rid.')&('.
979: $hash{'condid_'.$hash{'undercond_'.$id}}.')');
980: } else {
981: $errtext.= '<br />'.
982: &mt('Undefined condition ID: [_1]',
983: $hash{'undercond_'.$id});
984: }
985: }
986: # Recurse to resoruces that have to's to us.
987: $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere,
988: $encflag,$hdnflag);
989: }
990: }
991: }
992: return $newsofar;
993: }
994:
995: # ------------------------------ Cascading conditions, quick access, parameters
996:
997: #
998: # Seems a rather strangely named sub given what the comment above says it does.
999:
1000:
1001: sub accinit {
1002: my ($uri,$short,$fn)=@_;
1003: my %acchash=();
1004: my %captured=();
1005: my $condcounter=0;
1006: $acchash{'acc.cond.'.$short.'.0'}=0;
1007:
1008: # This loop is only interested in conditions and
1009: # parameters in the big hash:
1010:
1011: foreach my $key (keys(%hash)) {
1012:
1013: # conditions:
1014:
1015: if ($key=~/^conditions/) {
1016: my $expr=$hash{$key};
1017:
1018: # try to find and factor out common sub-expressions
1019: # Any subexpression that is found is simplified, removed from
1020: # the original condition expression and the simplified sub-expression
1021: # substituted back in to the epxression..I'm not actually convinced this
1022: # factors anything out...but instead maybe simplifies common factors(?)
1023:
1024: foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
1025: my $orig=$sub;
1026:
1027: my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
1028: next if (!defined($factor));
1029:
1030: $sub=~s/\Q$factor\E//g;
1031: $sub=~s/^\(/\($factor\(/;
1032: $sub.=')';
1033: $sub=simplify($sub);
1034: $expr=~s/\Q$orig\E/$sub/;
1035: }
1036: $hash{$key}=$expr;
1037:
1038: # If not yet seen, record in acchash and that we've seen it.
1039:
1040: unless (defined($captured{$expr})) {
1041: $condcounter++;
1042: $captured{$expr}=$condcounter;
1043: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
1044: }
1045: # Parameters:
1046:
1047: } elsif ($key=~/^param_(\d+)\.(\d+)/) {
1048: my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2,
1049: $hash{'src_'.$1.'.'.$2});
1050: foreach my $param (split(/\&/,$hash{$key})) {
1051: my ($typename,$value)=split(/\=/,$param);
1052: my ($type,$name)=split(/\:/,$typename);
1053: $parmhash{$prefix.'.'.&unescape($name)}=
1054: &unescape($value);
1055: $parmhash{$prefix.'.'.&unescape($name).'.type'}=
1056: &unescape($type);
1057: }
1058: }
1059: }
1060: # This loop only processes id entries in the big hash.
1061:
1062: foreach my $key (keys(%hash)) {
1063: if ($key=~/^ids/) {
1064: foreach my $resid (split(/\,/,$hash{$key})) {
1065: my $uri=$hash{'src_'.$resid};
1066: my ($uripath,$urifile) =
1067: &Apache::lonnet::split_uri_for_cond($uri);
1068: if ($uripath) {
1069: my $uricond='0';
1070: if (defined($hash{'conditions_'.$resid})) {
1071: $uricond=$captured{$hash{'conditions_'.$resid}};
1072: }
1073: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
1074: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
1075: /(\&\Q$urifile\E\:[^\&]*)/) {
1076: my $replace=$1;
1077: my $regexp=$replace;
1078: #$regexp=~s/\|/\\\|/g;
1079: $acchash{'acc.res.'.$short.'.'.$uripath} =~
1080: s/\Q$regexp\E/$replace\|$uricond/;
1081: } else {
1082: $acchash{'acc.res.'.$short.'.'.$uripath}.=
1083: $urifile.':'.$uricond.'&';
1084: }
1085: } else {
1086: $acchash{'acc.res.'.$short.'.'.$uripath}=
1087: '&'.$urifile.':'.$uricond.'&';
1088: }
1089: }
1090: }
1091: }
1092: }
1093: $acchash{'acc.res.'.$short.'.'}='&:0&';
1094: my $courseuri=$uri;
1095: $courseuri=~s/^\/res\///;
1096: my $regexp = 1;
1097: &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp);
1098: &Apache::lonnet::appenv(\%acchash);
1099: }
1100:
1101: # ---------------- Selectively delete from randompick maps and hidden url parms
1102:
1103: sub hiddenurls {
1104: my $randomoutentry='';
1105: foreach my $rid (keys(%randompick)) {
1106: my $rndpick=$randompick{$rid};
1107: my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
1108: # ------------------------------------------- put existing resources into array
1109: my @currentrids=();
1110: foreach my $key (sort(keys(%hash))) {
1111: if ($key=~/^src_($mpc\.\d+)/) {
1112: if ($hash{'src_'.$1}) { push @currentrids, $1; }
1113: }
1114: }
1115: # rids are number.number and we want to numercially sort on
1116: # the second number
1117: @currentrids=sort {
1118: my (undef,$aid)=split(/\./,$a);
1119: my (undef,$bid)=split(/\./,$b);
1120: $aid <=> $bid;
1121: } @currentrids;
1122: next if ($#currentrids<$rndpick);
1123: # -------------------------------- randomly eliminate the ones that should stay
1124: my (undef,$id)=split(/\./,$rid);
1125: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
1126: my $setcode;
1127: if (defined($randomizationcode{$rid})) {
1128: if ($env{'form.CODE'} eq '') {
1129: $env{'form.CODE'} = $randomizationcode{$rid};
1130: $setcode = 1;
1131: }
1132: }
1133: my $rndseed=&Apache::lonnet::rndseed($id); # use id instead of symb
1134: if ($setcode) {
1135: undef($env{'form.CODE'});
1136: undef($setcode);
1137: }
1138: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1139: my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
1140: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
1141: #&Apache::lonnet::logthis("$id,$rndseed,".join(':',@whichids));
1142: # -------------------------------------------------------- delete the leftovers
1143: for (my $k=0; $k<=$#currentrids; $k++) {
1144: if ($currentrids[$k]) {
1145: $hash{'randomout_'.$currentrids[$k]}=1;
1146: my ($mapid,$resid)=split(/\./,$currentrids[$k]);
1147: if ($rescount{$mapid}) {
1148: $rescount{$mapid} --;
1149: }
1150: if ($hash{'is_map_'.$currentrids[$k]}) {
1151: if ($mapcount{$mapid}) {
1152: $mapcount{$mapid} --;
1153: }
1154: }
1155: $randomoutentry.='&'.
1156: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
1157: $resid,
1158: $hash{'src_'.$currentrids[$k]}
1159: ).'&';
1160: }
1161: }
1162: }
1163: # ------------------------------ take care of explicitly hidden urls or folders
1164: foreach my $rid (keys(%hiddenurl)) {
1165: $hash{'randomout_'.$rid}=1;
1166: my ($mapid,$resid)=split(/\./,$rid);
1167: if ($rescount{$mapid}) {
1168: $rescount{$mapid} --;
1169: }
1170: if ($hash{'is_map_'.$rid}) {
1171: if ($mapcount{$mapid}) {
1172: $mapcount{$mapid} --;
1173: }
1174: }
1175: $randomoutentry.='&'.
1176: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,
1177: $hash{'src_'.$rid}).'&';
1178: }
1179: # --------------------------------------- append randomout entry to environment
1180: if ($randomoutentry) {
1181: &Apache::lonnet::appenv({'acc.randomout' => $randomoutentry});
1182: }
1183: }
1184:
1185: # -------------------------------------- populate big hash with map breadcrumbs
1186:
1187: # Create map_breadcrumbs_$pc from map_hierarchy_$pc by omitting intermediate
1188: # maps not shown in Course Contents table.
1189:
1190: sub mapcrumbs {
1191: foreach my $key (keys(%rescount)) {
1192: if ($hash{'map_hierarchy_'.$key}) {
1193: my $skipnext = 0;
1194: foreach my $id (split(/,/,$hash{'map_hierarchy_'.$key}),$key) {
1195: unless ($skipnext) {
1196: $hash{'map_breadcrumbs_'.$key} .= "$id,";
1197: }
1198: unless (($id == 0) || ($id == 1)) {
1199: if ((!$rescount{$id}) || ($rescount{$id} == 1 && $mapcount{$id} == 1)) {
1200: $skipnext = 1;
1201: } else {
1202: $skipnext = 0;
1203: }
1204: }
1205: }
1206: $hash{'map_breadcrumbs_'.$key} =~ s/,$//;
1207: }
1208: }
1209: }
1210:
1211: # ---------------------------------------------------- Read map and all submaps
1212:
1213: sub readmap {
1214: my ($short,$critmsg_check) = @_;
1215: $short=~s/^\///;
1216:
1217: # TODO: Hidden dependency on current user:
1218:
1219: my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
1220:
1221: my $fn=$cenv{'fn'};
1222: my $uri;
1223: $short=~s/\//\_/g;
1224: unless ($uri=$cenv{'url'}) {
1225: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1226: "Could not load course $short.</font>");
1227: return ('',&mt('No course data available.'));;
1228: }
1229: @cond=('true:normal');
1230:
1231: unless (open(LOCKFILE,">","$fn.db.lock")) {
1232: #
1233: # Most likely a permissions problem on the lockfile or its directory.
1234: #
1235: $retfurl = '';
1236: return ($retfurl,'<br />'.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.');
1237: }
1238: my $lock=0;
1239: my $gotstate=0;
1240:
1241: # If we can get the lock without delay any files there are idle
1242: # and from some prior request. We'll kill them off and regenerate them:
1243:
1244: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1245: $lock=1; # Remember that we hold the lock.
1246: &unlink_tmpfiles($fn);
1247: }
1248: undef %randompick;
1249: undef %randompickseed;
1250: undef %randomorder;
1251: undef %randomizationcode;
1252: undef %hiddenurl;
1253: undef %encurl;
1254: undef %deeplinkonly;
1255: undef %rescount;
1256: undef %mapcount;
1257: $retfrid='';
1258: $errtext='';
1259: my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags.
1260:
1261: # if we got the lock, regenerate course regnerate empty files and tie them.
1262:
1263: if ($lock) {
1264: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1265: $tiedhash = 1;
1266: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1267: $tiedparmhash = 1;
1268: $gotstate = &build_tmp_hashes($uri,
1269: $fn,
1270: $short,
1271: \%cenv); # TODO: Need to provide requested user@dom
1272: unless ($gotstate) {
1273: &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.</font>');
1274: }
1275: $untiedparmhash = untie(%parmhash);
1276: unless ($untiedparmhash) {
1277: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1278: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1279: }
1280: }
1281: $untiedhash = untie(%hash);
1282: unless ($untiedhash) {
1283: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1284: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1285: }
1286: }
1287: flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other
1288: # unlocked places the remainder happens..seems like if we
1289: # just kept the lock here the rest of the code would have
1290: # been much easier?
1291: }
1292: unless ($lock && $tiedhash && $tiedparmhash) {
1293: # if we are here it is likely because we are already trying to
1294: # initialize the course in another child, busy wait trying to
1295: # tie the hashes for the next 90 seconds, if we succeed forward
1296: # them on to navmaps, if we fail, throw up the Could not init
1297: # course screen
1298: #
1299: # RF: I'm not seeing the case where the ties/unties can fail in a way
1300: # that can be remedied by this. Since we owned the lock seems
1301: # Tie/untie failures are a result of something like a permissions problem instead?
1302: #
1303:
1304: # In any vent, undo what we did manage to do above first:
1305: if ($lock) {
1306: # Got the lock but not the DB files
1307: flock(LOCKFILE,LOCK_UN);
1308: $lock = 0;
1309: }
1310: if ($tiedhash) {
1311: unless($untiedhash) {
1312: untie(%hash);
1313: }
1314: }
1315: if ($tiedparmhash) {
1316: unless($untiedparmhash) {
1317: untie(%parmhash);
1318: }
1319: }
1320: # Log our failure:
1321:
1322: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1323: "Could not tie coursemap $fn for $uri.</font>");
1324: $tiedhash = '';
1325: $tiedparmhash = '';
1326: my $i=0;
1327:
1328: # Keep on retrying the lock for 90 sec until we succeed.
1329:
1330: while($i<90) {
1331: $i++;
1332: sleep(1);
1333: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1334:
1335: # Got the lock, tie the hashes...the assumption in this code is
1336: # that some other worker thread has created the db files quite recently
1337: # so no load is needed:
1338:
1339: $lock = 1;
1340: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
1341: $tiedhash = 1;
1342: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
1343: $tiedparmhash = 1;
1344: if (-e "$fn.state") {
1345: $retfurl='/adm/navmaps';
1346:
1347: # BUG BUG: Side effect!
1348: # Should conditionalize on something so that we can use this
1349: # to load maps for courses that are not current?
1350: #
1351: &Apache::lonnet::appenv({"request.course.id" => $short,
1352: "request.course.fn" => $fn,
1353: "request.course.uri" => $uri,
1354: "request.course.tied" => time});
1355:
1356: $untiedhash = untie(%hash);
1357: $untiedparmhash = untie(%parmhash);
1358: $gotstate = 1;
1359: last;
1360: }
1361: $untiedparmhash = untie(%parmhash);
1362: }
1363: $untiedhash = untie(%hash);
1364: }
1365: }
1366: }
1367: if ($lock) {
1368: flock(LOCKFILE,LOCK_UN);
1369: $lock = 0;
1370: if ($tiedparmhash) {
1371: unless ($untiedparmhash) {
1372: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1373: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1374: }
1375: }
1376: if ($tiedparmhash) {
1377: unless ($untiedhash) {
1378: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1379: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1380: }
1381: }
1382: }
1383: }
1384: # I think this branch of code is all about what happens if we just did the stuff above,
1385: # but found that the state file did not exist...again if we'd just held the lock
1386: # would that have made this logic simpler..as generating all the files would be
1387: # an atomic operation with respect to the lock.
1388: #
1389: unless ($gotstate) {
1390: $lock = 0;
1391: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1392: 'Could not read statemap '.$fn.' for '.$uri.'.</font>');
1393: &unlink_tmpfiles($fn);
1394: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1395: $lock=1;
1396: }
1397: undef %randompick;
1398: undef %randompickseed;
1399: undef %randomorder;
1400: undef %randomizationcode;
1401: undef %hiddenurl;
1402: undef %encurl;
1403: undef %deeplinkonly;
1404: undef %rescount;
1405: undef %mapcount;
1406: $errtext='';
1407: $retfrid='';
1408: #
1409: # Once more through the routine of tying and loading and so on.
1410: #
1411: if ($lock) {
1412: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1413: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1414: $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent?
1415: unless ($gotstate) {
1416: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1417: 'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.</font>');
1418: }
1419: unless (untie(%parmhash)) {
1420: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1421: 'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.</font>');
1422: }
1423: } else {
1424: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1425: 'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.</font>');
1426: }
1427: unless (untie(%hash)) {
1428: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1429: 'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1430: }
1431: } else {
1432: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1433: 'Could not tie coursemap '.$fn.'.db for '.$uri.'.</font>');
1434: }
1435: flock(LOCKFILE,LOCK_UN);
1436: $lock = 0;
1437: } else {
1438: # Failed to get the immediate lock.
1439:
1440: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1441: 'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1442: }
1443: }
1444: close(LOCKFILE);
1445: unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
1446: &Apache::lonmsg::author_res_msg($env{'request.course.uri'},
1447: $errtext); # TODO: User dependent?
1448: }
1449: # ------------------------------------------------- Check for critical messages
1450:
1451: # Depends on user must parameterize this as well..or separate as this is:
1452: # more part of determining what someone sees on entering a course?
1453: # When lonuserstate::readmap() is called from lonroles.pm, i.e.,
1454: # after selecting a role in a course, critical_redirect will be called,
1455: # unless the course has a blocking event in effect, when suppresses
1456: # critical message checking (users without evb priv).
1457: #
1458:
1459: if ($critmsg_check) {
1460: my ($redirect,$url) = &Apache::loncommon::critical_redirect();
1461: if ($redirect) {
1462: $retfurl = $url;
1463: }
1464: }
1465: return ($retfurl,$errtext);
1466: }
1467:
1468: #
1469: # This sub is called when the course hash and the param hash have been tied and
1470: # their lock file is held.
1471: # Parameters:
1472: # $uri - URI that identifies the course.
1473: # $fn - The base path/filename of the files that make up the context
1474: # being built.
1475: # $short - Short course name.
1476: # $cenvref - Reference to the course environment hash returned by
1477: # Apache::lonnet::coursedescription
1478: #
1479: # Assumptions:
1480: # The globals
1481: # %hash, %paramhash are tied to their gdbm files and we hold the lock on them.
1482: #
1483: sub build_tmp_hashes {
1484: my ($uri,$fn,$short,$cenvref) = @_;
1485:
1486: unless(ref($cenvref) eq 'HASH') {
1487: return;
1488: }
1489: my %cenv = %{$cenvref};
1490: my $gotstate = 0;
1491: %hash=(); # empty the global course and parameter hashes.
1492: %parmhash=();
1493: $errtext=''; # No error messages yet.
1494: $pc=0;
1495: &clear_mapalias_count();
1496: &processversionfile(%cenv);
1497:
1498: # URI Of the map file.
1499:
1500: my $furi=&Apache::lonnet::clutter($uri);
1501: #
1502: # the map staring points.
1503: #
1504: $hash{'src_0.0'}=&versiontrack($furi);
1505: $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
1506: $hash{'ids_'.$furi}='0.0';
1507: $hash{'is_map_0.0'}=1;
1508:
1509: # Load the map.. note that loadmap may implicitly recurse if the map contains
1510: # sub-maps.
1511:
1512:
1513: &loadmap($uri,'0.0',$short);
1514:
1515: # The code below only executes if there is a starting point for the map>
1516: # Q/BUG??? If there is no start resource for the map should that be an error?
1517: #
1518:
1519: if (defined($hash{'map_start_'.$uri})) {
1520: &Apache::lonnet::appenv({"request.course.id" => $short,
1521: "request.course.fn" => $fn,
1522: "request.course.uri" => $uri,
1523: "request.course.tied" => time});
1524: $env{'request.course.id'}=$short;
1525: &traceroute('0',$hash{'map_start_'.$uri},'&');
1526: &accinit($uri,$short,$fn);
1527: &hiddenurls();
1528: &mapcrumbs();
1529: }
1530: $errtext .= &get_mapalias_errors();
1531: # ------------------------------------------------------- Put versions into src
1532: foreach my $key (keys(%hash)) {
1533: if ($key=~/^src_/) {
1534: $hash{$key}=&putinversion($hash{$key});
1535: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
1536: my ($type, $url) = ($1,$2);
1537: my $value = $hash{$key};
1538: $hash{$type.&putinversion($url)}=$value;
1539: }
1540: }
1541: # ---------------------------------------------------------------- Encrypt URLs
1542: foreach my $id (keys(%encurl)) {
1543: # $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
1544: $hash{'encrypted_'.$id}=1;
1545: }
1546: # ------------------------------------------------------------ Deep-linked URLs
1547: foreach my $id (keys(%deeplinkonly)) {
1548: $hash{'deeplinkonly_'.$id}=$deeplinkonly{$id};
1549: }
1550: # ----------------------------------------------- Close hashes to finally store
1551: # --------------------------------- Routine must pass this point, no early outs
1552: $hash{'first_rid'}=$retfrid;
1553: my ($mapid,$resid)=split(/\./,$retfrid);
1554: $hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
1555: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
1556: $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
1557: if ($hash{'encrypted_'.$retfrid}) {
1558: $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
1559: }
1560: $hash{'first_url'}=$retfurl;
1561: # ---------------------------------------------------- Store away initial state
1562: {
1563: my $cfh;
1564: if (open($cfh,">","$fn.state")) {
1565: print $cfh join("\n",@cond);
1566: $gotstate = 1;
1567: } else {
1568: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1569: "Could not write statemap $fn for $uri.</font>");
1570: }
1571: }
1572: return $gotstate;
1573: }
1574:
1575: sub unlink_tmpfiles {
1576: my ($fn) = @_;
1577: my $file_dir = dirname($fn);
1578:
1579: if ("$file_dir/" eq LONCAPA::tempdir()) {
1580: my @files = qw (.db _symb.db .state _parms.db);
1581: foreach my $file (@files) {
1582: if (-e $fn.$file) {
1583: unless (unlink($fn.$file)) {
1584: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1585: "Could not unlink ".$fn.$file."</font>");
1586: }
1587: }
1588: }
1589: }
1590: return;
1591: }
1592:
1593: # ------------------------------------------------------- Evaluate state string
1594:
1595: sub evalstate {
1596: my $fn=$env{'request.course.fn'}.'.state';
1597: my $state='';
1598: if (-e $fn) {
1599: my @conditions=();
1600: {
1601: open(my $fh,"<",$fn);
1602: @conditions=<$fh>;
1603: close($fh);
1604: }
1605: my $safeeval = new Safe;
1606: my $safehole = new Safe::Hole;
1607: $safeeval->permit("entereval");
1608: $safeeval->permit(":base_math");
1609: $safeeval->deny(":base_io");
1610: $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
1611: foreach my $line (@conditions) {
1612: chomp($line);
1613: my ($condition,$weight)=split(/\:/,$line);
1614: if ($safeeval->reval($condition)) {
1615: if ($weight eq 'force') {
1616: $state.='3';
1617: } else {
1618: $state.='2';
1619: }
1620: } else {
1621: if ($weight eq 'stop') {
1622: $state.='0';
1623: } else {
1624: $state.='1';
1625: }
1626: }
1627: }
1628: }
1629: &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state});
1630: return $state;
1631: }
1632:
1633: # This block seems to have code to manage/detect doubly defined
1634: # aliases in maps.
1635:
1636: {
1637: my %mapalias_cache;
1638: sub count_mapalias {
1639: my ($value,$resid) = @_;
1640: push(@{ $mapalias_cache{$value} }, $resid);
1641: }
1642:
1643: sub get_mapalias_errors {
1644: my $error_text;
1645: foreach my $mapalias (sort(keys(%mapalias_cache))) {
1646: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
1647: my $count;
1648: my $which =
1649: join('</li><li>',
1650: map {
1651: my $id = $_;
1652: if (exists($hash{'src_'.$id})) {
1653: $count++;
1654: }
1655: my ($mapid) = split(/\./,$id);
1656: &mt('Resource [_1][_2]in Map [_3]',
1657: $hash{'title_'.$id},'<br />',
1658: $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}});
1659: } (@{ $mapalias_cache{$mapalias} }));
1660: next if ($count < 2);
1661: $error_text .= '<div class="LC_error">'.
1662: &mt('Error: Found the mapalias "[_1]" defined multiple times.',
1663: $mapalias).
1664: '</div><ul><li>'.$which.'</li></ul>';
1665: }
1666: &clear_mapalias_count();
1667: return $error_text;
1668: }
1669: sub clear_mapalias_count {
1670: undef(%mapalias_cache);
1671: }
1672: }
1673: 1;
1674: __END__
1675:
1676: =head1 NAME
1677:
1678: Apache::lonuserstate - Construct and maintain state and binary representation
1679: of course for user
1680:
1681: =head1 SYNOPSIS
1682:
1683: Invoked by lonroles.pm.
1684:
1685: &Apache::lonuserstate::readmap($cdom.'/'.$cnum);
1686:
1687: =head1 INTRODUCTION
1688:
1689: This module constructs and maintains state and binary representation
1690: of course for user.
1691:
1692: This is part of the LearningOnline Network with CAPA project
1693: described at http://www.lon-capa.org.
1694:
1695: =head1 SUBROUTINES
1696:
1697: =over
1698:
1699: =item loadmap()
1700:
1701: Loads map from disk
1702:
1703: =item simplify()
1704:
1705: Simplify expression
1706:
1707: =item traceroute()
1708:
1709: Build condition hash
1710:
1711: =item accinit()
1712:
1713: Cascading conditions, quick access, parameters
1714:
1715: =item readmap()
1716:
1717: Read map and all submaps
1718:
1719: =item evalstate()
1720:
1721: Evaluate state string
1722:
1723: =back
1724:
1725: =cut
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