1: # The LearningOnline Network with CAPA
2: # Construct and maintain state and binary representation of course for user
3: #
4: # $Id: lonuserstate.pm,v 1.157 2018/11/13 03:59:17 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: my $advanced;
297: if ($env{'request.course.id'}) {
298: $advanced = (&Apache::lonnet::allowed('adv') eq 'F');
299: } else {
300: $env{'request.course.id'} = $courseid;
301: $advanced = (&Apache::lonnet::allowed('adv') eq 'F');
302: $env{'request.course.id'} = '';
303: }
304: unless ($advanced) {
305: # Order of resources is not randomized if user has and advanced role in the course.
306: my $seed;
307:
308: # If the map's random seed parameter has been specified
309: # it is used as the basis for computing the seed ...
310:
311: if (defined($randompickseed{$parent_rid})) {
312: $seed = $randompickseed{$parent_rid};
313: } else {
314:
315: # Otherwise the parent's fully encoded symb is used.
316:
317: my ($mapid,$resid)=split(/\./,$parent_rid);
318: my $symb=
319: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
320: $resid,$hash{'src_'.$parent_rid});
321:
322: $seed = $symb;
323: }
324:
325: # TODO: Here for sure we need to pass along the username/domain
326: # so that we can impersonate users in lonprintout e.g.
327:
328: my $setcode;
329: if (defined($randomizationcode{$parent_rid})) {
330: if ($env{'form.CODE'} eq '') {
331: $env{'form.CODE'} = $randomizationcode{$parent_rid};
332: $setcode = 1;
333: }
334: }
335:
336: my $rndseed=&Apache::lonnet::rndseed($seed);
337: &Apache::lonnet::setup_random_from_rndseed($rndseed);
338:
339: if ($setcode) {
340: undef($env{'form.CODE'});
341: undef($setcode);
342: }
343:
344: # Take the set of map ids we have decoded and permute them to a
345: # random order based on the seed set above. All of this is
346: # processing the randomorder parameter if it is set, not
347: # randompick.
348:
349: @map_ids=&Math::Random::random_permutation(@map_ids);
350: }
351:
352: my $from = shift(@map_ids);
353: my $from_rid = $lpc.'.'.$from;
354: $hash{'map_start_'.$uri} = $from_rid;
355: $hash{'type_'.$from_rid}='start';
356:
357: # Create links to reflect the random re-ordering done above.
358: # In the code to process the map XML, we did not process links or conditions
359: # if randomorder was set. This means that for an instructor to choose
360:
361: while (my $to = shift(@map_ids)) {
362: &make_link(++$linkpc,$lpc,$to,$from);
363: my $to_rid = $lpc.'.'.$to;
364: $hash{'type_'.$to_rid}='normal';
365: $from = $to;
366: $from_rid = $to_rid;
367: }
368:
369: $hash{'map_finish_'.$uri}= $from_rid;
370: $hash{'type_'.$from_rid}='finish';
371: }
372:
373: $parser = HTML::TokeParser->new(\$instr);
374: $parser->attr_encoded(1);
375:
376: # last parse out the mapalias params. These provide mnemonic
377: # tags to resources that can be used in conditions
378:
379: while (my $token = $parser->get_token) {
380: next if ($token->[0] ne 'S');
381: if ($token->[1] eq 'param') {
382: &parse_mapalias_param($token,$lpc);
383: }
384: }
385: }
386:
387:
388: # -------------------------------------------------------------------- Resource
389: #
390: # Parses a resource tag to produce the value to push into the
391: # map_ids array.
392: #
393: #
394: # Information about the actual type of resource is provided by the file extension
395: # of the uri (e.g. .problem, .sequence etc. etc.).
396: #
397: # Parameters:
398: # $token - A token from HTML::TokeParser
399: # This is an array that describes the most recently parsed HTML item.
400: # $lpc - Map nesting level (?)
401: # $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
402: # $uri - URI of the enclosing resource.
403: # $courseid - Course id of the course containing the resource being parsed.
404: # Returns:
405: # Value of the id attribute of the tag.
406: #
407: # Note:
408: # The token is an array that contains the following elements:
409: # [0] => 'S' indicating this is a start token
410: # [1] => 'resource' indicating this tag is a <resource> tag.
411: # [2] => Hash of attribute =>value pairs.
412: # [3] => @(keys [2]).
413: # [4] => unused.
414: #
415: # The attributes of the resourcde tag include:
416: #
417: # id - The resource id.
418: # src - The URI of the resource.
419: # type - The resource type (e.g. start and finish).
420: # title - The resource title.
421:
422:
423: sub parse_resource {
424: my ($token,$lpc,$ispage,$uri,$courseid) = @_;
425:
426: # I refuse to countenance code like this that has
427: # such a dirty side effect (and forcing this sub to be called within a loop).
428: #
429: # if ($token->[2]->{'type'} eq 'zombie') { next; }
430: #
431: # The original code both returns _and_ skips to the next pass of the >caller's<
432: # loop, that's just dirty.
433: #
434:
435: # Zombie resources don't produce anything useful.
436:
437: if ($token->[2]->{'type'} eq 'zombie') {
438: return undef;
439: }
440:
441: my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
442:
443: # Save the hash element type and title:
444:
445: $hash{'kind_'.$rid}='res';
446: $hash{'title_'.$rid}=$token->[2]->{'title'};
447:
448: # Get the version free URI for the resource.
449: # If a 'version' attribute was supplied, and this resource's version
450: # information has not yet been stored, store it.
451: #
452:
453: my $turi=&versiontrack($token->[2]->{'src'});
454: if ($token->[2]->{'version'}) {
455: unless ($hash{'version_'.$turi}) {
456: $hash{'version_'.$turi}=$1;
457: }
458: }
459: # Pull out the title and do entity substitution on &colon
460: # Q: Why no other entity substitutions?
461:
462: my $title=$token->[2]->{'title'};
463: $title=~s/\&colon\;/\:/gs;
464:
465:
466:
467: # I think the point of all this code is to construct a final
468: # URI that apache and its rewrite rules can use to
469: # fetch the resource. Thi s sonly necessary if the resource
470: # is not a page. If the resource is a page then it must be
471: # assembled (at fetch time?).
472:
473: unless ($ispage) {
474: $turi=~/\.(\w+)$/;
475: my $embstyle=&Apache::loncommon::fileembstyle($1);
476: if ($token->[2]->{'external'} eq 'true') { # external
477: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
478: } elsif ($turi=~/^\/*uploaded\//) { # uploaded
479: if (($embstyle eq 'img')
480: || ($embstyle eq 'emb')
481: || ($embstyle eq 'wrp')) {
482: $turi='/adm/wrapper'.$turi;
483: } elsif ($embstyle eq 'ssi') {
484: #do nothing with these
485: } elsif ($turi!~/\.(sequence|page)$/) {
486: $turi='/adm/coursedocs/showdoc'.$turi;
487: }
488: } elsif ($turi=~ m{^/adm/$match_domain/$match_courseid/\d+/ext\.tool$}) {
489: $turi='/adm/wrapper'.$turi;
490: } elsif ($turi=~/\S/) { # normal non-empty internal resource
491: my $mapdir=$uri;
492: $mapdir=~s/[^\/]+$//;
493: $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
494: if (($embstyle eq 'img')
495: || ($embstyle eq 'emb')
496: || ($embstyle eq 'wrp')) {
497: $turi='/adm/wrapper'.$turi;
498: }
499: }
500: }
501: # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
502: # If the URI appears more than one time in the sequence, it's resourcde
503: # id's are constructed as a comma spearated list.
504:
505: my $idsuri=$turi;
506: $idsuri=~s/\?.+$//;
507: if (defined($hash{'ids_'.$idsuri})) {
508: $hash{'ids_'.$idsuri}.=','.$rid;
509: } else {
510: $hash{'ids_'.$idsuri}=''.$rid;
511: }
512:
513:
514:
515: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
516: $turi.='?register=1';
517: }
518:
519:
520: # resource id lookup: 'src'_resourc-di => URI decorated with a query
521: # parameter as above if necessary due to the resource type.
522:
523: $hash{'src_'.$rid}=$turi;
524:
525: # Mark the external-ness of the resource:
526:
527: if ($token->[2]->{'external'} eq 'true') {
528: $hash{'ext_'.$rid}='true:';
529: } else {
530: $hash{'ext_'.$rid}='false:';
531: }
532:
533: # If the resource is a start/finish resource set those
534: # entries in the has so that navigation knows where everything starts.
535: # TODO? If there is a malformed sequence that has no start or no finish
536: # resource, should this be detected and errors thrown? How would such a
537: # resource come into being other than being manually constructed by a person
538: # and then uploaded? Could that happen if an author decided a sequence was almost
539: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
540: # start or finish resources?
541: #
542: # All resourcess also get a type_id => (start | finish | normal) hash entr.
543: #
544: if ($token->[2]->{'type'}) {
545: $hash{'type_'.$rid}=$token->[2]->{'type'};
546: if ($token->[2]->{'type'} eq 'start') {
547: $hash{'map_start_'.$uri}="$rid";
548: }
549: if ($token->[2]->{'type'} eq 'finish') {
550: $hash{'map_finish_'.$uri}="$rid";
551: }
552: } else {
553: $hash{'type_'.$rid}='normal';
554: }
555:
556: # Sequences end pages are constructed entities. They require that the
557: # map that defines _them_ be loaded as well into the hash...with this resourcde
558: # as the base of the nesting.
559: # Resources like that are also marked with is_map_id => 1 entries.
560: #
561:
562: if (($turi=~/\.sequence$/) ||
563: ($turi=~/\.page$/)) {
564: $hash{'is_map_'.$rid}=1;
565: &loadmap($turi,$rid,$courseid);
566: }
567: return $token->[2]->{'id'};
568: }
569:
570: #-------------------------------------------------------------------- link
571: # Links define how you are allowed to move from one resource to another.
572: # They are the transition edges in the directed graph that a map is.
573: # This sub takes informatino from a <link> tag and constructs the
574: # navigation bits and pieces of a map. There is no requirement that the
575: # resources that are linke are already defined, however clearly the map is
576: # badly broken if they are not _eventually_ defined.
577: #
578: # Note that links can be unconditional or conditional.
579: #
580: # Parameters:
581: # linkpc - The link counter for this level of map nesting (this is
582: # reset to zero by loadmap prior to starting to process
583: # links for map).
584: # lpc - The map level ocounter (how deeply nested this map is in
585: # the hierarchy of maps that are recursively read in.
586: # to - resource id (within the XML) of the target of the edge.
587: # from - resource id (within the XML) of the source of the edge.
588: # condition- id of condition associated with the edge (also within the XML).
589: #
590:
591: sub make_link {
592: my ($linkpc,$lpc,$to,$from,$condition) = @_;
593:
594: # Compute fully qualified ids for the link, the
595: # and from/to by prepending lpc.
596: #
597:
598: my $linkid=$lpc.'.'.$linkpc;
599: my $goesto=$lpc.'.'.$to;
600: my $comesfrom=$lpc.'.'.$from;
601: my $undercond=0;
602:
603:
604: # If there is a condition, qualify it with the level counter.
605:
606: if ($condition) {
607: $undercond=$lpc.'.'.$condition;
608: }
609:
610: # Links are represnted by:
611: # goesto_.fuullyqualifedlinkid => fully qualified to
612: # comesfrom.fullyqualifiedlinkid => fully qualified from
613: # undercond_.fullyqualifiedlinkid => fully qualified condition id.
614:
615: $hash{'goesto_'.$linkid}=$goesto;
616: $hash{'comesfrom_'.$linkid}=$comesfrom;
617: $hash{'undercond_'.$linkid}=$undercond;
618:
619: # In addition:
620: # to_.fully qualified from => comma separated list of
621: # link ids with that from.
622: # Similarly:
623: # from_.fully qualified to => comma separated list of link ids`
624: # with that to.
625: # That allows us given a resource id to know all edges that go to it
626: # and leave from it.
627: #
628:
629: if (defined($hash{'to_'.$comesfrom})) {
630: $hash{'to_'.$comesfrom}.=','.$linkid;
631: } else {
632: $hash{'to_'.$comesfrom}=''.$linkid;
633: }
634: if (defined($hash{'from_'.$goesto})) {
635: $hash{'from_'.$goesto}.=','.$linkid;
636: } else {
637: $hash{'from_'.$goesto}=''.$linkid;
638: }
639: }
640:
641: # ------------------------------------------------------------------- Condition
642: #
643: # Processes <condition> tags, storing sufficient information about them
644: # in the hash so that they can be evaluated and used to conditionalize
645: # what is presented to the student.
646: #
647: # these can have the following attributes
648: #
649: # id = A unique identifier of the condition within the map.
650: #
651: # value = Is a perl script-let that, when evaluated in safe space
652: # determines whether or not the condition is true.
653: # Normally this takes the form of a test on an Apache::lonnet::EXT call
654: # to find the value of variable associated with a resource in the
655: # map identified by a mapalias.
656: # Here's a fragment of XML code that illustrates this:
657: #
658: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
659: # <resource src="" id="1" type="start" title="Start" />
660: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" />
661: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
662: # <2 " id="61" type="stop" />
663: # <link to="5" index="1" from="1" condition="61" />
664: #
665: # In this fragment:
666: # - The param tag establishes an alias to resource id 5 of 'mainproblem'.
667: # - The resource that is the start of the map is identified.
668: # - The resource tag identifies the resource associated with this tag
669: # and gives it the id 5.
670: # - The condition is true if the tries variable associated with mainproblem
671: # is less than 2 (that is the user has had more than 2 tries).
672: # The condition type is a stop condition which inhibits(?) the associated
673: # link if the condition is false.
674: # - The link to resource 5 from resource 1 is affected by this condition.
675: #
676: # type = Type of the condition. The type determines how the condition affects the
677: # link associated with it and is one of
678: # - 'force'
679: # - 'stop'
680: # anything else including not supplied..which treated as:
681: # - 'normal'.
682: # Presumably maps get created by the resource assembly tool and therefore
683: # illegal type values won't squirm their way into the XML.
684: #
685: # Side effects:
686: # - The kind_level-qualified-condition-id hash element is set to 'cond'.
687: # - The condition text is pushed into the cond array and its element number is
688: # set in the condid_level-qualified-condition-id element of the hash.
689: # - The condition type is colon appneded to the cond array element for this condition.
690: sub parse_condition {
691: my ($token,$lpc) = @_;
692: my $rid=$lpc.'.'.$token->[2]->{'id'};
693:
694: $hash{'kind_'.$rid}='cond';
695:
696: my $condition = $token->[2]->{'value'};
697: $condition =~ s/[\n\r]+/ /gs;
698: push(@cond, $condition);
699: $hash{'condid_'.$rid}=$#cond;
700: if ($token->[2]->{'type'}) {
701: $cond[$#cond].=':'.$token->[2]->{'type'};
702: } else {
703: $cond[$#cond].=':normal';
704: }
705: }
706:
707: # ------------------------------------------------------------------- Parameter
708: # Parse a <parameter> tag in the map.
709: # Parmameters:
710: # $token Token array for a start tag from HTML::TokeParser
711: # [0] = 'S'
712: # [1] = tagname ("param")
713: # [2] = Hash of {attribute} = values.
714: # [3] = Array of the keys in [2].
715: # [4] = unused.
716: # $lpc Current map nesting level.a
717: #
718: # Typical attributes:
719: # to=n - Number of the resource the parameter applies to.
720: # type=xx - Type of parameter value (e.g. string_yesno or int_pos).
721: # name=xxx - Name of parameter (e.g. parameter_randompick or parameter_randomorder).
722: # value=xxx - value of the parameter.
723:
724: sub parse_param {
725: my ($token,$lpc) = @_;
726: my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to.
727: my $name=$token->[2]->{'name'}; # Name of parameter
728: my $part;
729:
730:
731: if ($name=~/^parameter_(.*)_/) {
732: $part=$1;
733: } else {
734: $part=0;
735: }
736:
737: # Peel the parameter_ off the parameter name.
738:
739: $name=~s/^.*_([^_]*)$/$1/;
740:
741: # The value is:
742: # type.part.name.value
743:
744: my $newparam=
745: &escape($token->[2]->{'type'}).':'.
746: &escape($part.'.'.$name).'='.
747: &escape($token->[2]->{'value'});
748:
749: # The hash key is param_resourceid.
750: # Multiple parameters for a single resource are & separated in the hash.
751:
752:
753: if (defined($hash{'param_'.$referid})) {
754: $hash{'param_'.$referid}.='&'.$newparam;
755: } else {
756: $hash{'param_'.$referid}=''.$newparam;
757: }
758: #
759: # These parameters have to do with randomly selecting
760: # resources, therefore a separate hash is also created to
761: # make it easy to locate them when actually computing the resource set later on
762: # See the code conditionalized by ($randomize) in loadmap().
763:
764: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
765: $randompick{$referid}=$token->[2]->{'value'};
766: }
767: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
768: $randompickseed{$referid}=$token->[2]->{'value'};
769: }
770: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
771: $randomorder{$referid}=$token->[2]->{'value'};
772: }
773:
774: # These parameters have to do with how the URLs of resources are presented to
775: # course members(?). encrypturl presents encypted url's while
776: # hiddenresource hides the URL.
777: #
778:
779: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
780: if ($token->[2]->{'value'}=~/^yes$/i) {
781: $encurl{$referid}=1;
782: }
783: }
784: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
785: if ($token->[2]->{'value'}=~/^yes$/i) {
786: $hiddenurl{$referid}=1;
787: }
788: }
789: }
790: #
791: # Parse mapalias parameters.
792: # these are tags of the form:
793: # <param to="nn"
794: # value="some-alias-for-resourceid-nn"
795: # name="parameter_0_mapalias"
796: # type="string" />
797: # A map alias is a textual name for a resource:
798: # - The to attribute identifies the resource (this gets level qualified below)
799: # - The value attributes provides the alias string.
800: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/
801: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings
802: # terminating with the string 'mapalias'.
803: # Examples:
804: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
805: # Invalid to ids are silently ignored.
806: #
807: # Parameters:
808: # token - The token array fromthe HMTML::TokeParser
809: # lpc - The current map level counter.
810: #
811: sub parse_mapalias_param {
812: my ($token,$lpc) = @_;
813:
814: # Fully qualify the to value and ignore the alias if there is no
815: # corresponding resource.
816:
817: my $referid=$lpc.'.'.$token->[2]->{'to'};
818: return if (!exists($hash{'src_'.$referid}));
819:
820: # If this is a valid mapalias parameter,
821: # Append the target id to the count_mapalias element for that
822: # alias so that we can detect doubly defined aliases
823: # e.g.:
824: # <param to="1" value="george" name="parameter_0_mapalias" type="string" />
825: # <param to="2" value="george" name="parameter_0_mapalias" type="string" />
826: #
827: # The example above is trivial but the case that's important has to do with
828: # constructing a map that includes a nested map where the nested map may have
829: # aliases that conflict with aliases established in the enclosing map.
830: #
831: # ...and create/update the hash mapalias entry to actually store the alias.
832: #
833:
834: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
835: &count_mapalias($token->[2]->{'value'},$referid);
836: $hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
837: }
838: }
839:
840: # --------------------------------------------------------- Simplify expression
841:
842:
843: #
844: # Someone should really comment this to describe what it does to what and why.
845: #
846: sub simplify {
847: my $expression=shift;
848: # (0&1) = 1
849: $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
850: # (8)=8
851: $expression=~s/\(([_\.\d]+)\)/$1/g;
852: # 8&8=8
853: $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
854: # 8|8=8
855: $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g;
856: # (5&3)&4=5&3&4
857: $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
858: # (((5&3)|(4&6)))=((5&3)|(4&6))
859: $expression=~
860: s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
861: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
862: $expression=~
863: s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
864: return $expression;
865: }
866:
867: # -------------------------------------------------------- Build condition hash
868:
869: #
870: # Traces a route recursively through the map after it has been loaded
871: # (I believe this really visits each resourcde that is reachable fromt he
872: # start top node.
873: #
874: # - Marks hidden resources as hidden.
875: # - Marks which resource URL's must be encrypted.
876: # - Figures out (if necessary) the first resource in the map.
877: # - Further builds the chunks of the big hash that define how
878: # conditions work
879: #
880: # Note that the tracing strategy won't visit resources that are not linked to
881: # anything or islands in the map (groups of resources that form a path but are not
882: # linked in to the path that can be traced from the start resource...but that's ok
883: # because by definition, those resources are not reachable by users of the course.
884: #
885: # Parameters:
886: # sofar - _URI of the prior entry or 0 if this is the top.
887: # rid - URI of the resource to visit.
888: # beenhere - list of resources (each resource enclosed by &'s) that have
889: # already been visited.
890: # encflag - If true the resource that resulted in a recursive call to us
891: # has an encoded URL (which means contained resources should too).
892: # hdnflag - If true,the resource that resulted in a recursive call to us
893: # was hidden (which means contained resources should be hidden too).
894: # Returns
895: # new value indicating how far the map has been traversed (the sofar).
896: #
897: sub traceroute {
898: my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_;
899: my $newsofar=$sofar=simplify($sofar);
900:
901: unless ($beenhere=~/\&\Q$rid\E\&/) {
902: $beenhere.=$rid.'&';
903: my ($mapid,$resid)=split(/\./,$rid);
904: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
905: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
906:
907: if ($hdnflag || lc($hidden) eq 'yes') {
908: $hiddenurl{$rid}=1;
909: }
910: if (!$hdnflag && lc($hidden) eq 'no') {
911: delete($hiddenurl{$rid});
912: }
913:
914: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
915: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
916:
917: if (($retfrid eq '') && ($hash{'src_'.$rid})
918: && ($hash{'src_'.$rid}!~/\.sequence$/)) {
919: $retfrid=$rid;
920: }
921: my @deeplink=&Apache::lonnet::EXT('resource.0.deeplink',$symb);
922: unless ((@deeplink == 0) || ($deeplink[0] eq 'full')) {
923: $deeplinkonly{$rid}=join(':',@deeplink);
924: if ($deeplink[1] eq 'map') {
925: my $parent = (split(/\,/,$hash{'map_hierarchy_'.$mapid}))[-1];
926: $deeplinkonly{"$parent.$mapid"}=$deeplinkonly{$rid};
927: }
928: }
929:
930: if (defined($hash{'conditions_'.$rid})) {
931: $hash{'conditions_'.$rid}=simplify(
932: '('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
933: } else {
934: $hash{'conditions_'.$rid}=$sofar;
935: }
936:
937: # if the expression is just the 0th condition keep it
938: # otherwise leave a pointer to this condition expression
939:
940: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
941:
942: # Recurse if the resource is a map:
943:
944: if (defined($hash{'is_map_'.$rid})) {
945: if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
946: $sofar=$newsofar=
947: &traceroute($sofar,
948: $hash{'map_start_'.$hash{'src_'.$rid}},
949: $beenhere,
950: $encflag || $encurl{$rid},
951: $hdnflag || $hiddenurl{$rid});
952: }
953: }
954:
955: # Processes links to this resource:
956: # - verify the existence of any conditionals on the link to here.
957: # - Recurse to any resources linked to us.
958: #
959: if (defined($hash{'to_'.$rid})) {
960: foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
961: my $further=$sofar;
962: #
963: # If there's a condition associated with this link be sure
964: # it's been defined else that's an error:
965: #
966: if ($hash{'undercond_'.$id}) {
967: if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) {
968: $further=simplify('('.'_'.$rid.')&('.
969: $hash{'condid_'.$hash{'undercond_'.$id}}.')');
970: } else {
971: $errtext.= '<br />'.
972: &mt('Undefined condition ID: [_1]',
973: $hash{'undercond_'.$id});
974: }
975: }
976: # Recurse to resoruces that have to's to us.
977: $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere,
978: $encflag,$hdnflag);
979: }
980: }
981: }
982: return $newsofar;
983: }
984:
985: # ------------------------------ Cascading conditions, quick access, parameters
986:
987: #
988: # Seems a rather strangely named sub given what the comment above says it does.
989:
990:
991: sub accinit {
992: my ($uri,$short,$fn)=@_;
993: my %acchash=();
994: my %captured=();
995: my $condcounter=0;
996: $acchash{'acc.cond.'.$short.'.0'}=0;
997:
998: # This loop is only interested in conditions and
999: # parameters in the big hash:
1000:
1001: foreach my $key (keys(%hash)) {
1002:
1003: # conditions:
1004:
1005: if ($key=~/^conditions/) {
1006: my $expr=$hash{$key};
1007:
1008: # try to find and factor out common sub-expressions
1009: # Any subexpression that is found is simplified, removed from
1010: # the original condition expression and the simplified sub-expression
1011: # substituted back in to the epxression..I'm not actually convinced this
1012: # factors anything out...but instead maybe simplifies common factors(?)
1013:
1014: foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
1015: my $orig=$sub;
1016:
1017: my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
1018: next if (!defined($factor));
1019:
1020: $sub=~s/\Q$factor\E//g;
1021: $sub=~s/^\(/\($factor\(/;
1022: $sub.=')';
1023: $sub=simplify($sub);
1024: $expr=~s/\Q$orig\E/$sub/;
1025: }
1026: $hash{$key}=$expr;
1027:
1028: # If not yet seen, record in acchash and that we've seen it.
1029:
1030: unless (defined($captured{$expr})) {
1031: $condcounter++;
1032: $captured{$expr}=$condcounter;
1033: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
1034: }
1035: # Parameters:
1036:
1037: } elsif ($key=~/^param_(\d+)\.(\d+)/) {
1038: my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2,
1039: $hash{'src_'.$1.'.'.$2});
1040: foreach my $param (split(/\&/,$hash{$key})) {
1041: my ($typename,$value)=split(/\=/,$param);
1042: my ($type,$name)=split(/\:/,$typename);
1043: $parmhash{$prefix.'.'.&unescape($name)}=
1044: &unescape($value);
1045: $parmhash{$prefix.'.'.&unescape($name).'.type'}=
1046: &unescape($type);
1047: }
1048: }
1049: }
1050: # This loop only processes id entries in the big hash.
1051:
1052: foreach my $key (keys(%hash)) {
1053: if ($key=~/^ids/) {
1054: foreach my $resid (split(/\,/,$hash{$key})) {
1055: my $uri=$hash{'src_'.$resid};
1056: my ($uripath,$urifile) =
1057: &Apache::lonnet::split_uri_for_cond($uri);
1058: if ($uripath) {
1059: my $uricond='0';
1060: if (defined($hash{'conditions_'.$resid})) {
1061: $uricond=$captured{$hash{'conditions_'.$resid}};
1062: }
1063: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
1064: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
1065: /(\&\Q$urifile\E\:[^\&]*)/) {
1066: my $replace=$1;
1067: my $regexp=$replace;
1068: #$regexp=~s/\|/\\\|/g;
1069: $acchash{'acc.res.'.$short.'.'.$uripath} =~
1070: s/\Q$regexp\E/$replace\|$uricond/;
1071: } else {
1072: $acchash{'acc.res.'.$short.'.'.$uripath}.=
1073: $urifile.':'.$uricond.'&';
1074: }
1075: } else {
1076: $acchash{'acc.res.'.$short.'.'.$uripath}=
1077: '&'.$urifile.':'.$uricond.'&';
1078: }
1079: }
1080: }
1081: }
1082: }
1083: $acchash{'acc.res.'.$short.'.'}='&:0&';
1084: my $courseuri=$uri;
1085: $courseuri=~s/^\/res\///;
1086: my $regexp = 1;
1087: &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp);
1088: &Apache::lonnet::appenv(\%acchash);
1089: }
1090:
1091: # ---------------- Selectively delete from randompick maps and hidden url parms
1092:
1093: sub hiddenurls {
1094: my $randomoutentry='';
1095: foreach my $rid (keys(%randompick)) {
1096: my $rndpick=$randompick{$rid};
1097: my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
1098: # ------------------------------------------- put existing resources into array
1099: my @currentrids=();
1100: foreach my $key (sort(keys(%hash))) {
1101: if ($key=~/^src_($mpc\.\d+)/) {
1102: if ($hash{'src_'.$1}) { push @currentrids, $1; }
1103: }
1104: }
1105: # rids are number.number and we want to numercially sort on
1106: # the second number
1107: @currentrids=sort {
1108: my (undef,$aid)=split(/\./,$a);
1109: my (undef,$bid)=split(/\./,$b);
1110: $aid <=> $bid;
1111: } @currentrids;
1112: next if ($#currentrids<$rndpick);
1113: # -------------------------------- randomly eliminate the ones that should stay
1114: my (undef,$id)=split(/\./,$rid);
1115: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
1116: my $setcode;
1117: if (defined($randomizationcode{$rid})) {
1118: if ($env{'form.CODE'} eq '') {
1119: $env{'form.CODE'} = $randomizationcode{$rid};
1120: $setcode = 1;
1121: }
1122: }
1123: my $rndseed=&Apache::lonnet::rndseed($id); # use id instead of symb
1124: if ($setcode) {
1125: undef($env{'form.CODE'});
1126: undef($setcode);
1127: }
1128: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1129: my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
1130: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
1131: #&Apache::lonnet::logthis("$id,$rndseed,".join(':',@whichids));
1132: # -------------------------------------------------------- delete the leftovers
1133: for (my $k=0; $k<=$#currentrids; $k++) {
1134: if ($currentrids[$k]) {
1135: $hash{'randomout_'.$currentrids[$k]}=1;
1136: my ($mapid,$resid)=split(/\./,$currentrids[$k]);
1137: if ($rescount{$mapid}) {
1138: $rescount{$mapid} --;
1139: }
1140: if ($hash{'is_map_'.$currentrids[$k]}) {
1141: if ($mapcount{$mapid}) {
1142: $mapcount{$mapid} --;
1143: }
1144: }
1145: $randomoutentry.='&'.
1146: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
1147: $resid,
1148: $hash{'src_'.$currentrids[$k]}
1149: ).'&';
1150: }
1151: }
1152: }
1153: # ------------------------------ take care of explicitly hidden urls or folders
1154: foreach my $rid (keys(%hiddenurl)) {
1155: $hash{'randomout_'.$rid}=1;
1156: my ($mapid,$resid)=split(/\./,$rid);
1157: if ($rescount{$mapid}) {
1158: $rescount{$mapid} --;
1159: }
1160: if ($hash{'is_map_'.$rid}) {
1161: if ($mapcount{$mapid}) {
1162: $mapcount{$mapid} --;
1163: }
1164: }
1165: $randomoutentry.='&'.
1166: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,
1167: $hash{'src_'.$rid}).'&';
1168: }
1169: # --------------------------------------- append randomout entry to environment
1170: if ($randomoutentry) {
1171: &Apache::lonnet::appenv({'acc.randomout' => $randomoutentry});
1172: }
1173: }
1174:
1175: # -------------------------------------- populate big hash with map breadcrumbs
1176:
1177: # Create map_breadcrumbs_$pc from map_hierarchy_$pc by omitting intermediate
1178: # maps not shown in Course Contents table.
1179:
1180: sub mapcrumbs {
1181: foreach my $key (keys(%rescount)) {
1182: if ($hash{'map_hierarchy_'.$key}) {
1183: my $skipnext = 0;
1184: foreach my $id (split(/,/,$hash{'map_hierarchy_'.$key}),$key) {
1185: unless ($skipnext) {
1186: $hash{'map_breadcrumbs_'.$key} .= "$id,";
1187: }
1188: unless (($id == 0) || ($id == 1)) {
1189: if ((!$rescount{$id}) || ($rescount{$id} == 1 && $mapcount{$id} == 1)) {
1190: $skipnext = 1;
1191: } else {
1192: $skipnext = 0;
1193: }
1194: }
1195: }
1196: $hash{'map_breadcrumbs_'.$key} =~ s/,$//;
1197: }
1198: }
1199: }
1200:
1201: # ---------------------------------------------------- Read map and all submaps
1202:
1203: sub readmap {
1204: my $short=shift;
1205: $short=~s/^\///;
1206:
1207: # TODO: Hidden dependency on current user:
1208:
1209: my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
1210:
1211: my $fn=$cenv{'fn'};
1212: my $uri;
1213: $short=~s/\//\_/g;
1214: unless ($uri=$cenv{'url'}) {
1215: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1216: "Could not load course $short.</font>");
1217: return ('',&mt('No course data available.'));;
1218: }
1219: @cond=('true:normal');
1220:
1221: unless (open(LOCKFILE,">","$fn.db.lock")) {
1222: #
1223: # Most likely a permissions problem on the lockfile or its directory.
1224: #
1225: $retfurl = '';
1226: return ($retfurl,'<br />'.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.');
1227: }
1228: my $lock=0;
1229: my $gotstate=0;
1230:
1231: # If we can get the lock without delay any files there are idle
1232: # and from some prior request. We'll kill them off and regenerate them:
1233:
1234: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1235: $lock=1; # Remember that we hold the lock.
1236: &unlink_tmpfiles($fn);
1237: }
1238: undef %randompick;
1239: undef %randompickseed;
1240: undef %randomorder;
1241: undef %randomizationcode;
1242: undef %hiddenurl;
1243: undef %encurl;
1244: undef %deeplinkonly;
1245: undef %rescount;
1246: undef %mapcount;
1247: $retfrid='';
1248: $errtext='';
1249: my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags.
1250:
1251: # if we got the lock, regenerate course regnerate empty files and tie them.
1252:
1253: if ($lock) {
1254: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1255: $tiedhash = 1;
1256: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1257: $tiedparmhash = 1;
1258: $gotstate = &build_tmp_hashes($uri,
1259: $fn,
1260: $short,
1261: \%cenv); # TODO: Need to provide requested user@dom
1262: unless ($gotstate) {
1263: &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.</font>');
1264: }
1265: $untiedparmhash = untie(%parmhash);
1266: unless ($untiedparmhash) {
1267: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1268: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1269: }
1270: }
1271: $untiedhash = untie(%hash);
1272: unless ($untiedhash) {
1273: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1274: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1275: }
1276: }
1277: flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other
1278: # unlocked places the remainder happens..seems like if we
1279: # just kept the lock here the rest of the code would have
1280: # been much easier?
1281: }
1282: unless ($lock && $tiedhash && $tiedparmhash) {
1283: # if we are here it is likely because we are already trying to
1284: # initialize the course in another child, busy wait trying to
1285: # tie the hashes for the next 90 seconds, if we succeed forward
1286: # them on to navmaps, if we fail, throw up the Could not init
1287: # course screen
1288: #
1289: # RF: I'm not seeing the case where the ties/unties can fail in a way
1290: # that can be remedied by this. Since we owned the lock seems
1291: # Tie/untie failures are a result of something like a permissions problem instead?
1292: #
1293:
1294: # In any vent, undo what we did manage to do above first:
1295: if ($lock) {
1296: # Got the lock but not the DB files
1297: flock(LOCKFILE,LOCK_UN);
1298: $lock = 0;
1299: }
1300: if ($tiedhash) {
1301: unless($untiedhash) {
1302: untie(%hash);
1303: }
1304: }
1305: if ($tiedparmhash) {
1306: unless($untiedparmhash) {
1307: untie(%parmhash);
1308: }
1309: }
1310: # Log our failure:
1311:
1312: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1313: "Could not tie coursemap $fn for $uri.</font>");
1314: $tiedhash = '';
1315: $tiedparmhash = '';
1316: my $i=0;
1317:
1318: # Keep on retrying the lock for 90 sec until we succeed.
1319:
1320: while($i<90) {
1321: $i++;
1322: sleep(1);
1323: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1324:
1325: # Got the lock, tie the hashes...the assumption in this code is
1326: # that some other worker thread has created the db files quite recently
1327: # so no load is needed:
1328:
1329: $lock = 1;
1330: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
1331: $tiedhash = 1;
1332: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
1333: $tiedparmhash = 1;
1334: if (-e "$fn.state") {
1335: $retfurl='/adm/navmaps';
1336:
1337: # BUG BUG: Side effect!
1338: # Should conditionalize on something so that we can use this
1339: # to load maps for courses that are not current?
1340: #
1341: &Apache::lonnet::appenv({"request.course.id" => $short,
1342: "request.course.fn" => $fn,
1343: "request.course.uri" => $uri,
1344: "request.course.tied" => time});
1345:
1346: $untiedhash = untie(%hash);
1347: $untiedparmhash = untie(%parmhash);
1348: $gotstate = 1;
1349: last;
1350: }
1351: $untiedparmhash = untie(%parmhash);
1352: }
1353: $untiedhash = untie(%hash);
1354: }
1355: }
1356: }
1357: if ($lock) {
1358: flock(LOCKFILE,LOCK_UN);
1359: $lock = 0;
1360: if ($tiedparmhash) {
1361: unless ($untiedparmhash) {
1362: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1363: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1364: }
1365: }
1366: if ($tiedparmhash) {
1367: unless ($untiedhash) {
1368: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1369: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1370: }
1371: }
1372: }
1373: }
1374: # I think this branch of code is all about what happens if we just did the stuff above,
1375: # but found that the state file did not exist...again if we'd just held the lock
1376: # would that have made this logic simpler..as generating all the files would be
1377: # an atomic operation with respect to the lock.
1378: #
1379: unless ($gotstate) {
1380: $lock = 0;
1381: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1382: 'Could not read statemap '.$fn.' for '.$uri.'.</font>');
1383: &unlink_tmpfiles($fn);
1384: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1385: $lock=1;
1386: }
1387: undef %randompick;
1388: undef %randompickseed;
1389: undef %randomorder;
1390: undef %randomizationcode;
1391: undef %hiddenurl;
1392: undef %encurl;
1393: undef %deeplinkonly;
1394: undef %rescount;
1395: undef %mapcount;
1396: $errtext='';
1397: $retfrid='';
1398: #
1399: # Once more through the routine of tying and loading and so on.
1400: #
1401: if ($lock) {
1402: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1403: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1404: $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent?
1405: unless ($gotstate) {
1406: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1407: 'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.</font>');
1408: }
1409: unless (untie(%parmhash)) {
1410: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1411: 'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.</font>');
1412: }
1413: } else {
1414: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1415: 'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.</font>');
1416: }
1417: unless (untie(%hash)) {
1418: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1419: 'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1420: }
1421: } else {
1422: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1423: 'Could not tie coursemap '.$fn.'.db for '.$uri.'.</font>');
1424: }
1425: flock(LOCKFILE,LOCK_UN);
1426: $lock = 0;
1427: } else {
1428: # Failed to get the immediate lock.
1429:
1430: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1431: 'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1432: }
1433: }
1434: close(LOCKFILE);
1435: unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
1436: &Apache::lonmsg::author_res_msg($env{'request.course.uri'},
1437: $errtext); # TODO: User dependent?
1438: }
1439: # ------------------------------------------------- Check for critical messages
1440:
1441: # Depends on user must parameterize this as well..or separate as this is:
1442: # more part of determining what someone sees on entering a course?
1443:
1444: my @what=&Apache::lonnet::dump('critical',$env{'user.domain'},
1445: $env{'user.name'});
1446: if ($what[0]) {
1447: if (($what[0] ne 'con_lost') && ($what[0]!~/^error\:/)) {
1448: $retfurl='/adm/email?critical=display';
1449: }
1450: }
1451: return ($retfurl,$errtext);
1452: }
1453:
1454: #
1455: # This sub is called when the course hash and the param hash have been tied and
1456: # their lock file is held.
1457: # Parameters:
1458: # $uri - URI that identifies the course.
1459: # $fn - The base path/filename of the files that make up the context
1460: # being built.
1461: # $short - Short course name.
1462: # $cenvref - Reference to the course environment hash returned by
1463: # Apache::lonnet::coursedescription
1464: #
1465: # Assumptions:
1466: # The globals
1467: # %hash, %paramhash are tied to their gdbm files and we hold the lock on them.
1468: #
1469: sub build_tmp_hashes {
1470: my ($uri,$fn,$short,$cenvref) = @_;
1471:
1472: unless(ref($cenvref) eq 'HASH') {
1473: return;
1474: }
1475: my %cenv = %{$cenvref};
1476: my $gotstate = 0;
1477: %hash=(); # empty the global course and parameter hashes.
1478: %parmhash=();
1479: $errtext=''; # No error messages yet.
1480: $pc=0;
1481: &clear_mapalias_count();
1482: &processversionfile(%cenv);
1483:
1484: # URI Of the map file.
1485:
1486: my $furi=&Apache::lonnet::clutter($uri);
1487: #
1488: # the map staring points.
1489: #
1490: $hash{'src_0.0'}=&versiontrack($furi);
1491: $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
1492: $hash{'ids_'.$furi}='0.0';
1493: $hash{'is_map_0.0'}=1;
1494:
1495: # Load the map.. note that loadmap may implicitly recurse if the map contains
1496: # sub-maps.
1497:
1498:
1499: &loadmap($uri,'0.0',$short);
1500:
1501: # The code below only executes if there is a starting point for the map>
1502: # Q/BUG??? If there is no start resource for the map should that be an error?
1503: #
1504:
1505: if (defined($hash{'map_start_'.$uri})) {
1506: &Apache::lonnet::appenv({"request.course.id" => $short,
1507: "request.course.fn" => $fn,
1508: "request.course.uri" => $uri,
1509: "request.course.tied" => time});
1510: $env{'request.course.id'}=$short;
1511: &traceroute('0',$hash{'map_start_'.$uri},'&');
1512: &accinit($uri,$short,$fn);
1513: &hiddenurls();
1514: &mapcrumbs();
1515: }
1516: $errtext .= &get_mapalias_errors();
1517: # ------------------------------------------------------- Put versions into src
1518: foreach my $key (keys(%hash)) {
1519: if ($key=~/^src_/) {
1520: $hash{$key}=&putinversion($hash{$key});
1521: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
1522: my ($type, $url) = ($1,$2);
1523: my $value = $hash{$key};
1524: $hash{$type.&putinversion($url)}=$value;
1525: }
1526: }
1527: # ---------------------------------------------------------------- Encrypt URLs
1528: foreach my $id (keys(%encurl)) {
1529: # $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
1530: $hash{'encrypted_'.$id}=1;
1531: }
1532: # ------------------------------------------------------------ Deep-linked URLs
1533: foreach my $id (keys(%deeplinkonly)) {
1534: $hash{'deeplinkonly_'.$id}=$deeplinkonly{$id};
1535: }
1536: # ----------------------------------------------- Close hashes to finally store
1537: # --------------------------------- Routine must pass this point, no early outs
1538: $hash{'first_rid'}=$retfrid;
1539: my ($mapid,$resid)=split(/\./,$retfrid);
1540: $hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
1541: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
1542: $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
1543: if ($hash{'encrypted_'.$retfrid}) {
1544: $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
1545: }
1546: $hash{'first_url'}=$retfurl;
1547: # ---------------------------------------------------- Store away initial state
1548: {
1549: my $cfh;
1550: if (open($cfh,">","$fn.state")) {
1551: print $cfh join("\n",@cond);
1552: $gotstate = 1;
1553: } else {
1554: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1555: "Could not write statemap $fn for $uri.</font>");
1556: }
1557: }
1558: return $gotstate;
1559: }
1560:
1561: sub unlink_tmpfiles {
1562: my ($fn) = @_;
1563: my $file_dir = dirname($fn);
1564:
1565: if ("$file_dir/" eq LONCAPA::tempdir()) {
1566: my @files = qw (.db _symb.db .state _parms.db);
1567: foreach my $file (@files) {
1568: if (-e $fn.$file) {
1569: unless (unlink($fn.$file)) {
1570: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1571: "Could not unlink ".$fn.$file."</font>");
1572: }
1573: }
1574: }
1575: }
1576: return;
1577: }
1578:
1579: # ------------------------------------------------------- Evaluate state string
1580:
1581: sub evalstate {
1582: my $fn=$env{'request.course.fn'}.'.state';
1583: my $state='';
1584: if (-e $fn) {
1585: my @conditions=();
1586: {
1587: open(my $fh,"<",$fn);
1588: @conditions=<$fh>;
1589: close($fh);
1590: }
1591: my $safeeval = new Safe;
1592: my $safehole = new Safe::Hole;
1593: $safeeval->permit("entereval");
1594: $safeeval->permit(":base_math");
1595: $safeeval->deny(":base_io");
1596: $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
1597: foreach my $line (@conditions) {
1598: chomp($line);
1599: my ($condition,$weight)=split(/\:/,$line);
1600: if ($safeeval->reval($condition)) {
1601: if ($weight eq 'force') {
1602: $state.='3';
1603: } else {
1604: $state.='2';
1605: }
1606: } else {
1607: if ($weight eq 'stop') {
1608: $state.='0';
1609: } else {
1610: $state.='1';
1611: }
1612: }
1613: }
1614: }
1615: &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state});
1616: return $state;
1617: }
1618:
1619: # This block seems to have code to manage/detect doubly defined
1620: # aliases in maps.
1621:
1622: {
1623: my %mapalias_cache;
1624: sub count_mapalias {
1625: my ($value,$resid) = @_;
1626: push(@{ $mapalias_cache{$value} }, $resid);
1627: }
1628:
1629: sub get_mapalias_errors {
1630: my $error_text;
1631: foreach my $mapalias (sort(keys(%mapalias_cache))) {
1632: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
1633: my $count;
1634: my $which =
1635: join('</li><li>',
1636: map {
1637: my $id = $_;
1638: if (exists($hash{'src_'.$id})) {
1639: $count++;
1640: }
1641: my ($mapid) = split(/\./,$id);
1642: &mt('Resource [_1][_2]in Map [_3]',
1643: $hash{'title_'.$id},'<br />',
1644: $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}});
1645: } (@{ $mapalias_cache{$mapalias} }));
1646: next if ($count < 2);
1647: $error_text .= '<div class="LC_error">'.
1648: &mt('Error: Found the mapalias "[_1]" defined multiple times.',
1649: $mapalias).
1650: '</div><ul><li>'.$which.'</li></ul>';
1651: }
1652: &clear_mapalias_count();
1653: return $error_text;
1654: }
1655: sub clear_mapalias_count {
1656: undef(%mapalias_cache);
1657: }
1658: }
1659: 1;
1660: __END__
1661:
1662: =head1 NAME
1663:
1664: Apache::lonuserstate - Construct and maintain state and binary representation
1665: of course for user
1666:
1667: =head1 SYNOPSIS
1668:
1669: Invoked by lonroles.pm.
1670:
1671: &Apache::lonuserstate::readmap($cdom.'/'.$cnum);
1672:
1673: =head1 INTRODUCTION
1674:
1675: This module constructs and maintains state and binary representation
1676: of course for user.
1677:
1678: This is part of the LearningOnline Network with CAPA project
1679: described at http://www.lon-capa.org.
1680:
1681: =head1 SUBROUTINES
1682:
1683: =over
1684:
1685: =item loadmap()
1686:
1687: Loads map from disk
1688:
1689: =item simplify()
1690:
1691: Simplify expression
1692:
1693: =item traceroute()
1694:
1695: Build condition hash
1696:
1697: =item accinit()
1698:
1699: Cascading conditions, quick access, parameters
1700:
1701: =item readmap()
1702:
1703: Read map and all submaps
1704:
1705: =item evalstate()
1706:
1707: Evaluate state string
1708:
1709: =back
1710:
1711: =cut
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to lonuserstate.pm CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / rat