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[LON-CAPA] /
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lonuserstate.pm
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1.158:
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Tue Mar 3 01:16:31 2020 UTC (4 years, 2 months ago) by
raeburn
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- URL for external resources in uploaded .page ("Composite page") changed
to begin /ext/ (but are not wrapped).
- Printouts of external resources include title of item in course, and link
unless encrypturl is set to yes for the resource.
1: # The LearningOnline Network with CAPA
2: # Construct and maintain state and binary representation of course for user
3: #
4: # $Id: lonuserstate.pm,v 1.158 2020/03/03 01:16:31 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: $title=~s/\&colon\;/\:/gs;
464:
465:
466:
467: # I think the point of all this code is to construct a final
468: # URI that apache and its rewrite rules can use to
469: # fetch the resource. Thi s sonly necessary if the resource
470: # is not a page. If the resource is a page then it must be
471: # assembled (at fetch time?).
472:
473: if ($ispage) {
474: if ($token->[2]->{'external'} eq 'true') { # external
475: $turi=~s{^http\://}{/ext/};
476: }
477: } else {
478: $turi=~/\.(\w+)$/;
479: my $embstyle=&Apache::loncommon::fileembstyle($1);
480: if ($token->[2]->{'external'} eq 'true') { # external
481: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
482: } elsif ($turi=~/^\/*uploaded\//) { # uploaded
483: if (($embstyle eq 'img')
484: || ($embstyle eq 'emb')
485: || ($embstyle eq 'wrp')) {
486: $turi='/adm/wrapper'.$turi;
487: } elsif ($embstyle eq 'ssi') {
488: #do nothing with these
489: } elsif ($turi!~/\.(sequence|page)$/) {
490: $turi='/adm/coursedocs/showdoc'.$turi;
491: }
492: } elsif ($turi=~ m{^/adm/$match_domain/$match_courseid/\d+/ext\.tool$}) {
493: $turi='/adm/wrapper'.$turi;
494: } elsif ($turi=~/\S/) { # normal non-empty internal resource
495: my $mapdir=$uri;
496: $mapdir=~s/[^\/]+$//;
497: $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
498: if (($embstyle eq 'img')
499: || ($embstyle eq 'emb')
500: || ($embstyle eq 'wrp')) {
501: $turi='/adm/wrapper'.$turi;
502: }
503: }
504: }
505: # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
506: # If the URI appears more than one time in the sequence, it's resourcde
507: # id's are constructed as a comma spearated list.
508:
509: my $idsuri=$turi;
510: $idsuri=~s/\?.+$//;
511: if (defined($hash{'ids_'.$idsuri})) {
512: $hash{'ids_'.$idsuri}.=','.$rid;
513: } else {
514: $hash{'ids_'.$idsuri}=''.$rid;
515: }
516:
517:
518:
519: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
520: $turi.='?register=1';
521: }
522:
523:
524: # resource id lookup: 'src'_resourc-di => URI decorated with a query
525: # parameter as above if necessary due to the resource type.
526:
527: $hash{'src_'.$rid}=$turi;
528:
529: # Mark the external-ness of the resource:
530:
531: if ($token->[2]->{'external'} eq 'true') {
532: $hash{'ext_'.$rid}='true:';
533: } else {
534: $hash{'ext_'.$rid}='false:';
535: }
536:
537: # If the resource is a start/finish resource set those
538: # entries in the has so that navigation knows where everything starts.
539: # TODO? If there is a malformed sequence that has no start or no finish
540: # resource, should this be detected and errors thrown? How would such a
541: # resource come into being other than being manually constructed by a person
542: # and then uploaded? Could that happen if an author decided a sequence was almost
543: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
544: # start or finish resources?
545: #
546: # All resourcess also get a type_id => (start | finish | normal) hash entr.
547: #
548: if ($token->[2]->{'type'}) {
549: $hash{'type_'.$rid}=$token->[2]->{'type'};
550: if ($token->[2]->{'type'} eq 'start') {
551: $hash{'map_start_'.$uri}="$rid";
552: }
553: if ($token->[2]->{'type'} eq 'finish') {
554: $hash{'map_finish_'.$uri}="$rid";
555: }
556: } else {
557: $hash{'type_'.$rid}='normal';
558: }
559:
560: # Sequences end pages are constructed entities. They require that the
561: # map that defines _them_ be loaded as well into the hash...with this resourcde
562: # as the base of the nesting.
563: # Resources like that are also marked with is_map_id => 1 entries.
564: #
565:
566: if (($turi=~/\.sequence$/) ||
567: ($turi=~/\.page$/)) {
568: $hash{'is_map_'.$rid}=1;
569: &loadmap($turi,$rid,$courseid);
570: }
571: return $token->[2]->{'id'};
572: }
573:
574: #-------------------------------------------------------------------- link
575: # Links define how you are allowed to move from one resource to another.
576: # They are the transition edges in the directed graph that a map is.
577: # This sub takes informatino from a <link> tag and constructs the
578: # navigation bits and pieces of a map. There is no requirement that the
579: # resources that are linke are already defined, however clearly the map is
580: # badly broken if they are not _eventually_ defined.
581: #
582: # Note that links can be unconditional or conditional.
583: #
584: # Parameters:
585: # linkpc - The link counter for this level of map nesting (this is
586: # reset to zero by loadmap prior to starting to process
587: # links for map).
588: # lpc - The map level ocounter (how deeply nested this map is in
589: # the hierarchy of maps that are recursively read in.
590: # to - resource id (within the XML) of the target of the edge.
591: # from - resource id (within the XML) of the source of the edge.
592: # condition- id of condition associated with the edge (also within the XML).
593: #
594:
595: sub make_link {
596: my ($linkpc,$lpc,$to,$from,$condition) = @_;
597:
598: # Compute fully qualified ids for the link, the
599: # and from/to by prepending lpc.
600: #
601:
602: my $linkid=$lpc.'.'.$linkpc;
603: my $goesto=$lpc.'.'.$to;
604: my $comesfrom=$lpc.'.'.$from;
605: my $undercond=0;
606:
607:
608: # If there is a condition, qualify it with the level counter.
609:
610: if ($condition) {
611: $undercond=$lpc.'.'.$condition;
612: }
613:
614: # Links are represnted by:
615: # goesto_.fuullyqualifedlinkid => fully qualified to
616: # comesfrom.fullyqualifiedlinkid => fully qualified from
617: # undercond_.fullyqualifiedlinkid => fully qualified condition id.
618:
619: $hash{'goesto_'.$linkid}=$goesto;
620: $hash{'comesfrom_'.$linkid}=$comesfrom;
621: $hash{'undercond_'.$linkid}=$undercond;
622:
623: # In addition:
624: # to_.fully qualified from => comma separated list of
625: # link ids with that from.
626: # Similarly:
627: # from_.fully qualified to => comma separated list of link ids`
628: # with that to.
629: # That allows us given a resource id to know all edges that go to it
630: # and leave from it.
631: #
632:
633: if (defined($hash{'to_'.$comesfrom})) {
634: $hash{'to_'.$comesfrom}.=','.$linkid;
635: } else {
636: $hash{'to_'.$comesfrom}=''.$linkid;
637: }
638: if (defined($hash{'from_'.$goesto})) {
639: $hash{'from_'.$goesto}.=','.$linkid;
640: } else {
641: $hash{'from_'.$goesto}=''.$linkid;
642: }
643: }
644:
645: # ------------------------------------------------------------------- Condition
646: #
647: # Processes <condition> tags, storing sufficient information about them
648: # in the hash so that they can be evaluated and used to conditionalize
649: # what is presented to the student.
650: #
651: # these can have the following attributes
652: #
653: # id = A unique identifier of the condition within the map.
654: #
655: # value = Is a perl script-let that, when evaluated in safe space
656: # determines whether or not the condition is true.
657: # Normally this takes the form of a test on an Apache::lonnet::EXT call
658: # to find the value of variable associated with a resource in the
659: # map identified by a mapalias.
660: # Here's a fragment of XML code that illustrates this:
661: #
662: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
663: # <resource src="" id="1" type="start" title="Start" />
664: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" />
665: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
666: # <2 " id="61" type="stop" />
667: # <link to="5" index="1" from="1" condition="61" />
668: #
669: # In this fragment:
670: # - The param tag establishes an alias to resource id 5 of 'mainproblem'.
671: # - The resource that is the start of the map is identified.
672: # - The resource tag identifies the resource associated with this tag
673: # and gives it the id 5.
674: # - The condition is true if the tries variable associated with mainproblem
675: # is less than 2 (that is the user has had more than 2 tries).
676: # The condition type is a stop condition which inhibits(?) the associated
677: # link if the condition is false.
678: # - The link to resource 5 from resource 1 is affected by this condition.
679: #
680: # type = Type of the condition. The type determines how the condition affects the
681: # link associated with it and is one of
682: # - 'force'
683: # - 'stop'
684: # anything else including not supplied..which treated as:
685: # - 'normal'.
686: # Presumably maps get created by the resource assembly tool and therefore
687: # illegal type values won't squirm their way into the XML.
688: #
689: # Side effects:
690: # - The kind_level-qualified-condition-id hash element is set to 'cond'.
691: # - The condition text is pushed into the cond array and its element number is
692: # set in the condid_level-qualified-condition-id element of the hash.
693: # - The condition type is colon appneded to the cond array element for this condition.
694: sub parse_condition {
695: my ($token,$lpc) = @_;
696: my $rid=$lpc.'.'.$token->[2]->{'id'};
697:
698: $hash{'kind_'.$rid}='cond';
699:
700: my $condition = $token->[2]->{'value'};
701: $condition =~ s/[\n\r]+/ /gs;
702: push(@cond, $condition);
703: $hash{'condid_'.$rid}=$#cond;
704: if ($token->[2]->{'type'}) {
705: $cond[$#cond].=':'.$token->[2]->{'type'};
706: } else {
707: $cond[$#cond].=':normal';
708: }
709: }
710:
711: # ------------------------------------------------------------------- Parameter
712: # Parse a <parameter> tag in the map.
713: # Parmameters:
714: # $token Token array for a start tag from HTML::TokeParser
715: # [0] = 'S'
716: # [1] = tagname ("param")
717: # [2] = Hash of {attribute} = values.
718: # [3] = Array of the keys in [2].
719: # [4] = unused.
720: # $lpc Current map nesting level.a
721: #
722: # Typical attributes:
723: # to=n - Number of the resource the parameter applies to.
724: # type=xx - Type of parameter value (e.g. string_yesno or int_pos).
725: # name=xxx - Name of parameter (e.g. parameter_randompick or parameter_randomorder).
726: # value=xxx - value of the parameter.
727:
728: sub parse_param {
729: my ($token,$lpc) = @_;
730: my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to.
731: my $name=$token->[2]->{'name'}; # Name of parameter
732: my $part;
733:
734:
735: if ($name=~/^parameter_(.*)_/) {
736: $part=$1;
737: } else {
738: $part=0;
739: }
740:
741: # Peel the parameter_ off the parameter name.
742:
743: $name=~s/^.*_([^_]*)$/$1/;
744:
745: # The value is:
746: # type.part.name.value
747:
748: my $newparam=
749: &escape($token->[2]->{'type'}).':'.
750: &escape($part.'.'.$name).'='.
751: &escape($token->[2]->{'value'});
752:
753: # The hash key is param_resourceid.
754: # Multiple parameters for a single resource are & separated in the hash.
755:
756:
757: if (defined($hash{'param_'.$referid})) {
758: $hash{'param_'.$referid}.='&'.$newparam;
759: } else {
760: $hash{'param_'.$referid}=''.$newparam;
761: }
762: #
763: # These parameters have to do with randomly selecting
764: # resources, therefore a separate hash is also created to
765: # make it easy to locate them when actually computing the resource set later on
766: # See the code conditionalized by ($randomize) in loadmap().
767:
768: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
769: $randompick{$referid}=$token->[2]->{'value'};
770: }
771: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
772: $randompickseed{$referid}=$token->[2]->{'value'};
773: }
774: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
775: $randomorder{$referid}=$token->[2]->{'value'};
776: }
777:
778: # These parameters have to do with how the URLs of resources are presented to
779: # course members(?). encrypturl presents encypted url's while
780: # hiddenresource hides the URL.
781: #
782:
783: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
784: if ($token->[2]->{'value'}=~/^yes$/i) {
785: $encurl{$referid}=1;
786: }
787: }
788: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
789: if ($token->[2]->{'value'}=~/^yes$/i) {
790: $hiddenurl{$referid}=1;
791: }
792: }
793: }
794: #
795: # Parse mapalias parameters.
796: # these are tags of the form:
797: # <param to="nn"
798: # value="some-alias-for-resourceid-nn"
799: # name="parameter_0_mapalias"
800: # type="string" />
801: # A map alias is a textual name for a resource:
802: # - The to attribute identifies the resource (this gets level qualified below)
803: # - The value attributes provides the alias string.
804: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/
805: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings
806: # terminating with the string 'mapalias'.
807: # Examples:
808: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
809: # Invalid to ids are silently ignored.
810: #
811: # Parameters:
812: # token - The token array fromthe HMTML::TokeParser
813: # lpc - The current map level counter.
814: #
815: sub parse_mapalias_param {
816: my ($token,$lpc) = @_;
817:
818: # Fully qualify the to value and ignore the alias if there is no
819: # corresponding resource.
820:
821: my $referid=$lpc.'.'.$token->[2]->{'to'};
822: return if (!exists($hash{'src_'.$referid}));
823:
824: # If this is a valid mapalias parameter,
825: # Append the target id to the count_mapalias element for that
826: # alias so that we can detect doubly defined aliases
827: # e.g.:
828: # <param to="1" value="george" name="parameter_0_mapalias" type="string" />
829: # <param to="2" value="george" name="parameter_0_mapalias" type="string" />
830: #
831: # The example above is trivial but the case that's important has to do with
832: # constructing a map that includes a nested map where the nested map may have
833: # aliases that conflict with aliases established in the enclosing map.
834: #
835: # ...and create/update the hash mapalias entry to actually store the alias.
836: #
837:
838: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
839: &count_mapalias($token->[2]->{'value'},$referid);
840: $hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
841: }
842: }
843:
844: # --------------------------------------------------------- Simplify expression
845:
846:
847: #
848: # Someone should really comment this to describe what it does to what and why.
849: #
850: sub simplify {
851: my $expression=shift;
852: # (0&1) = 1
853: $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
854: # (8)=8
855: $expression=~s/\(([_\.\d]+)\)/$1/g;
856: # 8&8=8
857: $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
858: # 8|8=8
859: $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g;
860: # (5&3)&4=5&3&4
861: $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
862: # (((5&3)|(4&6)))=((5&3)|(4&6))
863: $expression=~
864: s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
865: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
866: $expression=~
867: s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
868: return $expression;
869: }
870:
871: # -------------------------------------------------------- Build condition hash
872:
873: #
874: # Traces a route recursively through the map after it has been loaded
875: # (I believe this really visits each resourcde that is reachable fromt he
876: # start top node.
877: #
878: # - Marks hidden resources as hidden.
879: # - Marks which resource URL's must be encrypted.
880: # - Figures out (if necessary) the first resource in the map.
881: # - Further builds the chunks of the big hash that define how
882: # conditions work
883: #
884: # Note that the tracing strategy won't visit resources that are not linked to
885: # anything or islands in the map (groups of resources that form a path but are not
886: # linked in to the path that can be traced from the start resource...but that's ok
887: # because by definition, those resources are not reachable by users of the course.
888: #
889: # Parameters:
890: # sofar - _URI of the prior entry or 0 if this is the top.
891: # rid - URI of the resource to visit.
892: # beenhere - list of resources (each resource enclosed by &'s) that have
893: # already been visited.
894: # encflag - If true the resource that resulted in a recursive call to us
895: # has an encoded URL (which means contained resources should too).
896: # hdnflag - If true,the resource that resulted in a recursive call to us
897: # was hidden (which means contained resources should be hidden too).
898: # Returns
899: # new value indicating how far the map has been traversed (the sofar).
900: #
901: sub traceroute {
902: my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_;
903: my $newsofar=$sofar=simplify($sofar);
904:
905: unless ($beenhere=~/\&\Q$rid\E\&/) {
906: $beenhere.=$rid.'&';
907: my ($mapid,$resid)=split(/\./,$rid);
908: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
909: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
910:
911: if ($hdnflag || lc($hidden) eq 'yes') {
912: $hiddenurl{$rid}=1;
913: }
914: if (!$hdnflag && lc($hidden) eq 'no') {
915: delete($hiddenurl{$rid});
916: }
917:
918: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
919: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
920:
921: if (($retfrid eq '') && ($hash{'src_'.$rid})
922: && ($hash{'src_'.$rid}!~/\.sequence$/)) {
923: $retfrid=$rid;
924: }
925: my @deeplink=&Apache::lonnet::EXT('resource.0.deeplink',$symb);
926: unless ((@deeplink == 0) || ($deeplink[0] eq 'full')) {
927: $deeplinkonly{$rid}=join(':',@deeplink);
928: if ($deeplink[1] eq 'map') {
929: my $parent = (split(/\,/,$hash{'map_hierarchy_'.$mapid}))[-1];
930: $deeplinkonly{"$parent.$mapid"}=$deeplinkonly{$rid};
931: }
932: }
933:
934: if (defined($hash{'conditions_'.$rid})) {
935: $hash{'conditions_'.$rid}=simplify(
936: '('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
937: } else {
938: $hash{'conditions_'.$rid}=$sofar;
939: }
940:
941: # if the expression is just the 0th condition keep it
942: # otherwise leave a pointer to this condition expression
943:
944: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
945:
946: # Recurse if the resource is a map:
947:
948: if (defined($hash{'is_map_'.$rid})) {
949: if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
950: $sofar=$newsofar=
951: &traceroute($sofar,
952: $hash{'map_start_'.$hash{'src_'.$rid}},
953: $beenhere,
954: $encflag || $encurl{$rid},
955: $hdnflag || $hiddenurl{$rid});
956: }
957: }
958:
959: # Processes links to this resource:
960: # - verify the existence of any conditionals on the link to here.
961: # - Recurse to any resources linked to us.
962: #
963: if (defined($hash{'to_'.$rid})) {
964: foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
965: my $further=$sofar;
966: #
967: # If there's a condition associated with this link be sure
968: # it's been defined else that's an error:
969: #
970: if ($hash{'undercond_'.$id}) {
971: if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) {
972: $further=simplify('('.'_'.$rid.')&('.
973: $hash{'condid_'.$hash{'undercond_'.$id}}.')');
974: } else {
975: $errtext.= '<br />'.
976: &mt('Undefined condition ID: [_1]',
977: $hash{'undercond_'.$id});
978: }
979: }
980: # Recurse to resoruces that have to's to us.
981: $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere,
982: $encflag,$hdnflag);
983: }
984: }
985: }
986: return $newsofar;
987: }
988:
989: # ------------------------------ Cascading conditions, quick access, parameters
990:
991: #
992: # Seems a rather strangely named sub given what the comment above says it does.
993:
994:
995: sub accinit {
996: my ($uri,$short,$fn)=@_;
997: my %acchash=();
998: my %captured=();
999: my $condcounter=0;
1000: $acchash{'acc.cond.'.$short.'.0'}=0;
1001:
1002: # This loop is only interested in conditions and
1003: # parameters in the big hash:
1004:
1005: foreach my $key (keys(%hash)) {
1006:
1007: # conditions:
1008:
1009: if ($key=~/^conditions/) {
1010: my $expr=$hash{$key};
1011:
1012: # try to find and factor out common sub-expressions
1013: # Any subexpression that is found is simplified, removed from
1014: # the original condition expression and the simplified sub-expression
1015: # substituted back in to the epxression..I'm not actually convinced this
1016: # factors anything out...but instead maybe simplifies common factors(?)
1017:
1018: foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
1019: my $orig=$sub;
1020:
1021: my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
1022: next if (!defined($factor));
1023:
1024: $sub=~s/\Q$factor\E//g;
1025: $sub=~s/^\(/\($factor\(/;
1026: $sub.=')';
1027: $sub=simplify($sub);
1028: $expr=~s/\Q$orig\E/$sub/;
1029: }
1030: $hash{$key}=$expr;
1031:
1032: # If not yet seen, record in acchash and that we've seen it.
1033:
1034: unless (defined($captured{$expr})) {
1035: $condcounter++;
1036: $captured{$expr}=$condcounter;
1037: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
1038: }
1039: # Parameters:
1040:
1041: } elsif ($key=~/^param_(\d+)\.(\d+)/) {
1042: my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2,
1043: $hash{'src_'.$1.'.'.$2});
1044: foreach my $param (split(/\&/,$hash{$key})) {
1045: my ($typename,$value)=split(/\=/,$param);
1046: my ($type,$name)=split(/\:/,$typename);
1047: $parmhash{$prefix.'.'.&unescape($name)}=
1048: &unescape($value);
1049: $parmhash{$prefix.'.'.&unescape($name).'.type'}=
1050: &unescape($type);
1051: }
1052: }
1053: }
1054: # This loop only processes id entries in the big hash.
1055:
1056: foreach my $key (keys(%hash)) {
1057: if ($key=~/^ids/) {
1058: foreach my $resid (split(/\,/,$hash{$key})) {
1059: my $uri=$hash{'src_'.$resid};
1060: my ($uripath,$urifile) =
1061: &Apache::lonnet::split_uri_for_cond($uri);
1062: if ($uripath) {
1063: my $uricond='0';
1064: if (defined($hash{'conditions_'.$resid})) {
1065: $uricond=$captured{$hash{'conditions_'.$resid}};
1066: }
1067: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
1068: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
1069: /(\&\Q$urifile\E\:[^\&]*)/) {
1070: my $replace=$1;
1071: my $regexp=$replace;
1072: #$regexp=~s/\|/\\\|/g;
1073: $acchash{'acc.res.'.$short.'.'.$uripath} =~
1074: s/\Q$regexp\E/$replace\|$uricond/;
1075: } else {
1076: $acchash{'acc.res.'.$short.'.'.$uripath}.=
1077: $urifile.':'.$uricond.'&';
1078: }
1079: } else {
1080: $acchash{'acc.res.'.$short.'.'.$uripath}=
1081: '&'.$urifile.':'.$uricond.'&';
1082: }
1083: }
1084: }
1085: }
1086: }
1087: $acchash{'acc.res.'.$short.'.'}='&:0&';
1088: my $courseuri=$uri;
1089: $courseuri=~s/^\/res\///;
1090: my $regexp = 1;
1091: &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp);
1092: &Apache::lonnet::appenv(\%acchash);
1093: }
1094:
1095: # ---------------- Selectively delete from randompick maps and hidden url parms
1096:
1097: sub hiddenurls {
1098: my $randomoutentry='';
1099: foreach my $rid (keys(%randompick)) {
1100: my $rndpick=$randompick{$rid};
1101: my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
1102: # ------------------------------------------- put existing resources into array
1103: my @currentrids=();
1104: foreach my $key (sort(keys(%hash))) {
1105: if ($key=~/^src_($mpc\.\d+)/) {
1106: if ($hash{'src_'.$1}) { push @currentrids, $1; }
1107: }
1108: }
1109: # rids are number.number and we want to numercially sort on
1110: # the second number
1111: @currentrids=sort {
1112: my (undef,$aid)=split(/\./,$a);
1113: my (undef,$bid)=split(/\./,$b);
1114: $aid <=> $bid;
1115: } @currentrids;
1116: next if ($#currentrids<$rndpick);
1117: # -------------------------------- randomly eliminate the ones that should stay
1118: my (undef,$id)=split(/\./,$rid);
1119: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
1120: my $setcode;
1121: if (defined($randomizationcode{$rid})) {
1122: if ($env{'form.CODE'} eq '') {
1123: $env{'form.CODE'} = $randomizationcode{$rid};
1124: $setcode = 1;
1125: }
1126: }
1127: my $rndseed=&Apache::lonnet::rndseed($id); # use id instead of symb
1128: if ($setcode) {
1129: undef($env{'form.CODE'});
1130: undef($setcode);
1131: }
1132: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1133: my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
1134: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
1135: #&Apache::lonnet::logthis("$id,$rndseed,".join(':',@whichids));
1136: # -------------------------------------------------------- delete the leftovers
1137: for (my $k=0; $k<=$#currentrids; $k++) {
1138: if ($currentrids[$k]) {
1139: $hash{'randomout_'.$currentrids[$k]}=1;
1140: my ($mapid,$resid)=split(/\./,$currentrids[$k]);
1141: if ($rescount{$mapid}) {
1142: $rescount{$mapid} --;
1143: }
1144: if ($hash{'is_map_'.$currentrids[$k]}) {
1145: if ($mapcount{$mapid}) {
1146: $mapcount{$mapid} --;
1147: }
1148: }
1149: $randomoutentry.='&'.
1150: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
1151: $resid,
1152: $hash{'src_'.$currentrids[$k]}
1153: ).'&';
1154: }
1155: }
1156: }
1157: # ------------------------------ take care of explicitly hidden urls or folders
1158: foreach my $rid (keys(%hiddenurl)) {
1159: $hash{'randomout_'.$rid}=1;
1160: my ($mapid,$resid)=split(/\./,$rid);
1161: if ($rescount{$mapid}) {
1162: $rescount{$mapid} --;
1163: }
1164: if ($hash{'is_map_'.$rid}) {
1165: if ($mapcount{$mapid}) {
1166: $mapcount{$mapid} --;
1167: }
1168: }
1169: $randomoutentry.='&'.
1170: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,
1171: $hash{'src_'.$rid}).'&';
1172: }
1173: # --------------------------------------- append randomout entry to environment
1174: if ($randomoutentry) {
1175: &Apache::lonnet::appenv({'acc.randomout' => $randomoutentry});
1176: }
1177: }
1178:
1179: # -------------------------------------- populate big hash with map breadcrumbs
1180:
1181: # Create map_breadcrumbs_$pc from map_hierarchy_$pc by omitting intermediate
1182: # maps not shown in Course Contents table.
1183:
1184: sub mapcrumbs {
1185: foreach my $key (keys(%rescount)) {
1186: if ($hash{'map_hierarchy_'.$key}) {
1187: my $skipnext = 0;
1188: foreach my $id (split(/,/,$hash{'map_hierarchy_'.$key}),$key) {
1189: unless ($skipnext) {
1190: $hash{'map_breadcrumbs_'.$key} .= "$id,";
1191: }
1192: unless (($id == 0) || ($id == 1)) {
1193: if ((!$rescount{$id}) || ($rescount{$id} == 1 && $mapcount{$id} == 1)) {
1194: $skipnext = 1;
1195: } else {
1196: $skipnext = 0;
1197: }
1198: }
1199: }
1200: $hash{'map_breadcrumbs_'.$key} =~ s/,$//;
1201: }
1202: }
1203: }
1204:
1205: # ---------------------------------------------------- Read map and all submaps
1206:
1207: sub readmap {
1208: my $short=shift;
1209: $short=~s/^\///;
1210:
1211: # TODO: Hidden dependency on current user:
1212:
1213: my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
1214:
1215: my $fn=$cenv{'fn'};
1216: my $uri;
1217: $short=~s/\//\_/g;
1218: unless ($uri=$cenv{'url'}) {
1219: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1220: "Could not load course $short.</font>");
1221: return ('',&mt('No course data available.'));;
1222: }
1223: @cond=('true:normal');
1224:
1225: unless (open(LOCKFILE,">","$fn.db.lock")) {
1226: #
1227: # Most likely a permissions problem on the lockfile or its directory.
1228: #
1229: $retfurl = '';
1230: return ($retfurl,'<br />'.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.');
1231: }
1232: my $lock=0;
1233: my $gotstate=0;
1234:
1235: # If we can get the lock without delay any files there are idle
1236: # and from some prior request. We'll kill them off and regenerate them:
1237:
1238: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1239: $lock=1; # Remember that we hold the lock.
1240: &unlink_tmpfiles($fn);
1241: }
1242: undef %randompick;
1243: undef %randompickseed;
1244: undef %randomorder;
1245: undef %randomizationcode;
1246: undef %hiddenurl;
1247: undef %encurl;
1248: undef %deeplinkonly;
1249: undef %rescount;
1250: undef %mapcount;
1251: $retfrid='';
1252: $errtext='';
1253: my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags.
1254:
1255: # if we got the lock, regenerate course regnerate empty files and tie them.
1256:
1257: if ($lock) {
1258: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1259: $tiedhash = 1;
1260: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1261: $tiedparmhash = 1;
1262: $gotstate = &build_tmp_hashes($uri,
1263: $fn,
1264: $short,
1265: \%cenv); # TODO: Need to provide requested user@dom
1266: unless ($gotstate) {
1267: &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.</font>');
1268: }
1269: $untiedparmhash = untie(%parmhash);
1270: unless ($untiedparmhash) {
1271: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1272: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1273: }
1274: }
1275: $untiedhash = untie(%hash);
1276: unless ($untiedhash) {
1277: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1278: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1279: }
1280: }
1281: flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other
1282: # unlocked places the remainder happens..seems like if we
1283: # just kept the lock here the rest of the code would have
1284: # been much easier?
1285: }
1286: unless ($lock && $tiedhash && $tiedparmhash) {
1287: # if we are here it is likely because we are already trying to
1288: # initialize the course in another child, busy wait trying to
1289: # tie the hashes for the next 90 seconds, if we succeed forward
1290: # them on to navmaps, if we fail, throw up the Could not init
1291: # course screen
1292: #
1293: # RF: I'm not seeing the case where the ties/unties can fail in a way
1294: # that can be remedied by this. Since we owned the lock seems
1295: # Tie/untie failures are a result of something like a permissions problem instead?
1296: #
1297:
1298: # In any vent, undo what we did manage to do above first:
1299: if ($lock) {
1300: # Got the lock but not the DB files
1301: flock(LOCKFILE,LOCK_UN);
1302: $lock = 0;
1303: }
1304: if ($tiedhash) {
1305: unless($untiedhash) {
1306: untie(%hash);
1307: }
1308: }
1309: if ($tiedparmhash) {
1310: unless($untiedparmhash) {
1311: untie(%parmhash);
1312: }
1313: }
1314: # Log our failure:
1315:
1316: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1317: "Could not tie coursemap $fn for $uri.</font>");
1318: $tiedhash = '';
1319: $tiedparmhash = '';
1320: my $i=0;
1321:
1322: # Keep on retrying the lock for 90 sec until we succeed.
1323:
1324: while($i<90) {
1325: $i++;
1326: sleep(1);
1327: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1328:
1329: # Got the lock, tie the hashes...the assumption in this code is
1330: # that some other worker thread has created the db files quite recently
1331: # so no load is needed:
1332:
1333: $lock = 1;
1334: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
1335: $tiedhash = 1;
1336: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
1337: $tiedparmhash = 1;
1338: if (-e "$fn.state") {
1339: $retfurl='/adm/navmaps';
1340:
1341: # BUG BUG: Side effect!
1342: # Should conditionalize on something so that we can use this
1343: # to load maps for courses that are not current?
1344: #
1345: &Apache::lonnet::appenv({"request.course.id" => $short,
1346: "request.course.fn" => $fn,
1347: "request.course.uri" => $uri,
1348: "request.course.tied" => time});
1349:
1350: $untiedhash = untie(%hash);
1351: $untiedparmhash = untie(%parmhash);
1352: $gotstate = 1;
1353: last;
1354: }
1355: $untiedparmhash = untie(%parmhash);
1356: }
1357: $untiedhash = untie(%hash);
1358: }
1359: }
1360: }
1361: if ($lock) {
1362: flock(LOCKFILE,LOCK_UN);
1363: $lock = 0;
1364: if ($tiedparmhash) {
1365: unless ($untiedparmhash) {
1366: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1367: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1368: }
1369: }
1370: if ($tiedparmhash) {
1371: unless ($untiedhash) {
1372: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1373: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1374: }
1375: }
1376: }
1377: }
1378: # I think this branch of code is all about what happens if we just did the stuff above,
1379: # but found that the state file did not exist...again if we'd just held the lock
1380: # would that have made this logic simpler..as generating all the files would be
1381: # an atomic operation with respect to the lock.
1382: #
1383: unless ($gotstate) {
1384: $lock = 0;
1385: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1386: 'Could not read statemap '.$fn.' for '.$uri.'.</font>');
1387: &unlink_tmpfiles($fn);
1388: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1389: $lock=1;
1390: }
1391: undef %randompick;
1392: undef %randompickseed;
1393: undef %randomorder;
1394: undef %randomizationcode;
1395: undef %hiddenurl;
1396: undef %encurl;
1397: undef %deeplinkonly;
1398: undef %rescount;
1399: undef %mapcount;
1400: $errtext='';
1401: $retfrid='';
1402: #
1403: # Once more through the routine of tying and loading and so on.
1404: #
1405: if ($lock) {
1406: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1407: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1408: $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent?
1409: unless ($gotstate) {
1410: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1411: 'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.</font>');
1412: }
1413: unless (untie(%parmhash)) {
1414: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1415: 'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.</font>');
1416: }
1417: } else {
1418: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1419: 'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.</font>');
1420: }
1421: unless (untie(%hash)) {
1422: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1423: 'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1424: }
1425: } else {
1426: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1427: 'Could not tie coursemap '.$fn.'.db for '.$uri.'.</font>');
1428: }
1429: flock(LOCKFILE,LOCK_UN);
1430: $lock = 0;
1431: } else {
1432: # Failed to get the immediate lock.
1433:
1434: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1435: 'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1436: }
1437: }
1438: close(LOCKFILE);
1439: unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
1440: &Apache::lonmsg::author_res_msg($env{'request.course.uri'},
1441: $errtext); # TODO: User dependent?
1442: }
1443: # ------------------------------------------------- Check for critical messages
1444:
1445: # Depends on user must parameterize this as well..or separate as this is:
1446: # more part of determining what someone sees on entering a course?
1447:
1448: my @what=&Apache::lonnet::dump('critical',$env{'user.domain'},
1449: $env{'user.name'});
1450: if ($what[0]) {
1451: if (($what[0] ne 'con_lost') && ($what[0]!~/^error\:/)) {
1452: $retfurl='/adm/email?critical=display';
1453: }
1454: }
1455: return ($retfurl,$errtext);
1456: }
1457:
1458: #
1459: # This sub is called when the course hash and the param hash have been tied and
1460: # their lock file is held.
1461: # Parameters:
1462: # $uri - URI that identifies the course.
1463: # $fn - The base path/filename of the files that make up the context
1464: # being built.
1465: # $short - Short course name.
1466: # $cenvref - Reference to the course environment hash returned by
1467: # Apache::lonnet::coursedescription
1468: #
1469: # Assumptions:
1470: # The globals
1471: # %hash, %paramhash are tied to their gdbm files and we hold the lock on them.
1472: #
1473: sub build_tmp_hashes {
1474: my ($uri,$fn,$short,$cenvref) = @_;
1475:
1476: unless(ref($cenvref) eq 'HASH') {
1477: return;
1478: }
1479: my %cenv = %{$cenvref};
1480: my $gotstate = 0;
1481: %hash=(); # empty the global course and parameter hashes.
1482: %parmhash=();
1483: $errtext=''; # No error messages yet.
1484: $pc=0;
1485: &clear_mapalias_count();
1486: &processversionfile(%cenv);
1487:
1488: # URI Of the map file.
1489:
1490: my $furi=&Apache::lonnet::clutter($uri);
1491: #
1492: # the map staring points.
1493: #
1494: $hash{'src_0.0'}=&versiontrack($furi);
1495: $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
1496: $hash{'ids_'.$furi}='0.0';
1497: $hash{'is_map_0.0'}=1;
1498:
1499: # Load the map.. note that loadmap may implicitly recurse if the map contains
1500: # sub-maps.
1501:
1502:
1503: &loadmap($uri,'0.0',$short);
1504:
1505: # The code below only executes if there is a starting point for the map>
1506: # Q/BUG??? If there is no start resource for the map should that be an error?
1507: #
1508:
1509: if (defined($hash{'map_start_'.$uri})) {
1510: &Apache::lonnet::appenv({"request.course.id" => $short,
1511: "request.course.fn" => $fn,
1512: "request.course.uri" => $uri,
1513: "request.course.tied" => time});
1514: $env{'request.course.id'}=$short;
1515: &traceroute('0',$hash{'map_start_'.$uri},'&');
1516: &accinit($uri,$short,$fn);
1517: &hiddenurls();
1518: &mapcrumbs();
1519: }
1520: $errtext .= &get_mapalias_errors();
1521: # ------------------------------------------------------- Put versions into src
1522: foreach my $key (keys(%hash)) {
1523: if ($key=~/^src_/) {
1524: $hash{$key}=&putinversion($hash{$key});
1525: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
1526: my ($type, $url) = ($1,$2);
1527: my $value = $hash{$key};
1528: $hash{$type.&putinversion($url)}=$value;
1529: }
1530: }
1531: # ---------------------------------------------------------------- Encrypt URLs
1532: foreach my $id (keys(%encurl)) {
1533: # $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
1534: $hash{'encrypted_'.$id}=1;
1535: }
1536: # ------------------------------------------------------------ Deep-linked URLs
1537: foreach my $id (keys(%deeplinkonly)) {
1538: $hash{'deeplinkonly_'.$id}=$deeplinkonly{$id};
1539: }
1540: # ----------------------------------------------- Close hashes to finally store
1541: # --------------------------------- Routine must pass this point, no early outs
1542: $hash{'first_rid'}=$retfrid;
1543: my ($mapid,$resid)=split(/\./,$retfrid);
1544: $hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
1545: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
1546: $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
1547: if ($hash{'encrypted_'.$retfrid}) {
1548: $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
1549: }
1550: $hash{'first_url'}=$retfurl;
1551: # ---------------------------------------------------- Store away initial state
1552: {
1553: my $cfh;
1554: if (open($cfh,">","$fn.state")) {
1555: print $cfh join("\n",@cond);
1556: $gotstate = 1;
1557: } else {
1558: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1559: "Could not write statemap $fn for $uri.</font>");
1560: }
1561: }
1562: return $gotstate;
1563: }
1564:
1565: sub unlink_tmpfiles {
1566: my ($fn) = @_;
1567: my $file_dir = dirname($fn);
1568:
1569: if ("$file_dir/" eq LONCAPA::tempdir()) {
1570: my @files = qw (.db _symb.db .state _parms.db);
1571: foreach my $file (@files) {
1572: if (-e $fn.$file) {
1573: unless (unlink($fn.$file)) {
1574: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1575: "Could not unlink ".$fn.$file."</font>");
1576: }
1577: }
1578: }
1579: }
1580: return;
1581: }
1582:
1583: # ------------------------------------------------------- Evaluate state string
1584:
1585: sub evalstate {
1586: my $fn=$env{'request.course.fn'}.'.state';
1587: my $state='';
1588: if (-e $fn) {
1589: my @conditions=();
1590: {
1591: open(my $fh,"<",$fn);
1592: @conditions=<$fh>;
1593: close($fh);
1594: }
1595: my $safeeval = new Safe;
1596: my $safehole = new Safe::Hole;
1597: $safeeval->permit("entereval");
1598: $safeeval->permit(":base_math");
1599: $safeeval->deny(":base_io");
1600: $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
1601: foreach my $line (@conditions) {
1602: chomp($line);
1603: my ($condition,$weight)=split(/\:/,$line);
1604: if ($safeeval->reval($condition)) {
1605: if ($weight eq 'force') {
1606: $state.='3';
1607: } else {
1608: $state.='2';
1609: }
1610: } else {
1611: if ($weight eq 'stop') {
1612: $state.='0';
1613: } else {
1614: $state.='1';
1615: }
1616: }
1617: }
1618: }
1619: &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state});
1620: return $state;
1621: }
1622:
1623: # This block seems to have code to manage/detect doubly defined
1624: # aliases in maps.
1625:
1626: {
1627: my %mapalias_cache;
1628: sub count_mapalias {
1629: my ($value,$resid) = @_;
1630: push(@{ $mapalias_cache{$value} }, $resid);
1631: }
1632:
1633: sub get_mapalias_errors {
1634: my $error_text;
1635: foreach my $mapalias (sort(keys(%mapalias_cache))) {
1636: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
1637: my $count;
1638: my $which =
1639: join('</li><li>',
1640: map {
1641: my $id = $_;
1642: if (exists($hash{'src_'.$id})) {
1643: $count++;
1644: }
1645: my ($mapid) = split(/\./,$id);
1646: &mt('Resource [_1][_2]in Map [_3]',
1647: $hash{'title_'.$id},'<br />',
1648: $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}});
1649: } (@{ $mapalias_cache{$mapalias} }));
1650: next if ($count < 2);
1651: $error_text .= '<div class="LC_error">'.
1652: &mt('Error: Found the mapalias "[_1]" defined multiple times.',
1653: $mapalias).
1654: '</div><ul><li>'.$which.'</li></ul>';
1655: }
1656: &clear_mapalias_count();
1657: return $error_text;
1658: }
1659: sub clear_mapalias_count {
1660: undef(%mapalias_cache);
1661: }
1662: }
1663: 1;
1664: __END__
1665:
1666: =head1 NAME
1667:
1668: Apache::lonuserstate - Construct and maintain state and binary representation
1669: of course for user
1670:
1671: =head1 SYNOPSIS
1672:
1673: Invoked by lonroles.pm.
1674:
1675: &Apache::lonuserstate::readmap($cdom.'/'.$cnum);
1676:
1677: =head1 INTRODUCTION
1678:
1679: This module constructs and maintains state and binary representation
1680: of course for user.
1681:
1682: This is part of the LearningOnline Network with CAPA project
1683: described at http://www.lon-capa.org.
1684:
1685: =head1 SUBROUTINES
1686:
1687: =over
1688:
1689: =item loadmap()
1690:
1691: Loads map from disk
1692:
1693: =item simplify()
1694:
1695: Simplify expression
1696:
1697: =item traceroute()
1698:
1699: Build condition hash
1700:
1701: =item accinit()
1702:
1703: Cascading conditions, quick access, parameters
1704:
1705: =item readmap()
1706:
1707: Read map and all submaps
1708:
1709: =item evalstate()
1710:
1711: Evaluate state string
1712:
1713: =back
1714:
1715: =cut
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