Annotation of rat/lonuserstate.pm, revision 1.141
1.1 www 1: # The LearningOnline Network with CAPA
2: # Construct and maintain state and binary representation of course for user
3: #
1.141 ! raeburn 4: # $Id: lonuserstate.pm,v 1.140 2011/08/09 09:15:50 foxr Exp $
1.25 www 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: #
1.26 harris41 28: ###
1.1 www 29:
30: package Apache::lonuserstate;
31:
1.26 harris41 32: # ------------------------------------------------- modules used by this module
1.1 www 33: use strict;
34: use HTML::TokeParser;
1.89 albertel 35: use Apache::lonnet;
1.114 www 36: use Apache::lonlocal;
1.26 harris41 37: use Apache::loncommon();
1.1 www 38: use GDBM_File;
1.12 www 39: use Apache::lonmsg;
1.15 www 40: use Safe;
1.21 www 41: use Safe::Hole;
1.15 www 42: use Opcode;
1.73 www 43: use Apache::lonenc;
1.96 albertel 44: use Fcntl qw(:flock);
1.114 www 45: use LONCAPA;
1.138 foxr 46: use File::Basename;
47:
1.114 www 48:
1.15 www 49:
1.1 www 50: # ---------------------------------------------------- Globals for this package
51:
1.138 foxr 52: my $pc; # Package counter is this what 'Guts' calls the map counter?
1.1 www 53: my %hash; # The big tied hash
1.19 www 54: my %parmhash;# The hash with the parameters
1.1 www 55: my @cond; # Array with all of the conditions
56: my $errtext; # variable with all errors
1.116 www 57: my $retfrid; # variable with the very first RID in the course
58: my $retfurl; # first URL
1.29 www 59: my %randompick; # randomly picked resources
1.51 www 60: my %randompickseed; # optional seed for randomly picking resources
1.124 albertel 61: my %randomorder; # maps to order contents randomly
1.73 www 62: my %encurl; # URLs in this folder are supposed to be encrypted
63: my %hiddenurl; # this URL (or complete folder) is supposed to be hidden
1.61 www 64:
65: # ----------------------------------- Remove version from URL and store in hash
66:
1.134 www 67: sub versionerror {
68: my ($uri,$usedversion,$unusedversion)=@_;
69: return '<br />'.&mt('Version discrepancy: resource [_1] included in both version [_2] and version [_3]. Using version [_2].',
70: $uri,$usedversion,$unusedversion).'<br />';
71: }
72:
1.139 foxr 73: # Removes the version number from a URI and returns the resulting
74: # URI (e.g. mumbly.version.stuff => mumbly.stuff).
75: #
76: # If the URI has not been seen with a versio before the
77: # hash{'version_'.resultingURI} is set to the version number.
78: # If the URI has been seen and the version does not match and error
79: # is added to the error string.
80: #
81: # Parameters:
82: # URI potentially with a version.
83: # Returns:
84: # URI with the version cut out.
85: # See above for side effects.
86: #
87:
1.61 www 88: sub versiontrack {
89: my $uri=shift;
90: if ($uri=~/\.(\d+)\.\w+$/) {
91: my $version=$1;
92: $uri=~s/\.\d+\.(\w+)$/\.$1/;
1.62 www 93: unless ($hash{'version_'.$uri}) {
94: $hash{'version_'.$uri}=$version;
1.134 www 95: } elsif ($version!=$hash{'version_'.$uri}) {
96: $errtext.=&versionerror($uri,$hash{'version_'.$uri},$version);
97: }
1.61 www 98: }
99: return $uri;
100: }
101:
102: # -------------------------------------------------------------- Put in version
103:
104: sub putinversion {
105: my $uri=shift;
1.93 www 106: my $key=$env{'request.course.id'}.'_'.&Apache::lonnet::clutter($uri);
1.61 www 107: if ($hash{'version_'.$uri}) {
108: my $version=$hash{'version_'.$uri};
1.65 www 109: if ($version eq 'mostrecent') { return $uri; }
1.66 www 110: if ($version eq &Apache::lonnet::getversion(
111: &Apache::lonnet::filelocation('',$uri)))
112: { return $uri; }
1.61 www 113: $uri=~s/\.(\w+)$/\.$version\.$1/;
114: }
1.93 www 115: &Apache::lonnet::do_cache_new('courseresversion',$key,&Apache::lonnet::declutter($uri),600);
1.61 www 116: return $uri;
117: }
118:
119: # ----------------------------------------- Processing versions file for course
120:
121: sub processversionfile {
1.64 www 122: my %cenv=@_;
1.61 www 123: my %versions=&Apache::lonnet::dump('resourceversions',
124: $cenv{'domain'},
125: $cenv{'num'});
1.106 albertel 126: foreach my $ver (keys(%versions)) {
127: if ($ver=~/^error\:/) { return; }
128: $hash{'version_'.$ver}=$versions{$ver};
1.61 www 129: }
130: }
1.45 www 131:
1.138 foxr 132: # --------------------------------------------------------- Loads from disk
1.1 www 133:
1.140 foxr 134:
135: #
136: # Loads a map file.
137: # Note that this may implicitly recurse via parse_resource if one of the resources
138: # is itself composed.
139: #
140: # Parameters:
141: # uri - URI of the map file.
142: # parent_rid - Resource id in the map of the parent resource (0.0 for the top level map)
143: #
144: #
1.1 www 145: sub loadmap {
1.124 albertel 146: my ($uri,$parent_rid)=@_;
1.138 foxr 147:
148: # Is the map already included?
149:
1.114 www 150: if ($hash{'map_pc_'.$uri}) {
1.120 albertel 151: $errtext.='<p class="LC_error">'.
152: &mt('Multiple use of sequence/page [_1]! The course will not function properly.','<tt>'.$uri.'</tt>').
153: '</p>';
1.114 www 154: return;
155: }
1.138 foxr 156: # Register the resource in it's map_pc_ [for the URL]
157: # map_id.nnn is the nesting level -> to the URI.
158:
1.1 www 159: $pc++;
160: my $lpc=$pc;
161: $hash{'map_pc_'.$uri}=$lpc;
162: $hash{'map_id_'.$lpc}=$uri;
1.138 foxr 163:
164: # If the parent is of the form n.m hang this map underneath it in the
165: # map hierarchy.
166:
1.136 raeburn 167: if ($parent_rid =~ /^(\d+)\.\d+$/) {
168: my $parent_pc = $1;
169: if (defined($hash{'map_hierarchy_'.$parent_pc})) {
170: $hash{'map_hierarchy_'.$lpc}=$hash{'map_hierarchy_'.$parent_pc}.','.
171: $parent_pc;
172: } else {
173: $hash{'map_hierarchy_'.$lpc}=$parent_pc;
174: }
175: }
1.1 www 176:
1.138 foxr 177: # Determine and check filename of the sequence we need to read:
178:
1.62 www 179: my $fn=&Apache::lonnet::filelocation('',&putinversion($uri));
1.37 www 180:
181: my $ispage=($fn=~/\.page$/);
1.1 www 182:
1.138 foxr 183: # We can only nest sequences or pages. Anything else is an illegal nest.
184:
185: unless (($fn=~/\.sequence$/) || $ispage) {
1.114 www 186: $errtext.=&mt("<br />Invalid map: <tt>[_1]</tt>",$fn);
1.98 albertel 187: return;
1.1 www 188: }
189:
1.138 foxr 190: # Read the XML that constitutes the file.
191:
1.37 www 192: my $instr=&Apache::lonnet::getfile($fn);
193:
1.124 albertel 194: if ($instr eq -1) {
195: $errtext.=&mt('<br />Map not loaded: The file <tt>[_1]</tt> does not exist.',$fn);
196: return;
197: }
1.22 www 198:
1.138 foxr 199: # Successfully got file, parse it
200:
201: # parse for parameter processing.
202: # Note that these are <param... / > tags
203: # so we only care about 'S' (tag start) nodes.
204:
1.1 www 205:
1.124 albertel 206: my $parser = HTML::TokeParser->new(\$instr);
207: $parser->attr_encoded(1);
1.138 foxr 208:
1.124 albertel 209: # first get all parameters
1.138 foxr 210:
211:
1.124 albertel 212: while (my $token = $parser->get_token) {
213: next if ($token->[0] ne 'S');
214: if ($token->[1] eq 'param') {
215: &parse_param($token,$lpc);
216: }
217: }
1.138 foxr 218:
219: # Get set to take another pass through the XML:
220: # for resources and links.
221:
1.124 albertel 222: $parser = HTML::TokeParser->new(\$instr);
223: $parser->attr_encoded(1);
1.1 www 224:
1.124 albertel 225: my $linkpc=0;
1.1 www 226:
1.124 albertel 227: $fn=~/\.(\w+)$/;
1.1 www 228:
1.124 albertel 229: $hash{'map_type_'.$lpc}=$1;
1.1 www 230:
1.124 albertel 231: my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i);
1.1 www 232:
1.138 foxr 233: # Parse the resources, link and condition tags.
234: # Note that if randomorder or random select is chosen the links and
235: # conditions are meaningless but are determined by the randomization.
236: # This is handled in the next chunk of code.
237:
1.124 albertel 238: my @map_ids;
239: while (my $token = $parser->get_token) {
240: next if ($token->[0] ne 'S');
1.138 foxr 241:
242: # Resource
243:
1.124 albertel 244: if ($token->[1] eq 'resource') {
1.138 foxr 245: my $resource_id = &parse_resource($token,$lpc,$ispage,$uri);
246: if (defined $resource_id) {
1.139 foxr 247: push(@map_ids, $resource_id);
1.138 foxr 248: }
249:
250: # Link
251:
1.124 albertel 252: } elsif ($token->[1] eq 'link' && !$randomize) {
253: &make_link(++$linkpc,$lpc,$token->[2]->{'to'},
254: $token->[2]->{'from'},
1.139 foxr 255: $token->[2]->{'condition'}); # note ..condition may be undefined.
1.138 foxr 256:
257: # condition
258:
1.124 albertel 259: } elsif ($token->[1] eq 'condition' && !$randomize) {
260: &parse_condition($token,$lpc);
261: }
262: }
1.1 www 263:
1.138 foxr 264:
265: # Handle randomization and random selection
266:
1.124 albertel 267: if ($randomize) {
268: if (!$env{'request.role.adv'}) {
269: my $seed;
1.139 foxr 270:
271: # In the advanced role, the map's random seed
272: # parameter is used as the basis for computing the
273: # seed ... if it has been specified:
274:
1.124 albertel 275: if (defined($randompickseed{$parent_rid})) {
276: $seed = $randompickseed{$parent_rid};
277: } else {
1.139 foxr 278:
279: # Otherwise the parent's fully encoded symb is used.
280:
1.124 albertel 281: my ($mapid,$resid)=split(/\./,$parent_rid);
282: my $symb=
283: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
284: $resid,$hash{'src_'.$parent_rid});
1.85 albertel 285:
1.124 albertel 286: $seed = $symb;
287: }
1.138 foxr 288:
1.139 foxr 289: # TODO: Here for sure we need to pass along the username/domain
1.138 foxr 290: # so that we can impersonate users in lonprintout e.g.
291:
1.124 albertel 292: my $rndseed=&Apache::lonnet::rndseed($seed);
293: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1.140 foxr 294:
295: # Take the set of map ids we have decoded and permute them to a
296: # random order based on the seed set above. All of this is
297: # processing the randomorder parameter if it is set, not
298: # randompick.
299:
300: @map_ids=&math::Random::random_permutation(@map_ids);
1.124 albertel 301: }
1.139 foxr 302:
303:
1.124 albertel 304: my $from = shift(@map_ids);
305: my $from_rid = $lpc.'.'.$from;
306: $hash{'map_start_'.$uri} = $from_rid;
307: $hash{'type_'.$from_rid}='start';
308:
1.140 foxr 309: # Create links to reflect the random re-ordering done above.
310: # In the code to process the map XML, we did not process links or conditions
311: # if randomorder was set. This means that for an instructor to choose
1.139 foxr 312:
1.124 albertel 313: while (my $to = shift(@map_ids)) {
314: &make_link(++$linkpc,$lpc,$to,$from);
315: my $to_rid = $lpc.'.'.$to;
316: $hash{'type_'.$to_rid}='normal';
317: $from = $to;
318: $from_rid = $to_rid;
319: }
1.1 www 320:
1.124 albertel 321: $hash{'map_finish_'.$uri}= $from_rid;
322: $hash{'type_'.$from_rid}='finish';
1.1 www 323: }
1.121 albertel 324:
1.127 albertel 325: $parser = HTML::TokeParser->new(\$instr);
1.121 albertel 326: $parser->attr_encoded(1);
1.139 foxr 327:
1.140 foxr 328: # last parse out the mapalias params. Thes provide mnemonic
329: # tags to resources that can be used in conditions
1.139 foxr 330:
1.121 albertel 331: while (my $token = $parser->get_token) {
332: next if ($token->[0] ne 'S');
333: if ($token->[1] eq 'param') {
334: &parse_mapalias_param($token,$lpc);
335: }
336: }
337: }
338:
1.124 albertel 339:
340: # -------------------------------------------------------------------- Resource
1.138 foxr 341: #
342: # Parses a resource tag to produce the value to push into the
343: # map_ids array.
344: #
345: #
346: # Information about the actual type of resource is provided by the file extension
347: # of the uri (e.g. .problem, .sequence etc. etc.).
348: #
349: # Parameters:
350: # $token - A token from HTML::TokeParser
351: # This is an array that describes the most recently parsed HTML item.
352: # $lpc - Map nesting level (?)
353: # $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
354: # $uri - URI of the enclosing resource.
355: # Returns:
1.139 foxr 356: # Value of the id attribute of the tag.
1.138 foxr 357: #
358: # Note:
359: # The token is an array that contains the following elements:
360: # [0] => 'S' indicating this is a start token
361: # [1] => 'resource' indicating this tag is a <resource> tag.
362: # [2] => Hash of attribute =>value pairs.
363: # [3] => @(keys [2]).
364: # [4] => unused.
365: #
366: # The attributes of the resourcde tag include:
367: #
368: # id - The resource id.
369: # src - The URI of the resource.
370: # type - The resource type (e.g. start and finish).
371: # title - The resource title.
372:
373:
1.124 albertel 374: sub parse_resource {
375: my ($token,$lpc,$ispage,$uri) = @_;
1.138 foxr 376:
1.139 foxr 377: # I refuse to countenance code like this that has
1.138 foxr 378: # such a dirty side effect (and forcing this sub to be called within a loop).
379: #
380: # if ($token->[2]->{'type'} eq 'zombie') { next; }
1.139 foxr 381: #
382: # The original code both returns _and_ skips to the next pass of the >caller's<
383: # loop, that's just dirty.
384: #
1.138 foxr 385:
386: # Zombie resources don't produce anything useful.
387:
388: if ($token->[2]->{'type'} eq 'zombie') {
389: return undef;
390: }
391:
1.139 foxr 392: my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
393:
394: # Save the hash element type and title:
1.124 albertel 395:
396: $hash{'kind_'.$rid}='res';
397: $hash{'title_'.$rid}=$token->[2]->{'title'};
1.139 foxr 398:
399: # Get the version free URI for the resource.
400: # If a 'version' attribute was supplied, and this resource's version
401: # information has not yet been stored, store it.
402: #
403:
1.124 albertel 404: my $turi=&versiontrack($token->[2]->{'src'});
405: if ($token->[2]->{'version'}) {
406: unless ($hash{'version_'.$turi}) {
407: $hash{'version_'.$turi}=$1;
408: }
409: }
1.139 foxr 410: # Pull out the title and do entity substitution on &colon
411: # Q: Why no other entity substitutions?
412:
1.124 albertel 413: my $title=$token->[2]->{'title'};
414: $title=~s/\&colon\;/\:/gs;
1.139 foxr 415:
416:
417:
418: # I think the point of all this code is to construct a final
419: # URI that apache and its rewrite rules can use to
420: # fetch the resource. Thi s sonly necessary if the resource
421: # is not a page. If the resource is a page then it must be
422: # assembled (at fetch time?).
423:
1.124 albertel 424: unless ($ispage) {
425: $turi=~/\.(\w+)$/;
426: my $embstyle=&Apache::loncommon::fileembstyle($1);
427: if ($token->[2]->{'external'} eq 'true') { # external
1.130 raeburn 428: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
1.124 albertel 429: } elsif ($turi=~/^\/*uploaded\//) { # uploaded
430: if (($embstyle eq 'img')
431: || ($embstyle eq 'emb')
432: || ($embstyle eq 'wrp')) {
433: $turi='/adm/wrapper'.$turi;
434: } elsif ($embstyle eq 'ssi') {
435: #do nothing with these
436: } elsif ($turi!~/\.(sequence|page)$/) {
437: $turi='/adm/coursedocs/showdoc'.$turi;
438: }
439: } elsif ($turi=~/\S/) { # normal non-empty internal resource
440: my $mapdir=$uri;
441: $mapdir=~s/[^\/]+$//;
442: $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
443: if (($embstyle eq 'img')
444: || ($embstyle eq 'emb')
445: || ($embstyle eq 'wrp')) {
446: $turi='/adm/wrapper'.$turi;
447: }
448: }
449: }
1.139 foxr 450: # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
451: # If the URI appears more than one time in the sequence, it's resourcde
452: # id's are constructed as a comma spearated list.
453:
1.124 albertel 454: my $idsuri=$turi;
455: $idsuri=~s/\?.+$//;
456: if (defined($hash{'ids_'.$idsuri})) {
457: $hash{'ids_'.$idsuri}.=','.$rid;
458: } else {
459: $hash{'ids_'.$idsuri}=''.$rid;
460: }
461:
1.139 foxr 462:
463:
1.135 raeburn 464: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
1.124 albertel 465: $turi.='?register=1';
466: }
467:
1.139 foxr 468:
469: # resource id lookup: 'src'_resourc-di => URI decorated with a query
470: # parameter as above if necessary due to the resource type.
471:
1.124 albertel 472: $hash{'src_'.$rid}=$turi;
1.139 foxr 473:
474: # Mark the external-ness of the resource:
1.124 albertel 475:
476: if ($token->[2]->{'external'} eq 'true') {
477: $hash{'ext_'.$rid}='true:';
478: } else {
479: $hash{'ext_'.$rid}='false:';
480: }
1.139 foxr 481:
482: # If the resource is a start/finish resource set those
483: # entries in the has so that navigation knows where everything starts.
484: # TODO? If there is a malformed sequence that has no start or no finish
485: # resource, should this be detected and errors thrown? How would such a
486: # resource come into being other than being manually constructed by a person
487: # and then uploaded? Could that happen if an author decided a sequence was almost
488: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
489: # start or finish resources?
490: #
491: # All resourcess also get a type_id => (start | finish | normal) hash entr.
492: #
1.124 albertel 493: if ($token->[2]->{'type'}) {
494: $hash{'type_'.$rid}=$token->[2]->{'type'};
495: if ($token->[2]->{'type'} eq 'start') {
496: $hash{'map_start_'.$uri}="$rid";
497: }
498: if ($token->[2]->{'type'} eq 'finish') {
499: $hash{'map_finish_'.$uri}="$rid";
500: }
501: } else {
502: $hash{'type_'.$rid}='normal';
503: }
1.139 foxr 504:
505: # Sequences end pages are constructed entities. They require that the
506: # map that defines _them_ be loaded as well into the hash...with this resourcde
507: # as the base of the nesting.
508: # Resources like that are also marked with is_map_id => 1 entries.
509: #
1.124 albertel 510:
511: if (($turi=~/\.sequence$/) ||
512: ($turi=~/\.page$/)) {
513: $hash{'is_map_'.$rid}=1;
514: &loadmap($turi,$rid);
515: }
516: return $token->[2]->{'id'};
517: }
518:
1.139 foxr 519: #-------------------------------------------------------------------- link
520: # Links define how you are allowed to move from one resource to another.
521: # They are the transition edges in the directed graph that a map is.
522: # This sub takes informatino from a <link> tag and constructs the
523: # navigation bits and pieces of a map. There is no requirement that the
524: # resources that are linke are already defined, however clearly the map is
525: # badly broken if they are not _eventually_ defined.
526: #
527: # Note that links can be unconditional or conditional.
528: #
529: # Parameters:
530: # linkpc - The link counter for this level of map nesting (this is
531: # reset to zero by loadmap prior to starting to process
532: # links for map).
533: # lpc - The map level ocounter (how deeply nested this map is in
534: # the hierarchy of maps that are recursively read in.
535: # to - resource id (within the XML) of the target of the edge.
536: # from - resource id (within the XML) of the source of the edge.
537: # condition- id of condition associated with the edge (also within the XML).
538: #
539:
1.124 albertel 540: sub make_link {
541: my ($linkpc,$lpc,$to,$from,$condition) = @_;
542:
1.139 foxr 543: # Compute fully qualified ids for the link, the
544: # and from/to by prepending lpc.
545: #
546:
1.124 albertel 547: my $linkid=$lpc.'.'.$linkpc;
548: my $goesto=$lpc.'.'.$to;
549: my $comesfrom=$lpc.'.'.$from;
550: my $undercond=0;
551:
1.139 foxr 552:
553: # If there is a condition, qualify it with the level counter.
554:
1.124 albertel 555: if ($condition) {
556: $undercond=$lpc.'.'.$condition;
557: }
558:
1.139 foxr 559: # Links are represnted by:
560: # goesto_.fuullyqualifedlinkid => fully qualified to
561: # comesfrom.fullyqualifiedlinkid => fully qualified from
562: # undercond_.fullyqualifiedlinkid => fully qualified condition id.
563:
1.124 albertel 564: $hash{'goesto_'.$linkid}=$goesto;
565: $hash{'comesfrom_'.$linkid}=$comesfrom;
566: $hash{'undercond_'.$linkid}=$undercond;
567:
1.139 foxr 568: # In addition:
569: # to_.fully qualified from => comma separated list of
570: # link ids with that from.
571: # Similarly:
572: # from_.fully qualified to => comma separated list of link ids`
573: # with that to.
574: # That allows us given a resource id to know all edges that go to it
575: # and leave from it.
576: #
577:
1.124 albertel 578: if (defined($hash{'to_'.$comesfrom})) {
579: $hash{'to_'.$comesfrom}.=','.$linkid;
580: } else {
581: $hash{'to_'.$comesfrom}=''.$linkid;
582: }
583: if (defined($hash{'from_'.$goesto})) {
584: $hash{'from_'.$goesto}.=','.$linkid;
585: } else {
586: $hash{'from_'.$goesto}=''.$linkid;
587: }
588: }
589:
590: # ------------------------------------------------------------------- Condition
1.139 foxr 591: #
592: # Processes <condition> tags, storing sufficient information about them
593: # in the hash so that they can be evaluated and used to conditionalize
594: # what is presented to the student.
595: #
596: # these can have the following attributes
597: #
598: # id = A unique identifier of the condition within the map.
599: #
600: # value = Is a perl script-let that, when evaluated in safe space
601: # determines whether or not the condition is true.
602: # Normally this takes the form of a test on an Apache::lonnet::EXT call
603: # to find the value of variable associated with a resource in the
604: # map identified by a mapalias.
605: # Here's a fragment of XML code that illustrates this:
606: #
607: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
608: # <resource src="" id="1" type="start" title="Start" />
609: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" />
610: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
611: # <2 " id="61" type="stop" />
612: # <link to="5" index="1" from="1" condition="61" />
613: #
614: # In this fragment:
615: # - The param tag establishes an alias to resource id 5 of 'mainproblem'.
616: # - The resource that is the start of the map is identified.
617: # - The resource tag identifies the resource associated with this tag
618: # and gives it the id 5.
619: # - The condition is true if the tries variable associated with mainproblem
620: # is less than 2 (that is the user has had more than 2 tries).
621: # The condition type is a stop condition which inhibits(?) the associated
622: # link if the condition is false.
623: # - The link to resource 5 from resource 1 is affected by this condition.
624: #
625: # type = Type of the condition. The type determines how the condition affects the
626: # link associated with it and is one of
627: # - 'force'
628: # - 'stop'
629: # anything else including not supplied..which treated as:
630: # - 'normal'.
631: # Presumably maps get created by the resource assembly tool and therefore
632: # illegal type values won't squirm their way into the XML.
633: #
634: # Side effects:
635: # - The kind_level-qualified-condition-id hash element is set to 'cond'.
636: # - The condition text is pushed into the cond array and its element number is
637: # set in the condid_level-qualified-condition-id element of the hash.
638: # - The condition type is colon appneded to the cond array element for this condition.
1.124 albertel 639: sub parse_condition {
640: my ($token,$lpc) = @_;
641: my $rid=$lpc.'.'.$token->[2]->{'id'};
642:
643: $hash{'kind_'.$rid}='cond';
644:
645: my $condition = $token->[2]->{'value'};
646: $condition =~ s/[\n\r]+/ /gs;
647: push(@cond, $condition);
648: $hash{'condid_'.$rid}=$#cond;
649: if ($token->[2]->{'type'}) {
650: $cond[$#cond].=':'.$token->[2]->{'type'};
651: } else {
652: $cond[$#cond].=':normal';
653: }
654: }
655:
656: # ------------------------------------------------------------------- Parameter
1.138 foxr 657: # Parse a <parameter> tag in the map.
658: # Parmameters:
659: # $token Token array for a start tag from HTML::TokeParser
660: # [0] = 'S'
661: # [1] = tagname ("param")
662: # [2] = Hash of {attribute} = values.
663: # [3] = Array of the keys in [2].
664: # [4] = unused.
665: # $lpc Current map nesting level.a
666: #
667: # Typical attributes:
668: # to=n - Number of the resource the parameter applies to.
669: # type=xx - Type of parameter value (e.g. string_yesno or int_pos).
670: # name=xxx - Name ofr parameter (e.g. parameter_randompick or parameter_randomorder).
671: # value=xxx - value of the parameter.
1.124 albertel 672:
673: sub parse_param {
674: my ($token,$lpc) = @_;
1.138 foxr 675: my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to.
676: my $name=$token->[2]->{'name'}; # Name of parameter
1.124 albertel 677: my $part;
1.138 foxr 678:
679:
680: if ($name=~/^parameter_(.*)_/) {
1.124 albertel 681: $part=$1;
682: } else {
683: $part=0;
684: }
1.138 foxr 685:
686: # Peel the parameter_ off the parameter name.
687:
1.124 albertel 688: $name=~s/^.*_([^_]*)$/$1/;
1.138 foxr 689:
690: # The value is:
691: # type.part.name.value
692:
1.124 albertel 693: my $newparam=
694: &escape($token->[2]->{'type'}).':'.
695: &escape($part.'.'.$name).'='.
696: &escape($token->[2]->{'value'});
1.138 foxr 697:
698: # The hash key is param_resourceid.
699: # Multiple parameters for a single resource are & separated in the hash.
700:
701:
1.124 albertel 702: if (defined($hash{'param_'.$referid})) {
703: $hash{'param_'.$referid}.='&'.$newparam;
704: } else {
705: $hash{'param_'.$referid}=''.$newparam;
706: }
1.138 foxr 707: #
708: # These parameters have to do with randomly selecting
709: # resources, therefore a separate hash is also created to
710: # make it easy to locate them when actually computing the resource set later on
711: # See the code conditionalized by ($randomize) in loadmap().
712:
713: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
1.124 albertel 714: $randompick{$referid}=$token->[2]->{'value'};
715: }
1.138 foxr 716: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
1.124 albertel 717: $randompickseed{$referid}=$token->[2]->{'value'};
718: }
1.138 foxr 719: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
1.124 albertel 720: $randomorder{$referid}=$token->[2]->{'value'};
721: }
1.138 foxr 722:
723: # These parameters have to do with how the URLs of resources are presented to
724: # course members(?). encrypturl presents encypted url's while
725: # hiddenresource hides the URL.
726: #
727:
1.124 albertel 728: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
729: if ($token->[2]->{'value'}=~/^yes$/i) {
730: $encurl{$referid}=1;
731: }
732: }
733: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
734: if ($token->[2]->{'value'}=~/^yes$/i) {
735: $hiddenurl{$referid}=1;
736: }
737: }
738: }
1.140 foxr 739: #
740: # Parse mapalias parameters.
741: # these are tags of the form:
742: # <param to="nn"
743: # value="some-alias-for-resourceid-nn"
744: # name="parameter_0_mapalias"
745: # type="string" />
746: # A map alias is a textual name for a resource:
747: # - The to attribute identifies the resource (this gets level qualified below)
748: # - The value attributes provides the alias string.
749: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/
750: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings
751: # terminating with the string 'mapalias'.
752: # Examples:
753: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
754: # Invalid to ids are silently ignored.
755: #
756: # Parameters:
757: # token - The token array fromthe HMTML::TokeParser
758: # lpc - The current map level counter.
759: #
1.121 albertel 760: sub parse_mapalias_param {
761: my ($token,$lpc) = @_;
1.140 foxr 762:
763: # Fully qualify the to value and ignore the alias if there is no
764: # corresponding resource.
765:
1.121 albertel 766: my $referid=$lpc.'.'.$token->[2]->{'to'};
767: return if (!exists($hash{'src_'.$referid}));
768:
1.140 foxr 769: # If this is a valid mapalias parameter,
770: # Append the target id to the count_mapalias element for that
771: # alias so that we can detect doubly defined aliases
772: # e.g.:
773: # <param to="1" value="george" name="parameter_0_mapalias" type="string" />
774: # <param to="2" value="george" name="parameter_0_mapalias" type="string" />
775: #
776: # The example above is trivial but the case that's important has to do with
777: # constructing a map that includes a nested map where the nested map may have
778: # aliases that conflict with aliases established in the enclosing map.
779: #
780: # ...and create/update the hash mapalias entry to actually store the alias.
781: #
782:
1.121 albertel 783: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
1.122 albertel 784: &count_mapalias($token->[2]->{'value'},$referid);
1.121 albertel 785: $hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
786: }
1.1 www 787: }
788:
1.3 www 789: # --------------------------------------------------------- Simplify expression
790:
1.140 foxr 791:
792: #
793: # Someone should really comment this to describe what it does to what and why.
794: #
1.3 www 795: sub simplify {
1.85 albertel 796: my $expression=shift;
1.101 albertel 797: # (0&1) = 1
1.105 albertel 798: $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
1.3 www 799: # (8)=8
1.105 albertel 800: $expression=~s/\(([_\.\d]+)\)/$1/g;
1.3 www 801: # 8&8=8
1.105 albertel 802: $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
1.3 www 803: # 8|8=8
1.141 ! raeburn 804: $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g;
1.3 www 805: # (5&3)&4=5&3&4
1.105 albertel 806: $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
1.3 www 807: # (((5&3)|(4&6)))=((5&3)|(4&6))
1.105 albertel 808: $expression=~
809: s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
1.3 www 810: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
1.85 albertel 811: $expression=~
1.105 albertel 812: s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
1.85 albertel 813: return $expression;
1.3 www 814: }
815:
1.2 www 816: # -------------------------------------------------------- Build condition hash
817:
1.140 foxr 818: #
819: # Traces a route recursively through the map after it has been loaded
820: # (I believe this really visits each resourcde that is reachable fromt he
821: # start top node.
822: #
823: # - Marks hidden resources as hidden.
824: # - Marks which resource URL's must be encrypted.
825: # - Figures out (if necessary) the first resource in the map.
826: # - Further builds the chunks of the big hash that define how
827: # conditions work
828: #
829: # Note that the tracing strategy won't visit resources that are not linked to
830: # anything or islands in the map (groups of resources that form a path but are not
831: # linked in to the path that can be traced from the start resource...but that's ok
832: # because by definition, those resources are not reachable by users of the course.
833: #
834: # Parameters:
835: # sofar - _URI of the prior entry or 0 if this is the top.
836: # rid - URI of the resource to visit.
837: # beenhere - list of resources (each resource enclosed by &'s) that have
838: # already been visited.
839: # encflag - If true the resource that resulted in a recursive call to us
840: # has an encoded URL (which means contained resources should too).
841: # hdnflag - If true,the resource that resulted in a recursive call to us
842: # was hidden (which means contained resources should be hidden too).
843: # Returns
844: # new value indicating how far the map has been traversed (the sofar).
845: #
1.2 www 846: sub traceroute {
1.77 www 847: my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_;
1.81 albertel 848: my $newsofar=$sofar=simplify($sofar);
1.140 foxr 849:
1.120 albertel 850: unless ($beenhere=~/\&\Q$rid\E\&/) {
1.85 albertel 851: $beenhere.=$rid.'&';
852: my ($mapid,$resid)=split(/\./,$rid);
853: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
854: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
1.91 albertel 855:
1.90 albertel 856: if ($hdnflag || lc($hidden) eq 'yes') {
857: $hiddenurl{$rid}=1;
1.91 albertel 858: }
859: if (!$hdnflag && lc($hidden) eq 'no') {
1.90 albertel 860: delete($hiddenurl{$rid});
861: }
1.91 albertel 862:
1.85 albertel 863: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
864: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
1.140 foxr 865:
1.116 www 866: if (($retfrid eq '') && ($hash{'src_'.$rid})
1.85 albertel 867: && ($hash{'src_'.$rid}!~/\.sequence$/)) {
1.116 www 868: $retfrid=$rid;
1.85 albertel 869: }
1.140 foxr 870:
1.85 albertel 871: if (defined($hash{'conditions_'.$rid})) {
872: $hash{'conditions_'.$rid}=simplify(
1.103 albertel 873: '('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
1.85 albertel 874: } else {
875: $hash{'conditions_'.$rid}=$sofar;
876: }
1.107 albertel 877:
878: # if the expression is just the 0th condition keep it
879: # otherwise leave a pointer to this condition expression
1.140 foxr 880:
1.107 albertel 881: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
882:
1.140 foxr 883: # Recurse if the resource is a map:
884:
1.85 albertel 885: if (defined($hash{'is_map_'.$rid})) {
886: if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
887: $sofar=$newsofar=
888: &traceroute($sofar,
1.126 albertel 889: $hash{'map_start_'.$hash{'src_'.$rid}},
890: $beenhere,
1.85 albertel 891: $encflag || $encurl{$rid},
892: $hdnflag || $hiddenurl{$rid});
893: }
894: }
1.140 foxr 895:
896: # Processes links to this resource:
897: # - verify the existence of any conditionals on the link to here.
898: # - Recurse to any resources linked to us.
899: #
1.85 albertel 900: if (defined($hash{'to_'.$rid})) {
1.106 albertel 901: foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
1.2 www 902: my $further=$sofar;
1.140 foxr 903: #
904: # If there's a condition associated with this link be sure
905: # it's been defined else that's an error:
906: #
1.106 albertel 907: if ($hash{'undercond_'.$id}) {
908: if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) {
1.105 albertel 909: $further=simplify('('.'_'.$rid.')&('.
1.106 albertel 910: $hash{'condid_'.$hash{'undercond_'.$id}}.')');
1.85 albertel 911: } else {
1.114 www 912: $errtext.=&mt('<br />Undefined condition ID: [_1]',$hash{'undercond_'.$id});
1.85 albertel 913: }
1.2 www 914: }
1.140 foxr 915: # Recurse to resoruces that have to's to us.
1.106 albertel 916: $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere,
1.81 albertel 917: $encflag,$hdnflag);
1.85 albertel 918: }
919: }
1.2 www 920: }
1.81 albertel 921: return $newsofar;
1.2 www 922: }
1.1 www 923:
1.19 www 924: # ------------------------------ Cascading conditions, quick access, parameters
1.4 www 925:
1.140 foxr 926: #
927: # Seems a rather strangely named sub given what the comment above says it does.
928:
929:
1.4 www 930: sub accinit {
931: my ($uri,$short,$fn)=@_;
932: my %acchash=();
933: my %captured=();
934: my $condcounter=0;
1.5 www 935: $acchash{'acc.cond.'.$short.'.0'}=0;
1.140 foxr 936:
937: # This loop is only interested in conditions and
938: # parameters in the big hash:
939:
1.104 albertel 940: foreach my $key (keys(%hash)) {
1.140 foxr 941:
942: # conditions:
943:
1.104 albertel 944: if ($key=~/^conditions/) {
945: my $expr=$hash{$key};
1.140 foxr 946:
1.109 albertel 947: # try to find and factor out common sub-expressions
1.140 foxr 948: # Any subexpression that is found is simplified, removed from
949: # the original condition expression and the simplified sub-expression
950: # substituted back in to the epxression..I'm not actually convinced this
951: # factors anything out...but instead maybe simplifies common factors(?)
952:
1.105 albertel 953: foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
1.104 albertel 954: my $orig=$sub;
1.109 albertel 955:
956: my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
957: next if (!defined($factor));
958:
959: $sub=~s/\Q$factor\E//g;
1.85 albertel 960: $sub=~s/^\(/\($factor\(/;
961: $sub.=')';
962: $sub=simplify($sub);
1.109 albertel 963: $expr=~s/\Q$orig\E/$sub/;
1.85 albertel 964: }
1.104 albertel 965: $hash{$key}=$expr;
1.140 foxr 966:
967: # If not yet seen, record in acchash and that we've seen it.
968:
1.85 albertel 969: unless (defined($captured{$expr})) {
970: $condcounter++;
971: $captured{$expr}=$condcounter;
972: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
973: }
1.140 foxr 974: # Parameters:
975:
1.104 albertel 976: } elsif ($key=~/^param_(\d+)\.(\d+)/) {
1.86 albertel 977: my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2,
978: $hash{'src_'.$1.'.'.$2});
1.104 albertel 979: foreach my $param (split(/\&/,$hash{$key})) {
980: my ($typename,$value)=split(/\=/,$param);
1.85 albertel 981: my ($type,$name)=split(/\:/,$typename);
1.114 www 982: $parmhash{$prefix.'.'.&unescape($name)}=
983: &unescape($value);
984: $parmhash{$prefix.'.'.&unescape($name).'.type'}=
985: &unescape($type);
1.85 albertel 986: }
987: }
1.26 harris41 988: }
1.140 foxr 989: # This loop only processes id entries in the big hash.
990:
1.104 albertel 991: foreach my $key (keys(%hash)) {
992: if ($key=~/^ids/) {
993: foreach my $resid (split(/\,/,$hash{$key})) {
1.85 albertel 994: my $uri=$hash{'src_'.$resid};
1.100 albertel 995: my ($uripath,$urifile) =
996: &Apache::lonnet::split_uri_for_cond($uri);
1.85 albertel 997: if ($uripath) {
998: my $uricond='0';
999: if (defined($hash{'conditions_'.$resid})) {
1000: $uricond=$captured{$hash{'conditions_'.$resid}};
1001: }
1002: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
1003: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
1004: /(\&\Q$urifile\E\:[^\&]*)/) {
1005: my $replace=$1;
1006: my $regexp=$replace;
1007: #$regexp=~s/\|/\\\|/g;
1.105 albertel 1008: $acchash{'acc.res.'.$short.'.'.$uripath} =~
1.104 albertel 1009: s/\Q$regexp\E/$replace\|$uricond/;
1.85 albertel 1010: } else {
1011: $acchash{'acc.res.'.$short.'.'.$uripath}.=
1012: $urifile.':'.$uricond.'&';
1013: }
1014: } else {
1015: $acchash{'acc.res.'.$short.'.'.$uripath}=
1016: '&'.$urifile.':'.$uricond.'&';
1017: }
1018: }
1019: }
1020: }
1.26 harris41 1021: }
1.24 www 1022: $acchash{'acc.res.'.$short.'.'}='&:0&';
1.8 www 1023: my $courseuri=$uri;
1024: $courseuri=~s/^\/res\///;
1.131 raeburn 1025: my $regexp = 1;
1026: &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp);
1.128 raeburn 1027: &Apache::lonnet::appenv(\%acchash);
1.4 www 1028: }
1029:
1.73 www 1030: # ---------------- Selectively delete from randompick maps and hidden url parms
1.29 www 1031:
1.73 www 1032: sub hiddenurls {
1.31 www 1033: my $randomoutentry='';
1.29 www 1034: foreach my $rid (keys %randompick) {
1035: my $rndpick=$randompick{$rid};
1036: my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
1037: # ------------------------------------------- put existing resources into array
1038: my @currentrids=();
1.106 albertel 1039: foreach my $key (sort(keys(%hash))) {
1040: if ($key=~/^src_($mpc\.\d+)/) {
1.29 www 1041: if ($hash{'src_'.$1}) { push @currentrids, $1; }
1042: }
1043: }
1.50 albertel 1044: # rids are number.number and we want to numercially sort on
1045: # the second number
1046: @currentrids=sort {
1047: my (undef,$aid)=split(/\./,$a);
1048: my (undef,$bid)=split(/\./,$b);
1049: $aid <=> $bid;
1050: } @currentrids;
1.29 www 1051: next if ($#currentrids<$rndpick);
1052: # -------------------------------- randomly eliminate the ones that should stay
1.50 albertel 1053: my (undef,$id)=split(/\./,$rid);
1.51 www 1054: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
1.50 albertel 1055: my $rndseed=&Apache::lonnet::rndseed($id); # use id instead of symb
1.58 albertel 1056: &Apache::lonnet::setup_random_from_rndseed($rndseed);
1.50 albertel 1057: my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
1058: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
1059: #&Apache::lonnet::logthis("$id,$rndseed,".join(':',@whichids));
1.29 www 1060: # -------------------------------------------------------- delete the leftovers
1061: for (my $k=0; $k<=$#currentrids; $k++) {
1062: if ($currentrids[$k]) {
1063: $hash{'randomout_'.$currentrids[$k]}=1;
1.32 www 1064: my ($mapid,$resid)=split(/\./,$currentrids[$k]);
1065: $randomoutentry.='&'.
1.86 albertel 1066: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
1067: $resid,
1068: $hash{'src_'.$currentrids[$k]}
1069: ).'&';
1.29 www 1070: }
1071: }
1.31 www 1072: }
1.73 www 1073: # ------------------------------ take care of explicitly hidden urls or folders
1074: foreach my $rid (keys %hiddenurl) {
1075: $hash{'randomout_'.$rid}=1;
1076: my ($mapid,$resid)=split(/\./,$rid);
1077: $randomoutentry.='&'.
1.86 albertel 1078: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,
1079: $hash{'src_'.$rid}).'&';
1.73 www 1080: }
1081: # --------------------------------------- append randomout entry to environment
1.31 www 1082: if ($randomoutentry) {
1.128 raeburn 1083: &Apache::lonnet::appenv({'acc.randomout' => $randomoutentry});
1.29 www 1084: }
1085: }
1086:
1.1 www 1087: # ---------------------------------------------------- Read map and all submaps
1088:
1089: sub readmap {
1.85 albertel 1090: my $short=shift;
1091: $short=~s/^\///;
1.138 foxr 1092:
1093: # TODO: Hidden dependency on current user:
1094:
1095: my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
1096:
1.85 albertel 1097: my $fn=$cenv{'fn'};
1098: my $uri;
1099: $short=~s/\//\_/g;
1100: unless ($uri=$cenv{'url'}) {
1.133 raeburn 1101: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1.85 albertel 1102: "Could not load course $short.</font>");
1.114 www 1103: return ('',&mt('No course data available.'));;
1.85 albertel 1104: }
1105: @cond=('true:normal');
1.96 albertel 1106:
1.133 raeburn 1107: unless (open(LOCKFILE,">$fn.db.lock")) {
1.138 foxr 1108: #
1109: # Most likely a permissions problem on the lockfile or its directory.
1110: #
1.133 raeburn 1111: $errtext.='<br />'.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.';
1112: $retfurl = '';
1113: return ($retfurl,$errtext);
1114: }
1.96 albertel 1115: my $lock=0;
1.132 raeburn 1116: my $gotstate=0;
1.138 foxr 1117:
1118: # If we can get the lock without delay any files there are idle
1119: # and from some prior request. We'll kill them off and regenerate them:
1120:
1121: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1122: $lock=1; # Remember that we hold the lock.
1.132 raeburn 1123: &unlink_tmpfiles($fn);
1.96 albertel 1124: }
1.85 albertel 1125: undef %randompick;
1126: undef %hiddenurl;
1127: undef %encurl;
1.116 www 1128: $retfrid='';
1.138 foxr 1129: my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags.
1130:
1131: # if we got the lock, regenerate course regnerate empty files and tie them.
1132:
1.132 raeburn 1133: if ($lock) {
1134: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1135: $tiedhash = 1;
1136: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1137: $tiedparmhash = 1;
1.138 foxr 1138: $gotstate = &build_tmp_hashes($uri,
1139: $fn,
1140: $short,
1141: \%cenv); # TODO: Need to provide requested user@dom
1.132 raeburn 1142: unless ($gotstate) {
1143: &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.</font>');
1144: }
1145: $untiedparmhash = untie(%parmhash);
1146: unless ($untiedparmhash) {
1147: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1148: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1149: }
1150: }
1151: $untiedhash = untie(%hash);
1152: unless ($untiedhash) {
1153: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1154: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1155: }
1156: }
1.138 foxr 1157: flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other
1158: # unlocked places the remainder happens..seems like if we
1159: # just kept the lock here the rest of the code would have
1160: # been much easier?
1.132 raeburn 1161: }
1162: unless ($lock && $tiedhash && $tiedparmhash) {
1.87 albertel 1163: # if we are here it is likely because we are already trying to
1164: # initialize the course in another child, busy wait trying to
1165: # tie the hashes for the next 90 seconds, if we succeed forward
1166: # them on to navmaps, if we fail, throw up the Could not init
1167: # course screen
1.138 foxr 1168: #
1169: # RF: I'm not seeing the case where the ties/unties can fail in a way
1170: # that can be remedied by this. Since we owned the lock seems
1171: # Tie/untie failures are a result of something like a permissions problem instead?
1172: #
1173:
1174: # In any vent, undo what we did manage to do above first:
1.96 albertel 1175: if ($lock) {
1176: # Got the lock but not the DB files
1177: flock(LOCKFILE,LOCK_UN);
1.132 raeburn 1178: $lock = 0;
1.96 albertel 1179: }
1.132 raeburn 1180: if ($tiedhash) {
1181: unless($untiedhash) {
1182: untie(%hash);
1183: }
1184: }
1185: if ($tiedparmhash) {
1186: unless($untiedparmhash) {
1187: untie(%parmhash);
1188: }
1189: }
1.138 foxr 1190: # Log our failure:
1191:
1.133 raeburn 1192: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1.132 raeburn 1193: "Could not tie coursemap $fn for $uri.</font>");
1194: $tiedhash = '';
1195: $tiedparmhash = '';
1.87 albertel 1196: my $i=0;
1.138 foxr 1197:
1198: # Keep on retrying the lock for 90 sec until we succeed.
1199:
1.87 albertel 1200: while($i<90) {
1201: $i++;
1202: sleep(1);
1.132 raeburn 1203: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1.138 foxr 1204:
1205: # Got the lock, tie the hashes...the assumption in this code is
1206: # that some other worker thread has created the db files quite recently
1207: # so no load is needed:
1208:
1.132 raeburn 1209: $lock = 1;
1210: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
1211: $tiedhash = 1;
1212: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
1213: $tiedparmhash = 1;
1214: if (-e "$fn.state") {
1215: $retfurl='/adm/navmaps';
1.138 foxr 1216:
1217: # BUG BUG: Side effect!
1218: # Should conditionalize on something so that we can use this
1219: # to load maps for courses that are not current?
1220: #
1.132 raeburn 1221: &Apache::lonnet::appenv({"request.course.id" => $short,
1222: "request.course.fn" => $fn,
1223: "request.course.uri" => $uri});
1224: $untiedhash = untie(%hash);
1225: $untiedparmhash = untie(%parmhash);
1226: $gotstate = 1;
1227: last;
1228: }
1229: $untiedparmhash = untie(%parmhash);
1230: }
1231: $untiedhash = untie(%hash);
1232: }
1233: }
1.87 albertel 1234: }
1.132 raeburn 1235: if ($lock) {
1236: flock(LOCKFILE,LOCK_UN);
1.133 raeburn 1237: $lock = 0;
1.132 raeburn 1238: if ($tiedparmhash) {
1239: unless ($untiedparmhash) {
1240: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1241: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
1242: }
1243: }
1244: if ($tiedparmhash) {
1245: unless ($untiedhash) {
1246: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1247: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
1248: }
1249: }
1250: }
1251: }
1.138 foxr 1252: # I think this branch of code is all about what happens if we just did the stuff above,
1253: # but found that the state file did not exist...again if we'd just held the lock
1254: # would that have made this logic simpler..as generating all the files would be
1255: # an atomic operation with respect to the lock.
1256: #
1.132 raeburn 1257: unless ($gotstate) {
1.133 raeburn 1258: $lock = 0;
1.132 raeburn 1259: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1260: 'Could not read statemap '.$fn.' for '.$uri.'.</font>');
1261: &unlink_tmpfiles($fn);
1.133 raeburn 1262: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
1263: $lock=1;
1264: }
1265: undef %randompick;
1266: undef %hiddenurl;
1267: undef %encurl;
1268: $retfrid='';
1.138 foxr 1269: #
1270: # Once more through the routine of tying and loading and so on.
1271: #
1.133 raeburn 1272: if ($lock) {
1273: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
1274: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
1.138 foxr 1275: $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent?
1.133 raeburn 1276: unless ($gotstate) {
1.132 raeburn 1277: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1.133 raeburn 1278: 'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.</font>');
1.132 raeburn 1279: }
1.133 raeburn 1280: unless (untie(%parmhash)) {
1.132 raeburn 1281: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1.133 raeburn 1282: 'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.</font>');
1.132 raeburn 1283: }
1.133 raeburn 1284: } else {
1285: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1286: 'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.</font>');
1287: }
1288: unless (untie(%hash)) {
1289: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1290: 'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1291: }
1.132 raeburn 1292: } else {
1.133 raeburn 1293: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1294: 'Could not tie coursemap '.$fn.'.db for '.$uri.'.</font>');
1.132 raeburn 1295: }
1.133 raeburn 1296: flock(LOCKFILE,LOCK_UN);
1297: $lock = 0;
1298: } else {
1.138 foxr 1299: # Failed to get the immediate lock.
1300:
1.133 raeburn 1301: &Apache::lonnet::logthis('<font color="blue">WARNING: '.
1302: 'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
1.132 raeburn 1303: }
1304: }
1.133 raeburn 1305: close(LOCKFILE);
1.132 raeburn 1306: unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
1307: &Apache::lonmsg::author_res_msg($env{'request.course.uri'},
1.138 foxr 1308: $errtext); # TODO: User dependent?
1.1 www 1309: }
1.46 www 1310: # ------------------------------------------------- Check for critical messages
1311:
1.138 foxr 1312: # Depends on user must parameterize this as well..or separate as this is:
1313: # more part of determining what someone sees on entering a course?
1314:
1.89 albertel 1315: my @what=&Apache::lonnet::dump('critical',$env{'user.domain'},
1316: $env{'user.name'});
1.46 www 1317: if ($what[0]) {
1318: if (($what[0] ne 'con_lost') && ($what[0]!~/^error\:/)) {
1319: $retfurl='/adm/email?critical=display';
1320: }
1321: }
1.85 albertel 1322: return ($retfurl,$errtext);
1.1 www 1323: }
1.15 www 1324:
1.138 foxr 1325: #
1326: # This sub is called when the course hash and the param hash have been tied and
1327: # their lock file is held.
1328: # Parameters:
1329: # $uri - URI that identifies the course.
1330: # $fn - The base path/filename of the files that make up the context
1331: # being built.
1332: # $short - Short course name.
1333: # $cenvref - Reference to the course environment hash returned by
1334: # Apache::lonnet::coursedescription
1335: #
1336: # Assumptions:
1337: # The globals
1338: # %hash, %paramhash are tied to their gdbm files and we hold the lock on them.
1339: #
1.132 raeburn 1340: sub build_tmp_hashes {
1341: my ($uri,$fn,$short,$cenvref) = @_;
1.138 foxr 1342:
1.132 raeburn 1343: unless(ref($cenvref) eq 'HASH') {
1344: return;
1345: }
1346: my %cenv = %{$cenvref};
1347: my $gotstate = 0;
1.138 foxr 1348: %hash=(); # empty the global course and parameter hashes.
1.132 raeburn 1349: %parmhash=();
1.138 foxr 1350: $errtext=''; # No error messages yet.
1.132 raeburn 1351: $pc=0;
1352: &clear_mapalias_count();
1353: &processversionfile(%cenv);
1.140 foxr 1354:
1355: # URI Of the map file.
1356:
1.132 raeburn 1357: my $furi=&Apache::lonnet::clutter($uri);
1.138 foxr 1358: #
1359: # the map staring points.
1360: #
1.132 raeburn 1361: $hash{'src_0.0'}=&versiontrack($furi);
1362: $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
1363: $hash{'ids_'.$furi}='0.0';
1364: $hash{'is_map_0.0'}=1;
1.140 foxr 1365:
1366: # Load the map.. note that loadmap may implicitly recurse if the map contains
1367: # sub-maps.
1368:
1369:
1.132 raeburn 1370: &loadmap($uri,'0.0');
1.140 foxr 1371:
1372: # The code below only executes if there is a starting point for the map>
1373: # Q/BUG??? If there is no start resource for the map should that be an error?
1374: #
1375:
1.132 raeburn 1376: if (defined($hash{'map_start_'.$uri})) {
1377: &Apache::lonnet::appenv({"request.course.id" => $short,
1378: "request.course.fn" => $fn,
1379: "request.course.uri" => $uri});
1380: $env{'request.course.id'}=$short;
1381: &traceroute('0',$hash{'map_start_'.$uri},'&');
1382: &accinit($uri,$short,$fn);
1383: &hiddenurls();
1384: }
1385: $errtext .= &get_mapalias_errors();
1386: # ------------------------------------------------------- Put versions into src
1387: foreach my $key (keys(%hash)) {
1388: if ($key=~/^src_/) {
1389: $hash{$key}=&putinversion($hash{$key});
1390: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
1391: my ($type, $url) = ($1,$2);
1392: my $value = $hash{$key};
1393: $hash{$type.&putinversion($url)}=$value;
1394: }
1395: }
1396: # ---------------------------------------------------------------- Encrypt URLs
1397: foreach my $id (keys(%encurl)) {
1398: # $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
1399: $hash{'encrypted_'.$id}=1;
1400: }
1401: # ----------------------------------------------- Close hashes to finally store
1402: # --------------------------------- Routine must pass this point, no early outs
1403: $hash{'first_rid'}=$retfrid;
1404: my ($mapid,$resid)=split(/\./,$retfrid);
1405: $hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
1406: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
1407: $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
1408: if ($hash{'encrypted_'.$retfrid}) {
1409: $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
1410: }
1411: $hash{'first_url'}=$retfurl;
1412: # ---------------------------------------------------- Store away initial state
1413: {
1414: my $cfh;
1415: if (open($cfh,">$fn.state")) {
1416: print $cfh join("\n",@cond);
1417: $gotstate = 1;
1418: } else {
1419: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1420: "Could not write statemap $fn for $uri.</font>");
1421: }
1422: }
1423: return $gotstate;
1424: }
1425:
1426: sub unlink_tmpfiles {
1427: my ($fn) = @_;
1.138 foxr 1428: my $file_dir = dirname($fn);
1429:
1430: if ($fn eq LONCAPA::tempdir()) {
1.132 raeburn 1431: my @files = qw (.db _symb.db .state _parms.db);
1432: foreach my $file (@files) {
1433: if (-e $fn.$file) {
1434: unless (unlink($fn.$file)) {
1435: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
1436: "Could not unlink ".$fn.$file."</font>");
1437: }
1438: }
1439: }
1440: }
1441: return;
1442: }
1443:
1.15 www 1444: # ------------------------------------------------------- Evaluate state string
1445:
1446: sub evalstate {
1.89 albertel 1447: my $fn=$env{'request.course.fn'}.'.state';
1.80 albertel 1448: my $state='';
1.15 www 1449: if (-e $fn) {
1.80 albertel 1450: my @conditions=();
1451: {
1.115 raeburn 1452: open(my $fh,"<$fn");
1.80 albertel 1453: @conditions=<$fh>;
1.115 raeburn 1454: close($fh);
1.80 albertel 1455: }
1456: my $safeeval = new Safe;
1457: my $safehole = new Safe::Hole;
1458: $safeeval->permit("entereval");
1459: $safeeval->permit(":base_math");
1460: $safeeval->deny(":base_io");
1461: $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
1462: foreach my $line (@conditions) {
1463: chomp($line);
1464: my ($condition,$weight)=split(/\:/,$line);
1465: if ($safeeval->reval($condition)) {
1466: if ($weight eq 'force') {
1467: $state.='3';
1468: } else {
1469: $state.='2';
1470: }
1471: } else {
1472: if ($weight eq 'stop') {
1473: $state.='0';
1474: } else {
1475: $state.='1';
1476: }
1477: }
1478: }
1.15 www 1479: }
1.128 raeburn 1480: &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state});
1.15 www 1481: return $state;
1482: }
1483:
1.138 foxr 1484: # This block seems to have code to manage/detect doubly defined
1485: # aliases in maps.
1486:
1.122 albertel 1487: {
1488: my %mapalias_cache;
1489: sub count_mapalias {
1490: my ($value,$resid) = @_;
1491: push(@{ $mapalias_cache{$value} }, $resid);
1492: }
1493:
1494: sub get_mapalias_errors {
1495: my $error_text;
1496: foreach my $mapalias (sort(keys(%mapalias_cache))) {
1497: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
1498: my $count;
1499: my $which =
1500: join('</li><li>',
1501: map {
1502: my $id = $_;
1503: if (exists($hash{'src_'.$id})) {
1504: $count++;
1505: }
1506: my ($mapid) = split(/\./,$id);
1.125 albertel 1507: &mt('Resource "[_1]" <br /> in Map "[_2]"',
1508: $hash{'title_'.$id},
1.122 albertel 1509: $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}});
1510: } (@{ $mapalias_cache{$mapalias} }));
1511: next if ($count < 2);
1512: $error_text .= '<div class="LC_error">'.
1513: &mt('Error: Found the mapalias "[_1]" defined multiple times.',
1514: $mapalias).
1515: '</div><ul><li>'.$which.'</li></ul>';
1516: }
1517: &clear_mapalias_count();
1518: return $error_text;
1519: }
1520: sub clear_mapalias_count {
1521: undef(%mapalias_cache);
1522: }
1523: }
1.1 www 1524: 1;
1525: __END__
1526:
1.26 harris41 1527: =head1 NAME
1528:
1529: Apache::lonuserstate - Construct and maintain state and binary representation
1530: of course for user
1531:
1532: =head1 SYNOPSIS
1533:
1534: Invoked by lonroles.pm.
1535:
1536: &Apache::lonuserstate::readmap($cdom.'/'.$cnum);
1537:
1538: =head1 INTRODUCTION
1539:
1540: This module constructs and maintains state and binary representation
1541: of course for user.
1542:
1543: This is part of the LearningOnline Network with CAPA project
1544: described at http://www.lon-capa.org.
1545:
1.129 jms 1546: =head1 SUBROUTINES
1.26 harris41 1547:
1.129 jms 1548: =over
1.26 harris41 1549:
1.129 jms 1550: =item loadmap()
1.26 harris41 1551:
1.129 jms 1552: Loads map from disk
1.26 harris41 1553:
1.129 jms 1554: =item simplify()
1.26 harris41 1555:
1.129 jms 1556: Simplify expression
1.26 harris41 1557:
1.129 jms 1558: =item traceroute()
1.26 harris41 1559:
1.129 jms 1560: Build condition hash
1.26 harris41 1561:
1.129 jms 1562: =item accinit()
1.26 harris41 1563:
1.129 jms 1564: Cascading conditions, quick access, parameters
1.26 harris41 1565:
1.129 jms 1566: =item readmap()
1.26 harris41 1567:
1.129 jms 1568: Read map and all submaps
1.1 www 1569:
1.129 jms 1570: =item evalstate()
1.1 www 1571:
1.129 jms 1572: Evaluate state string
1.1 www 1573:
1.26 harris41 1574: =back
1.1 www 1575:
1.26 harris41 1576: =cut
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