File:  [LON-CAPA] / rat / lonuserstate.pm
Revision 1.167: download - view: text, annotated - select for diffs
Sat Aug 21 03:42:02 2021 UTC (2 years, 8 months ago) by raeburn
Branches: MAIN
CVS tags: HEAD
- Bug 6907 Content in a course can be set to be deep-link only.
  - escape the components in each deeplinkonly_$rid item in the big hash.

    1: # The LearningOnline Network with CAPA
    2: # Construct and maintain state and binary representation of course for user
    3: #
    4: # $Id: lonuserstate.pm,v 1.167 2021/08/21 03:42:02 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 $retfurl; # first URL
   59: my %randompick; # randomly picked resources
   60: my %randompickseed; # optional seed for randomly picking resources
   61: my %randomorder; # maps to order contents randomly
   62: my %randomizationcode; # code used to grade folder for bubblesheet exam 
   63: my %encurl; # URLs in this folder are supposed to be encrypted
   64: my %hiddenurl; # this URL (or complete folder) is supposed to be hidden
   65: my %deeplinkout; # this URL (or complete folder) unavailable in deep-link session
   66: my %rescount; # count of unhidden items in each map
   67: my %mapcount; # count of unhidden maps in each map
   68: 
   69: # ----------------------------------- Remove version from URL and store in hash
   70: 
   71: sub versionerror {
   72:     my ($uri,$usedversion,$unusedversion)=@_;
   73:     return '<br />'.&mt('Version discrepancy: resource [_1] included in both version [_2] and version [_3]. Using version [_2].',
   74:                     $uri,$usedversion,$unusedversion).'<br />';
   75: }
   76: 
   77: #  Removes the version number from a URI and returns the resulting
   78: #  URI (e.g. mumbly.version.stuff => mumbly.stuff).
   79: #
   80: #   If the URI has not been seen with a versio before the
   81: #   hash{'version_'.resultingURI} is set to the  version number.
   82: #   If the URI has been seen and the version does not match and error
   83: #   is added to the error string.
   84: #
   85: # Parameters:
   86: #   URI potentially with a version.
   87: # Returns:
   88: #   URI with the version cut out.
   89: # See above for side effects.
   90: #
   91: 
   92: sub versiontrack {
   93:     my $uri=shift;
   94:     if ($uri=~/\.(\d+)\.\w+$/) {
   95: 	my $version=$1;
   96: 	$uri=~s/\.\d+\.(\w+)$/\.$1/;
   97:         unless ($hash{'version_'.$uri}) {
   98: 	    $hash{'version_'.$uri}=$version;
   99: 	} elsif ($version!=$hash{'version_'.$uri}) {
  100:             $errtext.=&versionerror($uri,$hash{'version_'.$uri},$version);
  101:         }
  102:     }
  103:     return $uri;
  104: }
  105: 
  106: # -------------------------------------------------------------- Put in version
  107: 
  108: sub putinversion {
  109:     my $uri=shift;
  110:     my $key=$env{'request.course.id'}.'_'.&Apache::lonnet::clutter($uri);
  111:     if ($hash{'version_'.$uri}) {
  112: 	my $version=$hash{'version_'.$uri};
  113: 	if ($version eq 'mostrecent') { return $uri; }
  114: 	if ($version eq &Apache::lonnet::getversion(
  115: 			&Apache::lonnet::filelocation('',$uri))) 
  116: 	             { return $uri; }
  117: 	$uri=~s/\.(\w+)$/\.$version\.$1/;
  118:     }
  119:     &Apache::lonnet::do_cache_new('courseresversion',$key,&Apache::lonnet::declutter($uri),600);
  120:     return $uri;
  121: }
  122: 
  123: # ----------------------------------------- Processing versions file for course
  124: 
  125: sub processversionfile {
  126:     my %cenv=@_;
  127:     my %versions=&Apache::lonnet::dump('resourceversions',
  128: 				       $cenv{'domain'},
  129: 				       $cenv{'num'});
  130:     foreach my $ver (keys(%versions)) {
  131: 	if ($ver=~/^error\:/) { return; }
  132: 	$hash{'version_'.$ver}=$versions{$ver};
  133:     }
  134: }
  135: 
  136: # --------------------------------------------------------- Loads from disk
  137: 
  138: 
  139: #
  140: #  Loads a map file.
  141: #  Note that this may implicitly recurse via parse_resource if one of the resources
  142: #  is itself composed.
  143: #
  144: # Parameters:
  145: #    uri         - URI of the map file.
  146: #    parent_rid  - Resource id in the map of the parent resource (0.0 for the top level map)
  147: #    courseid    - Course id for the course for which the map is being loaded
  148: #
  149: sub loadmap { 
  150:     my ($uri,$parent_rid,$courseid)=@_;
  151: 
  152:     # Is the map already included?
  153: 
  154:     if ($hash{'map_pc_'.$uri}) { 
  155: 	$errtext.='<p class="LC_error">'.
  156: 	    &mt('Multiple use of sequence/page [_1]! The course will not function properly.','<tt>'.$uri.'</tt>').
  157: 	    '</p>';
  158: 	return; 
  159:     }
  160:     # Register the resource in it's map_pc_ [for the URL]
  161:     # map_id.nnn is the nesting level -> to the URI.
  162: 
  163:     $pc++;
  164:     my $lpc=$pc;
  165:     $hash{'map_pc_'.$uri}=$lpc;
  166:     $hash{'map_id_'.$lpc}=$uri;
  167: 
  168:     # If the parent is of the form n.m hang this map underneath it in the
  169:     # map hierarchy.
  170: 
  171:     if ($parent_rid =~ /^(\d+)\.\d+$/) {
  172:         my $parent_pc = $1;
  173:         if (defined($hash{'map_hierarchy_'.$parent_pc})) {
  174:             $hash{'map_hierarchy_'.$lpc}=$hash{'map_hierarchy_'.$parent_pc}.','.
  175:                                          $parent_pc;
  176:         } else {
  177:             $hash{'map_hierarchy_'.$lpc}=$parent_pc;
  178:         }
  179:     }
  180: 
  181: # Determine and check filename of the sequence we need to read:
  182: 
  183:     my $fn=&Apache::lonnet::filelocation('',&putinversion($uri));
  184: 
  185:     my $ispage=($fn=~/\.page$/);
  186: 
  187:     # We can only nest sequences or pages.  Anything else is an illegal nest.
  188: 
  189:     unless (($fn=~/\.sequence$/) || $ispage) { 
  190: 	$errtext.='<br />'.&mt('Invalid map: [_1]',"<tt>$fn</tt>");
  191: 	return; 
  192:     }
  193: 
  194:     # Read the XML that constitutes the file.
  195: 
  196:     my $instr=&Apache::lonnet::getfile($fn);
  197: 
  198:     if ($instr eq -1) {
  199:         $errtext.= '<br />'
  200:                   .&mt('Map not loaded: The file [_1] does not exist.',
  201:                        "<tt>$fn</tt>");
  202: 	return;
  203:     }
  204: 
  205:     # Successfully got file, parse it
  206: 
  207:     # parse for parameter processing.
  208:     # Note that these are <param... / > tags
  209:     # so we only care about 'S' (tag start) nodes.
  210: 
  211: 
  212:     my $parser = HTML::TokeParser->new(\$instr);
  213:     $parser->attr_encoded(1);
  214: 
  215:     # first get all parameters
  216: 
  217: 
  218:     while (my $token = $parser->get_token) {
  219: 	next if ($token->[0] ne 'S');
  220: 	if ($token->[1] eq 'param') {
  221: 	    &parse_param($token,$lpc);
  222: 	} 
  223:     }
  224: 
  225:     # Get set to take another pass through the XML:
  226:     # for resources and links.
  227: 
  228:     $parser = HTML::TokeParser->new(\$instr);
  229:     $parser->attr_encoded(1);
  230: 
  231:     my $linkpc=0;
  232: 
  233:     $fn=~/\.(\w+)$/;
  234: 
  235:     $hash{'map_type_'.$lpc}=$1;
  236: 
  237:     my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i);
  238: 
  239:     # Parse the resources, link and condition tags.
  240:     # Note that if randomorder or random select is chosen the links and
  241:     # conditions are meaningless but are determined by the randomization.
  242:     # This is handled in the next chunk of code.
  243: 
  244:     my @map_ids;
  245:     my $codechecked;
  246:     $rescount{$lpc} = 0;
  247:     $mapcount{$lpc} = 0;
  248:     while (my $token = $parser->get_token) {
  249: 	next if ($token->[0] ne 'S');
  250: 
  251: 	# Resource
  252: 
  253: 	if ($token->[1] eq 'resource') {
  254: 	    my $resource_id = &parse_resource($token,$lpc,$ispage,$uri,$courseid);
  255: 	    if (defined $resource_id) {
  256: 		push(@map_ids, $resource_id);
  257:                 if ($hash{'src_'.$lpc.'.'.$resource_id}) {
  258:                     $rescount{$lpc} ++;
  259:                     if (($hash{'src_'.$lpc.'.'.$resource_id}=~/\.sequence$/) || 
  260:                         ($hash{'src_'.$lpc.'.'.$resource_id}=~/\.page$/)) {
  261:                         $mapcount{$lpc} ++; 
  262:                     }
  263:                 }
  264:                 unless ($codechecked) {
  265:                     my $startsymb =
  266:                        &Apache::lonnet::encode_symb($hash{'map_id_'.$lpc},$resource_id,
  267:                                                     $hash{'src_'."$lpc.$resource_id"});
  268:                     my $code = 
  269:                         &Apache::lonnet::EXT('resource.0.examcode',$startsymb,undef,undef,
  270:                                              undef,undef,$courseid);
  271:                     if ($code) {
  272:                         $randomizationcode{$parent_rid} = $code;
  273:                     }
  274:                     $codechecked = 1; 
  275:                 }
  276: 	    }
  277: 
  278:        # Link
  279: 
  280: 	} elsif ($token->[1] eq 'link' && !$randomize) {
  281: 	    &make_link(++$linkpc,$lpc,$token->[2]->{'to'},
  282: 		       $token->[2]->{'from'},
  283: 		       $token->[2]->{'condition'}); # note ..condition may be undefined.
  284: 
  285: 	# condition
  286: 
  287: 	} elsif ($token->[1] eq 'condition' && !$randomize) {
  288: 	    &parse_condition($token,$lpc);
  289: 	}
  290:     }
  291:     undef($codechecked);
  292: 
  293:     # Handle randomization and random selection
  294: 
  295:     if ($randomize) {
  296:         unless (&is_advanced($courseid)) {
  297:             # Order of resources is not randomized if user has and advanced role in the course.
  298: 	    my $seed;
  299: 
  300:             # If the map's random seed parameter has been specified
  301:             # it is used as the basis for computing the seed ...
  302: 
  303: 	    if (defined($randompickseed{$parent_rid})) {
  304: 		$seed = $randompickseed{$parent_rid};
  305: 	    } else {
  306: 
  307: 		# Otherwise the parent's fully encoded symb is used.
  308: 
  309: 		my ($mapid,$resid)=split(/\./,$parent_rid);
  310: 		my $symb=
  311: 		    &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
  312: 						 $resid,$hash{'src_'.$parent_rid});
  313: 		
  314: 		$seed = $symb;
  315: 	    }
  316: 
  317: 	    # TODO: Here for sure we need to pass along the username/domain
  318: 	    # so that we can impersonate users in lonprintout e.g.
  319: 
  320:             my $setcode;
  321:             if (defined($randomizationcode{$parent_rid})) {
  322:                 if ($env{'form.CODE'} eq '') {
  323:                     $env{'form.CODE'} = $randomizationcode{$parent_rid};
  324:                     $setcode = 1;
  325:                 }
  326:             }
  327: 
  328: 	    my $rndseed=&Apache::lonnet::rndseed($seed);
  329: 	    &Apache::lonnet::setup_random_from_rndseed($rndseed);
  330: 
  331:             if ($setcode) {
  332:                 undef($env{'form.CODE'});
  333:                 undef($setcode);
  334:             }
  335: 
  336: 	    # Take the set of map ids we have decoded and permute them to a
  337: 	    # random order based on the seed set above. All of this is
  338: 	    # processing the randomorder parameter if it is set, not
  339: 	    # randompick.
  340: 
  341: 	    @map_ids=&Math::Random::random_permutation(@map_ids);
  342: 	}
  343: 
  344: 	my $from = shift(@map_ids);
  345: 	my $from_rid = $lpc.'.'.$from;
  346: 	$hash{'map_start_'.$uri} = $from_rid;
  347: 	$hash{'type_'.$from_rid}='start';
  348: 
  349: 	# Create links to reflect the random re-ordering done above.
  350: 	# In the code to process the map XML, we did not process links or conditions
  351: 	# if randomorder was set.  This means that for an instructor to choose
  352: 
  353: 	while (my $to = shift(@map_ids)) {
  354: 	    &make_link(++$linkpc,$lpc,$to,$from);
  355: 	    my $to_rid =  $lpc.'.'.$to;
  356: 	    $hash{'type_'.$to_rid}='normal';
  357: 	    $from = $to;
  358: 	    $from_rid = $to_rid;
  359: 	}
  360: 
  361: 	$hash{'map_finish_'.$uri}= $from_rid;
  362: 	$hash{'type_'.$from_rid}='finish';
  363:     }
  364: 
  365:     $parser = HTML::TokeParser->new(\$instr);
  366:     $parser->attr_encoded(1);
  367: 
  368:     # last parse out the mapalias params.  These provide mnemonic
  369:     # tags to resources that can be used in conditions
  370: 
  371:     while (my $token = $parser->get_token) {
  372: 	next if ($token->[0] ne 'S');
  373: 	if ($token->[1] eq 'param') {
  374: 	    &parse_mapalias_param($token,$lpc);
  375: 	} 
  376:     }
  377: }
  378: 
  379: sub is_advanced {
  380:     my ($courseid) = @_;
  381:     my $advanced;
  382:     if ($env{'request.course.id'}) {
  383:         $advanced = (&Apache::lonnet::allowed('adv') eq 'F');
  384:     } else {
  385:         $env{'request.course.id'} = $courseid;
  386:         $advanced = (&Apache::lonnet::allowed('adv') eq 'F');
  387:         $env{'request.course.id'} = '';
  388:     }
  389:     return $advanced;
  390: }
  391: 
  392: # -------------------------------------------------------------------- Resource
  393: #
  394: #  Parses a resource tag to produce the value to push into the
  395: #  map_ids array.
  396: # 
  397: #
  398: #  Information about the actual type of resource is provided by the file extension
  399: #  of the uri (e.g. .problem, .sequence etc. etc.).
  400: #
  401: #  Parameters:
  402: #    $token   - A token from HTML::TokeParser
  403: #               This is an array that describes the most recently parsed HTML item.
  404: #    $lpc     - Map nesting level (?)
  405: #    $ispage  - True if this resource is encapsulated in a .page (assembled resourcde).
  406: #    $uri     - URI of the enclosing resource.
  407: #    $courseid - Course id of the course containing the resource being parsed. 
  408: # Returns:
  409: #   Value of the id attribute of the tag.
  410: #
  411: # Note:
  412: #   The token is an array that contains the following elements:
  413: #   [0]   => 'S' indicating this is a start token
  414: #   [1]   => 'resource'  indicating this tag is a <resource> tag.
  415: #   [2]   => Hash of attribute =>value pairs.
  416: #   [3]   => @(keys [2]).
  417: #   [4]   => unused.
  418: #
  419: #   The attributes of the resourcde tag include:
  420: #
  421: #   id     - The resource id.
  422: #   src    - The URI of the resource.
  423: #   type   - The resource type (e.g. start and finish).
  424: #   title  - The resource title.
  425: 
  426: 
  427: sub parse_resource {
  428:     my ($token,$lpc,$ispage,$uri,$courseid) = @_;
  429:     
  430:     # I refuse to countenance code like this that has 
  431:     # such a dirty side effect (and forcing this sub to be called within a loop).
  432:     #
  433:     #  if ($token->[2]->{'type'} eq 'zombie') { next; }
  434:     #
  435:     #  The original code both returns _and_ skips to the next pass of the >caller's<
  436:     #  loop, that's just dirty.
  437:     #
  438: 
  439:     # Zombie resources don't produce anything useful.
  440: 
  441:     if ($token->[2]->{'type'} eq 'zombie') {
  442: 	return undef;
  443:     }
  444: 
  445:     my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
  446: 
  447:     # Save the hash element type and title:
  448: 	    
  449:     $hash{'kind_'.$rid}='res';
  450:     $hash{'title_'.$rid}=$token->[2]->{'title'};
  451: 
  452:     # Get the version free URI for the resource.
  453:     # If a 'version' attribute was supplied, and this resource's version 
  454:     # information has not yet been stored, store it.
  455:     #
  456: 
  457:     my $turi=&versiontrack($token->[2]->{'src'});
  458:     if ($token->[2]->{'version'}) {
  459: 	unless ($hash{'version_'.$turi}) {
  460: 	    $hash{'version_'.$turi}=$1;
  461: 	}
  462:     }
  463:     # Pull out the title and do entity substitution on &colon
  464:     # Q: Why no other entity substitutions?
  465: 
  466:     my $title=$token->[2]->{'title'};
  467:     $title=~s/\&colon\;/\:/gs;
  468: 
  469: 
  470: 
  471:     # I think the point of all this code is to construct a final
  472:     # URI that apache and its rewrite rules can use to
  473:     # fetch the resource.   Thi s sonly necessary if the resource
  474:     # is not a page.  If the resource is a page then it must be
  475:     # assembled (at fetch time?).
  476: 
  477:     if ($ispage) {
  478:         if ($token->[2]->{'external'} eq 'true') { # external
  479:             $turi=~s{^http\://}{/ext/};
  480:         }
  481:     } else {
  482: 	$turi=~/\.(\w+)$/;
  483: 	my $embstyle=&Apache::loncommon::fileembstyle($1);
  484: 	if ($token->[2]->{'external'} eq 'true') { # external
  485: 	    $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
  486: 	} elsif ($turi=~/^\/*uploaded\//) { # uploaded
  487: 	    if (($embstyle eq 'img') 
  488: 		|| ($embstyle eq 'emb')
  489: 		|| ($embstyle eq 'wrp')) {
  490: 		$turi='/adm/wrapper'.$turi;
  491: 	    } elsif ($embstyle eq 'ssi') {
  492: 		#do nothing with these
  493: 	    } elsif ($turi!~/\.(sequence|page)$/) {
  494: 		$turi='/adm/coursedocs/showdoc'.$turi;
  495: 	    }
  496:         } elsif ($turi=~ m{^/adm/$match_domain/$match_courseid/\d+/ext\.tool$}) {
  497:             $turi='/adm/wrapper'.$turi;
  498: 	} elsif ($turi=~/\S/) { # normal non-empty internal resource
  499: 	    my $mapdir=$uri;
  500: 	    $mapdir=~s/[^\/]+$//;
  501: 	    $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
  502: 	    if (($embstyle eq 'img') 
  503: 		|| ($embstyle eq 'emb')
  504: 		|| ($embstyle eq 'wrp')) {
  505: 		$turi='/adm/wrapper'.$turi;
  506: 	    }
  507: 	}
  508:     }
  509:     # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
  510:     # If the URI appears more than one time in the sequence, it's resourcde
  511:     # id's are constructed as a comma spearated list.
  512: 
  513:     my $idsuri=$turi;
  514:     $idsuri=~s/\?.+$//;
  515:     if (defined($hash{'ids_'.$idsuri})) {
  516: 	$hash{'ids_'.$idsuri}.=','.$rid;
  517:     } else {
  518: 	$hash{'ids_'.$idsuri}=''.$rid;
  519:     }
  520:     
  521: 
  522: 
  523:     if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
  524: 	$turi.='?register=1';
  525:     }
  526:     
  527: 
  528:     # resource id lookup:  'src'_resourc-di  => URI decorated with a query
  529:     # parameter as above if necessary due to the resource type.
  530:     
  531:     $hash{'src_'.$rid}=$turi;
  532: 
  533:     # Mark the external-ness of the resource:
  534:     
  535:     if ($token->[2]->{'external'} eq 'true') {
  536: 	$hash{'ext_'.$rid}='true:';
  537:     } else {
  538: 	$hash{'ext_'.$rid}='false:';
  539:     }
  540: 
  541:     # If the resource is a start/finish resource set those
  542:     # entries in the has so that navigation knows where everything starts.
  543:     # TODO?  If there is a malformed sequence that has no start or no finish
  544:     # resource, should this be detected and errors thrown?  How would such a 
  545:     # resource come into being other than being manually constructed by a person
  546:     # and then uploaded?  Could that happen if an author decided a sequence was almost
  547:     # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
  548:     #  start or finish resources?
  549:     #
  550:     #  All resourcess also get a type_id => (start | finish | normal)    hash entr.
  551:     #
  552:     if ($token->[2]->{'type'}) {
  553: 	$hash{'type_'.$rid}=$token->[2]->{'type'};
  554: 	if ($token->[2]->{'type'} eq 'start') {
  555: 	    $hash{'map_start_'.$uri}="$rid";
  556: 	}
  557: 	if ($token->[2]->{'type'} eq 'finish') {
  558: 	    $hash{'map_finish_'.$uri}="$rid";
  559: 	}
  560:     }  else {
  561: 	$hash{'type_'.$rid}='normal';
  562:     }
  563: 
  564:     # Sequences end pages are constructed entities.  They require that the 
  565:     # map that defines _them_ be loaded as well into the hash...with this resourcde
  566:     # as the base of the nesting.
  567:     # Resources like that are also marked with is_map_id => 1 entries.
  568:     #
  569:     
  570:     if (($turi=~/\.sequence$/) ||
  571: 	($turi=~/\.page$/)) {
  572: 	$hash{'is_map_'.$rid}=1;
  573: 	if ((!$hiddenurl{$rid}) || (&is_advanced($courseid))) {
  574: 	    &loadmap($turi,$rid,$courseid);
  575: 	}
  576:     } 
  577:     return $token->[2]->{'id'};
  578: }
  579: 
  580: #-------------------------------------------------------------------- link
  581: #  Links define how you are allowed to move from one resource to another.
  582: #  They are the transition edges in the directed graph that a map is.
  583: #  This sub takes informatino from a <link> tag and constructs the
  584: #  navigation bits and pieces of a map.  There is no requirement that the
  585: #  resources that are linke are already defined, however clearly the map is 
  586: #  badly broken if they are not _eventually_ defined.
  587: #
  588: #  Note that links can be unconditional or conditional.
  589: #
  590: #  Parameters:
  591: #     linkpc   - The link counter for this level of map nesting (this is 
  592: #                reset to zero by loadmap prior to starting to process
  593: #                links for map).
  594: #     lpc      - The map level ocounter (how deeply nested this map is in
  595: #                the hierarchy of maps that are recursively read in.
  596: #     to       - resource id (within the XML) of the target of the edge.
  597: #     from     - resource id (within the XML) of the source of the edge.
  598: #     condition- id of condition associated with the edge (also within the XML).
  599: #
  600: 
  601: sub make_link {
  602:     my ($linkpc,$lpc,$to,$from,$condition) = @_;
  603:     
  604:     #  Compute fully qualified ids for the link, the 
  605:     # and from/to by prepending lpc.
  606:     #
  607: 
  608:     my $linkid=$lpc.'.'.$linkpc;
  609:     my $goesto=$lpc.'.'.$to;
  610:     my $comesfrom=$lpc.'.'.$from;
  611:     my $undercond=0;
  612: 
  613: 
  614:     # If there is a condition, qualify it with the level counter.
  615: 
  616:     if ($condition) {
  617: 	$undercond=$lpc.'.'.$condition;
  618:     }
  619: 
  620:     # Links are represnted by:
  621:     #  goesto_.fuullyqualifedlinkid => fully qualified to
  622:     #  comesfrom.fullyqualifiedlinkid => fully qualified from
  623:     #  undercond_.fullyqualifiedlinkid => fully qualified condition id.
  624: 
  625:     $hash{'goesto_'.$linkid}=$goesto;
  626:     $hash{'comesfrom_'.$linkid}=$comesfrom;
  627:     $hash{'undercond_'.$linkid}=$undercond;
  628: 
  629:     # In addition:
  630:     #   to_.fully qualified from => comma separated list of 
  631:     #   link ids with that from.
  632:     # Similarly:
  633:     #   from_.fully qualified to => comma separated list of link ids`
  634:     #                               with that to.
  635:     #  That allows us given a resource id to know all edges that go to it
  636:     #  and leave from it.
  637:     #
  638: 
  639:     if (defined($hash{'to_'.$comesfrom})) {
  640: 	$hash{'to_'.$comesfrom}.=','.$linkid;
  641:     } else {
  642: 	$hash{'to_'.$comesfrom}=''.$linkid;
  643:     }
  644:     if (defined($hash{'from_'.$goesto})) {
  645: 	$hash{'from_'.$goesto}.=','.$linkid;
  646:     } else {
  647: 	$hash{'from_'.$goesto}=''.$linkid;
  648:     }
  649: }
  650: 
  651: # ------------------------------------------------------------------- Condition
  652: #
  653: #  Processes <condition> tags, storing sufficient information about them
  654: #  in the hash so that they can be evaluated and used to conditionalize
  655: #  what is presented to the student.
  656: #
  657: #  these can have the following attributes 
  658: #
  659: #    id    = A unique identifier of the condition within the map.
  660: #
  661: #    value = Is a perl script-let that, when evaluated in safe space
  662: #            determines whether or not the condition is true.
  663: #            Normally this takes the form of a test on an  Apache::lonnet::EXT call
  664: #            to find the value of variable associated with a resource in the
  665: #            map identified by a mapalias.
  666: #            Here's a fragment of XML code that illustrates this:
  667: #
  668: #           <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" />
  669: #           <resource src="" id="1" type="start" title="Start" />
  670: #           <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5"  title="p1.problem" />
  671: #           <condition value="&EXT('user.resource.resource.0.tries','mainproblem')
  672: #           <2 " id="61" type="stop" />
  673: #           <link to="5" index="1" from="1" condition="61" />    
  674: #
  675: #           In this fragment:
  676: #             - The param tag establishes an alias to resource id 5 of 'mainproblem'.
  677: #             - The resource that is the start of the map is identified.
  678: #             - The resource tag identifies the resource associated with this tag
  679: #               and gives it the id 5.
  680: #             - The condition is true if the tries variable associated with mainproblem
  681: #               is less than 2 (that is the user has had more than 2 tries).
  682: #               The condition type is a stop condition which inhibits(?) the associated
  683: #               link if the condition  is false. 
  684: #             - The link to resource 5 from resource 1 is affected by this condition.    
  685: #            
  686: #    type  = Type of the condition. The type determines how the condition affects the
  687: #            link associated with it and is one of
  688: #            -  'force'
  689: #            -  'stop'
  690: #              anything else including not supplied..which treated as:
  691: #            - 'normal'.
  692: #            Presumably maps get created by the resource assembly tool and therefore
  693: #            illegal type values won't squirm their way into the XML.
  694: #
  695: # Side effects:
  696: #   -  The kind_level-qualified-condition-id hash element is set to 'cond'.
  697: #   -  The condition text is pushed into the cond array and its element number is
  698: #      set in the condid_level-qualified-condition-id element of the hash.
  699: #   - The condition type is colon appneded to the cond array element for this condition.
  700: sub parse_condition {
  701:     my ($token,$lpc) = @_;
  702:     my $rid=$lpc.'.'.$token->[2]->{'id'};
  703:     
  704:     $hash{'kind_'.$rid}='cond';
  705: 
  706:     my $condition = $token->[2]->{'value'};
  707:     $condition =~ s/[\n\r]+/ /gs;
  708:     push(@cond, $condition);
  709:     $hash{'condid_'.$rid}=$#cond;
  710:     if ($token->[2]->{'type'}) {
  711: 	$cond[$#cond].=':'.$token->[2]->{'type'};
  712:     }  else {
  713: 	$cond[$#cond].=':normal';
  714:     }
  715: }
  716: 
  717: # ------------------------------------------------------------------- Parameter
  718: # Parse a <parameter> tag in the map.
  719: # Parmameters:
  720: #    $token Token array for a start tag from HTML::TokeParser
  721: #           [0] = 'S'
  722: #           [1] = tagname ("param")
  723: #           [2] = Hash of {attribute} = values.
  724: #           [3] = Array of the keys in [2].
  725: #           [4] = unused.
  726: #    $lpc   Current map nesting level.a
  727: #
  728: #  Typical attributes:
  729: #     to=n      - Number of the resource the parameter applies to.
  730: #     type=xx   - Type of parameter value (e.g. string_yesno or int_pos).
  731: #     name=xxx  - Name of parameter (e.g. parameter_randompick or parameter_randomorder).
  732: #     value=xxx - value of the parameter.
  733: 
  734: sub parse_param {
  735:     my ($token,$lpc) = @_;
  736:     my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to.
  737:     my $name=$token->[2]->{'name'};	      # Name of parameter
  738:     my $part;
  739: 
  740: 
  741:     if ($name=~/^parameter_(.*)_/) { 
  742: 	$part=$1;
  743:     } else {
  744: 	$part=0;
  745:     }
  746: 
  747:     # Peel the parameter_ off the parameter name.
  748: 
  749:     $name=~s/^.*_([^_]*)$/$1/;
  750: 
  751:     # The value is:
  752:     #   type.part.name.value
  753: 
  754:     my $newparam=
  755: 	&escape($token->[2]->{'type'}).':'.
  756: 	&escape($part.'.'.$name).'='.
  757: 	&escape($token->[2]->{'value'});
  758: 
  759:     # The hash key is param_resourceid.
  760:     # Multiple parameters for a single resource are & separated in the hash.
  761: 
  762: 
  763:     if (defined($hash{'param_'.$referid})) {
  764: 	$hash{'param_'.$referid}.='&'.$newparam;
  765:     } else {
  766: 	$hash{'param_'.$referid}=''.$newparam;
  767:     }
  768:     #
  769:     #  These parameters have to do with randomly selecting
  770:     # resources, therefore a separate hash is also created to 
  771:     # make it easy to locate them when actually computing the resource set later on
  772:     # See the code conditionalized by ($randomize) in loadmap().
  773: 
  774:     if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
  775: 	$randompick{$referid}=$token->[2]->{'value'};
  776:     }
  777:     if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
  778: 	$randompickseed{$referid}=$token->[2]->{'value'};
  779:     }
  780:     if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
  781: 	$randomorder{$referid}=$token->[2]->{'value'};
  782:     }
  783: 
  784:     # These parameters have to do with how the URLs of resources are presented to
  785:     # course members(?).  encrypturl presents encypted url's while
  786:     # hiddenresource hides the URL.
  787:     #
  788: 
  789:     if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
  790: 	if ($token->[2]->{'value'}=~/^yes$/i) {
  791: 	    $encurl{$referid}=1;
  792: 	}
  793:     }
  794:     if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) {
  795: 	if ($token->[2]->{'value'}=~/^yes$/i) {
  796: 	    $hiddenurl{$referid}=1;
  797: 	}
  798:     }
  799: }
  800: #
  801: #  Parse mapalias parameters.
  802: #  these are tags of the form:
  803: #  <param to="nn" 
  804: #         value="some-alias-for-resourceid-nn" 
  805: #         name="parameter_0_mapalias" 
  806: #         type="string" />
  807: #  A map alias is a textual name for a resource:
  808: #    - The to  attribute identifies the resource (this gets level qualified below)
  809: #    - The value attributes provides the alias string.
  810: #    - name must be of the regexp form: /^parameter_(0_)*mapalias$/
  811: #    - e.g. the string 'parameter_' followed by 0 or more "0_" strings
  812: #      terminating with the string 'mapalias'.
  813: #      Examples:
  814: #         'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias'
  815: #  Invalid to ids are silently ignored.
  816: #
  817: #  Parameters:
  818: #     token - The token array fromthe HMTML::TokeParser
  819: #     lpc   - The current map level counter.
  820: #
  821: sub parse_mapalias_param {
  822:     my ($token,$lpc) = @_;
  823: 
  824:     # Fully qualify the to value and ignore the alias if there is no
  825:     # corresponding resource.
  826: 
  827:     my $referid=$lpc.'.'.$token->[2]->{'to'};
  828:     return if (!exists($hash{'src_'.$referid}));
  829: 
  830:     # If this is a valid mapalias parameter, 
  831:     # Append the target id to the count_mapalias element for that
  832:     # alias so that we can detect doubly defined aliases
  833:     # e.g.:
  834:     #  <param to="1" value="george" name="parameter_0_mapalias" type="string" />
  835:     #  <param to="2" value="george" name="parameter_0_mapalias" type="string" />
  836:     #
  837:     #  The example above is trivial but the case that's important has to do with
  838:     #  constructing a map that includes a nested map where the nested map may have
  839:     #  aliases that conflict with aliases established in the enclosing map.
  840:     #
  841:     # ...and create/update the hash mapalias entry to actually store the alias.
  842:     #
  843: 
  844:     if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
  845: 	&count_mapalias($token->[2]->{'value'},$referid);
  846: 	$hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
  847:     }
  848: }
  849: 
  850: # --------------------------------------------------------- Simplify expression
  851: 
  852: 
  853: #
  854: #  Someone should really comment this to describe what it does to what and why.
  855: #
  856: sub simplify {
  857:     my $expression=shift;
  858: # (0&1) = 1
  859:     $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
  860: # (8)=8
  861:     $expression=~s/\(([_\.\d]+)\)/$1/g;
  862: # 8&8=8
  863:     $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
  864: # 8|8=8
  865:     $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g;
  866: # (5&3)&4=5&3&4
  867:     $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
  868: # (((5&3)|(4&6)))=((5&3)|(4&6))
  869:     $expression=~
  870: 	s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
  871: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
  872:     $expression=~
  873: 	s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
  874:     return $expression;
  875: }
  876: 
  877: # -------------------------------------------------------- Build condition hash
  878: 
  879: #
  880: #  Traces a route recursively through the map after it has been loaded
  881: #  (I believe this really visits each resourcde that is reachable fromt he
  882: #  start top node.
  883: #
  884: #  - Marks hidden resources as hidden.
  885: #  - Marks which resource URL's must be encrypted.
  886: #  - Figures out (if necessary) the first resource in the map.
  887: #  - Further builds the chunks of the big hash that define how 
  888: #    conditions work
  889: #
  890: #  Note that the tracing strategy won't visit resources that are not linked to
  891: #  anything or islands in the map (groups of resources that form a path but are not
  892: #  linked in to the path that can be traced from the start resource...but that's ok
  893: #  because by definition, those resources are not reachable by users of the course.
  894: #
  895: # Parameters:
  896: #   sofar    - _URI of the prior entry or 0 if this is the top.
  897: #   rid      - URI of the resource to visit.
  898: #   beenhere - list of resources (each resource enclosed by &'s) that have
  899: #              already been visited.
  900: #   encflag  - If true the resource that resulted in a recursive call to us
  901: #              has an encoded URL (which means contained resources should too). 
  902: #   hdnflag  - If true,the resource that resulted in a recursive call to us
  903: #              was hidden (which means contained resources should be hidden too).
  904: # Returns
  905: #    new value indicating how far the map has been traversed (the sofar).
  906: #
  907: sub traceroute {
  908:     my ($sofar,$rid,$beenhere,$encflag,$hdnflag,$cid)=@_;
  909:     my $newsofar=$sofar=simplify($sofar);
  910: 
  911:     unless ($beenhere=~/\&\Q$rid\E\&/) {
  912: 	$beenhere.=$rid.'&';  
  913: 	my ($mapid,$resid)=split(/\./,$rid);
  914: 	my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
  915: 	my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb);
  916: 
  917: 	if ($hdnflag || lc($hidden) eq 'yes') {
  918: 	    $hiddenurl{$rid}=1;
  919: 	}
  920: 	if (!$hdnflag && lc($hidden) eq 'no') {
  921: 	    delete($hiddenurl{$rid});
  922: 	}
  923: 
  924: 	my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
  925: 	if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
  926: 
  927: 	if (($retfrid eq '') && ($hash{'src_'.$rid})
  928: 	    && ($hash{'src_'.$rid}!~/\.sequence$/)) {
  929: 	    $retfrid=$rid;
  930: 	}
  931: 
  932:         my (@deeplink,@recurseup);
  933:         if ($hash{'is_map_'.$rid}) {
  934:             my ($cdom,$cnum) = split(/_/,$cid);
  935:             my $mapsrc = $hash{'src_'.$rid};
  936:             my $map_pc = $hash{'map_pc_'.$mapsrc};
  937:             my @pcs = split(/,/,$hash{'map_hierarchy_'.$map_pc});
  938:             shift(@pcs);
  939:             @recurseup = map { &Apache::lonnet::declutter($hash{'map_id_'.$_}) } reverse(@pcs);
  940:             my $mapname = &Apache::lonnet::declutter(&Apache::lonnet::deversion($mapsrc));
  941:             my $deeplinkval = &get_mapparam($env{'user.name'},$env{'user.domain'},$cnum,$cdom,
  942:                                             $rid,$mapname,'0.deeplink',\@recurseup);
  943:             if ($deeplinkval ne '') {
  944:                 @deeplink = ($deeplinkval,'map');
  945:             }
  946:         } else {
  947:             my @pcs = split(/,/,$hash{'map_hierarchy_'.$mapid});
  948:             shift(@pcs);
  949:             @recurseup = map { &Apache::lonnet::declutter($hash{'map_id_'.$_}) } reverse(@pcs);
  950:             @deeplink = &Apache::lonnet::EXT('resource.0.deeplink',$symb,'','','','',$cid,\@recurseup);
  951:         }
  952:         unless (@deeplink < 2) {
  953:             $hash{'deeplinkonly_'.$rid}=join(':',map { &escape($_); } @deeplink);
  954:         }
  955: 
  956: 	if (defined($hash{'conditions_'.$rid})) {
  957: 	    $hash{'conditions_'.$rid}=simplify(
  958:            '('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
  959: 	} else {
  960: 	    $hash{'conditions_'.$rid}=$sofar;
  961: 	}
  962: 
  963: 	# if the expression is just the 0th condition keep it
  964: 	# otherwise leave a pointer to this condition expression
  965: 
  966: 	$newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
  967: 
  968: 	# Recurse if the resource is a map:
  969: 
  970: 	if (defined($hash{'is_map_'.$rid})) {
  971: 	    if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
  972: 		$sofar=$newsofar=
  973: 		    &traceroute($sofar,
  974: 				$hash{'map_start_'.$hash{'src_'.$rid}},
  975: 				$beenhere,
  976: 				$encflag || $encurl{$rid},
  977: 				$hdnflag || $hiddenurl{$rid},
  978:                                 $cid);
  979: 	    }
  980: 	}
  981: 
  982: 	# Processes  links to this resource:
  983: 	#  - verify the existence of any conditionals on the link to here.
  984: 	#  - Recurse to any resources linked to us.
  985: 	#
  986: 	if (defined($hash{'to_'.$rid})) {
  987: 	    foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
  988: 		my $further=$sofar;
  989: 		#
  990: 		# If there's a condition associated with this link be sure
  991: 		# it's been defined else that's an error:
  992: 		#
  993:                 if ($hash{'undercond_'.$id}) {
  994: 		    if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) {
  995: 			$further=simplify('('.'_'.$rid.')&('.
  996: 					  $hash{'condid_'.$hash{'undercond_'.$id}}.')');
  997: 		    } else {
  998: 			$errtext.= '<br />'.
  999:                                    &mt('Undefined condition ID: [_1]',
 1000:                                        $hash{'undercond_'.$id});
 1001: 		    }
 1002:                 }
 1003: 		#  Recurse to resoruces that have to's to us.
 1004:                 $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere,
 1005: 				      $encflag,$hdnflag,$cid);
 1006: 	    }
 1007: 	}
 1008:     }
 1009:     return $newsofar;
 1010: }
 1011: 
 1012: # ------------------------------ Cascading conditions, quick access, parameters
 1013: 
 1014: #
 1015: #  Seems a rather strangely named sub given what the comment above says it does.
 1016: 
 1017: 
 1018: sub accinit {
 1019:     my ($uri,$short,$fn)=@_;
 1020:     my %acchash=();
 1021:     my %captured=();
 1022:     my $condcounter=0;
 1023:     $acchash{'acc.cond.'.$short.'.0'}=0;
 1024: 
 1025:     # This loop is only interested in conditions and 
 1026:     # parameters in the big hash:
 1027: 
 1028:     foreach my $key (keys(%hash)) {
 1029: 
 1030: 	# conditions:
 1031: 
 1032: 	if ($key=~/^conditions/) {
 1033: 	    my $expr=$hash{$key};
 1034: 
 1035: 	    # try to find and factor out common sub-expressions
 1036: 	    # Any subexpression that is found is simplified, removed from
 1037: 	    # the original condition expression and the simplified sub-expression
 1038: 	    # substituted back in to the epxression..I'm not actually convinced this
 1039: 	    # factors anything out...but instead maybe simplifies common factors(?)
 1040: 
 1041: 	    foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
 1042: 		my $orig=$sub;
 1043: 
 1044: 		my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
 1045: 		next if (!defined($factor));
 1046: 
 1047: 		$sub=~s/\Q$factor\E//g;
 1048: 		$sub=~s/^\(/\($factor\(/;
 1049: 		$sub.=')';
 1050: 		$sub=simplify($sub);
 1051: 		$expr=~s/\Q$orig\E/$sub/;
 1052: 	    }
 1053: 	    $hash{$key}=$expr;
 1054: 
 1055:            # If not yet seen, record in acchash and that we've seen it.
 1056: 
 1057: 	    unless (defined($captured{$expr})) {
 1058: 		$condcounter++;
 1059: 		$captured{$expr}=$condcounter;
 1060: 		$acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
 1061: 	    } 
 1062:         # Parameters:
 1063: 
 1064: 	} elsif ($key=~/^param_(\d+)\.(\d+)/) {
 1065: 	    my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2,
 1066: 						    $hash{'src_'.$1.'.'.$2});
 1067: 	    foreach my $param (split(/\&/,$hash{$key})) {
 1068: 		my ($typename,$value)=split(/\=/,$param);
 1069: 		my ($type,$name)=split(/\:/,$typename);
 1070: 		$parmhash{$prefix.'.'.&unescape($name)}=
 1071: 		    &unescape($value);
 1072: 		$parmhash{$prefix.'.'.&unescape($name).'.type'}=
 1073: 		    &unescape($type);
 1074: 	    }
 1075: 	}
 1076:     }
 1077:     # This loop only processes id entries in the big hash.
 1078: 
 1079:     foreach my $key (keys(%hash)) {
 1080: 	if ($key=~/^ids/) {
 1081: 	    foreach my $resid (split(/\,/,$hash{$key})) {
 1082: 		my $uri=$hash{'src_'.$resid};
 1083: 		my ($uripath,$urifile) =
 1084: 		    &Apache::lonnet::split_uri_for_cond($uri);
 1085: 		if ($uripath) {
 1086: 		    my $uricond='0';
 1087: 		    if (defined($hash{'conditions_'.$resid})) {
 1088: 			$uricond=$captured{$hash{'conditions_'.$resid}};
 1089: 		    }
 1090: 		    if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
 1091: 			if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
 1092: 			    /(\&\Q$urifile\E\:[^\&]*)/) {
 1093: 			    my $replace=$1;
 1094: 			    my $regexp=$replace;
 1095: 			    #$regexp=~s/\|/\\\|/g;
 1096: 			    $acchash{'acc.res.'.$short.'.'.$uripath} =~
 1097: 				s/\Q$regexp\E/$replace\|$uricond/;
 1098: 			} else {
 1099: 			    $acchash{'acc.res.'.$short.'.'.$uripath}.=
 1100: 				$urifile.':'.$uricond.'&';
 1101: 			}
 1102: 		    } else {
 1103: 			$acchash{'acc.res.'.$short.'.'.$uripath}=
 1104: 			    '&'.$urifile.':'.$uricond.'&';
 1105: 		    }
 1106: 		} 
 1107: 	    }
 1108: 	}
 1109:     }
 1110:     $acchash{'acc.res.'.$short.'.'}='&:0&';
 1111:     my $courseuri=$uri;
 1112:     $courseuri=~s/^\/res\///;
 1113:     my $regexp = 1;
 1114:     &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp);
 1115:     &Apache::lonnet::appenv(\%acchash);
 1116: }
 1117: 
 1118: # ---------------- Selectively delete from randompick maps and hidden url parms
 1119: 
 1120: sub hiddenurls {
 1121:     my $randomoutentry='';
 1122:     foreach my $rid (keys(%randompick)) {
 1123:         my $rndpick=$randompick{$rid};
 1124:         my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
 1125: # ------------------------------------------- put existing resources into array
 1126:         my @currentrids=();
 1127:         foreach my $key (sort(keys(%hash))) {
 1128: 	    if ($key=~/^src_($mpc\.\d+)/) {
 1129: 		if ($hash{'src_'.$1}) { push @currentrids, $1; }
 1130:             }
 1131:         }
 1132: 	# rids are number.number and we want to numercially sort on 
 1133:         # the second number
 1134: 	@currentrids=sort {
 1135: 	    my (undef,$aid)=split(/\./,$a);
 1136: 	    my (undef,$bid)=split(/\./,$b);
 1137: 	    $aid <=> $bid;
 1138: 	} @currentrids;
 1139:         next if ($#currentrids<$rndpick);
 1140: # -------------------------------- randomly eliminate the ones that should stay
 1141: 	my (undef,$id)=split(/\./,$rid);
 1142:         if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; }
 1143:         my $setcode;
 1144:         if (defined($randomizationcode{$rid})) {
 1145:             if ($env{'form.CODE'} eq '') {
 1146:                 $env{'form.CODE'} = $randomizationcode{$rid};
 1147:                 $setcode = 1;
 1148:             }
 1149:         }
 1150: 	my $rndseed=&Apache::lonnet::rndseed($id); # use id instead of symb
 1151:         if ($setcode) {
 1152:             undef($env{'form.CODE'});
 1153:             undef($setcode);
 1154:         }
 1155: 	&Apache::lonnet::setup_random_from_rndseed($rndseed);
 1156: 	my @whichids=&Math::Random::random_permuted_index($#currentrids+1);
 1157:         for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; }
 1158: 	#&Apache::lonnet::logthis("$id,$rndseed,".join(':',@whichids));
 1159: # -------------------------------------------------------- delete the leftovers
 1160:         for (my $k=0; $k<=$#currentrids; $k++) {
 1161:             if ($currentrids[$k]) {
 1162: 		$hash{'randomout_'.$currentrids[$k]}=1;
 1163:                 my ($mapid,$resid)=split(/\./,$currentrids[$k]);
 1164:                 if ($rescount{$mapid}) {
 1165:                     $rescount{$mapid} --;
 1166:                 }
 1167:                 if ($hash{'is_map_'.$currentrids[$k]}) {
 1168:                     if ($mapcount{$mapid}) {
 1169:                         $mapcount{$mapid} --;
 1170:                     }
 1171:                 }
 1172:                 $randomoutentry.='&'.
 1173: 		    &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
 1174: 						 $resid,
 1175: 						 $hash{'src_'.$currentrids[$k]}
 1176: 						 ).'&';
 1177:             }
 1178:         }
 1179:     }
 1180: # ------------------------------ take care of explicitly hidden urls or folders
 1181:     foreach my $rid (keys(%hiddenurl)) {
 1182: 	$hash{'randomout_'.$rid}=1;
 1183: 	my ($mapid,$resid)=split(/\./,$rid);
 1184:         if ($rescount{$mapid}) {
 1185:             $rescount{$mapid} --;
 1186:         }
 1187:         if ($hash{'is_map_'.$rid}) {
 1188:             if ($mapcount{$mapid}) {
 1189:                 $mapcount{$mapid} --;
 1190:             }
 1191:         }
 1192: 	$randomoutentry.='&'.
 1193: 	    &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,
 1194: 					 $hash{'src_'.$rid}).'&';
 1195:     }
 1196: # --------------------------------------- append randomout entry to environment
 1197:     if ($randomoutentry) {
 1198: 	&Apache::lonnet::appenv({'acc.randomout' => $randomoutentry});
 1199:     }
 1200: }
 1201: 
 1202: sub deeplinkouts {
 1203:     my $deeplinkoutentry;
 1204:     foreach my $rid (keys(%deeplinkout)) {
 1205:         $hash{'deeplinkout_'.$rid}=1;
 1206:         my ($mapid,$resid)=split(/\./,$rid);
 1207:         $deeplinkoutentry.='&'.
 1208:             &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,
 1209:                                          $hash{'src_'.$rid}).'&';
 1210:     }
 1211: # --------------------------------------- append deeplinkout entry to environment
 1212:     if ($deeplinkoutentry) {
 1213:         &Apache::lonnet::appenv({'acc.deeplinkout' => $deeplinkoutentry});
 1214:     }
 1215: }
 1216: 
 1217: # -------------------------------------- populate big hash with map breadcrumbs
 1218: 
 1219: # Create map_breadcrumbs_$pc from map_hierarchy_$pc by omitting intermediate
 1220: # maps not shown in Course Contents table.
 1221: 
 1222: sub mapcrumbs {
 1223:     my ($cid) = @_;
 1224:     foreach my $key (keys(%rescount)) {
 1225:         if ($hash{'map_hierarchy_'.$key}) {
 1226:             my $skipnext = 0;
 1227:             foreach my $id (split(/,/,$hash{'map_hierarchy_'.$key}),$key) {
 1228:                 my $rid = $hash{'ids_'.$hash{'map_id_'.$id}};
 1229:                 unless (($skipnext) || (!&is_advanced($cid) && $hash{'deeplinkout_'.$rid})) {
 1230:                     $hash{'map_breadcrumbs_'.$key} .= "$id,";
 1231:                 }
 1232:                 unless (($id == 0) || ($id == 1)) {
 1233:                     if ((!$rescount{$id}) || ($rescount{$id} == 1 && $mapcount{$id} == 1)) {
 1234:                         $skipnext = 1;
 1235:                     } else {
 1236:                         $skipnext = 0;
 1237:                     }
 1238:                 }
 1239:             }
 1240:             $hash{'map_breadcrumbs_'.$key} =~ s/,$//;
 1241:         }
 1242:     }
 1243: }
 1244: 
 1245: # ---------------------------------------------------- Read map and all submaps
 1246: 
 1247: sub readmap {
 1248:     my ($short,$critmsg_check) = @_;
 1249:     $short=~s/^\///;
 1250: 
 1251:     # TODO:  Hidden dependency on current user:
 1252: 
 1253:     my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1}); 
 1254: 
 1255:     my $fn=$cenv{'fn'};
 1256:     my $uri;
 1257:     $short=~s/\//\_/g;
 1258:     unless ($uri=$cenv{'url'}) { 
 1259: 	&Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1260: 				 "Could not load course $short.</font>"); 
 1261: 	return ('',&mt('No course data available.'));;
 1262:     }
 1263:     @cond=('true:normal');
 1264: 
 1265:     unless (open(LOCKFILE,">","$fn.db.lock")) {
 1266: 	# 
 1267: 	# Most likely a permissions problem on the lockfile or its directory.
 1268: 	#
 1269:         $retfurl = '';
 1270:         return ($retfurl,'<br />'.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.');
 1271:     }
 1272:     my $lock=0;
 1273:     my $gotstate=0;
 1274:     
 1275:     # If we can get the lock without delay any files there are idle
 1276:     # and from some prior request.  We'll kill them off and regenerate them:
 1277: 
 1278:     if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {	
 1279: 	$lock=1;		# Remember that we hold the lock.
 1280:         &unlink_tmpfiles($fn);
 1281:     }
 1282:     undef %randompick;
 1283:     undef %randompickseed;
 1284:     undef %randomorder;
 1285:     undef %randomizationcode;
 1286:     undef %hiddenurl;
 1287:     undef %encurl;
 1288:     undef %deeplinkout;
 1289:     undef %rescount;
 1290:     undef %mapcount;
 1291:     $retfrid='';
 1292:     $errtext='';
 1293:     my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags.
 1294: 
 1295:     # if we got the lock, regenerate course regnerate empty files and tie them.
 1296: 
 1297:     if ($lock) {
 1298:         if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
 1299:             $tiedhash = 1;
 1300:             if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
 1301:                 $tiedparmhash = 1;
 1302:                 $gotstate = &build_tmp_hashes($uri,
 1303: 					      $fn,
 1304: 					      $short,
 1305: 					      \%cenv); # TODO: Need to provide requested user@dom
 1306:                 unless ($gotstate) {
 1307:                     &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.</font>');
 1308:                 }
 1309:                 $untiedparmhash = untie(%parmhash);
 1310:                 unless ($untiedparmhash) {
 1311:                     &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1312:                         'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
 1313:                 }
 1314:             }
 1315:             $untiedhash = untie(%hash);
 1316:             unless ($untiedhash) {
 1317:                 &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1318:                     'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
 1319:             }
 1320:         }
 1321: 	flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other
 1322: 	                         # unlocked places the remainder happens..seems like if we
 1323:                                  # just kept the lock here the rest of the code would have
 1324:                                  # been much easier? 
 1325:     }
 1326:     unless ($lock && $tiedhash && $tiedparmhash) { 
 1327: 	# if we are here it is likely because we are already trying to 
 1328: 	# initialize the course in another child, busy wait trying to 
 1329: 	# tie the hashes for the next 90 seconds, if we succeed forward 
 1330: 	# them on to navmaps, if we fail, throw up the Could not init 
 1331: 	# course screen
 1332: 	#
 1333: 	# RF: I'm not seeing the case where the ties/unties can fail in a way
 1334: 	#     that can be remedied by this.  Since we owned the lock seems
 1335: 	#     Tie/untie failures are a result of something like a permissions problem instead?
 1336: 	#
 1337: 
 1338: 	#  In any vent, undo what we did manage to do above first:
 1339: 	if ($lock) {
 1340: 	    # Got the lock but not the DB files
 1341: 	    flock(LOCKFILE,LOCK_UN);
 1342:             $lock = 0;
 1343: 	}
 1344:         if ($tiedhash) {
 1345:             unless($untiedhash) {
 1346: 	        untie(%hash);
 1347:             }
 1348:         }
 1349:         if ($tiedparmhash) {
 1350:             unless($untiedparmhash) {
 1351:                 untie(%parmhash);
 1352:             }
 1353:         }
 1354: 	# Log our failure:
 1355: 
 1356: 	&Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1357: 				 "Could not tie coursemap $fn for $uri.</font>");
 1358:         $tiedhash = '';
 1359:         $tiedparmhash = '';
 1360: 	my $i=0;
 1361: 
 1362: 	# Keep on retrying the lock for 90 sec until we succeed.
 1363: 
 1364: 	while($i<90) {
 1365: 	    $i++;
 1366: 	    sleep(1);
 1367: 	    if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
 1368: 
 1369: 		# Got the lock, tie the hashes...the assumption in this code is
 1370: 		# that some other worker thread has created the db files quite recently
 1371: 		# so no load is needed:
 1372: 
 1373:                 $lock = 1;
 1374: 		if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
 1375:                     $tiedhash = 1;
 1376: 		    if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
 1377:                         $tiedparmhash = 1;
 1378:                         if (-e "$fn.state") {
 1379: 		            $retfurl='/adm/navmaps';
 1380: 
 1381: 			    # BUG BUG: Side effect!
 1382: 			    # Should conditionalize on something so that we can use this
 1383: 			    # to load maps for courses that are not current?
 1384: 			    #
 1385: 		            &Apache::lonnet::appenv({"request.course.id"  => $short,
 1386: 		   			             "request.course.fn"  => $fn,
 1387: 					             "request.course.uri" => $uri,
 1388:                                                      "request.course.tied" => time});
 1389:                             
 1390: 		            $untiedhash = untie(%hash);
 1391: 		            $untiedparmhash = untie(%parmhash);
 1392:                             $gotstate = 1;
 1393: 		            last;
 1394: 		        }
 1395:                         $untiedparmhash = untie(%parmhash);
 1396: 	            }
 1397: 	            $untiedhash = untie(%hash);
 1398:                 }
 1399:             }
 1400: 	}
 1401:         if ($lock) {
 1402:             flock(LOCKFILE,LOCK_UN);
 1403:             $lock = 0;
 1404:             if ($tiedparmhash) {
 1405:                 unless ($untiedparmhash) {
 1406:                     &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1407:                         'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
 1408:                 }
 1409:             }
 1410:             if ($tiedparmhash) {
 1411:                 unless ($untiedhash) {
 1412:                     &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1413:                         'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
 1414:                 }
 1415:             }
 1416:         }
 1417:     }
 1418:     # I think this branch of code is all about what happens if we just did the stuff above, 
 1419:     # but found that the  state file did not exist...again if we'd just held the lock
 1420:     # would that have made this logic simpler..as generating all the files would be
 1421:     # an atomic operation with respect to the lock.
 1422:     #
 1423:     unless ($gotstate) {
 1424:         $lock = 0;
 1425:         &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1426:                      'Could not read statemap '.$fn.' for '.$uri.'.</font>');
 1427:         &unlink_tmpfiles($fn);
 1428:         if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
 1429:             $lock=1;
 1430:         }
 1431:         undef %randompick;
 1432:         undef %randompickseed;
 1433:         undef %randomorder;
 1434:         undef %randomizationcode;
 1435:         undef %hiddenurl;
 1436:         undef %encurl;
 1437:         undef %deeplinkout;
 1438:         undef %rescount;
 1439:         undef %mapcount;
 1440:         $errtext='';
 1441:         $retfrid='';
 1442: 	#
 1443: 	# Once more through the routine of tying and loading and so on.
 1444: 	#
 1445:         if ($lock) {
 1446:             if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
 1447:                 if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
 1448:                     $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent?
 1449:                     unless ($gotstate) {
 1450:                         &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1451:                             'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.</font>');
 1452:                     }
 1453:                     unless (untie(%parmhash)) {
 1454:                         &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1455:                             'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.</font>');
 1456:                     }
 1457:                 } else {
 1458:                     &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1459:                         'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.</font>');
 1460:                 }
 1461:                 unless (untie(%hash)) {
 1462:                     &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1463:                         'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
 1464:                 }
 1465:             } else {
 1466:                &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1467:                    'Could not tie coursemap '.$fn.'.db for '.$uri.'.</font>');
 1468:             }
 1469:             flock(LOCKFILE,LOCK_UN);
 1470:             $lock = 0;
 1471:         } else {
 1472: 	    # Failed to get the immediate lock.
 1473: 
 1474:             &Apache::lonnet::logthis('<font color="blue">WARNING: '.
 1475:             'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
 1476:         }
 1477:     }
 1478:     close(LOCKFILE);
 1479:     unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
 1480:         &Apache::lonmsg::author_res_msg($env{'request.course.uri'},
 1481:                                         $errtext); # TODO: User dependent?
 1482:     }
 1483: # ------------------------------------------------- Check for critical messages
 1484: 
 1485: #  Depends on user must parameterize this as well..or separate as this is:
 1486: #  more part of determining what someone sees on entering a course?
 1487: #  When lonuserstate::readmap() is called from lonroles.pm, i.e.,
 1488: #  after selecting a role in a course, critical_redirect will be called,
 1489: #  unless the course has a blocking event in effect, which suppresses
 1490: #  critical message checking (users without evb priv).
 1491: #
 1492: 
 1493:     if ($critmsg_check) {
 1494:         my ($redirect,$url) = &Apache::loncommon::critical_redirect();
 1495:         if ($redirect) {
 1496:             $retfurl = $url;
 1497:         }
 1498:     }
 1499:     return ($retfurl,$errtext);
 1500: }
 1501: 
 1502: #
 1503: #  This sub is called when the course hash and the param hash have been tied and
 1504: #  their lock file is held.
 1505: #  Parameters:
 1506: #     $uri      -  URI that identifies the course.
 1507: #     $fn       -  The base path/filename of the files that make up the context
 1508: #                  being built.
 1509: #     $short    -  Short course name.
 1510: #     $cenvref  -  Reference to the course environment hash returned by 
 1511: #                  Apache::lonnet::coursedescription
 1512: #
 1513: #  Assumptions:
 1514: #    The globals
 1515: #    %hash, %paramhash are tied to their gdbm files and we hold the lock on them.
 1516: #
 1517: sub build_tmp_hashes {
 1518:     my ($uri,$fn,$short,$cenvref) = @_;
 1519:     
 1520:     unless(ref($cenvref) eq 'HASH') {
 1521:         return;
 1522:     }
 1523:     my %cenv = %{$cenvref};
 1524:     my $gotstate = 0;
 1525:     %hash=();			# empty the global course and  parameter hashes.
 1526:     %parmhash=();
 1527:     $errtext='';		# No error messages yet.
 1528:     $pc=0;
 1529:     &clear_mapalias_count();
 1530:     &processversionfile(%cenv);
 1531: 
 1532:     # URI Of the map file.
 1533: 
 1534:     my $furi=&Apache::lonnet::clutter($uri);
 1535:     #
 1536:     #  the map staring points.
 1537:     #
 1538:     $hash{'src_0.0'}=&versiontrack($furi);
 1539:     $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
 1540:     $hash{'ids_'.$furi}='0.0';
 1541:     $hash{'is_map_0.0'}=1;
 1542: 
 1543:     # Load the map.. note that loadmap may implicitly recurse if the map contains 
 1544:     # sub-maps.
 1545: 
 1546:     &loadmap($uri,'0.0',$short);
 1547: 
 1548:     #  The code below only executes if there is a starting point for the map>
 1549:     #  Q/BUG??? If there is no start resource for the map should that be an error?
 1550:     #
 1551: 
 1552:     if (defined($hash{'map_start_'.$uri})) {
 1553:         &Apache::lonnet::appenv({"request.course.id"  => $short,
 1554:                                  "request.course.fn"  => $fn,
 1555:                                  "request.course.uri" => $uri,
 1556:                                  "request.course.tied" => time});
 1557:         $env{'request.course.id'}=$short;
 1558:         &traceroute('0',$hash{'map_start_'.$uri},'&','','',$short);
 1559:         &accinit($uri,$short,$fn);
 1560:         &hiddenurls();
 1561:     }
 1562:     $errtext .= &get_mapalias_errors();
 1563: # ------------------------------------------------------- Put versions into src
 1564:     foreach my $key (keys(%hash)) {
 1565:         if ($key=~/^src_/) {
 1566:             $hash{$key}=&putinversion($hash{$key});
 1567:         } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
 1568:             my ($type, $url) = ($1,$2);
 1569:             my $value = $hash{$key};
 1570:             $hash{$type.&putinversion($url)}=$value;
 1571:         }
 1572:     }
 1573: # ---------------------------------------------------------------- Encrypt URLs
 1574:     foreach my $id (keys(%encurl)) {
 1575: #           $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
 1576:         $hash{'encrypted_'.$id}=1;
 1577:     }
 1578: # ----------------------------------------------- Close hashes to finally store
 1579: # --------------------------------- Routine must pass this point, no early outs
 1580:     $hash{'first_rid'}=$retfrid;
 1581:     my ($mapid,$resid)=split(/\./,$retfrid);
 1582:     $hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
 1583:     my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
 1584:     $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
 1585:     if ($hash{'encrypted_'.$retfrid}) {
 1586:         $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
 1587:     }
 1588:     $hash{'first_url'}=$retfurl;
 1589: # ---------------------------------------------------- Store away initial state
 1590:     {
 1591:         my $cfh;
 1592:         if (open($cfh,">","$fn.state")) {
 1593:             print $cfh join("\n",@cond);
 1594:             $gotstate = 1;
 1595:         } else {
 1596:             &Apache::lonnet::logthis("<font color=blue>WARNING: ".
 1597:                                      "Could not write statemap $fn for $uri.</font>");
 1598:         }
 1599:     }
 1600: 
 1601:     # Was initial access via a deep-link?
 1602:     my ($cdom,$cnum) = split(/_/,$short);
 1603:     if (($cdom ne '') && ($env{'request.deeplink.login'} ne '')) {
 1604:         my $deeplink_symb = &Apache::loncommon::deeplink_login_symb($cnum,$cdom);
 1605:         if ($deeplink_symb) {
 1606:             my ($loginrid,$deeplink_login_pc,$login_hierarchy);
 1607:             my ($map,$resid,$url) = &Apache::lonnet::decode_symb($deeplink_symb);
 1608:             $loginrid = $hash{'map_pc_'.&Apache::lonnet::clutter($map)}.'.'.$resid;
 1609:             if ($deeplink_symb =~ /\.(page|sequence)$/) {
 1610:                 $deeplink_login_pc = $hash{'map_pc_'.&Apache::lonnet::clutter($url)};
 1611:             } else {
 1612:                 $deeplink_login_pc = $hash{'map_pc_'.&Apache::lonnet::clutter($map)};
 1613:             }
 1614:             my $deeplink;
 1615:             if ($hash{'deeplinkonly_'.$loginrid} ne '') {
 1616:                 my @deeplinkinfo = map { &unescape($_); } split(/:/,$hash{'deeplinkonly_'.$loginrid});
 1617:                 unless (@deeplinkinfo < 2) {
 1618:                     $deeplink = $deeplinkinfo[0];
 1619:                 }
 1620:             }
 1621:             if ($deeplink) {
 1622:                 my $disallow;
 1623:                 my ($state,$others,$listed,$scope,$protect) = split(/,/,$deeplink);
 1624:                 if (($protect ne 'none') && ($protect ne '')) {
 1625:                     my ($acctype,$item) = split(/:/,$protect);
 1626:                     if ($acctype =~ /lti(c|d)$/) {
 1627:                         unless ($env{'request.linkprot'} eq $item.$1.':'.$env{'request.deeplink.login'}) {
 1628:                             $disallow = 1;
 1629:                         }
 1630:                     } elsif ($acctype eq 'key') {
 1631:                         unless ($env{'request.linkkey'} eq $item) {
 1632:                             $disallow = 1;
 1633:                         }
 1634:                     }
 1635:                 }
 1636:                 if ($disallow) {
 1637:                     &Apache::lonnet::delenv('request.deeplink.login');
 1638:                 } else {
 1639:                     if ($others eq 'hide') {
 1640:                         my @recfolders;
 1641:                         if ($scope eq 'rec') {
 1642:                             foreach my $key (keys(%hash)) {
 1643:                                 if ($key=~/^map_hierarchy_(\d+)$/) {
 1644:                                     my $mpc = $1;
 1645:                                     my @ids = split(/,/,$hash{$key});
 1646:                                     if (grep(/^$deeplink_login_pc$/,@ids)) {
 1647:                                         my $idx;
 1648:                                         foreach my $mapid (@ids) {
 1649:                                             if ($idx) {
 1650:                                                 push(@recfolders,$mapid);
 1651:                                             } elsif ($mapid == $deeplink_login_pc) {
 1652:                                                 push(@recfolders,$mapid);
 1653:                                                 $idx = $mapid;
 1654:                                             }
 1655:                                         }
 1656:                                         push(@recfolders,$mpc);
 1657:                                     }
 1658:                                 }
 1659:                             }
 1660:                         }
 1661:                         foreach my $key (keys(%hash)) {
 1662:                             if ($key=~/^src_(.+)$/) {
 1663:                                 my $rid = $1;
 1664:                                 next if ($rid eq '0.0');
 1665:                                 next if ($rid eq $loginrid);
 1666:                                 if ($scope ne 'res') {
 1667:                                     my $mapid = (split(/\./,$rid))[0];
 1668:                                     next if ($mapid eq $deeplink_login_pc);
 1669:                                     if ($scope eq 'rec') {
 1670:                                         next if (grep(/^$mapid$/,@recfolders));
 1671:                                     }
 1672:                                 }
 1673:                                 $deeplinkout{$rid} = 1;
 1674:                             }
 1675:                         }
 1676:                     }
 1677:                 }
 1678:                 &deeplinkouts();
 1679:             }
 1680:         }
 1681:     }
 1682:     &mapcrumbs();
 1683:     return $gotstate;
 1684: }
 1685: 
 1686: sub unlink_tmpfiles {
 1687:     my ($fn) = @_;
 1688:     my $file_dir = dirname($fn);
 1689: 
 1690:     if ("$file_dir/" eq LONCAPA::tempdir()) {
 1691:         my @files = qw (.db _symb.db .state _parms.db);
 1692:         foreach my $file (@files) {
 1693:             if (-e $fn.$file) {
 1694:                 unless (unlink($fn.$file)) {
 1695:                     &Apache::lonnet::logthis("<font color=blue>WARNING: ".
 1696:                                  "Could not unlink ".$fn.$file."</font>");
 1697:                 }
 1698:             }
 1699:         }
 1700:     }
 1701:     return;
 1702: }
 1703: 
 1704: # ------------------------------------------------------- Evaluate state string
 1705: 
 1706: sub evalstate {
 1707:     my $fn=$env{'request.course.fn'}.'.state';
 1708:     my $state='';
 1709:     if (-e $fn) {
 1710: 	my @conditions=();
 1711: 	{
 1712: 	    open(my $fh,"<",$fn);
 1713: 	    @conditions=<$fh>;
 1714:             close($fh);
 1715: 	}  
 1716: 	my $safeeval = new Safe;
 1717: 	my $safehole = new Safe::Hole;
 1718: 	$safeeval->permit("entereval");
 1719: 	$safeeval->permit(":base_math");
 1720: 	$safeeval->deny(":base_io");
 1721: 	$safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
 1722: 	foreach my $line (@conditions) {
 1723: 	    chomp($line);
 1724: 	    my ($condition,$weight)=split(/\:/,$line);
 1725: 	    if ($safeeval->reval($condition)) {
 1726: 		if ($weight eq 'force') {
 1727: 		    $state.='3';
 1728: 		} else {
 1729: 		    $state.='2';
 1730: 		}
 1731: 	    } else {
 1732: 		if ($weight eq 'stop') {
 1733: 		    $state.='0';
 1734: 		} else {
 1735: 		    $state.='1';
 1736: 		}
 1737: 	    }
 1738: 	}
 1739:     }
 1740:     &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state});
 1741:     return $state;
 1742: }
 1743: 
 1744: sub get_mapparam {
 1745:     my ($uname,$udom,$cnum,$cdom,$rid,$mapname,$what,$recurseupref) = @_;
 1746:     unless ($mapname) { return; }
 1747: 
 1748: # ------------------------------------------------- Get coursedata (if present)
 1749:     my $courseopt=&Apache::lonnet::get_courseresdata($cnum,$cdom);
 1750:     if (!ref($courseopt)) {
 1751:         undef($courseopt);
 1752:     }
 1753: 
 1754: # --------------------------------------------------- Get userdata (if present)
 1755:     my $useropt=&Apache::lonnet::get_userresdata($uname,$udom);
 1756:     if (!ref($useropt)) {
 1757:         undef($useropt);
 1758:     }
 1759: 
 1760:     my @recurseup;
 1761:     if (ref($recurseupref) eq 'ARRAY') {
 1762:         @recurseup = @{$recurseupref};
 1763:     }
 1764: 
 1765:     # Get the section if there is one.
 1766: 
 1767:     my $cid = $cdom.'_'.$cnum;
 1768:     my $csec=$env{'request.course.sec'};
 1769:     my $cgroup='';
 1770:     my @cgrps=split(/:/,$env{'request.course.groups'});
 1771:     if (@cgrps > 0) {
 1772:         @cgrps = sort(@cgrps);
 1773:         $cgroup = $cgrps[0];
 1774:     }
 1775: 
 1776:     my $rwhat=$what;
 1777:     $what=~s/^parameter\_//;
 1778:     $what=~s/\_/\./;
 1779: 
 1780:     # Build the hash keys for the lookup:
 1781: 
 1782:     my $mapparm=$mapname.'___(all).'.$what;
 1783:     my $recurseparm=$mapname.'___(rec).'.$what;
 1784:     my $usercourseprefix=$cid;
 1785: 
 1786:     my $grplevelm    = "$usercourseprefix.[$cgroup].$mapparm";
 1787:     my $seclevelm    = "$usercourseprefix.[$csec].$mapparm";
 1788:     my $courselevelm = "$usercourseprefix.$mapparm";
 1789: 
 1790:     my $grpleveli    = "$usercourseprefix.[$cgroup].$recurseparm";
 1791:     my $secleveli    = "$usercourseprefix.[$csec].$recurseparm";
 1792:     my $courseleveli = "$usercourseprefix.$recurseparm";
 1793: 
 1794:     # Check per user
 1795: 
 1796:     if ($uname and defined($useropt)) {
 1797:         if (defined($$useropt{$courselevelm})) {
 1798:             return $$useropt{$courselevelm};
 1799:         }
 1800:         if (defined($$useropt{$courseleveli})) {
 1801:             return $$useropt{$courseleveli};
 1802:         }
 1803:         foreach my $item (@recurseup) {
 1804:             my $norecursechk=$usercourseprefix.'.'.$item.'___(all).'.$what;
 1805:             if (defined($$useropt{$norecursechk})) {
 1806:                 if ($what =~ /\.(encrypturl|hiddenresource)$/) {
 1807:                     return $$useropt{$norecursechk};
 1808:                 } else {
 1809:                     last;
 1810:                 }
 1811:             }
 1812:             my $recursechk=$usercourseprefix.'.'.$item.'___(rec).'.$what;
 1813:             if (defined($$useropt{$recursechk})) {
 1814:                 return $$useropt{$recursechk};
 1815:             }
 1816:         }
 1817:     }
 1818: 
 1819:     # Check course -- group
 1820: 
 1821:     if ($cgroup ne '' and defined ($courseopt)) {
 1822:         if (defined($$courseopt{$grplevelm})) {
 1823:             return $$courseopt{$grplevelm};
 1824:         }
 1825:         if (defined($$courseopt{$grpleveli})) {
 1826:             return $$courseopt{$grpleveli};
 1827:         }
 1828:         foreach my $item (@recurseup) {
 1829:             my $norecursechk=$usercourseprefix.'.['.$cgroup.'].'.$item.'___(all).'.$what;
 1830:             if (defined($$courseopt{$norecursechk})) {
 1831:                 if ($what =~ /\.(encrypturl|hiddenresource)$/) {
 1832:                     return $$courseopt{$norecursechk};
 1833:                 } else {
 1834:                     last;
 1835:                 }
 1836:             }
 1837:             my $recursechk=$usercourseprefix.'.['.$cgroup.'].'.$item.'___(rec).'.$what;
 1838:             if (defined($$courseopt{$recursechk})) {
 1839:                 return $$courseopt{$recursechk};
 1840:             }
 1841:         }
 1842:     }
 1843: 
 1844:     # Check course -- section
 1845: 
 1846:     if ($csec ne '' and defined($courseopt)) {
 1847:         if (defined($$courseopt{$seclevelm})) {
 1848:             return $$courseopt{$seclevelm};
 1849:         }
 1850:         if (defined($$courseopt{$secleveli})) {
 1851:             return $$courseopt{$secleveli};
 1852:         }
 1853:         foreach my $item (@recurseup) {
 1854:             my $norecursechk=$usercourseprefix.'.['.$csec.'].'.$item.'___(all).'.$what;
 1855:             if (defined($$courseopt{$norecursechk})) {
 1856:                 if ($what =~ /\.(encrypturl|hiddenresource)$/) {
 1857:                     return $$courseopt{$norecursechk};
 1858:                 } else {
 1859:                     last;
 1860:                 }
 1861:             }
 1862:             my $recursechk=$usercourseprefix.'.['.$csec.'].'.$item.'___(rec).'.$what;
 1863:             if (defined($$courseopt{$recursechk})) {
 1864:                 return $$courseopt{$recursechk};
 1865:             }
 1866:         }
 1867:     }
 1868: 
 1869:     # Check the map parameters themselves:
 1870: 
 1871:     if ($hash{'param_'.$rid}) {
 1872:         my @items = split(/\&/,$hash{'param_'.$rid});
 1873:         my $thisparm;
 1874:         foreach my $item (@items) {
 1875:             my ($esctype,$escname,$escvalue) = ($item =~ /^([^:]+):([^=]+)=(.*)$/);
 1876:             my $name = &unescape($escname);
 1877:             my $value = &unescape($escvalue);
 1878:             if ($name eq $what) {
 1879:                 $thisparm = $value;
 1880:                 last;
 1881:             }
 1882:         }
 1883:         if (defined($thisparm)) {
 1884:             return $thisparm;
 1885:         }
 1886:     }
 1887: 
 1888:    # Additional course parameters:
 1889: 
 1890:     if (defined($courseopt)) {
 1891:         if (defined($$courseopt{$courselevelm})) {
 1892:             return $$courseopt{$courselevelm};
 1893:         }
 1894: 
 1895:         if (defined($$courseopt{$courseleveli})) {
 1896:             return $$courseopt{$courseleveli};
 1897:         }
 1898: 
 1899:         if (@recurseup) {
 1900:             foreach my $item (@recurseup) {
 1901:                 my $norecursechk=$usercourseprefix.'.'.$item.'___(all).'.$what;
 1902:                 if (defined($$courseopt{$norecursechk})) {
 1903:                     if ($what =~ /\.(encrypturl|hiddenresource)$/) {
 1904:                         return $$courseopt{$norecursechk};
 1905:                     } else {
 1906:                         last;
 1907:                     }
 1908:                 }
 1909:                 my $recursechk=$usercourseprefix.'.'.$item.'___(rec).'.$what;
 1910:                 if (defined($$courseopt{$recursechk})) {
 1911:                     return $$courseopt{$recursechk};
 1912:                 }
 1913:             }
 1914:         }
 1915:     }
 1916:     return undef;
 1917: }
 1918: 
 1919: #  This block seems to have code to manage/detect doubly defined
 1920: #  aliases in maps.
 1921: 
 1922: {
 1923:     my %mapalias_cache;
 1924:     sub count_mapalias {
 1925: 	my ($value,$resid) = @_;
 1926:  	push(@{ $mapalias_cache{$value} }, $resid);
 1927:     }
 1928: 
 1929:     sub get_mapalias_errors {
 1930: 	my $error_text;
 1931: 	foreach my $mapalias (sort(keys(%mapalias_cache))) {
 1932: 	    next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
 1933: 	    my $count;
 1934: 	    my $which =
 1935: 		join('</li><li>', 
 1936: 		     map {
 1937: 			 my $id = $_;
 1938: 			 if (exists($hash{'src_'.$id})) {
 1939: 			     $count++;
 1940: 			 }
 1941: 			 my ($mapid) = split(/\./,$id);
 1942:                          &mt('Resource [_1][_2]in Map [_3]',
 1943: 			     $hash{'title_'.$id},'<br />',
 1944: 			     $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}});
 1945: 		     } (@{ $mapalias_cache{$mapalias} }));
 1946: 	    next if ($count < 2);
 1947: 	    $error_text .= '<div class="LC_error">'.
 1948: 		&mt('Error: Found the mapalias "[_1]" defined multiple times.',
 1949: 		    $mapalias).
 1950: 		'</div><ul><li>'.$which.'</li></ul>';
 1951: 	}
 1952: 	&clear_mapalias_count();
 1953: 	return $error_text;
 1954:     }
 1955:     sub clear_mapalias_count {
 1956: 	undef(%mapalias_cache);
 1957:     }
 1958: }
 1959: 1;
 1960: __END__
 1961: 
 1962: =head1 NAME
 1963: 
 1964: Apache::lonuserstate - Construct and maintain state and binary representation
 1965: of course for user
 1966: 
 1967: =head1 SYNOPSIS
 1968: 
 1969: Invoked by lonroles.pm.
 1970: 
 1971: &Apache::lonuserstate::readmap($cdom.'/'.$cnum);
 1972: 
 1973: =head1 INTRODUCTION
 1974: 
 1975: This module constructs and maintains state and binary representation
 1976: of course for user.
 1977: 
 1978: This is part of the LearningOnline Network with CAPA project
 1979: described at http://www.lon-capa.org.
 1980: 
 1981: =head1 SUBROUTINES
 1982: 
 1983: =over
 1984: 
 1985: =item loadmap()
 1986: 
 1987: Loads map from disk
 1988: 
 1989: =item simplify()
 1990: 
 1991: Simplify expression
 1992: 
 1993: =item traceroute()
 1994: 
 1995: Build condition hash
 1996: 
 1997: =item accinit()
 1998: 
 1999: Cascading conditions, quick access, parameters
 2000: 
 2001: =item readmap()
 2002: 
 2003: Read map and all submaps
 2004: 
 2005: =item evalstate()
 2006: 
 2007: Evaluate state string
 2008: 
 2009: =back
 2010: 
 2011: =cut

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