rat/lonuserstate.pm - view

File: [LON-CAPA] / rat / lonuserstate.pm
Revision 1.158: download - view: text, annotated - select for diffs
Tue Mar 3 01:16:31 2020 UTC (4 years, 1 month ago) by raeburn
Branches: MAIN
CVS tags: HEAD

- URL for external resources in uploaded .page ("Composite page") changed
  to begin /ext/ (but are not wrapped).
- Printouts of external resources include title of item in course, and link
  unless encrypturl is set to yes for the resource.

1: # The LearningOnline Network with CAPA 2: # Construct and maintain state and binary representation of course for user 3: # 4: # $Id: lonuserstate.pm,v 1.158 2020/03/03 01:16:31 raeburn Exp $ 5: # 6: # Copyright Michigan State University Board of Trustees 7: # 8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA). 9: # 10: # LON-CAPA is free software; you can redistribute it and/or modify 11: # it under the terms of the GNU General Public License as published by 12: # the Free Software Foundation; either version 2 of the License, or 13: # (at your option) any later version. 14: # 15: # LON-CAPA is distributed in the hope that it will be useful, 16: # but WITHOUT ANY WARRANTY; without even the implied warranty of 17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18: # GNU General Public License for more details. 19: # 20: # You should have received a copy of the GNU General Public License 21: # along with LON-CAPA; if not, write to the Free Software 22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 23: # 24: # /home/httpd/html/adm/gpl.txt 25: # 26: # http://www.lon-capa.org/ 27: # 28: ### 29: 30: package Apache::lonuserstate; 31: 32: # ------------------------------------------------- modules used by this module 33: use strict; 34: use HTML::TokeParser; 35: use Apache::lonnet; 36: use Apache::lonlocal; 37: use Apache::loncommon(); 38: use GDBM_File; 39: use Apache::lonmsg; 40: use Safe; 41: use Safe::Hole; 42: use Opcode; 43: use Apache::lonenc; 44: use Fcntl qw(:flock); 45: use LONCAPA qw(:DEFAULT :match); 46: use File::Basename; 47: 48: 49: 50: # ---------------------------------------------------- Globals for this package 51: 52: my $pc; # Package counter is this what 'Guts' calls the map counter? 53: my %hash; # The big tied hash 54: my %parmhash;# The hash with the parameters 55: my @cond; # Array with all of the conditions 56: my $errtext; # variable with all errors 57: my $retfrid; # variable with the very first RID in the course 58: my $retfurl; # first URL 59: my %randompick; # randomly picked resources 60: my %randompickseed; # optional seed for randomly picking resources 61: my %randomorder; # maps to order contents randomly 62: my %randomizationcode; # code used to grade folder for bubblesheet exam 63: my %encurl; # URLs in this folder are supposed to be encrypted 64: my %hiddenurl; # this URL (or complete folder) is supposed to be hidden 65: my %deeplinkonly; # this URL (or complete folder) is deep-link only 66: my %rescount; # count of unhidden items in each map 67: my %mapcount; # count of unhidden maps in each map 68: 69: # ----------------------------------- Remove version from URL and store in hash 70: 71: sub versionerror { 72: my ($uri,$usedversion,$unusedversion)=@_; 73: return ' '.&mt('Version discrepancy: resource [_1] included in both version [_2] and version [_3]. Using version [_2].', 74: $uri,$usedversion,$unusedversion).' '; 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: $errtext.=''. 156: &mt('Multiple use of sequence/page [_1]! The course will not function properly.','<tt>'.$uri.'</tt>'). 157: ''; 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: $errtext.=' '.&mt('Invalid map: [_1]',"<tt>$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: $errtext.= ' ' 200: .&mt('Map not loaded: The file [_1] does not exist.', 201: "<tt>$fn</tt>"); 202: return; 203: } 204: 205: # Successfully got file, parse it 206: 207: # parse for parameter processing. 208: # Note that these are <param... / > tags 209: # so we only care about 'S' (tag start) nodes. 210: 211: 212: my $parser = HTML::TokeParser->new(\$instr); 213: $parser->attr_encoded(1); 214: 215: # first get all parameters 216: 217: 218: while (my $token = $parser->get_token) { 219: next if ($token->[0] ne 'S'); 220: if ($token->[1] eq 'param') { 221: &parse_param($token,$lpc); 222: } 223: } 224: 225: # Get set to take another pass through the XML: 226: # for resources and links. 227: 228: $parser = HTML::TokeParser->new(\$instr); 229: $parser->attr_encoded(1); 230: 231: my $linkpc=0; 232: 233: $fn=~/\.(\w+)$/; 234: 235: $hash{'map_type_'.$lpc}=$1; 236: 237: my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i); 238: 239: # Parse the resources, link and condition tags. 240: # Note that if randomorder or random select is chosen the links and 241: # conditions are meaningless but are determined by the randomization. 242: # This is handled in the next chunk of code. 243: 244: my @map_ids; 245: my $codechecked; 246: $rescount{$lpc} = 0; 247: $mapcount{$lpc} = 0; 248: while (my $token = $parser->get_token) { 249: next if ($token->[0] ne 'S'); 250: 251: # Resource 252: 253: if ($token->[1] eq 'resource') { 254: my $resource_id = &parse_resource($token,$lpc,$ispage,$uri,$courseid); 255: if (defined $resource_id) { 256: push(@map_ids, $resource_id); 257: if ($hash{'src_'.$lpc.'.'.$resource_id}) { 258: $rescount{$lpc} ++; 259: if (($hash{'src_'.$lpc.'.'.$resource_id}=~/\.sequence$/) || 260: ($hash{'src_'.$lpc.'.'.$resource_id}=~/\.page$/)) { 261: $mapcount{$lpc} ++; 262: } 263: } 264: unless ($codechecked) { 265: my $startsymb = 266: &Apache::lonnet::encode_symb($hash{'map_id_'.$lpc},$resource_id, 267: $hash{'src_'."$lpc.$resource_id"}); 268: my $code = 269: &Apache::lonnet::EXT('resource.0.examcode',$startsymb,undef,undef, 270: undef,undef,$courseid); 271: if ($code) { 272: $randomizationcode{$parent_rid} = $code; 273: } 274: $codechecked = 1; 275: } 276: } 277: 278: # Link 279: 280: } elsif ($token->[1] eq 'link' && !$randomize) { 281: &make_link(++$linkpc,$lpc,$token->[2]->{'to'}, 282: $token->[2]->{'from'}, 283: $token->[2]->{'condition'}); # note ..condition may be undefined. 284: 285: # condition 286: 287: } elsif ($token->[1] eq 'condition' && !$randomize) { 288: &parse_condition($token,$lpc); 289: } 290: } 291: undef($codechecked); 292: 293: # Handle randomization and random selection 294: 295: if ($randomize) { 296: my $advanced; 297: if ($env{'request.course.id'}) { 298: $advanced = (&Apache::lonnet::allowed('adv') eq 'F'); 299: } else { 300: $env{'request.course.id'} = $courseid; 301: $advanced = (&Apache::lonnet::allowed('adv') eq 'F'); 302: $env{'request.course.id'} = ''; 303: } 304: unless ($advanced) { 305: # Order of resources is not randomized if user has and advanced role in the course. 306: my $seed; 307: 308: # If the map's random seed parameter has been specified 309: # it is used as the basis for computing the seed ... 310: 311: if (defined($randompickseed{$parent_rid})) { 312: $seed = $randompickseed{$parent_rid}; 313: } else { 314: 315: # Otherwise the parent's fully encoded symb is used. 316: 317: my ($mapid,$resid)=split(/\./,$parent_rid); 318: my $symb= 319: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid}, 320: $resid,$hash{'src_'.$parent_rid}); 321: 322: $seed = $symb; 323: } 324: 325: # TODO: Here for sure we need to pass along the username/domain 326: # so that we can impersonate users in lonprintout e.g. 327: 328: my $setcode; 329: if (defined($randomizationcode{$parent_rid})) { 330: if ($env{'form.CODE'} eq '') { 331: $env{'form.CODE'} = $randomizationcode{$parent_rid}; 332: $setcode = 1; 333: } 334: } 335: 336: my $rndseed=&Apache::lonnet::rndseed($seed); 337: &Apache::lonnet::setup_random_from_rndseed($rndseed); 338: 339: if ($setcode) { 340: undef($env{'form.CODE'}); 341: undef($setcode); 342: } 343: 344: # Take the set of map ids we have decoded and permute them to a 345: # random order based on the seed set above. All of this is 346: # processing the randomorder parameter if it is set, not 347: # randompick. 348: 349: @map_ids=&Math::Random::random_permutation(@map_ids); 350: } 351: 352: my $from = shift(@map_ids); 353: my $from_rid = $lpc.'.'.$from; 354: $hash{'map_start_'.$uri} = $from_rid; 355: $hash{'type_'.$from_rid}='start'; 356: 357: # Create links to reflect the random re-ordering done above. 358: # In the code to process the map XML, we did not process links or conditions 359: # if randomorder was set. This means that for an instructor to choose 360: 361: while (my $to = shift(@map_ids)) { 362: &make_link(++$linkpc,$lpc,$to,$from); 363: my $to_rid = $lpc.'.'.$to; 364: $hash{'type_'.$to_rid}='normal'; 365: $from = $to; 366: $from_rid = $to_rid; 367: } 368: 369: $hash{'map_finish_'.$uri}= $from_rid; 370: $hash{'type_'.$from_rid}='finish'; 371: } 372: 373: $parser = HTML::TokeParser->new(\$instr); 374: $parser->attr_encoded(1); 375: 376: # last parse out the mapalias params. These provide mnemonic 377: # tags to resources that can be used in conditions 378: 379: while (my $token = $parser->get_token) { 380: next if ($token->[0] ne 'S'); 381: if ($token->[1] eq 'param') { 382: &parse_mapalias_param($token,$lpc); 383: } 384: } 385: } 386: 387: 388: # -------------------------------------------------------------------- Resource 389: # 390: # Parses a resource tag to produce the value to push into the 391: # map_ids array. 392: # 393: # 394: # Information about the actual type of resource is provided by the file extension 395: # of the uri (e.g. .problem, .sequence etc. etc.). 396: # 397: # Parameters: 398: # $token - A token from HTML::TokeParser 399: # This is an array that describes the most recently parsed HTML item. 400: # $lpc - Map nesting level (?) 401: # $ispage - True if this resource is encapsulated in a .page (assembled resourcde). 402: # $uri - URI of the enclosing resource. 403: # $courseid - Course id of the course containing the resource being parsed. 404: # Returns: 405: # Value of the id attribute of the tag. 406: # 407: # Note: 408: # The token is an array that contains the following elements: 409: # [0] => 'S' indicating this is a start token 410: # [1] => 'resource' indicating this tag is a <resource> tag. 411: # [2] => Hash of attribute =>value pairs. 412: # [3] => @(keys [2]). 413: # [4] => unused. 414: # 415: # The attributes of the resourcde tag include: 416: # 417: # id - The resource id. 418: # src - The URI of the resource. 419: # type - The resource type (e.g. start and finish). 420: # title - The resource title. 421: 422: 423: sub parse_resource { 424: my ($token,$lpc,$ispage,$uri,$courseid) = @_; 425: 426: # I refuse to countenance code like this that has 427: # such a dirty side effect (and forcing this sub to be called within a loop). 428: # 429: # if ($token->[2]->{'type'} eq 'zombie') { next; } 430: # 431: # The original code both returns _and_ skips to the next pass of the >caller's< 432: # loop, that's just dirty. 433: # 434: 435: # Zombie resources don't produce anything useful. 436: 437: if ($token->[2]->{'type'} eq 'zombie') { 438: return undef; 439: } 440: 441: my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml. 442: 443: # Save the hash element type and title: 444: 445: $hash{'kind_'.$rid}='res'; 446: $hash{'title_'.$rid}=$token->[2]->{'title'}; 447: 448: # Get the version free URI for the resource. 449: # If a 'version' attribute was supplied, and this resource's version 450: # information has not yet been stored, store it. 451: # 452: 453: my $turi=&versiontrack($token->[2]->{'src'}); 454: if ($token->[2]->{'version'}) { 455: unless ($hash{'version_'.$turi}) { 456: $hash{'version_'.$turi}=$1; 457: } 458: } 459: # Pull out the title and do entity substitution on &colon 460: # Q: Why no other entity substitutions? 461: 462: my $title=$token->[2]->{'title'}; 463: $title=~s/\&colon\;/\:/gs; 464: 465: 466: 467: # I think the point of all this code is to construct a final 468: # URI that apache and its rewrite rules can use to 469: # fetch the resource. Thi s sonly necessary if the resource 470: # is not a page. If the resource is a page then it must be 471: # assembled (at fetch time?). 472: 473: if ($ispage) { 474: if ($token->[2]->{'external'} eq 'true') { # external 475: $turi=~s{^http\://}{/ext/}; 476: } 477: } else { 478: $turi=~/\.(\w+)$/; 479: my $embstyle=&Apache::loncommon::fileembstyle($1); 480: if ($token->[2]->{'external'} eq 'true') { # external 481: $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//; 482: } elsif ($turi=~/^\/*uploaded\//) { # uploaded 483: if (($embstyle eq 'img') 484: || ($embstyle eq 'emb') 485: || ($embstyle eq 'wrp')) { 486: $turi='/adm/wrapper'.$turi; 487: } elsif ($embstyle eq 'ssi') { 488: #do nothing with these 489: } elsif ($turi!~/\.(sequence|page)$/) { 490: $turi='/adm/coursedocs/showdoc'.$turi; 491: } 492: } elsif ($turi=~ m{^/adm/$match_domain/$match_courseid/\d+/ext\.tool$}) { 493: $turi='/adm/wrapper'.$turi; 494: } elsif ($turi=~/\S/) { # normal non-empty internal resource 495: my $mapdir=$uri; 496: $mapdir=~s/[^\/]+$//; 497: $turi=&Apache::lonnet::hreflocation($mapdir,$turi); 498: if (($embstyle eq 'img') 499: || ($embstyle eq 'emb') 500: || ($embstyle eq 'wrp')) { 501: $turi='/adm/wrapper'.$turi; 502: } 503: } 504: } 505: # Store reverse lookup, remove query string resource 'ids'_uri => resource id. 506: # If the URI appears more than one time in the sequence, it's resourcde 507: # id's are constructed as a comma spearated list. 508: 509: my $idsuri=$turi; 510: $idsuri=~s/\?.+$//; 511: if (defined($hash{'ids_'.$idsuri})) { 512: $hash{'ids_'.$idsuri}.=','.$rid; 513: } else { 514: $hash{'ids_'.$idsuri}=''.$rid; 515: } 516: 517: 518: 519: if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) { 520: $turi.='?register=1'; 521: } 522: 523: 524: # resource id lookup: 'src'_resourc-di => URI decorated with a query 525: # parameter as above if necessary due to the resource type. 526: 527: $hash{'src_'.$rid}=$turi; 528: 529: # Mark the external-ness of the resource: 530: 531: if ($token->[2]->{'external'} eq 'true') { 532: $hash{'ext_'.$rid}='true:'; 533: } else { 534: $hash{'ext_'.$rid}='false:'; 535: } 536: 537: # If the resource is a start/finish resource set those 538: # entries in the has so that navigation knows where everything starts. 539: # TODO? If there is a malformed sequence that has no start or no finish 540: # resource, should this be detected and errors thrown? How would such a 541: # resource come into being other than being manually constructed by a person 542: # and then uploaded? Could that happen if an author decided a sequence was almost 543: # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the 544: # start or finish resources? 545: # 546: # All resourcess also get a type_id => (start | finish | normal) hash entr. 547: # 548: if ($token->[2]->{'type'}) { 549: $hash{'type_'.$rid}=$token->[2]->{'type'}; 550: if ($token->[2]->{'type'} eq 'start') { 551: $hash{'map_start_'.$uri}="$rid"; 552: } 553: if ($token->[2]->{'type'} eq 'finish') { 554: $hash{'map_finish_'.$uri}="$rid"; 555: } 556: } else { 557: $hash{'type_'.$rid}='normal'; 558: } 559: 560: # Sequences end pages are constructed entities. They require that the 561: # map that defines _them_ be loaded as well into the hash...with this resourcde 562: # as the base of the nesting. 563: # Resources like that are also marked with is_map_id => 1 entries. 564: # 565: 566: if (($turi=~/\.sequence$/) || 567: ($turi=~/\.page$/)) { 568: $hash{'is_map_'.$rid}=1; 569: &loadmap($turi,$rid,$courseid); 570: } 571: return $token->[2]->{'id'}; 572: } 573: 574: #-------------------------------------------------------------------- link 575: # Links define how you are allowed to move from one resource to another. 576: # They are the transition edges in the directed graph that a map is. 577: # This sub takes informatino from a <link> tag and constructs the 578: # navigation bits and pieces of a map. There is no requirement that the 579: # resources that are linke are already defined, however clearly the map is 580: # badly broken if they are not _eventually_ defined. 581: # 582: # Note that links can be unconditional or conditional. 583: # 584: # Parameters: 585: # linkpc - The link counter for this level of map nesting (this is 586: # reset to zero by loadmap prior to starting to process 587: # links for map). 588: # lpc - The map level ocounter (how deeply nested this map is in 589: # the hierarchy of maps that are recursively read in. 590: # to - resource id (within the XML) of the target of the edge. 591: # from - resource id (within the XML) of the source of the edge. 592: # condition- id of condition associated with the edge (also within the XML). 593: # 594: 595: sub make_link { 596: my ($linkpc,$lpc,$to,$from,$condition) = @_; 597: 598: # Compute fully qualified ids for the link, the 599: # and from/to by prepending lpc. 600: # 601: 602: my $linkid=$lpc.'.'.$linkpc; 603: my $goesto=$lpc.'.'.$to; 604: my $comesfrom=$lpc.'.'.$from; 605: my $undercond=0; 606: 607: 608: # If there is a condition, qualify it with the level counter. 609: 610: if ($condition) { 611: $undercond=$lpc.'.'.$condition; 612: } 613: 614: # Links are represnted by: 615: # goesto_.fuullyqualifedlinkid => fully qualified to 616: # comesfrom.fullyqualifiedlinkid => fully qualified from 617: # undercond_.fullyqualifiedlinkid => fully qualified condition id. 618: 619: $hash{'goesto_'.$linkid}=$goesto; 620: $hash{'comesfrom_'.$linkid}=$comesfrom; 621: $hash{'undercond_'.$linkid}=$undercond; 622: 623: # In addition: 624: # to_.fully qualified from => comma separated list of 625: # link ids with that from. 626: # Similarly: 627: # from_.fully qualified to => comma separated list of link ids` 628: # with that to. 629: # That allows us given a resource id to know all edges that go to it 630: # and leave from it. 631: # 632: 633: if (defined($hash{'to_'.$comesfrom})) { 634: $hash{'to_'.$comesfrom}.=','.$linkid; 635: } else { 636: $hash{'to_'.$comesfrom}=''.$linkid; 637: } 638: if (defined($hash{'from_'.$goesto})) { 639: $hash{'from_'.$goesto}.=','.$linkid; 640: } else { 641: $hash{'from_'.$goesto}=''.$linkid; 642: } 643: } 644: 645: # ------------------------------------------------------------------- Condition 646: # 647: # Processes <condition> tags, storing sufficient information about them 648: # in the hash so that they can be evaluated and used to conditionalize 649: # what is presented to the student. 650: # 651: # these can have the following attributes 652: # 653: # id = A unique identifier of the condition within the map. 654: # 655: # value = Is a perl script-let that, when evaluated in safe space 656: # determines whether or not the condition is true. 657: # Normally this takes the form of a test on an Apache::lonnet::EXT call 658: # to find the value of variable associated with a resource in the 659: # map identified by a mapalias. 660: # Here's a fragment of XML code that illustrates this: 661: # 662: # <param to="5" value="mainproblem" name="parameter_0_mapalias" type="string" /> 663: # <resource src="" id="1" type="start" title="Start" /> 664: # <resource src="/res/msu/albertel/b_and_c/p1.problem" id="5" title="p1.problem" /> 665: # <condition value="&EXT('user.resource.resource.0.tries','mainproblem') 666: # <2 " id="61" type="stop" /> 667: # <link to="5" index="1" from="1" condition="61" /> 668: # 669: # In this fragment: 670: # - The param tag establishes an alias to resource id 5 of 'mainproblem'. 671: # - The resource that is the start of the map is identified. 672: # - The resource tag identifies the resource associated with this tag 673: # and gives it the id 5. 674: # - The condition is true if the tries variable associated with mainproblem 675: # is less than 2 (that is the user has had more than 2 tries). 676: # The condition type is a stop condition which inhibits(?) the associated 677: # link if the condition is false. 678: # - The link to resource 5 from resource 1 is affected by this condition. 679: # 680: # type = Type of the condition. The type determines how the condition affects the 681: # link associated with it and is one of 682: # - 'force' 683: # - 'stop' 684: # anything else including not supplied..which treated as: 685: # - 'normal'. 686: # Presumably maps get created by the resource assembly tool and therefore 687: # illegal type values won't squirm their way into the XML. 688: # 689: # Side effects: 690: # - The kind_level-qualified-condition-id hash element is set to 'cond'. 691: # - The condition text is pushed into the cond array and its element number is 692: # set in the condid_level-qualified-condition-id element of the hash. 693: # - The condition type is colon appneded to the cond array element for this condition. 694: sub parse_condition { 695: my ($token,$lpc) = @_; 696: my $rid=$lpc.'.'.$token->[2]->{'id'}; 697: 698: $hash{'kind_'.$rid}='cond'; 699: 700: my $condition = $token->[2]->{'value'}; 701: $condition =~ s/[\n\r]+/ /gs; 702: push(@cond, $condition); 703: $hash{'condid_'.$rid}=$#cond; 704: if ($token->[2]->{'type'}) { 705: $cond[$#cond].=':'.$token->[2]->{'type'}; 706: } else { 707: $cond[$#cond].=':normal'; 708: } 709: } 710: 711: # ------------------------------------------------------------------- Parameter 712: # Parse a <parameter> tag in the map. 713: # Parmameters: 714: # $token Token array for a start tag from HTML::TokeParser 715: # [0] = 'S' 716: # [1] = tagname ("param") 717: # [2] = Hash of {attribute} = values. 718: # [3] = Array of the keys in [2]. 719: # [4] = unused. 720: # $lpc Current map nesting level.a 721: # 722: # Typical attributes: 723: # to=n - Number of the resource the parameter applies to. 724: # type=xx - Type of parameter value (e.g. string_yesno or int_pos). 725: # name=xxx - Name of parameter (e.g. parameter_randompick or parameter_randomorder). 726: # value=xxx - value of the parameter. 727: 728: sub parse_param { 729: my ($token,$lpc) = @_; 730: my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to. 731: my $name=$token->[2]->{'name'}; # Name of parameter 732: my $part; 733: 734: 735: if ($name=~/^parameter_(.*)_/) { 736: $part=$1; 737: } else { 738: $part=0; 739: } 740: 741: # Peel the parameter_ off the parameter name. 742: 743: $name=~s/^.*_([^_]*)$/$1/; 744: 745: # The value is: 746: # type.part.name.value 747: 748: my $newparam= 749: &escape($token->[2]->{'type'}).':'. 750: &escape($part.'.'.$name).'='. 751: &escape($token->[2]->{'value'}); 752: 753: # The hash key is param_resourceid. 754: # Multiple parameters for a single resource are & separated in the hash. 755: 756: 757: if (defined($hash{'param_'.$referid})) { 758: $hash{'param_'.$referid}.='&'.$newparam; 759: } else { 760: $hash{'param_'.$referid}=''.$newparam; 761: } 762: # 763: # These parameters have to do with randomly selecting 764: # resources, therefore a separate hash is also created to 765: # make it easy to locate them when actually computing the resource set later on 766: # See the code conditionalized by ($randomize) in loadmap(). 767: 768: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on 769: $randompick{$referid}=$token->[2]->{'value'}; 770: } 771: if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided. 772: $randompickseed{$referid}=$token->[2]->{'value'}; 773: } 774: if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on. 775: $randomorder{$referid}=$token->[2]->{'value'}; 776: } 777: 778: # These parameters have to do with how the URLs of resources are presented to 779: # course members(?). encrypturl presents encypted url's while 780: # hiddenresource hides the URL. 781: # 782: 783: if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) { 784: if ($token->[2]->{'value'}=~/^yes$/i) { 785: $encurl{$referid}=1; 786: } 787: } 788: if ($token->[2]->{'name'}=~/^parameter_(0_)*hiddenresource$/) { 789: if ($token->[2]->{'value'}=~/^yes$/i) { 790: $hiddenurl{$referid}=1; 791: } 792: } 793: } 794: # 795: # Parse mapalias parameters. 796: # these are tags of the form: 797: # <param to="nn" 798: # value="some-alias-for-resourceid-nn" 799: # name="parameter_0_mapalias" 800: # type="string" /> 801: # A map alias is a textual name for a resource: 802: # - The to attribute identifies the resource (this gets level qualified below) 803: # - The value attributes provides the alias string. 804: # - name must be of the regexp form: /^parameter_(0_)*mapalias$/ 805: # - e.g. the string 'parameter_' followed by 0 or more "0_" strings 806: # terminating with the string 'mapalias'. 807: # Examples: 808: # 'parameter_mapalias', 'parameter_0_mapalias', parameter_0_0_mapalias' 809: # Invalid to ids are silently ignored. 810: # 811: # Parameters: 812: # token - The token array fromthe HMTML::TokeParser 813: # lpc - The current map level counter. 814: # 815: sub parse_mapalias_param { 816: my ($token,$lpc) = @_; 817: 818: # Fully qualify the to value and ignore the alias if there is no 819: # corresponding resource. 820: 821: my $referid=$lpc.'.'.$token->[2]->{'to'}; 822: return if (!exists($hash{'src_'.$referid})); 823: 824: # If this is a valid mapalias parameter, 825: # Append the target id to the count_mapalias element for that 826: # alias so that we can detect doubly defined aliases 827: # e.g.: 828: # <param to="1" value="george" name="parameter_0_mapalias" type="string" /> 829: # <param to="2" value="george" name="parameter_0_mapalias" type="string" /> 830: # 831: # The example above is trivial but the case that's important has to do with 832: # constructing a map that includes a nested map where the nested map may have 833: # aliases that conflict with aliases established in the enclosing map. 834: # 835: # ...and create/update the hash mapalias entry to actually store the alias. 836: # 837: 838: if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) { 839: &count_mapalias($token->[2]->{'value'},$referid); 840: $hash{'mapalias_'.$token->[2]->{'value'}}=$referid; 841: } 842: } 843: 844: # --------------------------------------------------------- Simplify expression 845: 846: 847: # 848: # Someone should really comment this to describe what it does to what and why. 849: # 850: sub simplify { 851: my $expression=shift; 852: # (0&1) = 1 853: $expression=~s/$0\&([_\.\d]+)$/$1/g; 854: # (8)=8 855: $expression=~s/$([_\.\d]+)$/$1/g; 856: # 8&8=8 857: $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g; 858: # 8|8=8 859: $expression=~s/([^_\.\d])([_\.\d]+)(?:\|\2)+([^_\.\d])/$1$2$3/g; 860: # (5&3)&4=5&3&4 861: $expression=~s/$([_\.\d]+)((?:\&[_\.\d]+)+)$\&([_\.\d]+[^_\.\d])/$1$2\&$3/g; 862: # (((5&3)|(4&6)))=((5&3)|(4&6)) 863: $expression=~ 864: s/$(\(\([_\.\d]+(?:\&[_\.\d]+)*$(?:\|$[_\.\d]+(?:\&[_\.\d]+)*$)+\))\)/$1/g; 865: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2) 866: $expression=~ 867: s/$(\([_\.\d]+(?:\&[_\.\d]+)*$)((?:\|$[_\.\d]+(?:\&[_\.\d]+)*$)+)\)\|($[_\.\d]+(?:\&[_\.\d]+)*$)/$$1$2\|$3$/g; 868: return $expression; 869: } 870: 871: # -------------------------------------------------------- Build condition hash 872: 873: # 874: # Traces a route recursively through the map after it has been loaded 875: # (I believe this really visits each resourcde that is reachable fromt he 876: # start top node. 877: # 878: # - Marks hidden resources as hidden. 879: # - Marks which resource URL's must be encrypted. 880: # - Figures out (if necessary) the first resource in the map. 881: # - Further builds the chunks of the big hash that define how 882: # conditions work 883: # 884: # Note that the tracing strategy won't visit resources that are not linked to 885: # anything or islands in the map (groups of resources that form a path but are not 886: # linked in to the path that can be traced from the start resource...but that's ok 887: # because by definition, those resources are not reachable by users of the course. 888: # 889: # Parameters: 890: # sofar - _URI of the prior entry or 0 if this is the top. 891: # rid - URI of the resource to visit. 892: # beenhere - list of resources (each resource enclosed by &'s) that have 893: # already been visited. 894: # encflag - If true the resource that resulted in a recursive call to us 895: # has an encoded URL (which means contained resources should too). 896: # hdnflag - If true,the resource that resulted in a recursive call to us 897: # was hidden (which means contained resources should be hidden too). 898: # Returns 899: # new value indicating how far the map has been traversed (the sofar). 900: # 901: sub traceroute { 902: my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_; 903: my $newsofar=$sofar=simplify($sofar); 904: 905: unless ($beenhere=~/\&\Q$rid\E\&/) { 906: $beenhere.=$rid.'&'; 907: my ($mapid,$resid)=split(/\./,$rid); 908: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid}); 909: my $hidden=&Apache::lonnet::EXT('resource.0.hiddenresource',$symb); 910: 911: if ($hdnflag || lc($hidden) eq 'yes') { 912: $hiddenurl{$rid}=1; 913: } 914: if (!$hdnflag && lc($hidden) eq 'no') { 915: delete($hiddenurl{$rid}); 916: } 917: 918: my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb); 919: if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; } 920: 921: if (($retfrid eq '') && ($hash{'src_'.$rid}) 922: && ($hash{'src_'.$rid}!~/\.sequence$/)) { 923: $retfrid=$rid; 924: } 925: my @deeplink=&Apache::lonnet::EXT('resource.0.deeplink',$symb); 926: unless ((@deeplink == 0) || ($deeplink[0] eq 'full')) { 927: $deeplinkonly{$rid}=join(':',@deeplink); 928: if ($deeplink[1] eq 'map') { 929: my $parent = (split(/\,/,$hash{'map_hierarchy_'.$mapid}))[-1]; 930: $deeplinkonly{"$parent.$mapid"}=$deeplinkonly{$rid}; 931: } 932: } 933: 934: if (defined($hash{'conditions_'.$rid})) { 935: $hash{'conditions_'.$rid}=simplify( 936: '('.$hash{'conditions_'.$rid}.')|('.$sofar.')'); 937: } else { 938: $hash{'conditions_'.$rid}=$sofar; 939: } 940: 941: # if the expression is just the 0th condition keep it 942: # otherwise leave a pointer to this condition expression 943: 944: $newsofar = ($sofar eq '0') ? $sofar : '_'.$rid; 945: 946: # Recurse if the resource is a map: 947: 948: if (defined($hash{'is_map_'.$rid})) { 949: if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) { 950: $sofar=$newsofar= 951: &traceroute($sofar, 952: $hash{'map_start_'.$hash{'src_'.$rid}}, 953: $beenhere, 954: $encflag || $encurl{$rid}, 955: $hdnflag || $hiddenurl{$rid}); 956: } 957: } 958: 959: # Processes links to this resource: 960: # - verify the existence of any conditionals on the link to here. 961: # - Recurse to any resources linked to us. 962: # 963: if (defined($hash{'to_'.$rid})) { 964: foreach my $id (split(/\,/,$hash{'to_'.$rid})) { 965: my $further=$sofar; 966: # 967: # If there's a condition associated with this link be sure 968: # it's been defined else that's an error: 969: # 970: if ($hash{'undercond_'.$id}) { 971: if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) { 972: $further=simplify('('.'_'.$rid.')&('. 973: $hash{'condid_'.$hash{'undercond_'.$id}}.')'); 974: } else { 975: $errtext.= ' '. 976: &mt('Undefined condition ID: [_1]', 977: $hash{'undercond_'.$id}); 978: } 979: } 980: # Recurse to resoruces that have to's to us. 981: $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere, 982: $encflag,$hdnflag); 983: } 984: } 985: } 986: return $newsofar; 987: } 988: 989: # ------------------------------ Cascading conditions, quick access, parameters 990: 991: # 992: # Seems a rather strangely named sub given what the comment above says it does. 993: 994: 995: sub accinit { 996: my ($uri,$short,$fn)=@_; 997: my %acchash=(); 998: my %captured=(); 999: my $condcounter=0; 1000: $acchash{'acc.cond.'.$short.'.0'}=0; 1001: 1002: # This loop is only interested in conditions and 1003: # parameters in the big hash: 1004: 1005: foreach my $key (keys(%hash)) { 1006: 1007: # conditions: 1008: 1009: if ($key=~/^conditions/) { 1010: my $expr=$hash{$key}; 1011: 1012: # try to find and factor out common sub-expressions 1013: # Any subexpression that is found is simplified, removed from 1014: # the original condition expression and the simplified sub-expression 1015: # substituted back in to the epxression..I'm not actually convinced this 1016: # factors anything out...but instead maybe simplifies common factors(?) 1017: 1018: foreach my $sub ($expr=~m/($\([_\.\d]+(?:\&[_\.\d]+)+$(?:\|$[_\.\d]+(?:\&[_\.\d]+)+$)+\))/g) { 1019: my $orig=$sub; 1020: 1021: my ($factor) = ($sub=~/$\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+$(?:\|$\1(?:[_\.\d]+\&*)+$)+\)/); 1022: next if (!defined($factor)); 1023: 1024: $sub=~s/\Q$factor\E//g; 1025: $sub=~s/^\(/\($factor\(/; 1026: $sub.=')'; 1027: $sub=simplify($sub); 1028: $expr=~s/\Q$orig\E/$sub/; 1029: } 1030: $hash{$key}=$expr; 1031: 1032: # If not yet seen, record in acchash and that we've seen it. 1033: 1034: unless (defined($captured{$expr})) { 1035: $condcounter++; 1036: $captured{$expr}=$condcounter; 1037: $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr; 1038: } 1039: # Parameters: 1040: 1041: } elsif ($key=~/^param_(\d+)\.(\d+)/) { 1042: my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2, 1043: $hash{'src_'.$1.'.'.$2}); 1044: foreach my $param (split(/\&/,$hash{$key})) { 1045: my ($typename,$value)=split(/\=/,$param); 1046: my ($type,$name)=split(/\:/,$typename); 1047: $parmhash{$prefix.'.'.&unescape($name)}= 1048: &unescape($value); 1049: $parmhash{$prefix.'.'.&unescape($name).'.type'}= 1050: &unescape($type); 1051: } 1052: } 1053: } 1054: # This loop only processes id entries in the big hash. 1055: 1056: foreach my $key (keys(%hash)) { 1057: if ($key=~/^ids/) { 1058: foreach my $resid (split(/\,/,$hash{$key})) { 1059: my $uri=$hash{'src_'.$resid}; 1060: my ($uripath,$urifile) = 1061: &Apache::lonnet::split_uri_for_cond($uri); 1062: if ($uripath) { 1063: my $uricond='0'; 1064: if (defined($hash{'conditions_'.$resid})) { 1065: $uricond=$captured{$hash{'conditions_'.$resid}}; 1066: } 1067: if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) { 1068: if ($acchash{'acc.res.'.$short.'.'.$uripath}=~ 1069: /(\&\Q$urifile\E\:[^\&]*)/) { 1070: my $replace=$1; 1071: my $regexp=$replace; 1072: #$regexp=~s/\|/\\\|/g; 1073: $acchash{'acc.res.'.$short.'.'.$uripath} =~ 1074: s/\Q$regexp\E/$replace\|$uricond/; 1075: } else { 1076: $acchash{'acc.res.'.$short.'.'.$uripath}.= 1077: $urifile.':'.$uricond.'&'; 1078: } 1079: } else { 1080: $acchash{'acc.res.'.$short.'.'.$uripath}= 1081: '&'.$urifile.':'.$uricond.'&'; 1082: } 1083: } 1084: } 1085: } 1086: } 1087: $acchash{'acc.res.'.$short.'.'}='&:0&'; 1088: my $courseuri=$uri; 1089: $courseuri=~s/^\/res\///; 1090: my $regexp = 1; 1091: &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp); 1092: &Apache::lonnet::appenv(\%acchash); 1093: } 1094: 1095: # ---------------- Selectively delete from randompick maps and hidden url parms 1096: 1097: sub hiddenurls { 1098: my $randomoutentry=''; 1099: foreach my $rid (keys(%randompick)) { 1100: my $rndpick=$randompick{$rid}; 1101: my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}}; 1102: # ------------------------------------------- put existing resources into array 1103: my @currentrids=(); 1104: foreach my $key (sort(keys(%hash))) { 1105: if ($key=~/^src_($mpc\.\d+)/) { 1106: if ($hash{'src_'.$1}) { push @currentrids, $1; } 1107: } 1108: } 1109: # rids are number.number and we want to numercially sort on 1110: # the second number 1111: @currentrids=sort { 1112: my (undef,$aid)=split(/\./,$a); 1113: my (undef,$bid)=split(/\./,$b); 1114: $aid <=> $bid; 1115: } @currentrids; 1116: next if ($#currentrids<$rndpick); 1117: # -------------------------------- randomly eliminate the ones that should stay 1118: my (undef,$id)=split(/\./,$rid); 1119: if ($randompickseed{$rid}) { $id=$randompickseed{$rid}; } 1120: my $setcode; 1121: if (defined($randomizationcode{$rid})) { 1122: if ($env{'form.CODE'} eq '') { 1123: $env{'form.CODE'} = $randomizationcode{$rid}; 1124: $setcode = 1; 1125: } 1126: } 1127: my $rndseed=&Apache::lonnet::rndseed($id); # use id instead of symb 1128: if ($setcode) { 1129: undef($env{'form.CODE'}); 1130: undef($setcode); 1131: } 1132: &Apache::lonnet::setup_random_from_rndseed($rndseed); 1133: my @whichids=&Math::Random::random_permuted_index($#currentrids+1); 1134: for (my $i=1;$i<=$rndpick;$i++) { $currentrids[$whichids[$i]]=''; } 1135: #&Apache::lonnet::logthis("$id,$rndseed,".join(':',@whichids)); 1136: # -------------------------------------------------------- delete the leftovers 1137: for (my $k=0; $k<=$#currentrids; $k++) { 1138: if ($currentrids[$k]) { 1139: $hash{'randomout_'.$currentrids[$k]}=1; 1140: my ($mapid,$resid)=split(/\./,$currentrids[$k]); 1141: if ($rescount{$mapid}) { 1142: $rescount{$mapid} --; 1143: } 1144: if ($hash{'is_map_'.$currentrids[$k]}) { 1145: if ($mapcount{$mapid}) { 1146: $mapcount{$mapid} --; 1147: } 1148: } 1149: $randomoutentry.='&'. 1150: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid}, 1151: $resid, 1152: $hash{'src_'.$currentrids[$k]} 1153: ).'&'; 1154: } 1155: } 1156: } 1157: # ------------------------------ take care of explicitly hidden urls or folders 1158: foreach my $rid (keys(%hiddenurl)) { 1159: $hash{'randomout_'.$rid}=1; 1160: my ($mapid,$resid)=split(/\./,$rid); 1161: if ($rescount{$mapid}) { 1162: $rescount{$mapid} --; 1163: } 1164: if ($hash{'is_map_'.$rid}) { 1165: if ($mapcount{$mapid}) { 1166: $mapcount{$mapid} --; 1167: } 1168: } 1169: $randomoutentry.='&'. 1170: &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid, 1171: $hash{'src_'.$rid}).'&'; 1172: } 1173: # --------------------------------------- append randomout entry to environment 1174: if ($randomoutentry) { 1175: &Apache::lonnet::appenv({'acc.randomout' => $randomoutentry}); 1176: } 1177: } 1178: 1179: # -------------------------------------- populate big hash with map breadcrumbs 1180: 1181: # Create map_breadcrumbs_$pc from map_hierarchy_$pc by omitting intermediate 1182: # maps not shown in Course Contents table. 1183: 1184: sub mapcrumbs { 1185: foreach my $key (keys(%rescount)) { 1186: if ($hash{'map_hierarchy_'.$key}) { 1187: my $skipnext = 0; 1188: foreach my $id (split(/,/,$hash{'map_hierarchy_'.$key}),$key) { 1189: unless ($skipnext) { 1190: $hash{'map_breadcrumbs_'.$key} .= "$id,"; 1191: } 1192: unless (($id == 0) || ($id == 1)) { 1193: if ((!$rescount{$id}) || ($rescount{$id} == 1 && $mapcount{$id} == 1)) { 1194: $skipnext = 1; 1195: } else { 1196: $skipnext = 0; 1197: } 1198: } 1199: } 1200: $hash{'map_breadcrumbs_'.$key} =~ s/,$//; 1201: } 1202: } 1203: } 1204: 1205: # ---------------------------------------------------- Read map and all submaps 1206: 1207: sub readmap { 1208: my $short=shift; 1209: $short=~s/^\///; 1210: 1211: # TODO: Hidden dependency on current user: 1212: 1213: my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1}); 1214: 1215: my $fn=$cenv{'fn'}; 1216: my $uri; 1217: $short=~s/\//\_/g; 1218: unless ($uri=$cenv{'url'}) { 1219: &Apache::lonnet::logthis('WARNING: '. 1220: "Could not load course $short."); 1221: return ('',&mt('No course data available.'));; 1222: } 1223: @cond=('true:normal'); 1224: 1225: unless (open(LOCKFILE,">","$fn.db.lock")) { 1226: # 1227: # Most likely a permissions problem on the lockfile or its directory. 1228: # 1229: $retfurl = ''; 1230: return ($retfurl,' '.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.'); 1231: } 1232: my $lock=0; 1233: my $gotstate=0; 1234: 1235: # If we can get the lock without delay any files there are idle 1236: # and from some prior request. We'll kill them off and regenerate them: 1237: 1238: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) { 1239: $lock=1; # Remember that we hold the lock. 1240: &unlink_tmpfiles($fn); 1241: } 1242: undef %randompick; 1243: undef %randompickseed; 1244: undef %randomorder; 1245: undef %randomizationcode; 1246: undef %hiddenurl; 1247: undef %encurl; 1248: undef %deeplinkonly; 1249: undef %rescount; 1250: undef %mapcount; 1251: $retfrid=''; 1252: $errtext=''; 1253: my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags. 1254: 1255: # if we got the lock, regenerate course regnerate empty files and tie them. 1256: 1257: if ($lock) { 1258: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) { 1259: $tiedhash = 1; 1260: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) { 1261: $tiedparmhash = 1; 1262: $gotstate = &build_tmp_hashes($uri, 1263: $fn, 1264: $short, 1265: \%cenv); # TODO: Need to provide requested user@dom 1266: unless ($gotstate) { 1267: &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.'); 1268: } 1269: $untiedparmhash = untie(%parmhash); 1270: unless ($untiedparmhash) { 1271: &Apache::lonnet::logthis('WARNING: '. 1272: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.'); 1273: } 1274: } 1275: $untiedhash = untie(%hash); 1276: unless ($untiedhash) { 1277: &Apache::lonnet::logthis('WARNING: '. 1278: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.'); 1279: } 1280: } 1281: flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other 1282: # unlocked places the remainder happens..seems like if we 1283: # just kept the lock here the rest of the code would have 1284: # been much easier? 1285: } 1286: unless ($lock && $tiedhash && $tiedparmhash) { 1287: # if we are here it is likely because we are already trying to 1288: # initialize the course in another child, busy wait trying to 1289: # tie the hashes for the next 90 seconds, if we succeed forward 1290: # them on to navmaps, if we fail, throw up the Could not init 1291: # course screen 1292: # 1293: # RF: I'm not seeing the case where the ties/unties can fail in a way 1294: # that can be remedied by this. Since we owned the lock seems 1295: # Tie/untie failures are a result of something like a permissions problem instead? 1296: # 1297: 1298: # In any vent, undo what we did manage to do above first: 1299: if ($lock) { 1300: # Got the lock but not the DB files 1301: flock(LOCKFILE,LOCK_UN); 1302: $lock = 0; 1303: } 1304: if ($tiedhash) { 1305: unless($untiedhash) { 1306: untie(%hash); 1307: } 1308: } 1309: if ($tiedparmhash) { 1310: unless($untiedparmhash) { 1311: untie(%parmhash); 1312: } 1313: } 1314: # Log our failure: 1315: 1316: &Apache::lonnet::logthis('WARNING: '. 1317: "Could not tie coursemap $fn for $uri."); 1318: $tiedhash = ''; 1319: $tiedparmhash = ''; 1320: my $i=0; 1321: 1322: # Keep on retrying the lock for 90 sec until we succeed. 1323: 1324: while($i<90) { 1325: $i++; 1326: sleep(1); 1327: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) { 1328: 1329: # Got the lock, tie the hashes...the assumption in this code is 1330: # that some other worker thread has created the db files quite recently 1331: # so no load is needed: 1332: 1333: $lock = 1; 1334: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) { 1335: $tiedhash = 1; 1336: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) { 1337: $tiedparmhash = 1; 1338: if (-e "$fn.state") { 1339: $retfurl='/adm/navmaps'; 1340: 1341: # BUG BUG: Side effect! 1342: # Should conditionalize on something so that we can use this 1343: # to load maps for courses that are not current? 1344: # 1345: &Apache::lonnet::appenv({"request.course.id" => $short, 1346: "request.course.fn" => $fn, 1347: "request.course.uri" => $uri, 1348: "request.course.tied" => time}); 1349: 1350: $untiedhash = untie(%hash); 1351: $untiedparmhash = untie(%parmhash); 1352: $gotstate = 1; 1353: last; 1354: } 1355: $untiedparmhash = untie(%parmhash); 1356: } 1357: $untiedhash = untie(%hash); 1358: } 1359: } 1360: } 1361: if ($lock) { 1362: flock(LOCKFILE,LOCK_UN); 1363: $lock = 0; 1364: if ($tiedparmhash) { 1365: unless ($untiedparmhash) { 1366: &Apache::lonnet::logthis('WARNING: '. 1367: 'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.'); 1368: } 1369: } 1370: if ($tiedparmhash) { 1371: unless ($untiedhash) { 1372: &Apache::lonnet::logthis('WARNING: '. 1373: 'Could not untie coursemap hash '.$fn.' for '.$uri.'.'); 1374: } 1375: } 1376: } 1377: } 1378: # I think this branch of code is all about what happens if we just did the stuff above, 1379: # but found that the state file did not exist...again if we'd just held the lock 1380: # would that have made this logic simpler..as generating all the files would be 1381: # an atomic operation with respect to the lock. 1382: # 1383: unless ($gotstate) { 1384: $lock = 0; 1385: &Apache::lonnet::logthis('WARNING: '. 1386: 'Could not read statemap '.$fn.' for '.$uri.'.'); 1387: &unlink_tmpfiles($fn); 1388: if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) { 1389: $lock=1; 1390: } 1391: undef %randompick; 1392: undef %randompickseed; 1393: undef %randomorder; 1394: undef %randomizationcode; 1395: undef %hiddenurl; 1396: undef %encurl; 1397: undef %deeplinkonly; 1398: undef %rescount; 1399: undef %mapcount; 1400: $errtext=''; 1401: $retfrid=''; 1402: # 1403: # Once more through the routine of tying and loading and so on. 1404: # 1405: if ($lock) { 1406: if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) { 1407: if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) { 1408: $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent? 1409: unless ($gotstate) { 1410: &Apache::lonnet::logthis('WARNING: '. 1411: 'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.'); 1412: } 1413: unless (untie(%parmhash)) { 1414: &Apache::lonnet::logthis('WARNING: '. 1415: 'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.'); 1416: } 1417: } else { 1418: &Apache::lonnet::logthis('WARNING: '. 1419: 'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.'); 1420: } 1421: unless (untie(%hash)) { 1422: &Apache::lonnet::logthis('WARNING: '. 1423: 'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.'); 1424: } 1425: } else { 1426: &Apache::lonnet::logthis('WARNING: '. 1427: 'Could not tie coursemap '.$fn.'.db for '.$uri.'.'); 1428: } 1429: flock(LOCKFILE,LOCK_UN); 1430: $lock = 0; 1431: } else { 1432: # Failed to get the immediate lock. 1433: 1434: &Apache::lonnet::logthis('WARNING: '. 1435: 'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.'); 1436: } 1437: } 1438: close(LOCKFILE); 1439: unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) { 1440: &Apache::lonmsg::author_res_msg($env{'request.course.uri'}, 1441: $errtext); # TODO: User dependent? 1442: } 1443: # ------------------------------------------------- Check for critical messages 1444: 1445: # Depends on user must parameterize this as well..or separate as this is: 1446: # more part of determining what someone sees on entering a course? 1447: 1448: my @what=&Apache::lonnet::dump('critical',$env{'user.domain'}, 1449: $env{'user.name'}); 1450: if ($what[0]) { 1451: if (($what[0] ne 'con_lost') && ($what[0]!~/^error\:/)) { 1452: $retfurl='/adm/email?critical=display'; 1453: } 1454: } 1455: return ($retfurl,$errtext); 1456: } 1457: 1458: # 1459: # This sub is called when the course hash and the param hash have been tied and 1460: # their lock file is held. 1461: # Parameters: 1462: # $uri - URI that identifies the course. 1463: # $fn - The base path/filename of the files that make up the context 1464: # being built. 1465: # $short - Short course name. 1466: # $cenvref - Reference to the course environment hash returned by 1467: # Apache::lonnet::coursedescription 1468: # 1469: # Assumptions: 1470: # The globals 1471: # %hash, %paramhash are tied to their gdbm files and we hold the lock on them. 1472: # 1473: sub build_tmp_hashes { 1474: my ($uri,$fn,$short,$cenvref) = @_; 1475: 1476: unless(ref($cenvref) eq 'HASH') { 1477: return; 1478: } 1479: my %cenv = %{$cenvref}; 1480: my $gotstate = 0; 1481: %hash=(); # empty the global course and parameter hashes. 1482: %parmhash=(); 1483: $errtext=''; # No error messages yet. 1484: $pc=0; 1485: &clear_mapalias_count(); 1486: &processversionfile(%cenv); 1487: 1488: # URI Of the map file. 1489: 1490: my $furi=&Apache::lonnet::clutter($uri); 1491: # 1492: # the map staring points. 1493: # 1494: $hash{'src_0.0'}=&versiontrack($furi); 1495: $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title'); 1496: $hash{'ids_'.$furi}='0.0'; 1497: $hash{'is_map_0.0'}=1; 1498: 1499: # Load the map.. note that loadmap may implicitly recurse if the map contains 1500: # sub-maps. 1501: 1502: 1503: &loadmap($uri,'0.0',$short); 1504: 1505: # The code below only executes if there is a starting point for the map> 1506: # Q/BUG??? If there is no start resource for the map should that be an error? 1507: # 1508: 1509: if (defined($hash{'map_start_'.$uri})) { 1510: &Apache::lonnet::appenv({"request.course.id" => $short, 1511: "request.course.fn" => $fn, 1512: "request.course.uri" => $uri, 1513: "request.course.tied" => time}); 1514: $env{'request.course.id'}=$short; 1515: &traceroute('0',$hash{'map_start_'.$uri},'&'); 1516: &accinit($uri,$short,$fn); 1517: &hiddenurls(); 1518: &mapcrumbs(); 1519: } 1520: $errtext .= &get_mapalias_errors(); 1521: # ------------------------------------------------------- Put versions into src 1522: foreach my $key (keys(%hash)) { 1523: if ($key=~/^src_/) { 1524: $hash{$key}=&putinversion($hash{$key}); 1525: } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) { 1526: my ($type, $url) = ($1,$2); 1527: my $value = $hash{$key}; 1528: $hash{$type.&putinversion($url)}=$value; 1529: } 1530: } 1531: # ---------------------------------------------------------------- Encrypt URLs 1532: foreach my $id (keys(%encurl)) { 1533: # $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id}); 1534: $hash{'encrypted_'.$id}=1; 1535: } 1536: # ------------------------------------------------------------ Deep-linked URLs 1537: foreach my $id (keys(%deeplinkonly)) { 1538: $hash{'deeplinkonly_'.$id}=$deeplinkonly{$id}; 1539: } 1540: # ----------------------------------------------- Close hashes to finally store 1541: # --------------------------------- Routine must pass this point, no early outs 1542: $hash{'first_rid'}=$retfrid; 1543: my ($mapid,$resid)=split(/\./,$retfrid); 1544: $hash{'first_mapurl'}=$hash{'map_id_'.$mapid}; 1545: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid}); 1546: $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb }); 1547: if ($hash{'encrypted_'.$retfrid}) { 1548: $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F')); 1549: } 1550: $hash{'first_url'}=$retfurl; 1551: # ---------------------------------------------------- Store away initial state 1552: { 1553: my $cfh; 1554: if (open($cfh,">","$fn.state")) { 1555: print $cfh join("\n",@cond); 1556: $gotstate = 1; 1557: } else { 1558: &Apache::lonnet::logthis("WARNING: ". 1559: "Could not write statemap $fn for $uri."); 1560: } 1561: } 1562: return $gotstate; 1563: } 1564: 1565: sub unlink_tmpfiles { 1566: my ($fn) = @_; 1567: my $file_dir = dirname($fn); 1568: 1569: if ("$file_dir/" eq LONCAPA::tempdir()) { 1570: my @files = qw (.db _symb.db .state _parms.db); 1571: foreach my $file (@files) { 1572: if (-e $fn.$file) { 1573: unless (unlink($fn.$file)) { 1574: &Apache::lonnet::logthis("WARNING: ". 1575: "Could not unlink ".$fn.$file.""); 1576: } 1577: } 1578: } 1579: } 1580: return; 1581: } 1582: 1583: # ------------------------------------------------------- Evaluate state string 1584: 1585: sub evalstate { 1586: my $fn=$env{'request.course.fn'}.'.state'; 1587: my $state=''; 1588: if (-e $fn) { 1589: my @conditions=(); 1590: { 1591: open(my $fh,"<",$fn); 1592: @conditions=<$fh>; 1593: close($fh); 1594: } 1595: my $safeeval = new Safe; 1596: my $safehole = new Safe::Hole; 1597: $safeeval->permit("entereval"); 1598: $safeeval->permit(":base_math"); 1599: $safeeval->deny(":base_io"); 1600: $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT'); 1601: foreach my $line (@conditions) { 1602: chomp($line); 1603: my ($condition,$weight)=split(/\:/,$line); 1604: if ($safeeval->reval($condition)) { 1605: if ($weight eq 'force') { 1606: $state.='3'; 1607: } else { 1608: $state.='2'; 1609: } 1610: } else { 1611: if ($weight eq 'stop') { 1612: $state.='0'; 1613: } else { 1614: $state.='1'; 1615: } 1616: } 1617: } 1618: } 1619: &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state}); 1620: return $state; 1621: } 1622: 1623: # This block seems to have code to manage/detect doubly defined 1624: # aliases in maps. 1625: 1626: { 1627: my %mapalias_cache; 1628: sub count_mapalias { 1629: my ($value,$resid) = @_; 1630: push(@{ $mapalias_cache{$value} }, $resid); 1631: } 1632: 1633: sub get_mapalias_errors { 1634: my $error_text; 1635: foreach my $mapalias (sort(keys(%mapalias_cache))) { 1636: next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1); 1637: my $count; 1638: my $which = 1639: join('</li><li>', 1640: map { 1641: my $id = $_; 1642: if (exists($hash{'src_'.$id})) { 1643: $count++; 1644: } 1645: my ($mapid) = split(/\./,$id); 1646: &mt('Resource [_1][_2]in Map [_3]', 1647: $hash{'title_'.$id},' ', 1648: $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}}); 1649: } (@{ $mapalias_cache{$mapalias} })); 1650: next if ($count < 2); 1651: $error_text .= '<div class="LC_error">'. 1652: &mt('Error: Found the mapalias "[_1]" defined multiple times.', 1653: $mapalias). 1654: '</div><ul><li>'.$which.'</li></ul>'; 1655: } 1656: &clear_mapalias_count(); 1657: return $error_text; 1658: } 1659: sub clear_mapalias_count { 1660: undef(%mapalias_cache); 1661: } 1662: } 1663: 1; 1664: __END__ 1665: 1666: =head1 NAME 1667: 1668: Apache::lonuserstate - Construct and maintain state and binary representation 1669: of course for user 1670: 1671: =head1 SYNOPSIS 1672: 1673: Invoked by lonroles.pm. 1674: 1675: &Apache::lonuserstate::readmap($cdom.'/'.$cnum); 1676: 1677: =head1 INTRODUCTION 1678: 1679: This module constructs and maintains state and binary representation 1680: of course for user. 1681: 1682: This is part of the LearningOnline Network with CAPA project 1683: described at http://www.lon-capa.org. 1684: 1685: =head1 SUBROUTINES 1686: 1687: =over 1688: 1689: =item loadmap() 1690: 1691: Loads map from disk 1692: 1693: =item simplify() 1694: 1695: Simplify expression 1696: 1697: =item traceroute() 1698: 1699: Build condition hash 1700: 1701: =item accinit() 1702: 1703: Cascading conditions, quick access, parameters 1704: 1705: =item readmap() 1706: 1707: Read map and all submaps 1708: 1709: =item evalstate() 1710: 1711: Evaluate state string 1712: 1713: =back 1714: 1715: =cut