File:  [LON-CAPA] / rat / lonuserstate.pm
Revision 1.18: download - view: text, annotated - select for diffs
Tue Nov 14 11:13:12 2000 UTC (23 years, 5 months ago) by www
Branches: MAIN
CVS tags: HEAD
Reads resource parameters

    1: # The LearningOnline Network with CAPA
    2: # Construct and maintain state and binary representation of course for user
    3: #
    4: # (Server for RAT Maps
    5: #
    6: # (Edit Handler for RAT Maps
    7: # (TeX Content Handler
    8: #
    9: # 05/29/00,05/30 Gerd Kortemeyer)
   10: # 7/1 Gerd Kortemeyer)
   11: # 7/1,7/3,7/4,7/7,7/8,7/10 Gerd Kortemeyer)
   12: #
   13: # 7/15,7/17,7/18,8/1,8/2,8/4,8/5,8/21,8/22,8/23,8/30,
   14: # 9/2,9/4,9/29,9/30,10/2,10/11,10/30,10/31,11/1,11/2,11/14 Gerd Kortemeyer
   15: 
   16: package Apache::lonuserstate;
   17: 
   18: use strict;
   19: use Apache::Constants qw(:common :http);
   20: use Apache::File;
   21: use HTML::TokeParser;
   22: use Apache::lonnet();
   23: use GDBM_File;
   24: use Apache::lonmsg;
   25: use Safe;
   26: use Opcode;
   27: 
   28: # ---------------------------------------------------- Globals for this package
   29: 
   30: my $pc;      # Package counter
   31: my %hash;    # The big tied hash
   32: my @cond;    # Array with all of the conditions
   33: my $errtext; # variable with all errors
   34: 
   35: # --------------------------------------------------------- Loads map from disk
   36: 
   37: sub loadmap { 
   38:     my $uri=shift;
   39:     if ($hash{'map_pc_'.$uri}) { return OK; }
   40: 
   41:     $pc++;
   42:     my $lpc=$pc;
   43:     $hash{'map_pc_'.$uri}=$lpc;
   44:     $hash{'map_id_'.$lpc}=$uri;
   45: 
   46:     my $fn='/home/httpd/html'.$uri;
   47: 
   48:     unless (($fn=~/\.sequence$/) ||
   49:             ($fn=~/\.page$/)) { 
   50:        $errtext.="Invalid map: $fn\n";
   51:        return OK; 
   52:     }
   53: 
   54:     unless (-e $fn) {
   55: 	my $returned=Apache::lonnet::repcopy($fn);
   56:         unless ($returned eq OK) {
   57:            $errtext.="Could not import: $fn - ";
   58:            if ($returned eq HTTP_SERVICE_UNAVAILABLE) {
   59: 	      $errtext.="Server unavailable\n";
   60:            }
   61:            if ($returned eq HTTP_NOT_FOUND) {
   62: 	      $errtext.="File not found\n";
   63:            }
   64:            if ($returned eq FORBIDDEN) {
   65: 	      $errtext.="Access forbidden\n";
   66:            }
   67:            return OK;
   68:        }
   69:     }
   70: 
   71:     if (-e $fn) {
   72:         my @content;
   73:         {
   74: 	    my $fh=Apache::File->new($fn);
   75:             @content=<$fh>;
   76:         }
   77:         my $instr=join('',@content);
   78:         my $parser = HTML::TokeParser->new(\$instr);
   79:         my $token;
   80: 
   81:         my $linkpc=0;
   82: 
   83:         $fn=~/\.(\w+)$/;
   84: 
   85:         $hash{'map_type_'.$lpc}=$1;
   86: 
   87:         while ($token = $parser->get_token) {
   88: 	    if ($token->[0] eq 'S') {
   89:                 if ($token->[1] eq 'resource') {
   90: # -------------------------------------------------------------------- Resource
   91: 
   92:                     my $rid=$lpc.'.'.$token->[2]->{'id'};
   93: 
   94:                     $hash{'kind_'.$rid}='res';
   95:                     $hash{'title_'.$rid}=$token->[2]->{'title'};
   96:                     my $turi=$token->[2]->{'src'};
   97:                     $hash{'src_'.$rid}=$turi;
   98: 
   99:                     if (defined($hash{'ids_'.$turi})) {
  100:                         $hash{'ids_'.$turi}.=','.$rid;
  101:                     } else {
  102:                         $hash{'ids_'.$turi}=''.$rid;
  103:                     }
  104: 
  105:                     if ($token->[2]->{'src'}=~/\/\//) {
  106:                         $hash{'ext_'.$rid}='true:';
  107:                     } else {
  108:                         $hash{'ext_'.$rid}='false:';
  109:                     }
  110:                     if ($token->[2]->{'type'}) {
  111: 			$hash{'type_'.$rid}=$token->[2]->{'type'};
  112:                         if ($token->[2]->{'type'} eq 'start') {
  113: 			    $hash{'map_start_'.$uri}="$rid";
  114:                         }
  115:                         if ($token->[2]->{'type'} eq 'finish') {
  116: 			    $hash{'map_finish_'.$uri}="$rid";
  117:                         }
  118:                     }  else {
  119:                         $hash{'type_'.$rid}='normal';
  120:                     }
  121: 
  122:                     if (($turi=~/\.sequence$/) ||
  123:                         ($turi=~/\.page$/)) {
  124:                         $hash{'is_map_'.$rid}=1;
  125:                         &loadmap($turi);
  126:                     } 
  127:                     
  128:                 } elsif ($token->[1] eq 'condition') {
  129: # ------------------------------------------------------------------- Condition
  130: 
  131:                     my $rid=$lpc.'.'.$token->[2]->{'id'};
  132: 
  133:                     $hash{'kind_'.$rid}='cond';
  134:                     $cond[$#cond+1]=$token->[2]->{'value'};
  135:                     $hash{'condid_'.$rid}=$#cond;
  136:                     if ($token->[2]->{'type'}) {
  137:                         $cond[$#cond].=':'.$token->[2]->{'type'};
  138:                     }  else {
  139:                         $cond[$#cond].=':normal';
  140:                     }
  141: 
  142:                 } elsif ($token->[1] eq 'link') {
  143: # ----------------------------------------------------------------------- Links
  144: 
  145:                     $linkpc++;
  146:                     my $linkid=$lpc.'.'.$linkpc;
  147: 
  148:                     my $goesto=$lpc.'.'.$token->[2]->{'to'};
  149:                     my $comesfrom=$lpc.'.'.$token->[2]->{'from'};
  150:                     my $undercond=0;
  151: 
  152:                     if ($token->[2]->{'condition'}) {
  153: 			$undercond=$lpc.'.'.$token->[2]->{'condition'};
  154:                     }
  155: 
  156:                     $hash{'goesto_'.$linkid}=$goesto;
  157:                     $hash{'comesfrom_'.$linkid}=$comesfrom;
  158:                     $hash{'undercond_'.$linkid}=$undercond;
  159: 
  160:                     if (defined($hash{'to_'.$comesfrom})) {
  161:                         $hash{'to_'.$comesfrom}.=','.$linkid;
  162:                     } else {
  163:                         $hash{'to_'.$comesfrom}=''.$linkid;
  164:                     }
  165:                     if (defined($hash{'from_'.$goesto})) {
  166:                         $hash{'from_'.$goesto}.=','.$linkid;
  167:                     } else {
  168:                         $hash{'from_'.$goesto}=''.$linkid;
  169:                     }
  170:                 } elsif ($token->[1] eq 'param') {
  171: # ------------------------------------------------------------------- Parameter
  172: 
  173:                     my $referid=$lpc.'.'.$token->[2]->{'to'};
  174:                     my $newparam=
  175: 			&Apache::lonnet::escape($token->[2]->{'type'}).':'.
  176: 			&Apache::lonnet::escape($token->[2]->{'name'}).'='.
  177: 			&Apache::lonnet::escape($token->[2]->{'value'});
  178:                     if (defined($hash{'param_'.$referid})) {
  179:                         $hash{'param_'.$referid}.='&'.$newparam;
  180:                     } else {
  181:                         $hash{'param_'.$referid}=''.$newparam;
  182:                     }
  183: 
  184:                 } 
  185: 
  186:             }
  187:         }
  188: 
  189:     } else {
  190:         $errtext.='Map not loaded: The file does not exist. ';
  191:     }
  192: }
  193: 
  194: # --------------------------------------------------------- Simplify expression
  195: 
  196: sub simplify {
  197:    my $expression=shift;
  198: # (8)=8
  199:    $expression=~s/\((\d+)\)/$1/g;
  200: # 8&8=8
  201:    $expression=~s/(\D)(\d+)\&\2(\D)/$1$2$3/g;
  202: # 8|8=8
  203:    $expression=~s/(\D)(\d+)\|\2(\D)/$1$2$3/g;
  204: # (5&3)&4=5&3&4
  205:    $expression=~s/\((\d+)((?:\&\d+)+)\)\&(\d+\D)/$1$2\&$3/g;
  206: # (((5&3)|(4&6)))=((5&3)|(4&6))
  207:    $expression=~
  208:        s/\((\(\(\d+(?:\&\d+)*\)(?:\|\(\d+(?:\&\d+)*\))+\))\)/$1/g;
  209: # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
  210:    $expression=~
  211:        s/\((\(\d+(?:\&\d+)*\))((?:\|\(\d+(?:\&\d+)*\))+)\)\|(\(\d+(?:\&\d+)*\))/\($1$2\|$3\)/g;
  212:    return $expression;
  213: }
  214: 
  215: # -------------------------------------------------------- Build condition hash
  216: 
  217: sub traceroute {
  218:     my ($sofar,$rid,$beenhere)=@_;
  219:     $sofar=simplify($sofar);
  220:     unless ($beenhere=~/\&$rid\&/) {
  221:        $beenhere.=$rid.'&';  
  222:        if (defined($hash{'conditions_'.$rid})) {
  223: 	   $hash{'conditions_'.$rid}=simplify(
  224:            '('.$hash{'conditions_'.$rid}.')|('.$sofar.')');
  225:        } else {
  226:            $hash{'conditions_'.$rid}=$sofar;
  227:        }
  228:        if (defined($hash{'is_map_'.$rid})) {
  229:            if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
  230: 	       &traceroute($sofar,$hash{'map_start_'.$hash{'src_'.$rid}},'&');
  231:                if (defined($hash{'map_finish_'.$hash{'src_'.$rid}})) {
  232: 		   $sofar=
  233:                   $hash{'conditions_'.$hash{'map_finish_'.$hash{'src_'.$rid}}};
  234:                }
  235:            }
  236:        }
  237:        if (defined($hash{'to_'.$rid})) {
  238:           map {
  239: 		my $further=$sofar;
  240:                 if ($hash{'undercond_'.$_}) {
  241: 		   if (defined($hash{'condid_'.$hash{'undercond_'.$_}})) {
  242:   		       $further=simplify('('.$further.')&('.
  243:                               $hash{'condid_'.$hash{'undercond_'.$_}}.')');
  244: 		   } else {
  245:                        $errtext.='Undefined condition ID: '
  246:                                  .$hash{'undercond_'.$_}.'. ';
  247:                    }
  248:                 }
  249:                 &traceroute($further,$hash{'goesto_'.$_},$beenhere);
  250:           } split(/\,/,$hash{'to_'.$rid});
  251:        }
  252:     }
  253: }
  254: 
  255: # ------------------------------------------ Cascading conditions, quick access
  256: 
  257: sub accinit {
  258:     my ($uri,$short,$fn)=@_;
  259:     my %acchash=();
  260:     my %captured=();
  261:     my $condcounter=0;
  262:     $acchash{'acc.cond.'.$short.'.0'}=0;
  263:     map {
  264:        if ($_=~/^conditions/) {
  265: 	  my $expr=$hash{$_};
  266:           map {
  267:              my $sub=$_;
  268:              my $orig=$_;
  269:       $sub=~/\(\((\d+\&(:?\d+\&)*)(?:\d+\&*)+\)(?:\|\(\1(?:\d+\&*)+\))+\)/;
  270:              my $factor=$1;
  271:              $sub=~s/$factor//g;
  272:              $sub=~s/^\(/\($factor\(/;
  273: 	     $sub.=')';
  274:              $sub=simplify($sub);
  275:              $orig=~s/(\W)/\\$1/g;
  276:  	     $expr=~s/$orig/$sub/;
  277: 	  } ($expr=~m/(\(\(\d+(?:\&\d+)+\)(?:\|\(\d+(?:\&\d+)+\))+\))/g);
  278:           $hash{$_}=$expr;
  279:           unless (defined($captured{$expr})) {
  280: 	      $condcounter++;
  281:               $captured{$expr}=$condcounter;
  282:               $acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
  283:           } 
  284:         }
  285:     } keys %hash;
  286:     map {
  287: 	if ($_=~/^ids/) {
  288: 	  map {
  289: 	    my $resid=$_;
  290:             my $uri=$hash{'src_'.$resid};
  291:             my @uriparts=split(/\//,$uri);
  292:             my $urifile=$uriparts[$#uriparts];
  293:             $#uriparts--;
  294:             my $uripath=join('/',@uriparts);
  295:             $uripath=~s/^\/res\///;
  296:             my $uricond='0';
  297:             if (defined($hash{'conditions_'.$resid})) {
  298:  		$uricond=$captured{$hash{'conditions_'.$resid}};
  299:             }
  300:             if (defined($acchash{'acc.res.'.$short.'.'.$uripath})) {
  301:                 if ($acchash{'acc.res.'.$short.'.'.$uripath}=~
  302:                    /(\&$urifile\:[^\&]*)/) {
  303: 		    my $replace=$1;
  304:                     $acchash{'acc.res.'.$short.'.'.$uripath}
  305:                      =~s/$replace/$replace\|$uricond/;
  306:                 } else {
  307: 		   $acchash{'acc.res.'.$short.'.'.$uripath}.=
  308:                      $urifile.':'.$uricond.'&';
  309: 	        }
  310:             } else {
  311:                 $acchash{'acc.res.'.$short.'.'.$uripath}=
  312:                  '&'.$urifile.':'.$uricond.'&';
  313:             } 
  314:          } split(/\,/,$hash{$_});
  315:       }
  316:     } keys %hash;
  317:     my $courseuri=$uri;
  318:     $courseuri=~s/^\/res\///;
  319:     &Apache::lonnet::delenv('(acc\.|httpref\.|resource\.parms)');
  320:     &Apache::lonnet::appenv(%acchash,
  321:                             "request.course.id"  => $short,
  322:                             "request.course.fn"  => $fn,
  323:                             "request.course.uri" => $courseuri); 
  324: }
  325: 
  326: # ---------------------------------------------------- Read map and all submaps
  327: 
  328: sub readmap {
  329:    my $short=shift;
  330:    $short=~s/^\///;
  331:    my %cenv=&Apache::lonnet::coursedescription($short);
  332:    my $fn=$cenv{'fn'};
  333:    my $uri;
  334:    $short=~s/\//\_/g;
  335:    unless ($uri=$cenv{'url'}) { 
  336:       &Apache::lonnet::logthis("<font color=blue>WARNING: ".
  337:                        "Could not load course $short.</font>"); 
  338:       return 'No course data available.';
  339:    }
  340:    @cond=('true:normal');
  341:    unlink($fn.'.db');
  342:    unlink($fn.'_symb.db');
  343:    unlink($fn.'.state');
  344:    if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT,0640)) {
  345:     %hash=();
  346:     $errtext='';
  347:     $pc=0;
  348:     loadmap($uri);
  349:     if (defined($hash{'map_start_'.$uri})) {
  350:         &traceroute('0',$hash{'map_start_'.$uri},'&');
  351:         &accinit($uri,$short,$fn);
  352:     }
  353:     unless (untie(%hash)) {
  354:       &Apache::lonnet::logthis("<font color=blue>WARNING: ".
  355:                        "Could not untie coursemap $fn for $uri.</font>"); 
  356:     }
  357:     {
  358:      my $cfh;
  359:      if ($cfh=Apache::File->new(">$fn.state")) {
  360:         print $cfh join("\n",@cond);
  361:      } else {
  362:       &Apache::lonnet::logthis("<font color=blue>WARNING: ".
  363:                        "Could not write statemap $fn for $uri.</font>"); 
  364:      }
  365:     }  
  366:    } else {
  367:       &Apache::lonnet::logthis("<font color=blue>WARNING: ".
  368:                        "Could not tie coursemap $fn for $uri.</font>"); 
  369:    }
  370:    &Apache::lonmsg::author_res_msg($ENV{'request.course.uri'},$errtext);
  371:    return $errtext;
  372: }
  373: 
  374: # ------------------------------------------------------- Evaluate state string
  375: 
  376: sub evalstate {
  377:     my $safeeval = new Safe;
  378:     my $fn=$ENV{'request.course.fn'}.'.state';
  379:     my $state='2';
  380:     if (-e $fn) {
  381:        my @conditions=();
  382:        {
  383:         my $fh=Apache::File->new($fn);
  384:         @conditions=<$fh>;
  385:        }  
  386:        $safeeval->permit("entereval");
  387:        $safeeval->permit(":base_math");
  388:        $safeeval->deny(":base_io");
  389:        $safeeval->share_from('Apache::lonnet',['&EXT']);
  390:        map {
  391: 	   my $line=$_;
  392:            chomp($line);
  393: 	   my ($condition,$weight)=split(/\:/,$_);
  394:            if ($safeeval->reval($condition)) {
  395: 	       if ($weight eq 'force') {
  396: 		   $state.='3';
  397:                } else {
  398:                    $state.='2';
  399:                }
  400:            } else {
  401:                if ($weight eq 'stop') {
  402: 		   $state.='0';
  403:                } else {
  404:                    $state.='1';
  405:                }
  406:            }
  407:        } @conditions;
  408:     }
  409:     &Apache::lonnet::appenv('user.state.'.$ENV{'request.course.id'} => $state);
  410:     return $state;
  411: }
  412: 
  413: 1;
  414: __END__
  415: 
  416: 
  417: 
  418: 
  419: 
  420: 
  421: 

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