File:  [LON-CAPA] / loncom / xml / lonxml.pm
Revision 1.9: download - view: text, annotated - select for diffs
Wed Jul 5 18:04:45 2000 UTC (23 years, 11 months ago) by albertel
Branches: MAIN
CVS tags: HEAD
- fixed end tag to work like start tag

    1: # The LearningOnline Network with CAPA
    2: # XML Parser Module 
    3: #
    4: # last modified 06/26/00 by Alexander Sakharuk
    5: 
    6: package Apache::lonxml; 
    7: 
    8: use strict;
    9: use HTML::TokeParser;
   10: use Safe;
   11: 
   12: sub register {
   13:   my $space;
   14:   my @taglist;
   15:   my $temptag;
   16:   ($space,@taglist) = @_;
   17:   foreach $temptag (@taglist) {
   18:     $Apache::lonxml::alltags{$temptag}=$space;
   19:   }
   20: }
   21: 
   22: use Apache::style;
   23: use Apache::lontexconvert;
   24: use Apache::run;
   25: use Apache::londefdef;
   26: use Apache::scripttag;
   27: #==================================================   Main subroutine: xmlparse  
   28: 
   29: sub xmlparse {
   30: 
   31:  my ($target,$content_file_string,%style_for_target) = @_;
   32:  my $pars = HTML::TokeParser->new(\$content_file_string);
   33:  my $currentstring = '';
   34:  my $finaloutput = ''; 
   35:  my $newarg = '';
   36:  my $safeeval = new Safe;
   37:  $safeeval->permit("entereval");
   38: #-------------------- Redefinition of the target in the case of compound target
   39: 
   40:  ($target, my @tenta) = split('&&',$target);
   41: 
   42: #------------------------- Stack definition (in stack we have all current tags)
   43: 
   44:  my @stack = (); 
   45:  my @parstack = ();
   46: 
   47: #------------------------------------- Parse input string (content_file_string)
   48:  
   49:  my $token;
   50:  
   51:  while ($token = $pars->get_token) {
   52:    if ($token->[0] eq 'T') {
   53:      $finaloutput .= &Apache::run::evaluate($token->[1],$safeeval,'');
   54:    } elsif ($token->[0] eq 'S') {
   55:      # add tag to stack 	    
   56:      push (@stack,$token->[1]);
   57:      # add parameters list to another stack
   58:      push (@parstack,&parstring($token));
   59:      
   60:      if (exists $style_for_target{$token->[1]}) {
   61:        #basically recurse, but we never got more than one level down so just 
   62:        #create the new context here
   63:        my @innerstack = (); 
   64:        my @innerparstack = ();
   65:        # use style file definition
   66:        $newarg = $style_for_target{$token->[1]};       
   67:        my $pat = HTML::TokeParser->new(\$newarg);
   68:        my $tokenpat = '';
   69:        my $partstring = '';
   70: 
   71:        while  ($tokenpat = $pat->get_token) {
   72: 	 if ($tokenpat->[0] eq 'T') {
   73: 	   $partstring = $tokenpat->[1];
   74: 	 } elsif ($tokenpat->[0] eq 'S') {
   75: 	   push (@innerstack,$tokenpat->[1]);
   76: 	   push (@innerparstack,&parstring($tokenpat));
   77: 	   $partstring = &callsub("start_$tokenpat->[1]", 
   78: 				  $target, $tokenpat, \@innerparstack)
   79: 	 } elsif ($tokenpat->[0] eq 'E') {
   80: 	   #clear out any tags that didn't end
   81: 	   while ($tokenpat->[1] ne $innerstack[$#innerstack] 
   82: 		  && ($#innerstack > 0)) {pop @innerstack;pop @innerparstack;}
   83: 	   $partstring = &callsub("end_$tokenpat->[1]",
   84: 				  $target, $tokenpat, \@innerparstack)
   85: 	 }
   86: 	 #pass both the variable to the style tag, and the tag we 
   87: 	 #are processing inside the <definedtag>
   88: 	 $finaloutput .= &Apache::run::evaluate($partstring,$safeeval,
   89: 		$parstack[$#parstack].$innerparstack[$#innerparstack]);
   90: 	 if ($tokenpat->[0] eq 'E') { pop @innerstack;pop @innerparstack; }
   91:        }
   92:      } else {
   93:        my $result = &callsub("start_$token->[1]", $target, $token, \@parstack);
   94:        $finaloutput .= &Apache::run::evaluate($result,$safeeval,
   95: 					      $parstack[$#parstack]);
   96:      }              
   97:    } elsif ($token->[0] eq 'E')  {
   98:      #clear out any tags that didn't end
   99:      while ($token->[1] ne $stack[$#stack] 
  100: 	    && ($#stack > 0)) {pop @stack;pop @parstack;}
  101: 
  102:      if (exists $style_for_target{'/'."$token->[1]"}) {
  103:        my @innerstack = (); 
  104:        my @innerparstack = ();
  105:        $newarg = $style_for_target{'/'."$token->[1]"};
  106:        my $pat = HTML::TokeParser->new(\$newarg);
  107:        my $tokenpat;
  108:        my $partstring = '';
  109:        
  110:        while  ($tokenpat = $pat->get_token) {
  111: 	 if ($tokenpat->[0] eq 'T') {
  112: 	   $partstring .= $tokenpat->[1];
  113: 	 } elsif ($tokenpat->[0] eq 'S') {
  114: 	   push (@innerstack,$tokenpat->[1]);
  115: 	   push (@innerparstack,&parstring($tokenpat));
  116: 	   $partstring = &callsub("start_$tokenpat->[1]", 
  117: 				  $target, $tokenpat, \@innerparstack)
  118: 	 } elsif ($tokenpat->[0] eq 'E') {
  119: 	   #clear out any tags that didn't end
  120: 	   while ($tokenpat->[1] ne $innerstack[$#innerstack] 
  121: 		  && ($#innerstack > 0)) {pop @innerstack;pop @innerparstack;}
  122: 	   $partstring = &callsub("end_$tokenpat->[1]",
  123: 				  $target, $tokenpat, \@innerparstack)
  124: 	 }
  125: 	 #pass both the variable to the style tag, and the tag we 
  126: 	 #are processing inside the <definedtag>
  127: 	 $finaloutput .= &Apache::run::evaluate($partstring,$safeeval,
  128: 		$parstack[$#parstack].$innerparstack[$#innerparstack]);
  129: 	 if ($tokenpat->[0] eq 'E') { pop @innerstack;pop @innerparstack; }
  130:        }
  131:      } else {
  132:        my $result = &callsub("start_$token->[1]", $target, $token, \@parstack);
  133:        $finaloutput .= &Apache::run::evaluate($result,$safeeval,
  134: 					      $parstack[$#parstack]);
  135:      }
  136:      pop @stack; 
  137:      pop @parstack;
  138:    }
  139:  }
  140:  return $finaloutput;
  141: }
  142: 
  143: sub callsub {
  144:   my ($sub,$target,$token,@parstack)=@_;
  145:   my $currentstring='';
  146:   {
  147:     no strict 'refs';
  148:     if (my $space=$Apache::lonxml::alltags{$token->[1]}) {
  149:       #print "Calling sub $sub in $space \n";
  150:       $sub="$space\:\:$sub";
  151:       $currentstring = &$sub($target,$token,\@parstack);
  152:     } else {
  153:       #print "NOT Calling sub $sub\n";
  154:       if (defined($token->[4])) {
  155: 	$currentstring = $token->[4];
  156:       } else {
  157: 	$currentstring = $token->[2];
  158:       }
  159:     }
  160:     use strict 'refs';
  161:   }
  162:   return $currentstring;
  163: }
  164: 
  165: sub parstring {
  166:   my ($token) = @_;
  167:   my $temp='';
  168:   map {$temp .= "my \$$_=\"$token->[2]->{$_}\";"} @{$token->[3]};
  169:   return $temp;
  170: }
  171: 1;
  172: __END__

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