Hi,

I've done a script to parse a huge XML file and right now i'm trying to speed it up adding some filter options.

I've set a start_tag_handler with the objective of ignoring all tree in case of current tag exists in my option hash. First time that start_tag_handler sub is raised everything works fine, but at second time start_tag_handler is called without the attribute hash???

Maybe I'm doing something wrong or i don't understand it right. Bellow I've copy paste a sample of what i'm trying to do. As you can see in got an error 2nd time i try to print attribute hash of start_tag_handler.

there's any monk that can help me? 
use strict;
use warnings;
use XML::Twig;

my $xml = <<XML;
<doc>
  <fileHeader name='myTest'/>
  <SubNetwork id='CGRA01'>
    <MeContext id='Lisboa_1'>
      <data>
        <type>aaa</type>
        <var>a</var>
      </data>
    </MeContext>
    <MeContext id='Moscavide_2'>
      <data>
        <type>bbb</type>
        <var>b</var>
      </data>
    </MeContext>
  </SubNetwork>
  <SubNetwork id='CLOU01'>
    <MeContext id='Loures_3'>
      <data>
        <type>ccc</type>
        <var>c</var>
      </data>
    </MeContext>
    <MeContext id='Odivelas_3'>
      <data>
        <type>ddd</type>
        <var>d</var>
      </data>
    </MeContext>
  </SubNetwork>
</doc>
XML

my $SUBNETWORK_EXCLUDE_LIST = {
                                #'CLOU01' => 1
                                'CGRA01' => 1
                              };
                             
my $start_tag_handlers = {
                          'SubNetwork' => \&SubNetwork,
                        };
                         
my $twig_roots = {
                    'fileHeader' => \&fileHeader,
                    'MeContext' => 1
                  };
                             
                                      
local our $twig_handlers = {
                    'MeContext' => \&MeContext
                  };
 
 
  my $twig= new XML::Twig(
                          start_tag_handlers => $start_tag_handlers,
                          twig_roots => $twig_roots,
                          twig_handlers => $twig_handlers
                          );
 
print "\n### Parsing XML file ###\n";
my $root = $twig->parse( $xml );

sub SubNetwork {
  my ($twig, $tag, %att) = @_;
  print "\nSubNetwork: ".$att{id};
  if (exists $SUBNETWORK_EXCLUDE_LIST->{$att{id}}) {
    print " => Excluded\n";
    my $handler = sub { print $_[1]->att('id')." => Excluded\n"; $_[1]
+->ignore() };
    $twig->setStartTagHandler ('MeContext', $handler);
  }
  else {
    my $handler = {
                    'SubNetwork' => \&SubNetwork
                  };
    $twig->setStartTagHandlers ($handler);
  }
  return 0;
}

sub fileHeader {
  my ( $twig, $fileHeader) = @_;
  print "Name: ".$fileHeader->att('name')."\n";
  return 0;
}

sub MeContext {
  my ( $twig, $MeContext) = @_;
  print "MeContext: ".$MeContext->att('id')."\n";
  print "\tType: ".$MeContext->first_child('data')->first_child('type'
+)->text."\n";
  print "\tVar: ".$MeContext->first_child('data')->first_child('var')-
+>text."\n";
  $MeContext->purge;
  return 1;
}

[download]

Thanks in advance,

Ricardo Dinis

In reply to Strange start_tag_handlers behaviour using twig module by basalto

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