I'm writing an object oriented parser for complex XML documents (blast output). I need to parse certain fields out of a complex tree and I want to skip over the ones that I don't need (or avoid saving the data).

Hit_num is the first element that I'd like to save in the file (it is a child element of other things that I don't want to save).

The main problem (right now) is that I'm not sure if this is going to work with object oriented style and whether I should just dump that part. What I'm running into is that I can't pass variables between the start_handler, char_handler, and end_handler. I don't know if there's a way in XML::Parser to do this, I've looked at the docs and can't figure that part out. Perhaps this is because I'm using parsefile instead of parse?

As you can probably tell by now, this is my first script involving XML and any advice would be appreciated.

----- 
my $pack = NCBIXML->new;
 
$pack->createHandlers;
 
my $parser = $pack->retrieve('HNDL');
 
$parser->parsefile($file);
 
my %data = $parser->retrieve('RES'); 

##############

sub createHandlers {
  my $obj = shift;
 
  my $parser = new XML::Parser(ErrorContext=>2);
 
  $parser->setHandlers( Start => \&start_handler);
  $parser->setHandlers( End => \&end_handler);
  $parser->setHandlers( Char => \&char_handler);
 
  $obj->{'HNDL'} = $parser;
} 
sub start_handler {
  my ($obj, $element, %attrs) = @_;
  $tag = $element;  # primary key for the array
 
  $obj->{'TAG'} = $tag;
}
 
 
 
sub char_handler {
  my ($obj, $data) = @_;
 
  my $tag = $obj->retrieve('TAG');
 
  my %info = $obj->retrieve('RES');
  if ($tag eq 'Hit_num') {
     $key = $data;
      next;
  }
 
   $info{$key}{$tag} = $data;
 
   $obj->{'RES'} = \%info;
 
}

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Thanks for any help. Ineff

In reply to XML::Parser and objects by Ineffectual

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