bug in HTML::Element::traverse (repost)

Barney Dalton (barneyd@cyllene.uwa.edu.au)
Thu, 7 Jan 1999 08:48:54 +0800 (WST) 

I'm reposting this as I got no response, changed the title from problem to
bug in the hope that someone may look at it.

---------- Forwarded message ----------
Date: Tue, 22 Dec 1998 08:55:23 +0800 (WST)
From: Barney Dalton <barneyd@cyllene.uwa.edu.au>
Reply-To: barney@mech.uwa.edu.au
To: libwww-perl@ics.uci.edu
Subject: problem with HTML::Element::traverse 


Hi,

I'm having a problem using the traverse function in element.pm. If I do
anything with $_ in my callback function this messes up the HTML tree.
Here's an example:

#!/usr/local/bin/perl
use HTML::TreeBuilder;

$htmltext = <<HTML;
test document

TreeBuilder Test

HTML

$p = HTML::TreeBuilder->new;
$p->parse($htmltext);
$p->traverse(\&process_elements);
print $p->as_HTML();

sub process_elements
{
	my $element = shift;
	$_="HELLO";
	return 1;
}

This prints:
HELLOHELLOHELLOHELLOHELLO if I change traverse.pm to use a my variable to iterate over the list, this problem disappears eg. element.pm is now: sub traverse { my($self, $callback, $ignoretext, $depth) = @_; $depth ||= 0; --> my $element; #new my variable instead of $_ if (&$callback($self, 1, $depth)) { for $element (@{$self->{'_content'}}) { if (ref $element) { #$element where previously we had $_ $element->traverse($callback, $ignoretext, $depth+1); } else { &$callback($element, 1, $depth+1) unless $ignoretext; } } &$callback($self, 0, $depth) unless $emptyElement{$self->{'_tag'}}; } $self; } Is this a bug or a misunderstanding on my part. barney /**********************************************************/ / Barney Dalton / / Computer support support@mech.uwa.edu.au / / Personal email barney@mech.uwa.edu.au / / Work Phone (61) (8) 9380 3058 / / Twist my arm : http://telerobot.mech.uwa.edu.au / /**********************************************************/