How can I find the contents of a div using Perl's HTML modules, if I know a tag inside of it?

Question

Ever since I asked how to parse html with regex and got bashed a bit (rightfully so), I've been studying HTML::TreeBuilder, HTML::Parser, HTML::TokeParser, and HTML::Elements Perl modules.

I have HTML like this:

<div id="listSubtitlesFilm">
  <dt id="a1">
    <a href="/45/subtitles-67624.aspx">
      .45 (2006)
    </a>
  </dt>
</div>

I want to parse out the /45/subtitles-67624.asp, but more importantly I want to know how to parse out the contents of the div.

I was given this example on a previous question:

while ( my $anchor = $parser->get_tag('a') ) {
    if ( my $href = $anchor->get_attr('href') ) {
 #http://subscene.com/english/Sit-Down-Shut-Up-First-Season/subtitles-272112.aspx
        push @dnldLinks, $1 if $href =~ m!/subtitle-(\d{2,8})\.aspx!;
    }

This worked perfectly for that, but when I tried to edit it a bit and use it on a ``div` it didn't work. Here is the code I tried:

I tried using this code:

while (my $anchor = $p->get_tag("dt")) {
  if($stuff = $anchor->get_attr('a1')) {
    print $stuff."\n";
  }
}

Answer 1

To address, your specific question, given the HTML:

<div id="listSubtitlesFilm">
  <dt id="a1">
    <a href="/45/subtitles-67624.aspx">
      .45 (2006)
    </a>
  </dt>
</div>

I am assuming you are interested in the anchor text, i.e. ".45 (2006)", in this case, but only if the anchor occurs in a div with id listSubtitlesFilm.

#!/usr/bin/perl

use strict;
use warnings;

use HTML::TokeParser::Simple;

my $parser = HTML::TokeParser::Simple->new(handle => \*DATA);

my @dnldLinks;

while ( my $div = $parser->get_tag('div') ) {
    my $id = $div->get_attr('id');
    next unless defined($id) and $id eq 'listSubtitlesFilm';

    my $anchor = $parser->get_tag('a');
    my $href = $anchor->get_attr('href');
    next unless defined($href)
        and $href =~ m!/subtitles-(\d{2,8})\.aspx\z!;
    push @dnldLinks, [$parser->get_trimmed_text('/a'), $1];
}

use Data::Dumper;
print Dumper \@dnldLinks;


__DATA__
<div id="listSubtitlesFilm">
  <dt id="a1">
    <a href="/45/subtitles-67624.aspx">
      .45 (2006)
    </a>
  </dt>
</div>

Output:

$VAR1 = [
          [
            '.45 (2006)',
            '67624'
          ]
        ];

Answer 2

You could use (yet another module!) HTML::TreeBuilder::XPath, which, as per its name, will let you use XPath on HTML::TreeBuilder objects.

#!/usr/bin/perl

use strict;
use warnings;

use HTML::TreeBuilder::XPath;

my $root = HTML::TreeBuilder::XPath->new_from_file( "my.html");

# print $root->as_HTML; # useful to see how HTML::TreeBuilder
# understands your HTML. For example it will wrap the implied
# dl element around dt, which you need to take into account
# when writing the XPath query below

my $id= "a1";
# you need the .//dt because of the extra dl
my @divs= $root->findnodes( qq{//div[.//dt[\@id="$id"]]});

print $divs[0]->as_HTML; # or as_text