So this code works perfectly until I come across a blank tag. Any suggestions how to handle a situation where the tag exists, but has no text? Currently when the script comes across this situation it dies instead of inserting the new text. Here's the code with sample html:

Code:

#Find the indext.txt config files 
#and edit the index.htm files one dir up from the config file
use warnings;
use HTML::TreeBuilder;
use File::Find;


my $dir = $ARGV[0];
my $html_file;
my $cfg_path;
my $index_pref;


find(\&file_finds, $dir);

sub file_finds{

    if ($_=/index.htm/){

        $html_file = $File::Find::name;
        $cfg_path = $File::Find::dir."/index/index.txt";
        &config;
        &edit;
    }
}

sub config{

    open (CF, "$cfg_path") or die ("Can't open $cfg_path $!");

    while (<CF>) {
            chomp;                  # no newline
            s/#.*//;                # no comments
            s/^\s+//;               # no leading white
            s/\s+$//;               # no trailing white
            next unless length;     # anything left?
            my ($var, $value) = split(/\s*=\s*/, $_, 2);
            $index_pref{$var} = $value;
    }
    close CF;

}

sub edit{

    my $root = HTML::TreeBuilder->new_from_file($html_file)
      or die qq{cant build tree\n}; 

    my $class1 = $root->look_down(
    _tag  => q{div}, 
    class => q{class1},
    );
    die qq{client not found\n$html_file\n} unless $class1;

    my $class2 = $root->look_down(
      _tag  => q{div}, 
      class => q{class2},
    );
    die qq{class2 not found\n$html_file\n} unless $class2;

    my $class3 = $root->look_down(
      _tag  => q{div}, 
      class => q{class3},
    );
    die qq{class3 not found\n$html_file\n} unless $class3;

    my $rep_class1;
    for my $item_r ($class1->content_refs_list) {
        
        next if ref ${$item_r};
          ${$item_r} = $index_pref{"class1"};
          $rep_class1++;

    }
    die qq{Class1 not replaced\n$html_file\n} unless $rep_class1;

    my $rep_class2;
    for my $item_r ($class2->content_refs_list) {
      
        next if ref ${$item_r};
          ${$item_r} = $index_pref{"class2"};
          $rep_class2++;
    }
    die qq{Class2 not replaced\n$html_file\n} unless $rep_class2;

    my $rep_class3;
    for my $item_r ($class3->content_refs_list) {

          next if ref ${$item_r};
          ${$item_r} = $index_pref{"class3"};
          $rep_class3++;

    }
    die qq{Class3 not replaced\n$html_file\n} unless $rep_class3;

    my $html = $root->as_HTML(undef, qq{  }, {});

    open (FH, ">$html_file") or die $!;
    print FH $html;
    close FH;
}
[download]

HTML:
<!--Class 3 has no text-->

<div align="center" class="class1">something</div>
<div align="center" class="class2">something else</div>
<div align="center" class="class3"></div>
[download]