gistfile1.txt

  $self->helper(
    url_with => sub {
      my $this  = shift;
      my $args  = ref $_[-1] eq 'HASH' ? pop : {};
      my $url   = @_ ? $this->url_for(@_) : $this->req->url->clone;
      my $query = $this->req->url->query->clone;

      $url->query($query);

      for my $key (keys %$args) {
        my $value = $args->{$key};
        if (defined($value) and $value ne '') {
          $query->param($key => $args->{$key});
        }
        else {
          $query->remove($key);
        }
      }
      return $url;
    }
  );