Twig - sorting XML error

Melly has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I have the following XML that I want to sort by 'TabOrder':

<?xml version="1.0" encoding="windows-1252"?>
<TPersonId name="PersonId" type="inherited">
  <TcxTabSheet name="cxTabSheetIdentity" type="object">

    <TScrollBox name="ScrollBox2" type="object">
      <TabOrder type="shortint">2</TabOrder>
      <TcxDBDateEdit name="cxDBDateEdit4" type="object">
        <TabOrder type="shortint">2</TabOrder>
      </TcxDBDateEdit>
      <TcxDBDateEdit name="cxDBDateEdit3" type="object">
        <TabOrder type="shortint">1</TabOrder>
      </TcxDBDateEdit>
    </TScrollBox>

    <TScrollBox name="ScrollBox1" type="object">
      <TabOrder type="shortint">1</TabOrder>
      <TcxDBDateEdit name="cxDBDateEdit2" type="object">
        <TabOrder type="shortint">2</TabOrder>
      </TcxDBDateEdit>
      <TcxDBDateEdit name="cxDBDateEdit1" type="object">
        <TabOrder type="shortint">1</TabOrder>
      </TcxDBDateEdit>
    </TScrollBox>

  </TcxTabSheet>
</TPersonId>
[download]

The following perl script does what I want, but it also issues two identical warnings - Argument "" isn't numeric in numeric comparison (<=>) - how do I prevent the script from attempting to sort children who do not have a TabOrder? (which is what I assume is going on)

use strict;
use warnings;

use XML::Twig;
my $twig = XML::Twig -> new(pretty_print => 'indented');
$twig->parsefile('test.xml');
foreach my $element($twig -> get_xpath('.//')){
  $element -> sort_children_on_field('TabOrder', type => 'numeric');
}
$twig -> print;
[download]

map{$a=1-$_/10;map{$d=$a;$e=$b=$_/20-2;map{($d,$e)=(2*$d*$e+$a,$e**2
-$d**2+$b);$c=$d**2+$e**2>4?$d=8:_}1..50;print$c}0..59;print$/}0..20
[download]

Tom Melly, mellytom2 (at) gmail (stop) com

Comment on Twig - sorting XML error Select or Download Code

Replies are listed 'Best First'.
Re: Twig - sorting XML error by choroba (Cardinal) on Sep 24, 2024 at 13:35 UTC
Use the more general `sort_children`, provide a subroutine that returns the TabOrder if it exists, and zero otherwise: `$element->sort_children(sub { my ($elt) = @_; my $to = $elt->first_child('TabOrde +r'); $to ? $to->text : 0 }, type => 'numeric');` [download] `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]