#!/usr/bin/perl
use strict;
use warnings;
use XML::Twig;

my $tagname="ait:date-delivered";
my $att1="month";
my $att2="year";
my $att3="day";

changeTagAttrOrder();

sub changeTagAttrOrder {
  my $t= XML::Twig->new(
			output_filter=>'safe',
			twig_handlers => { 
							   '_default_' => sub { },
							   *[@att='type'] => \&changeTagAttrOrderHandler;
							 },
						pretty_print => 'indented',	
			keep_atts_order => 1,#Tie::IxHash needs to be installed for this option to be available. 
            );			
			$t->parse(\*DATA); 
			$t->print;
			$t->purge;
}#end of changeTagAttrOrder

sub changeTagAttrOrderHandler
{ 	
	my( $t,$rootElt)= @_;
	my $curEltPath = $rootElt->path;
	if($curEltPath =~ m/$tagname/){
		print "Found tag $tagname in path $curEltPath\n";
		print $rootElt->att($att1)."\t".$rootElt->att($att2)."\t".$rootElt->att($att3);
		my $att1Val=$rootElt->att($att1);
		my $att2Val=$rootElt->att($att2);
		my $att3Val=$rootElt->att($att3);
		$rootElt->del_atts;
		print "after delete  \tAttributes are ::".join(",",$rootElt->att_names())."\n";
		$rootElt->set_atts( { $att1 => $att1Val, $att2 => $att2Val, $att3 => $att3Val});
		print "after new set \tAttributes are ::".join(",",$rootElt->att_names())."\n";
	}
}#end of changeTagAttrOrderHandler
__DATA__
<item>
<ait:process-info>
<ait:date-delivered year="2010" month="02" day="09"/>
<ait:date-sort year="2008" month="1" day="1"/>
<ait:status type="core" state="new" stage="S300"/>
</ait:process-info>
</item>