Update: Replaced code with tested , working code.

This creates an artificial sort order, in order to implement higher priority for specifed elements (Up to 9999 of these). 

#!/bin/perl -w
use strict;
use XML::Twig;

my $twig= XML::Twig->new(pretty_print=>'indented');

$twig->parse(\*DATA);
my $root=$twig->root;

$root->first_child->sort_children_on_att("type");

#Specify list of items (mainterm) that are forced FIRST in the sort or
+der
sort_my_kids($root,['mainterm',]);

$twig->print;

sub sort_my_kids{
   my ($me,$OrderTheseFirst) = @_;
   $me->sort_children(
         # Use special sort "get_key" sub, to specify artificial sort 
+order
         # Generated key is: 4-digit "Specified order", Tag, Value
     sub{my $el=shift; 
             my $tag=$el->tag; 
             my ($i)= (grep({$tag eq $OrderTheseFirst->[$_]} 0..$#$Ord
+erTheseFirst) , 9999);
             ##Debug# printf "  %04d%s\t",$i,$tag;
             return (sprintf "%04d%s%s",$i,$tag,$el->text_only());
             }        
    );
    foreach my $kid($me->children){
        sort_my_kids($kid,$OrderTheseFirst); # Recursive
    }    
}

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     Theory is when you know something, but it doesn't work.
    Practice is when something works, but you don't know why it works.
    Programmers combine Theory and Practice: Nothing works and they don't know why.         -Anonymous

In reply to Re^3: twig inbuilt methods to sort whole xml tree by NetWallah
in thread twig inbuilt methods to sort whole xml tree by bharathinc

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