Hello Monks, I've been getting a lot of use out of XML Twig, but have been sticking primarily to calling handlers based on element tags. Now I have a block of XML where the naming conventions caused duplicate tags for distinct elements. After poking around the CPAN docs for both twig and xpath, the XML::Twig website, and the Perl monks archives, I still can't figure out the appropriate syntax for calling a handler on an attribute/value pairing. Here's a snippet of the XML I'm dealing with. 
<us:ItemMaster>
   <us:ItemMasterHeader>
      <oa:ItemID agencyRole="Product_Number">
         <oa:ID>0123456</oa:ID>
      </oa:ItemID>
      <oa:ItemID agencyRole="Prefix_Number">
         <oa:ID>AAA</oa:ID>
      </oa:ItemID>
      <oa:ItemID agencyRole="Stock_Number_Butted">
         <oa:ID>01234</oa:ID>
      </oa:ItemID>
   </us:ItemMasterHeader>
</us:ItemMaster>

[download]
I can't simply call a handler on the ItemID tag because of the duplication. The number I'm looking for is a concatenation of the prefix and stock number. Here's what I'm trying. 
use strict;
use warnings;
use xml::twig;
use utf8;

my $file= "itemsANDstuff.xml";

my $twig_handlers = {oa:ItemID[my @agencyRole='Prefix_Number']=> \&ITE
+Mnumber};

my $twig= new XML::Twig(TwigRoots => {'us:ItemMasterHeader' => 1},
                                                                      
+      TwigHandlers => $twig_handlers);
$twig->parsefile($file);


sub ITEMnumber{
        my ($twig, $Item)= @_;
        my $prefix=($Item->first_child->text);
        my $stock = (next_sibling->first_child->text);
        my $itemNUMBER = $prefix.$stock;
    print "$itemNUMBER \n";};

[download]
The line raising an exception is my $twig_handlers = {oa:ItemID[my @agencyRole='Prefix_Number']=> \&ITEMnumber}; I've tried a variety of fixes on this line, including using * between the element tag and the [, escaping the @ using double quotes and single quotes, single quotes and double quotes on the element tag alone, omitting the element tag in favor of an *, praying and kicking my machine. None of these have helped much. Any help would be greatly appreciated.

In reply to XML Twig Handler Triggers Syntax by Mr.Churka

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