XML::Twig oddity

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

Brethren & Sisters,

I expected the code below (simplified example) to print "AB", instead I get a Can't call method "att" without a package or object reference at foo.pl line 17 and I simply don't grok why. Can someone shed some light on that?

use warnings;
use strict;

use Data::Dumper;
use XML::Twig;

my $t= XML::Twig->new
(
    twig_handlers =>
    { 
        '/foo/bar' => sub 
        { 
            my $bay = $_->get_xpath('bay');
            my $baz = $_->get_xpath('baz');
            
            print $bay->att("V");
            print $baz->att("V");
            
        } 
    }
);

$t->parse(join("", <DATA>));
__DATA__
<foo>
    <bar>
        <bay V="A" />
        <baz V="B" />
    </bar>
</foo>
[download]

holli, /regexed monk/

Comment on XML::Twig oddity Select or Download Code

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Re: XML::Twig oddity by mirod (Canon) on Jan 29, 2007 at 13:48 UTC
`get_xpath` returns a list (see the docs), so in your case when you write `$bay = $_->get_xpath('bay')`, `$bay`, gets assigned the number of elements in the list, presumably 1. I believe what you want is `$bay= $_->first_child( 'bay');`. You can also use `$bay = $_->get_xpath('bay', 0)`, but I believe it is much less clear than simply using `first_child`.	[reply] [d/l] [select]
Re: XML::Twig oddity by convenientstore (Pilgrim) on Nov 15, 2008 at 05:24 UTC
I am just going through all XML::Twig posts and ran to this one and was just testing out the code.. `use strict; use warnings; use XML::Twig; my $xml = <<XML <foo> <bar> <bay V="A" /> <baz V="B" /> </bar> </foo> XML my $t = XML::Twig->new ( twig_handlers => { '/foo/bar' => sub { my $bay = $_->first_child('bay'); my $baz = $_->first_child('baz'); print $bay->att("V"); print $baz->att("V"); } } ); $t->parse ($xml);` [download] but it says `./xml_test1.pl syntax error at ./xml_test1.pl line 17, near "my " Global symbol "$t" requires explicit package name at ./xml_test1.pl li +ne 17. Can't use global $_ in "my" at ./xml_test1.pl line 21, near "= $_" syntax error at ./xml_test1.pl line 26, near "}" Execution of ./xml_test1.pl aborted due to compilation errors.` [download] what am I doing wrong?	[reply] [d/l] [select]
Re^2: XML::Twig oddity by Anonymous Monk on Nov 15, 2008 at 07:10 UTC
You know, you shouldn't reply to old posts with questions about your typos. Start a new one in seekers of perl wisdom `my $xml = <<XML <foo> <bar> <bay V="A" /> <baz V="B" /> </bar> </foo> XML` [download] is wrong. See Here, doccy doccy. nice doccy. heredoc, treat., Why don't my <<HERE documents work?, perlop	[reply] [d/l]
Re^2: XML::Twig oddity by convenientstore (Pilgrim) on Nov 15, 2008 at 07:34 UTC
that was silly of me thank you for pointing it out `use strict; use warnings; use XML::Twig; my $xml = <<XML; <foo> <bar> <bay V="A" /> <baz V="B" /> </bar> </foo> XML my $t = XML::Twig->new ( twig_handlers => { '/foo/bar' => sub { my $bay = $_->first_child('bay'); my $baz = $_->first_child('baz'); print $bay->att("V"); print $baz->att("V"); } } ); $t->parse ($xml);` [download]	[reply] [d/l]
Re^3: XML::Twig oddity by Anonymous Monk on Nov 15, 2008 at 08:23 UTC
hi :) you should also click the correct "reply" link, or "comment on" link, that way you avoid talking to yourself, and readers can follow what is going on :)	[reply]
Re^4: XML::Twig oddity by convenientstore (Pilgrim) on Nov 15, 2008 at 20:48 UTC