Using XML::Simple for retrieving data in Perl - perl

Question

I've created the below XML file for retrieving data.
Input:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<ExecutionLogs>
<category cname='Condition1' cid='T1'>
<log>value1</log>
<log>value2</log>
<log>value3</log>
</category>
<category cname='Condition2' cid='T2'>
<log>value4</log>
<log>value5</log>
<log>value6</log>
</category>
<category cname='Condition3' cid='T3'>
<log>value7</log>
</category>
</ExecutionLogs>
I want the output like below,
Condition1 -> value1,value2,value3
Condition2 -> value4,value5,value6
Condition3 -> value7
I have tried the code below,
use strict;
use XML::Simple;
my $filename = "input.xml";
$config = XML::Simple->new();
$config = XMLin($filename);
#values = #{$config->{'category'}{'log'}};
Please help me on this. Thanks in advance.

Answer 1

A way to do this using XML::Twig:
#!/usr/bin/perl
use strict;
use warnings;
use XML::Twig;
XML::Twig->new( twig_handlers => {
category => sub { print $_->att( 'cname'), ': ',
join( ',', $_->children_text( 'log')), "\n";
},
},
)
->parsefile( 'my.xml');
The handler is called each time a category element has been parsed. $_ is the element itself.

Answer 2

What I would do :
use strict; use warnings;
use XML::Simple;
my $config = XML::Simple->new();
$config = XMLin($filename, ForceArray => [ 'log' ]);
# we want an array here ^---------------------^
my #category = #{ $config->{'category'} };
# ^------------------------^
# de-reference of an ARRAY ref
foreach my $hash (#category) {
print $hash->{cname}, ' -> ', join(",", #{ $hash->{log} }), "\n";
}
OUTPUT
Condition1 -> value1,value2,value3
Condition2 -> value4,value5,value6
Condition3 -> value7
NOTE
ForceArray => [ 'log' ] is there to ensure treating same types in {category}->[#]->{log]
unless that, we try to dereferencing an ARRAY ref on a string for the last "Condition3".
Check XML::Simple#ForceArray
and
perldoc perlreftut
perldoc ref
perldoc perlref