Changing code from using XML::XPath to XML::LibXML

Question

I have a perl script working fine. Script is taking an xml file as input and returning a JSON format of same and also value of a specific element within XML file.

#!/usr/bin/perl
use strict;
use warnings;
use JSON;
use XML::Simple;
use XML::XPath;

my $xmlFileName = "jsonconversion.xml";
my $fileNameElement = "//FileName";

# Create the object of XML Simple
$xmlSimple = new XML::Simple(KeepRoot   => 1);

# Load the xml file in object
$dataXML = $xmlSimple->XMLin($xmlFileName);

#Searching value using xpath
my $xp = XML::XPath->new(filename => $xmlFileName);
my $filename = $xp->find($fileNameElement);

my $ElementValue = "";

#Fetching value of 'FileName' in 'fileNameValue' variable
if( length $filename ) {
   foreach my $node ($filename->get_nodelist) {
     $fileNameValue = $node->string_value;
     last;
 }
}

# use encode json function to convert xml object in json.
my $jsonString = encode_json($dataXML);

#Printing fileNameValue
print "\n\nFile Name is: ".$fileNameValue;

Due to certain restrictions in company i am not allowed to use XML::Xpath perl module, I can use XML:LibXML. i tried understanding how i can make my current code still work by replacing XML::Xpath with XML:LibXML perl module. I refer perl documentations and old post on stackoverflow as well.

here is one sample solution:

my $dom = XML::LibXML->new->parse_file('data.xml');
for my $node ($dom->findnodes('/category/event/@name')) {
   my value = $node->toString;
}

but this code involves change my original code completely.

My question here is how can i make use of XML:LibXML perl module replacing perl module XML:XPath with minimal changes. I don't want to re write the whole code again just for sake of using an existing library.

Sample xml file:

<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<Person SchemaVersion="1.0.8">

   <ID>0</ID>

  <Home ID="ABC-XYZ" State="Unknown">
     <Location>

      <SiteName></SiteName>
      <Number>62</Number>
      <MaxSize>0</MaxSize>
      <Comment></Comment>
     </Location>

   <Laptop>
      <FileName>/usr/temp/RPM_020515_.tar.gz</FileName>
   </Laptop>
   </Home>
  </Person>

Let me know if any suggestions.

Thanks

NOTE: I got lot of help from folks in stack overflow for writing current perl module and understanding the functionality.

Answer 1

This gets the first like your code:

use XML::LibXML qw( );
my $dom = XML::LibXML->new->parse_file('data.xml');
my ($file_name_node) = $dom->findnodes('//FileName');
my $file_name = $file_name_node ? $file_name_node->textContent() : '';

Or if there can only be one,

use XML::LibXML qw( );
my $dom = XML::LibXML->new->parse_file('data.xml');
my $file_name = $dom->findvalue('//FileName/text()');