Iterate through XML data using Perl module XML::LibXML

Question

Can anyone please translate this (XML::DOM to XML::LibXML)?

I have been at it for hours so I won't put up all of the code that I have tried as it would fill pages

foreach my $review ($review_details->getElementsByTagName("review")) { # find the node review{

  # scroll through each review to get the details that we want

  foreach my $details ($review->getChildNodes) {

    if ($details->getNodeName eq "movie_title") {
      foreach my $movie_title ($details->getChildNodes) {
        print $movie_title->getNodeValue . "\n";
      }
    }

    if ($details->getNodeName eq "reviewer") {
      foreach my $reviewer ($details->getChildNodes) {
        print $reviewer->getNodeValue . "\n";
      }
    }

  }
}

and this is a basic representation of the data

<results>
  <review>
    <movie_title>First Movie</movie_title>
    <reviewer>Annie</reviewer>
  </review>
  <review>
    <movie_title>Second Movie</movie_title>
    <reviewer>Bob</reviewer>
  </review>
  <review>
    <movie_title>Third Movie</movie_title>
    <reviewer>Charlie</reviewer>
  </review>
  <review>
    <movie_title>Fourth Movie</movie_title>
    <reviewer>Don</reviewer>
  </review>
</results>

Some of the things that I tried using XML::LibXML involved different versions of lines such as

foreach my $review ($review_details>findnodes('//display_name')) { 
  print $review->findvalue('movie_title')
}

Answer 1

I'd probably not use so many loops in XML::LibXML:

#!/usr/bin/perl
use warnings;
use strict;

use XML::LibXML;

my $review_details = 'XML::LibXML'->load_xml( location => shift );

for my $review ($review_details->findnodes('/results/review')) {
    print $review->findvalue($_), "\n" for 'movie_title', 'reviewer';
}

Or, I'd use XML::XSH2, a wrapper around XML::LibXML:

open file.xml ;
for /results/review echo :s (movie_title) {"\n"} (reviewer) ;

Answer 2

This is very straightforward if you use XPath expressions and iterate over all the review elements.

use strict;
use warnings;

use XML::LibXML;

my $doc = XML::LibXML->load_xml(IO => *DATA);

for my $review ( $doc->findnodes('/results/review') ) {
  print $review->findvalue('movie_title'), "\n";
  print $review->findvalue('reviewer'), "\n";
}

__DATA__
<results>
  <review>
    <movie_title>First Movie</movie_title>
    <reviewer>Annie</reviewer>
  </review>
  <review>
    <movie_title>Second Movie</movie_title>
    <reviewer>Bob</reviewer>
  </review>
  <review>
    <movie_title>Third Movie</movie_title>
    <reviewer>Charlie</reviewer>
  </review>
  <review>
    <movie_title>Fourth Movie</movie_title>
    <reviewer>Don</reviewer>
  </review>
</results>

output

First Movie
Annie
Second Movie
Bob
Third Movie
Charlie
Fourth Movie
Don