http://www.perlmonks.org?node_id=1214724

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

Hi PerlMonks

I have the following problem to solve and need your help!

I have two XML files (that should be identical but not always) and I would to extract some values and align them.

My XML files look like this:

<file original="File_1.xml">
<body>
    <unit id="id1">
        <title>Part 1_file1</title>
    </unit>
    <unit id="id2">
        <title>Part 2</title>
    </unit>
</body>
</file>
<file original="File_2.xml">
<body>
    <unit id="id1">
        <title>Part 1</title>
    </unit>
</body>
</file>

[download]

I would like to align them in this way:

File_1.xml    id1    title_value_from_first_xml    title_value_from_se
+cond_xml
File_1.xml    id2    title_value_from_first_xml    title_value_from_se
+cond_xml
File_2.xml    id1    title_value_from_first_xml    title_value_from_se
+cond_xml

[download]

Any suggestions?

Replies are listed 'Best First'.
Re: Parsing two XML at the same time and align them
by choroba (Cardinal) on May 17, 2018 at 12:00 UTC
    Note that the XML chunk you posted is not a well-formed XML, as it lacks a root node. I wrapped it into 
    <root>
...
</root>

    [download]

    and used XML::LibXML to get the desired output: 

    #!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use XML::LibXML;

my @files = @ARGV[0, 1];

my %extracted;

for my $xml_file (@files) {
    my $dom = 'XML::LibXML'->load_xml(location => $xml_file);
    for my $file ($dom->findnodes('/root/file')) {
        my $original = $file->{original};
        for my $unit ($file->findnodes('body/unit')) {
            my $id = $unit->{id};
            my $title = $unit->findvalue('title');
            $extracted{$original}{$id}{$xml_file} = $title;
        }
    }
}

for my $file (keys %extracted) {
    for my $id (keys %{ $extracted{$file} }) {
        say join "\t", $file, $id, @{ $extracted{$file}{$id} }{@files}
+;
    }
}

    [download]

    ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

    [download]
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[d/l]
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      <>Thank you so much for your help and I apologize for my late response.

      I tested and it works! However, since my XML uses some namespaces it is not possible to parse the file as is but I need to replace them. In header, it has

      <... xmlns:oka="ok-fram:xml-extensions" ...>

      and some elements start with oka i.e. (oka:inputEncoding="US-ASCII")

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Re: Parsing two XML at the same time and align them
by Discipulus (Canon) on May 17, 2018 at 11:49 UTC
    Hello corfuitl,

    > Any suggestions?

    Yes! avoid XML::Simple

    I'm used with XML::Twig and you can profit twig_handler to trap your id

    You can use a hash to store results, as in:  $res{ $filename."\t".$id } = [] so during the parsing of the two files you can push there first result from file1 and then results from file2.

    L*

    There are no rules, there are no thumbs..
    Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
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Re: Parsing two XML at the same time and align them
by james28909 (Deacon) on May 17, 2018 at 19:11 UTC
    I am trying to put together something that might work for you, but I am unsure about the input data (there is only one "title value from second xml... does it need to be printed everytime?... am i missing a key piece of evidence here? xD). If you could kindly post some better examples we would all sure appreciate it. Otherwise, I am not to sure about input data. Also, are these the only elements that will be in the input data? Please elaborate the question and include better examples. ;)
[reply]
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