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

Hello Monks

Again a problem with XML::Simple. I have a quite simple data structure

<?xml version="1.0"?>
<DB>
        <termEntry>
            <ShortInfo>Ciao</ShortInfo>
            <langSet xml:lang="Italian">
                <termGrp>
                    <term>Ricerca scientifica</term>
                </termGrp>
            </langSet>
            <langSet xml:lang="English">
                <termGrp>
                <term>research</term>
                </termGrp>
            </langSet>
        </termEntry>
        <termEntry>
            <ShortInfo></ShortInfo>
            <langSet xml:lang="Italian">
                <termGrp>
                <term>università</term>
                </termGrp>
            </langSet>
            <langSet xml:lang="English">
                <termGrp>
                <term>university</term>
                </termGrp>
            </langSet>
        </termEntry>
</DB>

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For each <termEntry>I need to read the values in <term> and the corrisponding attribute saved in <langSet> for further processing, i.e.

Italian: Ricerca scientifica
English: research

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I am failing... This is what I have so far. Any help would be appreciated

use strict;
use warnings;

use XML::Simple;
use Data::Dumper;

my $xml = XML::Simple->new(SuppressEmpty => q());
my $data = $xml->XMLin('myxml.xml');

for my $entry ( @{ $data->{termEntry} } ) {
    print Dumper( $entry );
    print my $Term = $entry->{langSet}->{termGrp}->{term};
}

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I have no idea how to read the attribute, and I have even problems with the basic variable $Term which seems to me straightforward to read with the above code. Ok: I am very new to XML parsing and this is for me just a 1 time task. But I have already lost 1 full day...

Replies are listed 'Best First'.
Re: Parsing XML::Simple
by kevbot (Vicar) on May 02, 2017 at 03:44 UTC

    Hello Anonymous Monk,

    The documentation for XML::Simple states that it should not be used in new code (see the STATUS OF THIS MODULE section). The author recommends alternatives such as XML::LibXML or XML::Twig. Perl XML::LibXML by Example looks like a good resource for getting started with XML::LibXML. Using information that I found there, I put together this example: 

    #!/usr/bin/env perl

use strict;
use warnings;
use v5.10;

use XML::LibXML;

my $file = 'myxml.xml';
my $dom = XML::LibXML->load_xml(location => $file);

foreach my $lang_set ($dom->findnodes('/DB/termEntry/langSet')) {
    my $lang = $lang_set->getAttribute('xml:lang');
    foreach my $term_grp ($lang_set->findnodes('./termGrp')){
        say '$lang : '. $term_grp->findvalue('./term');
    }
}

exit;

    [download]
    I hope you find this helpful.
[reply]
[d/l]

      Thank you!

[reply]

      After trying for hours to adapt the other proposals to a slighty different XML input without success I started with XML::LibXML and this example... and I can say it was much much easier to adapt! Nice module, thank you!

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Re: Parsing XML::Simple
by Discipulus (Canon) on May 02, 2017 at 08:22 UTC
    ..or using XML::Twig

    i need to add encoding="ISO-8859-1" to the first line of XML data

    I always make confusion with XML terminology and traversing, but this quick hack works: 

    use strict;
use warnings;
use XML::Twig;

my $twig=XML::Twig->new(
  twig_handlers =>
    {
      'termEntry/langSet'=>sub{print $_[1]->att('xml:lang'),
                                     ": ",
                                     $_[1]->first_child('termGrp')->te
+xt,
                                     "\n"
                              }
                                     
    },
);

$twig->parse( \*DATA );

__DATA__
<?xml version="1.0" encoding="ISO-8859-1"?>
<DB>
        <termEntry>
            <ShortInfo>Ciao</ShortInfo>
            <langSet xml:lang="Italian">
                <termGrp>
                    <term>Ricerca scientifica</term>
                </termGrp>
            </langSet>
            <langSet xml:lang="English">
                <termGrp>
                <term>research</term>
                </termGrp>
            </langSet>
        </termEntry>
        <termEntry>
            <ShortInfo></ShortInfo>
            <langSet xml:lang="Italian">
                <termGrp>
                <term>università</term>
                </termGrp>
            </langSet>
            <langSet xml:lang="English">
                <termGrp>
                <term>university</term>
                </termGrp>
            </langSet>
        </termEntry>
</DB>

    [download]

    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.
[reply]
[d/l]
[select]
Re: Parsing XML::Simple
by Anonymous Monk on May 01, 2017 at 21:04 UTC
    langSet is an array of things: 
    for my $entry ( @{ $data->{termEntry} } ) {
    for (@{ $entry->{langSet} }) {
        printf "term: %s\n", $_->{termGrp}{term};
    }
}

    [download]
[reply]
[d/l]

      Ah, I had not thought about it. I was now playing with the option "forcearray => 1" to change the data structure, but your solution works perfectly. Thanks.

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