(jeffa) Re: XML::Simple

This looks familiar ... ;)

Have been introduced to Data::Dumper yet? Here is what it makes of the XML 'tree' that is built by XML::Simple:

use Data::Dumper;

my $data = do {local $/;<DATA>};
my $xml  = XMLin($data);

print Dumper $xml;
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Yields:

$VAR1 = {
   'label' => 'gene_of_interest',
   'id' => '3'
};

From this we see that label and id are the 'top level' keys, there is no 'gene' key. However, had the XML been a bit more proper ...

use strict;
use warnings;
use XML::Simple;

my $data = do {local $/;<DATA>};
my $xml  = XMLin($data);

# ... and you use the correct syntax ;)
print $xml->{gene}->{id}, "\n";
print $xml->{gene}->{label}, "\n";

__DATA__
<?xml version="1.0" ?>
<genes>
<gene id = "3" label = "gene_of_interest" />
</genes>
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Then all is well. :)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Comment on (jeffa) Re: XML::Simple Select or Download Code

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Re: (jeffa) Re: XML::Simple
by jdporter (Paladin) on Dec 18, 2002 at 01:08 UTC

jeffa

PodMaster

you can't do this:

print $xml->{'gene' => {'id', 'label'}}, "\n";

print "$xml->{'gene'}{'id'}, $xml->{'gene'}{'label'}\n";

print @{ $xml->{'gene'} }{'id','label'}, "\n";

jdporter
...porque es dificil estar guapo y blanco.

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Re: Re: (jeffa) Re: XML::Simple

by PodMaster (Abbot) on Dec 18, 2002 at 01:20 UTC

It is syntactically valid, it just won't do what he wants (no chance in hell).

~~The expression will evaluate to $xml->{{}}, and that key (the stringified version of that anonymous hashref) is not defined, so a warning will be thrown.~~
something like that ;)(actually $xml->{gene}{{}} , but it's not really important)

If you didn't know what the comma operator would do in this expression, read "List" is a Four-Letter Word, as well as perldoc perlop

update:

use Data::Dumper;
local $\="\n";

$a = {
    gene => { id => 3, label => 'generrrous' }
};

print $a->{ gene, id}=1;
print $a->{ gene => id };
print Dumper $a;

__END__
1
1
$VAR1 = {
          'gene' => {
                      'label' => 'generrrous',
                      'id' => 3
                    },
          'gene∟id' => 1
        };
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MJD says you can't just make shit up and expect the computer to know what you mean, retardo!
** The Third rule of perl club is a statement of fact: pod is sexy.

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Re: Re: Re: (jeffa) Re: XML::Simple

by matth (Monk) on Dec 18, 2002 at 23:23 UTC

If I want to access something nested within the gene tags. For example, <gene id = "1"><gene_seq id = "1"></gene_seq></gene>. How do I do that?


    print $xml->{gene_seq}{$id}{'startpos'}, "\n";
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