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

Hello all, Looking for help adding nested elements to my data structure so that XML::Simple will output properly. Here are the significant portions of my code:
use XML::Simple;
my $xs = XML::Simple->new( ForceArray => 1, KeepRoot => 1, NoAttr => 1
+ );
my $data = { 'Things' => { 'Thing' => [] } };

...

push @{ $data->{Things}->{Thing} },
    {
    'Item' => $var1,
    'Number' => $var2,
    'Details' => {
            'Detail' => {
                    'Color' => $var3
                        }
             }
    };

...

my $xml = $xs->XMLout($data);
print $xml;

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When I print the XML I get: 
<Things>
    <Thing>
        <Item>XXX</Item>
        <Number>9999</Number>
        <Details>
            <name>Detail</name>
            <Color>Blue</Color>
        </Details>
    </Thing>
</Things>

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What I'm looking for is: 
<Things>
    <Thing>
        <Item>XXX</Item>
        <Number>9999</Number>
        <Details>
            <Detail>
                <Color>Blue</Color>
            </Detail>
        </Details>
    </Thing>
</Things>

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This is probably a simple problem and I'm assuming that XML::Simple can't go that deep. Any help is greatly appreciated.

Rob

Replies are listed 'Best First'.
Re: XML::Simple and Adding Nested Elements
by psini (Deacon) on May 21, 2008 at 12:50 UTC

    From the POD for XML::Simple I found this:

    Note 1: The default value for 'KeyAttr' is ['name', 'key', 'id']. If you do not want folding on input or unfolding on output you must setting this option to an empty list to disable the feature.

    I think that your problem will go away if you add a KeyAttr=>() in the parameter list as in:

    my $xs = XML::Simple->new( ForceArray => 1, KeepRoot => 1, NoAttr => 1, KeyAttr => ());

    Rule One: Do not act incautiously when confronting a little bald wrinkly smiling man.

[reply]
[d/l]
[select]
      That was it! Well, it was actually: 
      my $xs = XML::Simple->new( ForceArray => 1, KeepRoot => 1, NoAttr => 1
+, KeyAttr => []);

      [download]
      ...with square brackets.
      I had read this but I figured you wouldn't need to set a key attribute to empty if you set NoAttr => 1. That's what I get for making assumptions!
      Thanks!

      Rob
[reply]
[d/l]

        No, KeyAttr e NoAttr refer to completely different things. It is just a bit confusing...

        Rule One: Do not act incautiously when confronting a little bald wrinkly smiling man.

[reply]
XML::Simple and Adding Additional Nested Elements
by Ozeroc (Novice) on May 23, 2008 at 07:49 UTC
    Hello all, Looking for help adding additional nested elements to my data structure for eventual output with XML:Simple. Here are the significant portions of my code:
    use XML::Simple;
my $xs = XML::Simple->new( ForceArray => 1, KeepRoot => 1, NoAttr => 1
+, KeyAttr => [] );
my $data = { 'Things' => { 'Thing' => [] } };

...

push @{ $data->{Things}->{Thing} },
    {
    'Item' => $var1,
    'Number' => $var2,
    'Details' => {
            'Detail' => {
                    'Color' => $var3
                        }
             },
    };

...

push @{ $data->{Things}->{Thing} },
    {
    'AdditionalInfo' => {
        'Info' => $var4,
        'Stuff' => $var5,
        'MoreDetails' => {
                'ExtraColor' => $var6
                 }
        }
    };

    [download]
    I'd like to add one or more chunks of 'additional info' as needed. I'd like my resulting XML to look like this: 
    <Things>
    <Thing>
        <Item>Item1</Item>
        <Number>123</Number>
        <Details>
            <Detail>
                <Color>Blue</Color>
            </Detail>
        </Details>
        <AdditionalInfo>
            <Info>data</Info>
            <Stuff>moredata</Stuff>
            <MoreDetails>
                <ExtraColor>Purple</ExtraColor>
            </MoreDetails>
        </AdditionalInfo>
    </Thing>
</Things>

    [download]
    How can I add a hash of additional infomation to a specific Item? When I run the code above the 'AdditionInfo' hash gets appended to the end of the data structure, which makes sense. How do I add data deeper than the initial data structure declaration?
    Thanks for any insight provided. I've already read perldata, BTW...

    Rob
[reply]
[d/l]
[select]

      Obviously you can do this:

      push @{ $data->{Things}->{Thing} },
    {
    'Item' => $var1,
    'Number' => $var2,
    'Details' => {
            'Detail' => {
                    'Color' => $var3
                        }
             },
    'AdditionalInfo' => {
        'Info' => $var4,
        'Stuff' => $var5,
        'MoreDetails' => {
                'ExtraColor' => $var6
                 }
        }
    };

      [download]

      But probably it is not what you really want. If the real question is "How can I dinamically build the structure that will generate my XML?", the answer is not so simple (aka, I can't make it for you :)):

      The right path to enlightment is to understand how complex data structures work in perl (your example id a HoHoHoHoH, not the very simplest) so you can handle them in a better way

      As an example, the following code probably do what you expect:

      $struc={
        'Item' => $var1,
        'Number' => $var2,
        'Details' => {
                      'Detail' => {
                                   'Color' => $var3
                                  }
                     }
       }
$struc->{AdditionalInfo}={
                          'Info' => $var4,
                          'Stuff' => $var5,
                          'MoreDetails' => {
                                            'ExtraColor' => $var6
                                           }
                         };
push @{ $data->{Things}->{Thing} },$struc;

      [download]

      Not sure, I can't try it now

      Rule One: Do not act incautiously when confronting a little bald wrinkly smiling man.

[reply]
[d/l]
[select]
        Thank you. That's a good idea. One last question. How would I find a specific Item? I was thinking along these lines: 
        if ($data{Things}{Thing}{Item} = "aValue") {
...

        [download]
[reply]
[d/l]

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