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

Hi, how can i create an empty element like 
<element />

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with xml::smart? I did all the coding so far for an export interface with perl and xml::smart and this is the point where i am still failing. some elements need to be there, but empty, since i dont have values every time in every row... can you please help, me? thanks in advance, makro

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Re: empty element with xml::smart
by ikegami (Patriarch) on Mar 18, 2008 at 06:06 UTC

    Can you do <element></element>? That's exactly the same thing as <element/>.

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      Installed the module... It actually produces <element/> for empty elements: 

      use XML::Smart qw( );
my $xml = XML::Smart->new();
$xml->{foo}{bar}{empty} = {};
print scalar $xml->data();

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      <?xml version="1.0" encoding="iso-8859-1" ?>
<?meta name="GENERATOR" content="XML::Smart/1.6.8 Perl/5.008008 [MSWin
+32]" ?>
<foo>
  <bar>
    <empty/>
  </bar>
</foo>

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      If you use a DTD, then you need to specify the "EMPTY" keyword or else it'll generate <empty></empty> (which is fine cause it means the same thing). 

      use XML::Smart qw( );
my $xml = XML::Smart->new();
$xml->{foo}{bar}{empty} = {};
$xml->apply_dtd(<<'__EOI__');
<!DOCTYPE foo [
<!ELEMENT foo (bar*)>
<!ELEMENT bar (empty*)>
<!ELEMENT empty EMPTY>
]>
__EOI__
print scalar $xml->data();

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        thanks for the reply/solution. i was trying '' and undef as source values (from the db) for xml::smart, that didnt work the way i expected perl to work. sure, the empty hash, i should have tried that too. thanks for help!
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