in reply to Use Storable for storing XML::LibXML object

The problem is that an XML::LibXML node is really just a pointer to a libxml struct that lives in XS land. It has no real meaning once the DOM is disposed of.

What to do about it? Firstly, an important question. Say you've stored a node which represents a deeply nested XML element. Once you've retrieved the object from storage, should you only be allowed to query "down" from the node, or should $node->parentNode Just Work™?

toby döt ink

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Re^2: Use Storable for storing XML::LibXML object
by buff (Acolyte) on Jul 05, 2014 at 10:24 UTC
    Thank you. Querying down from the node is enough in my case.
[reply]

      Then you may be able to define a couple of hooks for freezing and thawing XML::LibXML::Element objects

      # these are completely untested!

sub XML::LibXML::Elemment::STORABLE_freeze {
   my $self = shift;
   $self->toString;
}

sub XML::LibXML::Elemment::STORABLE_thaw {
   my $class = shift;
   my (undef, $str) = @_;
   XML::LibXML->parse_xml(string => $str)->documentElement;
}

      [download]

      See the "Hooks" section in the Storable documentation.

      toby döt ink
[reply]
[d/l]
        Note that if you serialize two elements from the same document, they will be part of two documents when deserialized.
[reply]

        Thanks very much for your help. After some tweaking it seems to work. I've ended up with this code:

        sub XML::LibXML::Element::STORABLE_freeze {
    shift->toString
}

sub XML::LibXML::Element::STORABLE_attach {
    'XML::LibXML'->load_xml(string => pop)->documentElement
}

        [download]
[reply]
[d/l]

        Thank you very much! I'll give it a try on Monday and post the result here.

[reply]

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