XML serialization with attributes handling

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

Hello, Monks

I'm writing a module which sends XML queries to specific service. So I've already written stupid serialization method (using XML::LibXML) which takes perl variables and returns XML.
According to service's protocol specification there are some complex tags in queries which contains attributes.
Please suggest any ideas of how can I add attributes handling to my serialization method.

sub _xml_serialize {
    my $self = shift;
    
    my($parent_node, $tree) = @_;
    
    no warnings 'uninitialized';
    
    while(my($k, $v) = each %$tree) {
        if(ref $v eq 'HASH') {
            my $child_node = XML::LibXML::Element->new($k);
            $self->_xml_serialize($child_node, $v);
            $parent_node->appendChild($child_node)
        }
        elsif(ref $v eq 'ARRAY') {
            foreach(@$v) {
                my $child_node = XML::LibXML::Element->new($k);
                if(ref eq 'HASH' or ref eq 'ARRAY') { $self->_xml_seri
+alize($child_node, $_) }
                else { $child_node->appendText($_ || '') }
                $parent_node->appendChild($child_node)
            }
        }
        else {
            $parent_node->appendTextChild($k, $v || '')
        }
    }
}
[download]

Usage example:

$self->_xml_serialize(
    $doc_root,
    outer => { inner => 'value' }
)
[download]

Example output:

...<outer><inner>value</inner></outer>...
[download]

Comment on XML serialization with attributes handling Select or Download Code

Replies are listed 'Best First'.
Re: XML serialization with attributes handling by holli (Abbot) on Jan 30, 2009 at 18:38 UTC
I personally prefer a templating mechanism over any XML-module when it comes to generating XML from data-structures. If it's good for HTML, it's good for XML too. See Creating huge files with the Template Toolkit. holli When you're up to your ass in alligators, it's difficult to remember that your original purpose was to drain the swamp.	[reply] [d/l]
Re: XML serialization with attributes handling by Your Mother (Archbishop) on Jan 30, 2009 at 23:09 UTC
The difference between element/nodes and attributes is somewhat arbitrary in some cases so it would really depend on the service spec how to do it. If you have an XML example with attributes from them and perhaps a Perl data structure you think should match, I'm sure someone will be able to help you. (Me, later, if you put something to that effect up.)	[reply]
Re^2: XML serialization with attributes handling by KSURi (Monk) on Jan 31, 2009 at 08:47 UTC
Thanks for the replay I've already solved my problem. Dunno why I haven't done it earlier... The code is simple stupid again, but seems working: sub _xml_serialize { my $self = shift; my($parent_node, $tree) = @_; no warnings 'uninitialized'; while(my($k, $v) = each %$tree) { if(ref $v eq 'HASH') { my $child_node = XML::LibXML::Element->new($k); $self->_xml_serialize($child_node, $v); $parent_node->appendChild($child_node) } elsif(ref $v eq 'ARRAY') { foreach(@$v) { my $child_node = XML::LibXML::Element->new($k); if(ref eq 'HASH' or ref eq 'ARRAY') { $self->_xml_seri +alize($child_node, $_) } else { $child_node->appendText($_) } $parent_node->appendChild($child_node) } } else { if($k =~ s/^-//o) { $parent_node->setAttribute($k, $v) } # + just one line of code for handling attributes elsif($k =~ s/^\+//o) { $parent_node->appendText($v) } # a +nd one for text childs else { $parent_node->appendTextChild($k, $v) } } } } [download] Now I can pass attributes with '-' prefix: `$qiwi->_xml_create(outer => {'-outer-attr' => 'val', '+' => 'outer tex +t'})` [download] Output: `...<outer outer-attr="val">outer text</outer>...` [download]	[reply] [d/l] [select]
Re: XML serialization with attributes handling by runrig (Abbot) on Jan 30, 2009 at 18:23 UTC
It seems like you could do this a lot more simply with XML::Simple. If the default output is not good enough for your purposes (and it probably isn't), then you can tweak the output with the options.	[reply]