(Perl) Traverse Direct Children via FirstChild / NextSibling, or LastChild / PreviousSibling

Demonstrates some ways to iterate over direct child nodes using the FirstChild / NextSibling and LastChild / PreviousSibling methods.

The input XML, available at http://www.chilkatsoft.com/data/fruit.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

 Chilkat Perl Module Downloads for Windows, Linux, and MAC OS X

use chilkat();

$xml = new chilkat::CkXml();

#  The sample input XML is available at http://www.chilkatsoft.com/data/fruit.xml
$success = $xml->LoadXmlFile("fruit.xml");
if ($success != 1) {
    print $xml->lastErrorText() . "\r\n";
    exit;
}

#  Iterate over the direct children by using FirstChild / NextSibling
# child is a CkXml
$child = $xml->FirstChild();
while (!($child eq null )) {
    print $child->tag() . " : " . $child->content() . "\r\n";
    # nextSibling is a CkXml
    $nextSibling = $child->NextSibling();

    # child is a CkXml
    $child = $nextSibling;
}

print "-----" . "\r\n";

#  Do the same, but with FirstChild2 / NextSibling2 to avoid
#  creating so many XML object instances:
$success = $xml->FirstChild2();
while ($success == 1) {
    print $xml->tag() . " : " . $xml->content() . "\r\n";
    $success = $xml->NextSibling2();
}

#  Revert back up to the parent:
$xml->GetParent2();

print "-----" . "\r\n";

#  Iterate in reverse order using LastChild / PreviousSibling
# child is a CkXml
$child = $xml->LastChild();
while (!($child eq null )) {
    print $child->tag() . " : " . $child->content() . "\r\n";
    # prevSibling is a CkXml
    $prevSibling = $child->PreviousSibling();

    # child is a CkXml
    $child = $prevSibling;
}

print "-----" . "\r\n";

#  Do the same, but with LastChild2 / PreviousSibling2 to avoid
#  creating so many XML object instances:
$success = $xml->LastChild2();
while ($success == 1) {
    print $xml->tag() . " : " . $xml->content() . "\r\n";
    $success = $xml->PreviousSibling2();
}

#  Revert back up to the parent:
$xml->GetParent2();