Perl

Removing / Deleting Child Nodes from XML

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Demonstrates various methods for removing child nodes from an XML document.

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>

Perl

use chilkat();

$success = 0;

$xml = chilkat::CkXml->new();

# 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;
}

# The RemoveChild method removes (discards) all direct
# children having the specified tag:
$xml->RemoveChild("fruit");

# Show the resulting XML:
print "Result with all direct children having a tag equal to \"fruit\" removed:" . "\r\n";
print $xml->getXml() . "\r\n";

# The XML with the "fruit" direct children removed is shown below:
# Notice that the "fruit" node beneath "xyz" was not removed.
# This correct because it was not a direct child of the calling node.

# <root>
#     <veg color="orange">carrot</veg>
#     <meat animal="cow">beef</meat>
#     <xyz>
#         <fruit color="blue">blueberry</fruit>
#         <veg color="green">broccoli</veg>
#     </xyz>
#     <cheese color="yellow">cheddar</cheese>
# </root>

# --------------------------------------------------------------------------
# Restore the original XML:
$success = $xml->LoadXmlFile("fruit.xml");

# The RemoveChildWithContent method removes the child
# having the exact content specified, regardless of the tag.  
# For example:
$xml->RemoveChildWithContent("pear");

# Show the resulting XML:
print "Result with the node containing \"pear\" removed:" . "\r\n";
print $xml->getXml() . "\r\n";

# --------------------------------------------------------------------------
# Restore the original XML:
$success = $xml->LoadXmlFile("fruit.xml");

# The RemoveChildByIndex method removes the Nth direct
# child.  Indexing begins at 0.  The "xyz" child is at index 4:
$xml->RemoveChildByIndex(4);

# Show the resulting XML:
# Notice that the entire "xyz" subtree is removed.
print "Result with the node at index 4 removed:" . "\r\n";
print $xml->getXml() . "\r\n";

# --------------------------------------------------------------------------
# Restore the original XML:
$success = $xml->LoadXmlFile("fruit.xml");

# Navigate to the node with tag "xyz"
# xyz is a Xml
$xyz = $xml->FindChild("xyz");

# Remove the "xyz" subtree making it it's own XML document
# with the "xyz" node at the root:
$xyz->RemoveFromTree();

# Show both XML documents:
print $xyz->getXml() . "\r\n";
print $xml->getXml() . "\r\n";

# Also, the TreeId property is an integer value assigned
# to nodes in an XML document.  All nodes belonging to
# the same XML document will have the same TreeId.
# Notice that the "xyz" node now has a different TreeId:
print "xyz TreeId = " . $xyz->get_TreeId() . "\r\n";
print "xml TreeId = " . $xml->get_TreeId() . "\r\n";