(PHP 5 >= 5.2.0, PHP 7)
DOMNode::getNodePath — Get an XPath for a node
Gets an XPath location path for the node.
This function has no parameters.
   Returns a string containing the XPath, or NULL in case of an error.
  
Example #1 DOMNode::getNodePath() example
<?php
// Create a new DOMDocument instance
$dom = new DOMDocument;
// Load the XML
$dom->loadXML('
<fruits>
 <apples>
  <apple>braeburn</apple>
  <apple>granny smith</apple>
 </apples>
 <pears>
  <pear>conference</pear>
 </pears>
</fruits>
');
// Print XPath for each element
foreach ($dom->getElementsByTagName('*') as $node) {
    echo $node->getNodePath() . "\n";
}
?>
The above example will output:
/fruits /fruits/apples /fruits/apples/apple[1] /fruits/apples/apple[2] /fruits/pears /fruits/pears/pear