(PHP 8 >= 8.4.0)
Dom\Attr::isId — Checks if attribute is a defined ID
This function checks if the attribute is a defined ID.
According to the DOM standard this requires a DTD which defines the
attribute ID to be of type ID. To utilise this method the document
must be validated at parse time by passing
LIBXML_DTDVALID as an option.
This function has no parameters.
Example #1 Dom\Attr::isId() Example
<?php
/ We need to validate our document before referring to the id
$doc = Dom\XMLDocument::createFromFile('examples/book-docbook.xml', LIBXML_DTDVALID);
/ We retrieve the attribute named id of the chapter element
$attr = $doc->getElementsByTagName('chapter')->item(0)->getAttributeNode('id');
var_dump($attr->isId()); / bool(true)
?>