DOMNode::insertBefore

This function inserts a new node right before the reference node

public function insertBefore<T as DOMNode>(
  DOMNode $newnode,
  DOMNode $refnode = NULL,
): T;

If you plan to do further modifications on the appended child you must use the returned node.

Parameters

DOMNode$newnode - The new node.
DOMNode$refnode = NULL - The reference node. If not supplied, newnode is appended to the children.