InsertBefore

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

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.

Returns

• mixed - - The inserted node.