Export WooCommerce orders to XML file

functions.php

<?php
/**
  * Export WooCommerce orders to xml file
  *
  * @return void|string Return nothing or xml file
  */
function motivast_export_xml_with_woocommerce_orders() {

	/**
	 * Check for credentials or IP address to allow download
	 * xml for particular users only.
	 */

	$allowed_ip = '127.0.0.1';

	if ( get_current_ip() !== $allowed_ip ) {
		return;
	}

	/**
	 * If there is not export parameter in url do nothing
	 */
	$export = filter_input( INPUT_GET, 'export_xml', FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE );

	if( true !== $export ) {
		return;
	}

	/**
	 * Get last 10 orders.
	 */
	$orders_to_xml = array();

	$query  = new WC_Order_Query();
	$orders = $query->get_orders();

	/**
	 * Iterate over orders to prepare xml ready array
	 */
	foreach ( $orders as $order ) {

		$orders_to_xml['status'] = $order->get_status();
		$orders_to_xml['total'] = $order->get_total();

		$orders_to_xml['items'] = array();

		$items = $order->get_items();

		foreach( $items as $key => $item ) {

			$orders_to_xml['items'][$key]['product_id'] = $item->get_id();
			$orders_to_xml['items'][$key]['name'] = $item->get_name();
		}
	}

	/**
	 * Create XML
	 */
	$xml = new SimpleXMLElement('<?xml version="1.0"?><root></root>');
	array_to_xml( $orders_to_xml, $xml );

	echo $xml->asXML();

	/**
	 * Terminate to not print anything else
	 */
	exit;
}

add_action('init', 'motivast_export_xml_with_woocommerce_orders');

/**
 * Generate xml document from array
 *
 * @param array 		   $data 	 Array to convert
 * @param SimpleXMLElement $xml XML document to work on
 */
function array_to_xml( $data, &$xml ) {

	foreach( $data as $key => $value ) {

		if( is_numeric( $key ) ){
			$key = 'item';
		}

		if( is_array($value) ) {

			$subnode = $xml->addChild( $key );
			array_to_xml( $value, $subnode );

		} else {

			$xml->addChild( $key, htmlspecialchars( $value ) );
		}
	}
}

/**
 * Get current IP
 *
 * @return string Current IP address
 */
function get_current_ip() {

	$http_client_ip     = filter_input( INPUT_SERVER, 'HTTP_CLIENT_IP', FILTER_VALIDATE_IP, FILTER_NULL_ON_FAILURE );
	$http_forwarded_for = filter_input( INPUT_SERVER, 'HTTP_X_FORWARDED_FOR', FILTER_VALIDATE_IP, FILTER_NULL_ON_FAILURE );
	$remote_addr        = filter_input( INPUT_SERVER, 'REMOTE_ADDR', FILTER_VALIDATE_IP, FILTER_NULL_ON_FAILURE );

	return $http_client_ip ? $http_client_ip : ($http_forwarded_for ? $http_forwarded_for : $remote_addr );
}