Convert WooCommerce order note to custom field - Parse order notes to extract a shipping tracking number, creating a custom field if found.

wc-convert-order-note-to-custom-field.php

<?php
/*
Plugin Name: Convert WooCommerce order note to custom field
Plugin URI: https://www.damiencarbery.com/
Description: Parse order notes to extract a shipping tracking number, creating a custom field if found.
Author: Damien Carbery
Version: 0.2
*/


add_action( 'woocommerce_order_note_added', 'dcwd_parse_order_note', 10, 2 );
function dcwd_parse_order_note( $comment_id, $order ) {
	$comment = get_comment( $comment_id, ARRAY_A );

	$tracking_str = 'Tracking number: ';
	// If $tracking_str found in the comment then extract the tracking number
	// and add it to a custom field.
	if ( false !== strpos( $comment[ 'comment_content' ], $tracking_str ) ) {
		$tracking_number = substr( $comment[ 'comment_content' ], strlen( $tracking_str ) );
		//error_log( 'Tracking found: ' . $tracking_number );
		update_post_meta( $order->get_id(), 'tracking_number', $tracking_number );
		update_post_meta( $order->get_id(), 'tracking_url', 'https://www.royalmail.com/track-your-item#/' . $tracking_number );
	}
}