[Plugin: WooCommerce] Order Admin – Searching for order notes

Being able to search the Order Notes in the Order Admin screen in WooCommerce is not a standard feature today. As I spent some significant time resolving it and I also believe it is relevant for others I will share it with you. Hopefully it will be useful for someone else too.

I found very few articles on this subject matter. Two very helpful sources of inspiration and guiding were:
1. Tamara Zuk’s reply to a person asking for order notes search functionality
2. Scott Anderson’s article about overriding WooCommerce/WP core class functions

What did I do?

1. All modifications were put in the child themes functions.php
2. Made a filter searching in order notes which actually are put in the WP comments table as comment_type = ‘order_note’.
3. Overrided the function WC_Admin_Post_Types::shop_order_search_custom_fields in a sub-class called My_WC Admin_Post_Types
4. Added a filter hook (shop_order_search_custom_order_ids) to the overridden function above. Doing this I was now able to merge post_ids from the filter into the post__in variable.

The code looks like this:

add_filter( 'shop_order_search_custom_order_ids', 'shop_order_search_order_notes');
function shop_order_search_order_notes ($post_ids) {
		global $pagenow, $wpdb;

		// Search order notes (from comments table)
		$post_ids = array_unique( array_merge(
				$wpdb->get_col(
						$wpdb->prepare( "
								SELECT comment_post_ID
								FROM {$wpdb->prefix}comments as comments
								WHERE comment_type = 'order_note'
								AND comment_content LIKE '%%%s%%'
								",
								esc_attr( $_GET['s'] )
						)
				)
				, array()
		) );

		return $post_ids;
}

class My_WC_Admin_Post_Types {

		public function shop_order_search_custom_fields( $wp ) {
			global $pagenow;

			if ( 'edit.php' != $pagenow || empty( $wp->query_vars['s'] ) || $wp->query_vars['post_type'] != 'shop_order' ) {
				echo 'RETURNED';
				return;
			}

			$post_ids = wc_order_search( $_GET['s'] );

			// BF: Added this line to enable to hook into the post_ids
			$post_ids = array_unique(array_merge( $post_ids, apply_filters('shop_order_search_custom_order_ids',array())));

			if ( ! empty( $post_ids ) ) {
				// Remove "s" - we don't want to search order name.
				unset( $wp->query_vars['s'] );

				// so we know we're doing this.
				$wp->query_vars['shop_order_search'] = true;

				// Search by found posts.
				$wp->query_vars['post__in'] = array_merge( $post_ids, array( 0 ) );
			}
		}
	}

	remove_action( 'parse_query', 'WC_Admin_Post_Types::shop_order_search_custom_fields' );
	add_action( 'parse_query', 'My_WC_Admin_Post_Types::shop_order_search_custom_fields' );

Thanks for any reply on improvements to the code itself or suggestions for other strategies to resolve this functionality.

[moderator note – removed “modlook” tag; please do not use this tag unless a post/thread is actually breaking the forum rules]