woocommerce_thankyou_order_key │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_thankyou_order_key', 'wp_kama_woocommerce_thankyou_order_key_filter' );

/**
 * Function for `woocommerce_thankyou_order_key` filter-hook.
 * 
 * @param  $empty 
 *
 * @return 
 */
function wp_kama_woocommerce_thankyou_order_key_filter( $empty ){

	// filter...
	return $empty;
}

$empty

-

Where the hook is called

$order_key = apply_filters( 'woocommerce_thankyou_order_key', empty( $_GET['key'] ) ? '' : wc_clean( wp_unslash( $_GET['key'] ) ) ); // WPCS: input var ok, CSRF ok.

Where the hook is used in WooCommerce