woocommerce_order_get_total_discount │ хук-фильтр │ WC 1.0

Использование

add_filter( 'woocommerce_order_get_total_discount', 'wp_kama_woocommerce_order_get_total_discount_filter', 10, 2 );

/**
 * Function for `woocommerce_order_get_total_discount` filter-hook.
 * 
 * @param  $NumberUtil::round 
 * @param  $that              
 *
 * @return 
 */
function wp_kama_woocommerce_order_get_total_discount_filter( $NumberUtil::round, $that ){

	// filter...
	return $NumberUtil::round;
}

$NumberUtil::round

-

$that

-

Где вызывается хук

return apply_filters( 'woocommerce_order_get_total_discount', NumberUtil::round( $total_discount, WC_ROUNDING_PRECISION ), $this );

Где используется хук в WooCommerce