WC_Product_Variable::validate_props PHP Method

    public function validate_props()
    {
        // Before updating, ensure stock props are all aligned. Qty and backorders are not needed if not stock managed.
        if (!$this->get_manage_stock()) {
            $this->set_stock_quantity('');
            $this->set_backorders('no');
            // If we are stock managing and we don't have stock, force out of stock status.
        } elseif ($this->get_stock_quantity() <= get_option('woocommerce_notify_no_stock_amount')) {
            $this->set_stock_status('outofstock');
            // If the stock level is changing and we do now have enough, force in stock status.
        } elseif ($this->get_stock_quantity() > get_option('woocommerce_notify_no_stock_amount') && array_key_exists('stock_quantity', $this->get_changes())) {
            $this->set_stock_status('instock');
            // Otherwise revert to status the children have.
        } else {
            $this->set_stock_status($this->child_is_in_stock() ? 'instock' : 'outofstock');
        }
    }