What I am trying to do is show a breakdown of the Woocommerce transaction fee being applied after the order total:

It would something like this:

• Items Subtotal: £375.00
• Shipping: £0.00
• VAT: £75.00
• Order Total: £450.00
• Paid: £450.00
• Transaction Fee: £7.00
• Total (after fee): £443.00

A visual of where it should go, I have highlighted it and as you see it's just an error at the moment:

The code in my functions .php

    // Calculate and save transaction fee after order is created/paid
add_action('woocommerce_order_status_changed', 'add_transaction_fee_to_order_meta', 10, 3);
function add_transaction_fee_to_order_meta($order_id, $old_status, $new_status) {
    if ($new_status == 'processing' || $new_status == 'completed') {
        $order = wc_get_order($order_id);

        if (get_post_meta($order_id, '_transaction_fee', true) == '') {
            $order_total = $order->get_total();
            $transaction_fee = ($order_total * 0.015) + 0.25;

            update_post_meta($order_id, '_transaction_fee', $transaction_fee);

        }
    }
}


// Display transaction fee in admin order details *after* "Paid" line
add_action('woocommerce_admin_order_totals_after_total', 'display_transaction_fee_in_admin_order_details', 10, 2);
function display_transaction_fee_in_admin_order_details($order_id, $order) {
    $transaction_fee = get_post_meta($order_id, '_transaction_fee', true);

    if ($transaction_fee) {
        if (is_object($order) && is_a($order, 'WC_Order')) {
            ?>  <tr>
                <td class="label">Transaction Fee:</td>
                <td width="1%"></td>
                <td class="total">
                    <?php echo wc_price($transaction_fee); ?>
                </td>
            </tr>
            <tr>
                <td class="label">Total (after fee):</td>
                <td width="1%"></td>
                <td class="total">
                    <?php echo wc_price($order->get_total() - $transaction_fee); ?>
                </td>
            </tr>
            <?php
        } else {
            error_log("WC_Order object not available in display_transaction_fee_in_admin_order_details for order ID: " . $order_id);
        }
    }
}

What I am trying to do is show a breakdown of the Woocommerce transaction fee being applied after the order total:

It would something like this:

• Items Subtotal: £375.00
• Shipping: £0.00
• VAT: £75.00
• Order Total: £450.00
• Paid: £450.00
• Transaction Fee: £7.00
• Total (after fee): £443.00

A visual of where it should go, I have highlighted it and as you see it's just an error at the moment:

The code in my functions .php

    // Calculate and save transaction fee after order is created/paid
add_action('woocommerce_order_status_changed', 'add_transaction_fee_to_order_meta', 10, 3);
function add_transaction_fee_to_order_meta($order_id, $old_status, $new_status) {
    if ($new_status == 'processing' || $new_status == 'completed') {
        $order = wc_get_order($order_id);

        if (get_post_meta($order_id, '_transaction_fee', true) == '') {
            $order_total = $order->get_total();
            $transaction_fee = ($order_total * 0.015) + 0.25;

            update_post_meta($order_id, '_transaction_fee', $transaction_fee);

        }
    }
}


// Display transaction fee in admin order details *after* "Paid" line
add_action('woocommerce_admin_order_totals_after_total', 'display_transaction_fee_in_admin_order_details', 10, 2);
function display_transaction_fee_in_admin_order_details($order_id, $order) {
    $transaction_fee = get_post_meta($order_id, '_transaction_fee', true);

    if ($transaction_fee) {
        if (is_object($order) && is_a($order, 'WC_Order')) {
            ?>  <tr>
                <td class="label">Transaction Fee:</td>
                <td width="1%"></td>
                <td class="total">
                    <?php echo wc_price($transaction_fee); ?>
                </td>
            </tr>
            <tr>
                <td class="label">Total (after fee):</td>
                <td width="1%"></td>
                <td class="total">
                    <?php echo wc_price($order->get_total() - $transaction_fee); ?>
                </td>
            </tr>
            <?php
        } else {
            error_log("WC_Order object not available in display_transaction_fee_in_admin_order_details for order ID: " . $order_id);
        }
    }
}

• php
• wordpress
• woocommerce
• metadata
• orders

• The message is only stating that there was some error, but gives no details. Check your admin email, as it says there, and/or enable WP debug mode, to first of all figure out what the error actually was. – C3roe Commented 17 hours ago
• Yes you're right apologies, debugging was turned on, I have had a look and I didn't receive any emails regarding the error, I can't see any specific errors in the log that relate to my code, just: Function _load_textdomain_just_in_time was called <strong>incorrectly</strong> and PHP Notice: ob_end_flush(): Failed to send buffer of zlib output compression – A.Copland Commented 17 hours ago
• Neither of those sounds like "critical" errors. On the frontend, is there any further content after this message, or does the page just appear to "end" there? – C3roe Commented 16 hours ago
• PHP Deprecated: Creation of dynamic property WooCommerce\Square\Gateway\Gift_Card::$is_default_placeholder is deprecated in /home/teconnexpower/public_html/wp-content/plugins/woocommerce-square/includes/Framework/PaymentGateway/Payment_Gateway.php – A.Copland Commented 16 hours ago
• PHP Deprecated: Creation of dynamic property WooCommerce\Square\Gateway\Gift_Card::$placeholder_id is deprecated in /home/teconnexpower/public_html/wp-content/plugins/woocommerce-square/includes/Framework/PaymentGateway/Payment_Gateway.php – A.Copland Commented 16 hours ago

1 Answer 1

Your code is not compatible High-Performance Order Storage (HPOS) and there are multiple mistakes, like:

• woocommerce_order_status_changed has already $order available via its 4th argument,
• woocommerce_admin_order_totals_after_total has only $order_id as available argument, but not any $order as 2nd argument…

Try the following instead:

// Calculate and save transaction fee after order is created/paid
add_action('woocommerce_order_status_changed', 'add_transaction_fee_to_order_meta', 10, 4 );
function add_transaction_fee_to_order_meta( $order_id, $old_status, $new_status, $order ) {
    $targeted_statuses = array('processing', 'completed');

    if ( in_array( $new_status, $targeted_statuses) && ! $order->get_meta('_transaction_fee') && $order->get_total() > 0 ) {
        $order->update_meta_data('_transaction_fee', ($order->get_total() * 0.015) + 0.25 );
        $order->save();
    }
}


// Display transaction fee in admin order details *after* "Paid" line
add_action('woocommerce_admin_order_totals_after_total', 'display_transaction_fee_in_admin_order_details' );
function display_transaction_fee_in_admin_order_details( $order_id ) {
    $order = wc_get_order($order_id);
    $args  = array( 'currency' => $order->get_currency() );

    if ( $transaction_fee = $order->get_meta('_transaction_fee') ) {
        printf('<tr>
            <td class="label">%s</td>
            <td width="%s"></td>
            <td class="total">%s</td>
        </tr>', esc_html__('Transaction Fee:'), '1%', wc_price($transaction_fee, $args ) );

        printf('<tr>
            <td class="label">%s</td>
            <td width="%s"></td>
            <td class="total">%s</td>
        </tr>', esc_html__('Total (after fee):'), '1%', wc_price( $order->get_total() - $transaction_fee, $args ) );
    }
}

It should better work without errors, and will be compatible with HPOS.

You may need to target the concerned payment gateway(s) in your first function, as actually your code is executed on all processing or completed orders, no matter what payment method has been used.