To calculate custom product variation totals or prices in WooCommerce, you can use custom hooks and WooCommerce functions. Here’s a step-by-step guide to achieve this:
1. Understanding Custom Variation Calculation
When dealing with custom calculations for product variations (e.g., based on user input, extra fields, or specific attributes), you’ll likely need to:
- Modify the variation price dynamically.
- Calculate totals based on selected attributes or custom fields.
2. Example: Adding Custom Variation Price Calculation
Here’s an example where we calculate a custom price for product variations:
Add a Custom Field for Input (e.g., Text Field)
You can use WooCommerce hooks to add custom fields on the product page.
Add this to your theme’s functions.php file:
// Add custom field for additional input (e.g., custom engraving)
add_action('woocommerce_before_add_to_cart_button', 'add_custom_variation_field');
function add_custom_variation_field() {
echo '<div class="custom-variation-field">
<label for="custom_input">Custom Text (e.g., engraving): </label>
<input type="text" id="custom_input" name="custom_input" />
</div>';
}
// Validate the custom field
add_filter('woocommerce_add_to_cart_validation', 'validate_custom_field', 10, 3);
function validate_custom_field($passed, $product_id, $quantity) {
if (empty($_POST['custom_input'])) {
wc_add_notice(__('Please enter custom text.', 'woocommerce'), 'error');
$passed = false;
}
return $passed;
}
// Save the custom field to the cart
add_filter('woocommerce_add_cart_item_data', 'add_custom_field_to_cart', 10, 2);
function add_custom_field_to_cart($cart_item_data, $product_id) {
if (!empty($_POST['custom_input'])) {
$cart_item_data['custom_input'] = sanitize_text_field($_POST['custom_input']);
}
return $cart_item_data;
}
// Display custom field in the cart
add_filter('woocommerce_get_item_data', 'display_custom_field_in_cart', 10, 2);
function display_custom_field_in_cart($item_data, $cart_item) {
if (!empty($cart_item['custom_input'])) {
$item_data[] = array(
'name' => __('Custom Text', 'woocommerce'),
'value' => $cart_item['custom_input']
);
}
return $item_data;
}
// Add a custom price based on the custom input
add_filter('woocommerce_before_calculate_totals', 'add_custom_price_based_on_field', 10, 1);
function add_custom_price_based_on_field($cart) {
if (is_admin() && !defined('DOING_AJAX')) {
return;
}
foreach ($cart->get_cart() as $cart_item) {
if (!empty($cart_item['custom_input'])) {
$custom_price = $cart_item['data']->get_price() + 10; // Example: Add $10 for custom text
$cart_item['data']->set_price($custom_price);
}
}
}
3. Key Steps in the Code Above
- Custom Field: Adds a text input field for custom input (e.g., engraving).
- Validation: Ensures the custom field is filled before adding the item to the cart.
- Cart Data: Saves and displays custom data in the cart.
- Price Modification: Dynamically adjusts the product price based on custom input.
4. Advanced Customization
If you need calculations based on product attributes or complex formulas:
- Use custom attributes: Fetch them with
$product->get_attribute('attribute_name'). - Apply custom logic for the price calculation in the
woocommerce_before_calculate_totalsfilter. - Consider creating a custom plugin for modular code management.
5. Testing the Solution
- Add a variable product in WooCommerce.
- Enable the custom field logic by adding the code.
- Verify that the custom price is calculated and displayed correctly during checkout.