Php WooCommerce checkout 流程中基于所选选项添加自定义费用

您的代码中有一些错误，它无法按原样工作.它需要AJAX和一个WooCommerce会话变量.

以下是重新访问的完整代码(remove before all your existing related code):

// Displaying a checkout "select" custom field
add_action('woocommerce_checkout_fields', 'add_custom_select_field_to_checkout');
function add_custom_select_field_to_checkout($fields) {
    $fields['shipping']['card_type'] = array(
        'type' => 'select',
        'label' => __('Greeting Card', 'woocommerce'),
        'options' => array(
            '' => __('Select an option', 'woocommerce'),
            'nocard' => __('No Card', 'woocommerce'),
            'bestwishes' => __('Best Wishes (Free)', 'woocommerce'),
            'congratulations' => __('Congratulations ($0.99)', 'woocommerce'),
            'happybirthday' => __('Happy birthday ($0.99)', 'woocommerce'),
            'happyanniversary' => __('Happy Anniversary ($0.99)', 'woocommerce'),
        ),
        'required' => true,
        'class' => array('form-row-wide'),
        'clear' => true
    );

    return $fields;
}

// jQuery - Ajax script
add_filter( 'wp_footer' , 'checkout_delivery_script' );
function checkout_delivery_script() {
    // Only on checkout page
    if( ! ( is_checkout() && ! is_wc_endpoint_url() ) ) return;
    
    WC()->session->__unset('selected_card_type'); // Reset 'selected_card_type' session variable
    
    // Jquery / Ajax
    wc_enqueue_js( "jQuery(function($){
        if (typeof wc_checkout_params === 'undefined')
            return false;
        
        // Ajax 
        $('form.checkout').on('change', 'select#card_type', function(){
            var selected = $(this).val();
                console.log(selected); // just for testing | TO BE REMOVED

            $.ajax({
                type: 'POST',
                url: wc_checkout_params.ajax_url,
                data: {
                    'action':             'selected_card_type',
                    'selected_card_type': selected,
                },
                success: function (result) {
                    $('body').trigger('update_checkout');
                    console.log(result); // just for testing | TO BE REMOVED
                }
            });
        });
    });" );
}

// Get Ajax request and saving to WC session
add_action( 'wp_ajax_selected_card_type', 'wc_get_selected_card_type_ajax_data' );
add_action( 'wp_ajax_nopriv_selected_card_type', 'wc_get_selected_card_type_ajax_data' );
function wc_get_selected_card_type_ajax_data() {
    if ( isset($_POST['selected_card_type']) ){
        $selected_card_type = esc_attr($_POST['selected_card_type']);
        
        // Updating 'selected_card_type' WooCommerce Session variable
        WC()->session->set('selected_card_type', $selected_card_type );
        
        echo $selected_card_type; // Return the value to jQuery
    }
    die(); // Always Exit silently
}

// Add a Fee conditionally in checkout
add_action('woocommerce_cart_calculate_fees', 'add_selected_card_type_fee');
function add_selected_card_type_fee() {
    if ( is_admin() && !defined('DOING_AJAX') ) {
        return; // Do not add the fee when in the admin area
    }
    
    // Only on checkout page
    if( ! ( is_checkout() && ! is_wc_endpoint_url() ) ) {
        return;
    }
        
    // Get 'selected_card_type' WooCommerce Session variable
    $selected_card_type = WC()->session->get('selected_card_type' );
    
    if (isset($selected_card_type) && ! in_array( $selected_card_type, array('bestwishes', 'nocard') ) ) {
        $extra_charge = 0.99; 
        WC()->cart->add_fee( __('Greeting Card Fee', 'woocommerce'), $extra_charge );
    }
}

代码放在活动子主题(或活动主题)的函数.php文件中.经过测试，效果良好.