How to display custom fields of variable products under the product title of the front product page

Question

The code for adding custom fields in the background is as follows:

// 1. Add custom field input @ Product Data > Variations > Single Variation
function bbloomer_add_custom_field_to_variations( $loop, $variation_data, $variation ) {
woocommerce_wp_text_input( array( 
'id' => 'custom_field[' . $loop . ']', 
'class' => 'short', 
'label' => __( 'Custom Field', 'woocommerce' ),
'value' => get_post_meta( $variation->ID, 'custom_field', true )
) 
);      
}
add_action( 'woocommerce_variation_options_pricing', 'bbloomer_add_custom_field_to_variations', 10, 3 ); 
// 2. Save custom field on product variation save
function bbloomer_save_custom_field_variations( $variation_id, $i ) {
    $custom_field = $_POST['custom_field'][$i];
    if ( ! empty( $custom_field ) ) {
        update_post_meta( $variation_id, 'custom_field', esc_attr( $custom_field ) );
    } else delete_post_meta( $variation_id, 'custom_field' );
}
add_action( 'woocommerce_save_product_variation', 'bbloomer_save_custom_field_variations', 10, 2 );
// 3. Store custom field value into variation data
function bbloomer_add_custom_field_variation_data( $variations ) {
    $variations['custom_field'] = '<div class="woocommerce_custom_field">Custom Field: <span>' . get_post_meta( $variations[ 'variation_id' ], 'custom_field', true ) . '</span></div>';
    return $variations;
}
add_filter( 'woocommerce_available_variation', 'bbloomer_add_custom_field_variation_data' );

So, How to display this newly added custom field and the existing SKU field under the product title on the front product page at the same time, and: when selecting different variants, the corresponding custom field and SKU field will also be displayed dynamically.

I tried but it doesn't show up below the title

Answer 1

The code from BBloomer is a bit outdated...

To display the selected variation custom field below the product title, use the following instead:

// Add custom field(s) to product variations from specific variable products
add_action( 'woocommerce_variation_options_pricing', 'add_variation_setting_fields', 10, 3 ); 
function add_variation_setting_fields( $loop, $variation_data, $variation ) {
    $field_key = 'custom_field';

    woocommerce_wp_text_input( array( 
        'id'            => $field_key.'['.$loop.']', 
        'label'         => __( 'Custom Field', 'woocommerce' ),
        'class'         => 'short', 
        'wrapper_class' => 'form-row',
        'value'         => get_post_meta( $variation->ID, $field_key, true )
    ) );      
}

// Save the custom field from product variations
add_action('woocommerce_admin_process_variation_object', 'save_variation_setting_fields', 10, 2 );
function save_variation_setting_fields($variation, $i) {
    $field_key = 'custom_field';

    if ( isset($_POST[$field_key][$i]) ) {
        $variation->update_meta_data($field_key, sanitize_text_field($_POST[$field_key][$i]));
    }
}

// Add the custom field value to the product form data
add_filter( 'woocommerce_available_variation', 'available_variation_custom_field_value', 10, 3 );
function available_variation_custom_field_value( $variation_data, $product, $variation ) {
    $variation_data['custom_field'] = $variation->get_meta('custom_field');
    return $variation_data;
}
    
// Display selected variation custom field below product title
add_action('woocommerce_single_product_summary', 'display_custom_field_below_product_title', 7 );
function display_custom_field_below_product_title() {
    global $product;

    if ( $product->is_type('variable') ) :

    wc_enqueue_js("$('form.variations_form').on('show_variation', function(event, data){
        if ( data.custom_field ) {
            $('.custom-field').html(data.custom_field).show();
        }
    }).on('hide_variation', function(){
        $('div.custom-field').hide().html('');
    });");

    echo '<div class="custom-field" style="display:none;"></div>';

    endif;
}

Code goes in functions.php file of your child theme (or in a plugin). Tested and works.