Display ACF custom field in WooCommerce product variations

Question

I successfully created a ACF custom field in WooCommerce within my product variations in the backend. The field is properly shown within each variation.

But after editing this or other fields within the variations I can't save the whole variations tab anymore . The loading/saving indicator circle continues to rotate indefinitely. And the custom field is not showing in the single product variation in frontend.

What I did, was to add the following code to my functions.php :

/* ACF filter for Variations */

// Render fields at the bottom of variations - does not account for field group order or placement.
$GLOBALS['wc_loop_variation_id'] = null;

function is_field_group_for_variation($field_group, $variation_data, $variation_post) {
    return (preg_match( '/Variation/i', $field_group['title'] ) == true);
}

add_action( 'woocommerce_product_after_variable_attributes', function( $loop_index, $variation_data, $variation_post ) {
        $GLOBALS['wc_loop_variation_id'] = $variation_post->ID;

        foreach ( acf_get_field_groups() as $field_group ) {
            if ( is_field_group_for_variation( $field_group, $variation_data, $variation_post ) ) {
                acf_render_fields( $variation_post->ID, acf_get_fields( $field_group ) );
            }
        }

        $GLOBALS['wc_loop_variation_id'] = null;
    }, 10, 3 );

add_action( 'woocommerce_save_product_variation', function( $variation_id, $loop_index ) {
        if ( !isset( $_POST['acf_variation'][$variation_id] ) ) {
            return;
        }

        $_POST['acf'] = $_POST['acf_variation'][$variation_id];

        acf()->input->save_post( $variation_id );
    }, 10, 2 );

add_filter( 'acf/prepare_field', function ( $field ) {
        if ( !$GLOBALS['wc_loop_variation_id'] ) {
            return $field;
        }

        $field['name'] = preg_replace( '/^acf\[/', 'acf_variation[' . $GLOBALS['wc_loop_variation_id'] . '][', $field['name'] );

        return $field;
    }, 10, 1);

//add ACF rule
add_filter('acf/location/rule_values/post_type', 'acf_location_rule_values_Post');
function acf_location_rule_values_Post( $choices ) {
    $choices['product_variation'] = 'Product Variation';
    //print_r($choices);
    return $choices;
}

/* End */

Any help would be appreciated.

Answer 1

acf()->input->save_post( $variation_id );

Should be

do_action( 'acf/save_post', $variation_id );

Credit to onoweb from here https://support.advancedcustomfields.com/forums/topic/acf-on-product-variations-almost-works/