Woocommerce 3.1 product variation meta data - wordpress

Question

I have currently added metadata to a product variation woocommerce_product_after_variable_attributes and woocommerce_save_product_variation Guide here.
function custom_woocommerce_product_after_variable_attributes($loop, $variation_data, $variation)
{
woocommerce_wp_select([
'id' => 'field_1['.absint($variation->ID).']',
'label' => 'Field 1 ',
'value' => get_post_meta(absint($variation->ID), 'field_1', true),
'options' => [
'1' => '1',
'2' => '2',
'3' => '3',
],
]);
}
add_action('woocommerce_product_after_variable_attributes', 'custom_woocommerce_product_after_variable_attributes', 10, 3);
function custom_woocommerce_save_product_variation($post_id)
{
$field1 = $_POST['field_1'][$post_id];
if (! empty($field1)) {
update_post_meta(absint($post_id), 'field_1', esc_html($field1));
}
}
add_action('woocommerce_save_product_variation', 'custom_woocommerce_save_product_variation', 10, 2);
Then in the js hooked into single_variation_wrap when the variation was changed. This was working fine in 3.0.5 but since updating to 3.1.1 in the js i am no longer getting the custom meta_data for variations.
$('.single_variation_wrap').on('show_variation', function(event, variation) {
console.log(variation.meta_data);
});
The meta_data information no longer exists.
How can this be fixed?

Answer 1

I was able to fix this by adding a filter.
function custom_woocommerce_available_variation($variations, $product, $variation)
{
$metadata = $variation->get_meta_data();
if (!empty($metadata)) {
$variations = array_merge($variations, [
'meta_data' => $metadata,
]);
}
return $variations;
}
add_filter('woocommerce_available_variation', 'custom_woocommerce_available_variation', 10, 3);