Hi @giu-tae-kim
I think you can use the acf/update_value filter or the acf/save_post action hooks to do it. Here’s the example how to do it with acf/update_value:
function my_acf_update_value( $value, $post_id, $field ) {
// only do it to certain custom fields
if( $field['name'] == 'custom_field_name' ) {
// get the old (saved) value
$old_value = get_field('custom_field_name', $post_id);
// get the new (posted) value
$new_value = $_POST['acf']['field_1234567890abc'];
// check if the old value is the same as the new value
if( $old_value != $new_value ) {
// Do something if they are different
} else {
// Do something if they are the same
}
}
// don't forget to return to be saved in the database
return $value;
}
// acf/update_value - filter for every field
add_filter('acf/update_value', 'my_acf_update_value', 10, 3);
Where ‘field_1234567890abc’ is the field key of your custom field(‘custom_field_name’ in this case).
I hope this helps 🙂
