I’m wondering if its possible to unset a field (delete its value) when another field has a value entered?
http://www.advancedcustomfields.com/resources/acfsave_post/
add_action('acf/save_post', 'my_acf_save_post', 20);
function my_acf_save_post($post_id) {
$value get_post_meta($post_id, 'first_field_name', true);
if ($value) {
// delete the second value
delete_post_meta($post_id, 'second_field_name');
// delete the acf field key
delete_post_meta($post_id, '_second_field_name');
}
}