(As discovered here: nathanhornby/hashid_field#31)
At the moment, the field value is saved/updated:
- when an entry is created or edited in the backend
- when an entry is created from the frontend
It is not updated, however, when the entry is edited from the frontend.
This is a conceptual flaw. The idea of "registering" a field in the checkPostFieldData function doesn't work as expected, because Symphony won't call this function for fields that are not included in the POST data (if an entry is edited, i.e. existing).
I do not actively use the Reflectionfield, but I might send a PR if someone is willing to test it!