Prevent users from changing entity data fundamentally
Entities in a database represent things from the real world (for example products in an e-commerce system). A user should be able to
- add a new entity
- edit the entity to correct a mistake in the DB
- edit the entity because the thing in the real world changed, too
However, the user should not edit the entity so that it now represents something else from the real world. What is the best way to accomplish this?
Example: the e-commerce store doesn't sell apples anymore, but now wants to sell oranges. So the user should not edit the apple-entity to become the orange-entity (the user might be inclined to do this to be more efficient). Instead, they should delete the apple and create a new orange.
Reason: In a system with unversioned entities, we don't want to end up with past orders that look like they were for oranges even though they were for apples. Or, in a system with versioned entities, we don't want the orange entity to look like it's been around for a long time even though it was just entered.
I've considered not allowing the user to edit the name of the entity, but that would prevent them from correcting spelling mistakes.
I've also considered testing programmatically when the user hits the save button, and if the changes seem drastic, to bring up a modal panel and ask the user if they shouldn't rather create a new entity instead. But I worry that false-positives from that test could be annoying and that there's still a risk of false-negatives. I'd much rather proactively prevent this kind of user behavior if there's an elegant way to accomplish this.
Yet another option would be to have two save buttons below the form, one "Update product" and the other "Save as new product" and have the user decide which to click. But I fear this would be clunky, could result in mistakes, and make it difficult to support save-by-clicking-enter in the form.