At this time there is not a hook that runs on the configure product page. This means that, if I need to externally validate a configuration option, I probably need to do it during the actual check-out process.
That being said, there is no documentation on how to actually handle a negative result for a hook. In fact, there's no documentation I see on how to handle a successful result, either. The sample code, hook_create_forum_account, doesn't document either. It seems to simply assume that all hooks execute successfully.
1) Does anyone know how to get information to the user during the various hook processes?
2) In the case of an error (for example, the hook PreShoppingCartCheckout), how would I get that error message to the user and re-direct them to the shopping cart (or, in my case, the configure product page) so that they can change their options?
That being said, there is no documentation on how to actually handle a negative result for a hook. In fact, there's no documentation I see on how to handle a successful result, either. The sample code, hook_create_forum_account, doesn't document either. It seems to simply assume that all hooks execute successfully.
1) Does anyone know how to get information to the user during the various hook processes?
2) In the case of an error (for example, the hook PreShoppingCartCheckout), how would I get that error message to the user and re-direct them to the shopping cart (or, in my case, the configure product page) so that they can change their options?