CI 2.1.0 form validation external callbacks via the newly available param

[eluser]theshiftexchange[/eluser]
[quote author="chenx" date="1334897650"]
Because we're using the function external_callback, the error message only return the error for external_callback.

How can I return the error message from each of my model function?
[/quote]

You always use the 'external_callback' error message - it will display the error for each of your models as needed