DataMapper ORM v1.8.0

[eluser]WanWizard[/eluser]
There is no set way of doing this, like there is no set of way of using CI's form validation.

Datamapper provides the validation errors as part of the object, either as an array to iterate over, directly accessable by fieldname, or as a pre-formatted string.

It it up to you how you translate this to the screen, as it will depend on your application design and your applications styling. Some have error messages as a list at the top of the content body, some besides or under every form field.