fuel/core — pull request #626 by kapv89 (2011-10-29 21:51:41+00:00)
Title: Update classes/validation.php so that the validation rule 'valid_string' can also be added via piped strings

This allows you to do stuff like
$val->add_field('password', 'Your password', 'required|min_length[3]|max_length[10]|valid_string[alpha,numeric,dashes,dots]');