configuring username format in authlogic

Question

How can I configure username to only have alphabets (a-z, A-Z), numericals (0-9) and underscores (_) and no other characters...

Answer 1

validates_format_of :username, :with => /^[A-Za-z\d_]+$/

You can change that to be whatever you want, but just using normal rails validations seems appropriate. Above allows digits, A-Z, a-z, and underscores