Devise Configuration options

1. Database Authenticatable: encrypts and stores a password in the database to validate the authenticity of an user while signing in. The authentication can be done both through POST requests or HTTP Basic Authentication.
2. Token Authenticatable: signs in an user based on an authentication token (also known as “single access token”). The token can be given both through query string or HTTP Basic Authentication.
3. Oauthable: adds OAuth2 support
4. Confirmable: sends emails with confirmation instructions and verifies whether an account is already confirmed during sign in.
5. Recoverable: resets the user password and sends reset instructions.
6. Registerable: handles signing up users through a registration process, also allowing them to edit and destroy their account.
7. Rememberable: manages generating and clearing a token for remembering the user from a saved cookie.
8. Trackable: tracks sign in count, timestamps and IP address.
9. Timeoutable: expires sessions that have no activity in a specified period of time.
10. Validatable: provides validations of email and password. It’s optional and can be customized, so you’re able to define your own validations.
11. Lockable: locks an account after a specified number of failed sign-in attempts. Can unlock via email or after a specified time period.

Configuration is done using the devise statement in the User class (and subclasses).

Example: Use Confirmable and Validatable devise options/strategies

class User
  devise :confirmable, :validatable
end

Note: For Active Record your User table (via migration fx) must support the columns needed for the devise options you are using (See Devise documentation).