Question

I am using Devise for authentication in my application.

How do I forbid certain users from signing in – kind of disable a user?

Answer 1

Do it like this:

Create a column called is_active for the User model.

Then add the code below to the User model:

class User < ActiveRecord::Base
  #this method is called by devise to check for "active" state of the model
  def active_for_authentication?
    #remember to call the super
    #then put our own check to determine "active" state using 
    #our own "is_active" column
    super and self.is_active?
  end
end

UPDATE

As Matt Huggins notes, the method is now called active_for_authentication? (Documentation)