Modify Devise to check for permission to register?

Question

My app has a Permission model and permissions table with an email field. Existing users (User model) can add the email addresses of people who they would like to invite to view their information. Those email addresses are stored in the permissions.email field in the database.

How do I go about modifying Devise's registration process so that it only allows people with an email address in the permissions table to create an account?

Answer 1

did this before with a validator on the user model; e.g.

validates :email, :my_access_control => true

and then create something like this

class MyAccessControlValidator < ActiveModel::EachValidator
  def validate_each(object, attribute, value)
    if ... not in permissions table.. 
      ... add to objects error collection why they cannot register
    end
  end
end