Get ID of Rails Model before saving…?

Question

How do you get the id of a rails model before it is saved?

For example, if I create a new model instance, how can I get its ID before it is saved?

I know t

Answer 1

I know it's an old question, but might as well throw my answer in case anyone needs to reference it

UserModel

class User < ActiveRecord::Base
before_create :set_default_value

def set_default_value
   self.value ||= "#{User.last.id+1}"
end