Question

I have a “user” model that “has_one” “membership” (active at a time). For auditing and data integrity reasons, I’d like it so that if the membership changes for a user, the old/current record (if existing) has an inactive/active flag swapped, and a new row is added for the new changed record. If there are no changes to the membership, I’d like to just ignore the update. I’ve tried implementing this with a “before_save” call-back on my user model, but have failed many times. Any help is greatly appreciated.

models:

class User < ActiveRecord::Base
  has_one :membership, :dependent => :destroy
  accepts_nested_attributes_for :membership, :allow_destroy => true  
end

class Membership < ActiveRecord::Base
  default_scope :conditions => {:active => 1}
  belongs_to :user
end

Answer 1

Got it working. While it’s probably not the best implementation, all my tests are passing. Thanks for the input guys.

---

  before_save :soft_delete_changed_membership

  def soft_delete_changed_membership
    if !membership.nil? then
      if !membership.new_record? && membership.trial_expire_at_changed? then
        Membership.update_all( "active = 0", [ "id = ?", self.membership.id ] )
        trial_expire_at = self.membership.trial_expire_at
        self.membership = nil
        Membership.create!( 
          :user_id => self.id, 
          :trial_expire_at => trial_expire_at, 
          :active => true 
        )
        self.reload
      end
    end
  end