before destroy on associated model update, errors not propagating

Question

I have a parent model, that is being updated via params like '@client.update_attributes(params[:client]'. In my params is a call to destroy a 'client_card'. I have a before_destroy method on the client_card that prevents it from being destroyed etc. My before_destroy method is working, however, the errors on the before_destroy do not propagate to the related model when updated. Any advice on how to propagate this model error to the associated model when updated?

class Client < ActiveRecord::Base
  has_many :client_cards, :dependent => :destroy
  validates_associated :client_cards

class ClientCard < ActiveRecord::Base
  belongs_to :client, :foreign_key => 'client_id'

  attr_accessible :id, :client_id, :card_hash, :last_four, :exp_date

  before_destroy :check_relationships

  def check_finished_appointments
    appointments = Appointment.select { |a| a.client_card == self && !a.has_started }
    if(appointments && appointments.length > 0 )
      errors.add(:base, "This card is tied to an appointment that hasn't occurred yet.")
      return false
    else
      return true
    end
  end

end

Answer 1

I suspect that validates_associated is only running the explicitly-declared validations for ClientCard, and won't trigger off the errors you added in the before_destroy callback. Your best option might be a before_update callback on Client:

class Client < ActiveRecord::Base
  has_many :client_cards, :dependent => :destroy

  before_update :check_client_cards

  # stuff

  def check_client_cards
    if client_cards.any_future_appointments?
      errors.add(:base, "One or more client cards has a future appointment.")
    end
  end
end

Then on ClientCard:

class ClientCard < ActiveRecord::Base
  belongs_to :client, :foreign_key => 'client_id'

  # stuff

  def self.any_future_appointments?
    all.detect {|card| !card.check_finished_appointments }
  end
end