Rails 3.2 - Custom validator class on parent model, clashing with validates_associated :child_models

event.rb

# encoding: utf-8
class Event < ActiveRecord::Base
  include LocalizedTexts

  has_many :texts, :class_name => 'EventText', :dependent => :destroy, :inverse_of => :event

  validates_with MultiTextValidator
  validates_associated :texts
  
end

event_text.rb

#encoding: utf-8
class EventText < ActiveRecord::Base
  belongs_to :event, inverse_of: :texts

  validates_presence_of :title, :intro
  validate :pricing_details


  private

  def pricing_details
    unless event.free? ^ pricing.present?
      msg = pricing.present?() ? "error_message_1" : "error_message_2"
      errors[:pricing] << msg
    end
  end

end

MultiTextValidator

# encoding: UTF-8

# This validator checks common validation rules for all models having associated text models
class MultiTextValidator < ActiveModel::Validator

  cattr_reader :error_messages
  @@error_messages = {
      italian_missing: 'activemodel.errors.event.texts.italian_missing',
      non_unique_languages: 'activemodel.errors.event.texts.non_unique_languages',
  }

  def validate record
    italian_required record
    unique_languages record
  end


  private

  def italian_required record
    unless record.texts.find { |t| t.language == :it }
      message = I18n.t self.class.error_messages[:italian_missing]
      record.errors.add :base, message
      record.errors.add :texts, message
      record.texts.last.errors.add(:language, message) unless record.texts.empty?
    end
  end


  def unique_languages record
    languages = record.texts.map(&:language)
    return if languages.uniq.length == languages.length

    counts = {}
    languages.uniq.each { |l| counts[l] = ( record.texts.to_a.count {|text| text.language == l} ) }
    counts.delete_if { |k, v| v == 1 }
    non_unique_languages = counts.keys
    non_unique_languages.each do |lang|
      message = I18n.t(self.class.error_messages[:non_unique_languages], language: lang)
      record.errors.add :base, message
      record.texts.each do |t|
        t.errors.add(:language, message) if t.language == lang 
      end
    end
  end



# Association Reflection Fancyness
  def supported_languages record
    record.class.reflect_on_association(:texts).options[:class_name].constantize::LANGUAGES
  end

end