Globalize gem uniqueness validation

translation_uniqueness_validator.rb

# Usage in model:
#
# validates :title, translation_uniqueness: true # will assume it must be uniq across all languages
# validates :title, translation_uniqueness: {scope: :locale, message: ''}
#
class TranslationUniquenessValidator < ActiveModel::EachValidator

  def validate_each(record, attribute, value)
    record.translations.each do |t|

      if options[:scope] == :locale
        records = t.class.where("locale = '#{t.locale.to_s}' AND #{attribute} = '#{t[attribute]}'")
      else
        records = t.class.where("#{attribute} = '#{t[attribute]}'")
      end

      # on create
      if record.id.nil?
        record.errors.add("#{attribute}_#{t.locale}", options[:message] || :uniqueness) unless records.count.zero?
      end

      # on update
      unless record.id.nil?
        if records.count > 0 && !records.pluck(:city_id).include?(record.id)
          record.errors.add("#{attribute}_#{t.locale}", options[:message] || :uniqueness)
        end
      end
    end
  end

end