UniqueTokenValidator Concern

unique_token_validator.rb

module UniqueTokenValidator
  extend ActiveSupport::Concern

  included do
    validates :unique_token, uniqueness: true, allow_nil: true
    before_validation :generate_unique_token
  end

  def generate_unique_token
    if !self.class::UNIQUE_FIELDS[:condition].present? ||
       self.class::UNIQUE_FIELDS[:condition].call(self)
      self.unique_token = Digest::SHA1.hexdigest(
        self.class::UNIQUE_FIELDS.except(:condition).values.flatten.map { |k| send(k).to_s }.join
      )
    end
  end
end