validate :full_name_length

  def full_name
    [forename, surname].compact.join(' ')
  end

  def full_name=(full_name_str)
    name_arr = full_name_str.split(' ',2)
    self.forename = name_arr.first
    self.surname = name_arr.last
  end
    
  private

  def full_name_length
    errors.add(:full_name, 'is not correct') if full_name.split(' ',2).length != 2
  end