class Champs::IntegerNumberChamp < Champ before_validation :format_value validates :value, numericality: { only_integer: true, allow_nil: true, allow_blank: true, message: -> (object, _data) { # i18n-tasks-use t('errors.messages.not_an_integer') object.errors.generate_message(:value, :not_an_integer) } }, if: :validate_champ_value_or_prefill? def format_value return if value.blank? self.value = value.gsub(/[[:space:]]/, "") end end