class Champs::DecimalNumberChamp < Champ validates :value, numericality: { allow_nil: true, allow_blank: true, message: -> (object, _data) { "« #{object.libelle} » " + object.errors.generate_message(:value, :not_a_number) } } def for_export processed_value end def for_api processed_value end private def processed_value value&.to_f end end