Spree promotion rule for properties

_property.html.erb

<!-- admin/promotions/rules/_property.html.erb -->
<div class="panel-body">
  <div class="form-group property_rule_property_id">
    <%= label_tag "#{param_prefix}_property_id_string", Spree.t('property_rule.choose_property') %>
    <%= select_tag "#{param_prefix}[preferred_property_id]", options_from_collection_for_select(Spree::Property.all, "id", "presentation", promotion_rule.preferred_property_id), class: 'select2' %>
    <%= label_tag "#{param_prefix}_value_string", Spree.t('property_rule.insert_value') %>
    <%= text_field_tag "#{param_prefix}[preferred_value]", promotion_rule.preferred_value, class: 'form-control' %>
  </div>
</div>

es.yml

# config/locales/es.yml
es:
  spree:
    promotion_rule_types:
      property:
        description: La orden incluye productos específicos con las propiedades correspondientes
        name: Propiedades
    property_rule:
      choose_property: Seleccione propiedad
      insert_value: Escriba valor para propiedad (nombre autor o editorial)
      label: Orden debe contener una cantidad x de estas categorías

property.rb

module Spree
  class Promotion
    module Rules
      class Property < Spree::PromotionRule
        preference :property_id, :integer
        preference :value, :string

        def applicable?(promotable)
          promotable.is_a?(Spree::Order)
        end

        def eligible?(order, options = {})
          order.line_items.any? { |item| actionable?(item) }
        end

        def actionable?(line_item)
          property = Spree::Property.find(preferred_property_id)
          line_item.product.property(property.name).downcase == preferred_value.downcase
        end
      end
    end
  end
end