Add our own SuppliedProduct with custom property

engines/dfc_provider/app/services/dfc_io.rb

@@ -1,8 +1,5 @@
 # frozen_string_literal: true
 
-# Load our monkey-patches:
-require "data_food_consortium/connector/connector"
-
 # Our interface to the DFC Connector library.
 module DfcIo
   # Serialise DFC Connector subjects as JSON-LD string.

engines/dfc_provider/app/services/dfc_loader.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require "data_food_consortium/connector/connector"
-
 class DfcLoader
   def self.connector
     @connector ||= load_vocabularies

engines/dfc_provider/app/services/supplied_product_builder.rb

@@ -7,17 +7,14 @@ class SuppliedProductBuilder < DfcBuilder
       id: variant.id,
     )
 
-    DataFoodConsortium::Connector::SuppliedProduct.new(
+    DfcProvider::SuppliedProduct.new(
       id,
       name: variant.name_to_display,
       description: variant.description,
       productType: product_type,
       quantity: QuantitativeValueBuilder.quantity(variant),
-    ).tap do |supplied_product|
-      supplied_product.registerSemanticProperty("ofn:spree_product_id") do
-        variant.product.id
-      end
-    end
+      spree_product_id: variant.product.id,
+    )
   end
 
   def self.import(supplied_product)

engines/dfc_provider/lib/dfc_provider.rb

@@ -1,6 +1,13 @@
 # frozen_string_literal: true
 
+# Load our monkey-patches of the DFC Connector:
+require "data_food_consortium/connector/connector"
+
+# Our Rails engine
 require "dfc_provider/engine"
 
+# Custom data types
+require "dfc_provider/supplied_product"
+
 module DfcProvider
 end

engines/dfc_provider/lib/dfc_provider/supplied_product.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module DfcProvider
+  class SuppliedProduct < DataFoodConsortium::Connector::SuppliedProduct
+    attr_accessor :spree_product_id
+
+    def initialize(semantic_id, spree_product_id: nil, **properties)
+      super(semantic_id, **properties)
+
+      self.spree_product_id = spree_product_id
+
+      registerSemanticProperty("ofn:spree_product_id") do
+        self.spree_product_id
+      end
+    end
+  end
+end