Remove shipping method field from product distributions

app/controllers/spree/admin/shipping_methods_controller_decorator.rb

@@ -3,19 +3,18 @@ module Spree
     ShippingMethodsController.class_eval do
       before_filter :do_not_destroy_referenced_shipping_methods, :only => :destroy
 
+      # This method was originally written because ProductDistributions referenced shipping
+      # methods, and deleting a referenced shipping method would break all the reports that
+      # queried it.
+      # This has changed, and now all we're protecting is Orders, which is a spree resource.
+      # Do we really need to protect it ourselves? Does spree do this, or provide some means
+      # of preserving the shipping method information for past orders?
       def do_not_destroy_referenced_shipping_methods
         order = Order.where(:shipping_method_id => @object).first
         if order
           flash[:error] = "That shipping method cannot be deleted as it is referenced by an order: #{order.number}."
           redirect_to collection_url and return
         end
-
-        product_distribution = ProductDistribution.where(:shipping_method_id => @object).first
-        if product_distribution
-          p = product_distribution.product
-          flash[:error] = "That shipping method cannot be deleted as it is referenced by a product distribution: #{p.id} - #{p.name}."
-          redirect_to collection_url and return
-        end
       end
     end
   end

app/models/product_distribution.rb

@@ -1,7 +1,6 @@
 class ProductDistribution < ActiveRecord::Base
   belongs_to :product, :class_name => 'Spree::Product'
   belongs_to :distributor, :class_name => 'Enterprise'
-  belongs_to :shipping_method, :class_name => 'Spree::ShippingMethod'
   belongs_to :enterprise_fee
 
   validates_presence_of :product_id, :on => :update

db/migrate/20130812233634_remove_shipping_method_from_product_distribution.rb

@@ -0,0 +1,9 @@
+class RemoveShippingMethodFromProductDistribution < ActiveRecord::Migration
+  def up
+    remove_column :product_distributions, :shipping_method_id
+  end
+
+  def down
+    add_column :product_distributions, :shipping_method_id, :integer
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20130809075103) do
+ActiveRecord::Schema.define(:version => 20130812233634) do
 
   create_table "adjustment_metadata", :force => true do |t|
     t.integer "adjustment_id"
@@ -229,7 +229,6 @@ ActiveRecord::Schema.define(:version => 20130809075103) do
   create_table "product_distributions", :force => true do |t|
     t.integer  "product_id"
     t.integer  "distributor_id"
-    t.integer  "shipping_method_id"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "enterprise_fee_id"

spec/lib/open_food_web/group_buy_report_spec.rb

@@ -13,8 +13,7 @@ module OpenFoodWeb
       @variant1 = create(:variant)
       @variant1.product.supplier = @supplier1
       @variant1.product.save!
-      shipping_method = create(:shipping_method)
-      product_distribution = create(:product_distribution, :product => @variant1.product, :distributor => distributor, :shipping_method => create(:shipping_method))
+      product_distribution = create(:product_distribution, :product => @variant1.product, :distributor => distributor)
       shipping_instructions = "pick up on thursday please!"
 
       order1 = create(:order, :distributor => distributor, :bill_address => bill_address, :special_instructions => shipping_instructions)
@@ -29,7 +28,7 @@ module OpenFoodWeb
       @variant2 = create(:variant)
       @variant2.product.supplier = @supplier1
       @variant2.product.save!
-      product_distribution = create(:product_distribution, :product => @variant2.product, :distributor => distributor, :shipping_method => create(:shipping_method))
+      product_distribution = create(:product_distribution, :product => @variant2.product, :distributor => distributor)
 
       line_item22 = create(:line_item, :variant => @variant2, :order => order2)
       order2.line_items << line_item22
@@ -39,7 +38,7 @@ module OpenFoodWeb
       @variant3 = create(:variant, :weight => nil)
       @variant3.product.supplier = @supplier2
       @variant3.product.save!
-      product_distribution = create(:product_distribution, :product => @variant3.product, :distributor => distributor, :shipping_method => create(:shipping_method))
+      product_distribution = create(:product_distribution, :product => @variant3.product, :distributor => distributor)
 
       order3 = create(:order, :distributor => distributor, :bill_address => bill_address, :special_instructions => shipping_instructions)
       line_item31 = create(:line_item, :variant => @variant3, :order => order3)

spec/lib/open_food_web/order_and_distributor_report_spec.rb

@@ -11,7 +11,7 @@ module OpenFoodWeb
         @distributor_address = create(:address, :address1 => "distributor address", :city => 'The Shire', :zipcode => "1234")
         @distributor = create(:distributor_enterprise, :address => @distributor_address)
         product = create(:product)
-        product_distribution = create(:product_distribution, :product => product, :distributor => @distributor, :shipping_method => create(:shipping_method))
+        product_distribution = create(:product_distribution, :product => product, :distributor => @distributor)
         @shipping_instructions = "pick up on thursday please!"
         @order = create(:order, :distributor => @distributor, :bill_address => @bill_address, :special_instructions => @shipping_instructions)
         @payment_method = create(:payment_method)