Fixed product matching and updated readme for promotions

README.md

@@ -42,7 +42,9 @@ You can access all related products regardless of RelationType by:
 Discounts
 You can optionally specify a discount amount to be applied if a customer purchases both products.
 
-Note: In order for the coupon to be automatically applied, you must create a promotion leaving the __code__ value empty, and adding an Action of type : __RelatedProductDiscount__  (blank codes are required for coupons to be automatically applied).
+Note: In order for the coupon to be automatically applied, you must create a promotion and add a "Create adjustment" action with a __Related Product Discount__ calculator.  You should be able to add any other criteria or actions that you want as well.  If you don't add any rules, it should be applied to all orders w/ matching products.
+
+Note: Item Total Threshold is NOT implemented
 
 Installation
 ------------

app/controllers/spree/admin/relations_controller.rb

@@ -3,7 +3,7 @@ module Admin
 		class RelationsController < BaseController
 		  before_filter :load_data, :only => [:create, :destroy]
 
-		  respond_to :js
+		  respond_to :js, :html
 
 		  def create
 		    @relation = Relation.new(params[:relation])
@@ -14,6 +14,13 @@ def create
 		    respond_with(@relation)
 		  end
 
+		  def update
+		    @relation = Relation.find(params[:id])
+		    @relation.update_attribute :discount_amount, params[:relation][:discount_amount] || 0
+
+		    redirect_to( related_admin_product_url(@relation.relatable) )
+		  end
+
 		  def destroy
 		    @relation = Relation.find(params[:id])
 		    @relation.destroy

app/models/spree/calculator/related_product_discount.rb

@@ -14,32 +14,38 @@ def compute(object)
         order = object
       end
 
-      return unless eligible?(order)
-      total = order.line_items.inject(0) do |total, line_item|
-        relations =  Spree::Relation.find(:all, :conditions => ["discount_amount <> 0.0 AND relatable_type = ? AND relatable_id = ?", "Spree::Product", line_item.variant.product.id])
-        discount_applies_to = relations.map {|rel| rel.related_to.master }
-
-        order.line_items.each do |li|
-          if discount_applies_to.include? li.variant
-            discount = relations.detect {|rel| rel.related_to.master == li.variant}.discount_amount
-
-            total += if li.quantity < line_item.quantity
-              (discount * li.quantity)
-            else
-              (discount * line_item.quantity)
-            end
+      # related_to is the one that gets the discount
+      product_ids = order.line_items.map{|i| i.variant.product_id}.uniq
+      discounts = Spree::Relation.where(["discount_amount <> 0.0 AND related_to_type = ? AND related_to_id IN (?)", "Spree::Product", product_ids]).all.group_by(&:related_to_id)
+      return if discounts.empty?
+
+      total = 0
+      order.line_items.each do |line_item|
+        relations_for_line_item = discounts[line_item.variant.product_id]
+        next if relations_for_line_item.blank?
+
+        discount_percent = 0
+        relations_for_line_item.each do |relation_for_line_item|
+          if product_ids.include?( relation_for_line_item.relatable_id )
+            # Apply the maximum available discount percentage
+            discount_percent = [discount_percent,
+                                relation_for_line_item.discount_amount].max
           end
         end
-
-        total
+        discount = ((line_item.price * discount_percent / 100.0) * line_item.quantity).round(2)
+        if line_item.respond_to?(:discount_percent)
+          line_item.update_column( :discount_percent, discount_percent )
+        end
+        total += discount
       end
 
       total == 0 ? nil : total
     end
 
     def eligible?(order)
-      order.line_items.any? { |line_item| Spree::Relation.exists?(["discount_amount <> 0.0 AND relatable_type = ? AND relatable_id = ?", "Spree::Product", line_item.variant.product.id])}
+      product_ids = order.line_items.map{|i| i.variant.product_id}.uniq
+      Spree::Relation.where(["discount_amount <> 0.0 AND related_to_type = ? AND related_to_id IN (?)", "Spree::Product", product_ids]).exists?
     end
 
   end
-end
+end

app/models/spree/product_decorator.rb

@@ -1,5 +1,6 @@
 Spree::Product.class_eval do
   has_many :relations, :as => :relatable
+  has_many :related_tos, :as => :related_to, :class_name => 'Relation'
 
   # Returns all the Spree::RelationType's which apply_to this class.
   def self.relation_types

app/models/spree/relation.rb

@@ -4,4 +4,5 @@ class Spree::Relation < ActiveRecord::Base
   belongs_to :related_to, :polymorphic => true
 
   validates_presence_of :relation_type, :relatable, :related_to
+  validates_inclusion_of :discount_amount, :in => 0..100
 end

app/views/spree/admin/products/_related_products_table.html.erb

@@ -10,8 +10,9 @@
   <tbody>
     <% product.relations.each do |relation| %>
       <tr id="<%= dom_id relation %>">
-        <td><%= relation.related_to.name %></td>
-        <td><%= relation.discount_amount != 0 ? number_to_currency(relation.discount_amount) : "-" %></td>
+        <td><%= link_to relation.related_to.name, relation.related_to %></td>
+        <td><%= form_for(relation, url:admin_product_relation_path(relation.relatable, relation)) do |f| %>
+           <%= f.text_field :discount_amount, :size => 4 %>% &nbsp; <%= f.submit 'Update' %> <% end %></td>
         <td><%= relation.relation_type.name %></td>
         <td width="70px">
           <%= link_to_delete relation, {:url => admin_product_relation_url(relation.relatable, relation)} %>

config/locales/en.yml

@@ -1,12 +1,12 @@
 en:
   new_relation_type: New Relation Type
-  discount_amount: Discount Amount
-  related_product_discount: Related Product Discount
+  discount_amount: Discount %
+  related_product_discount: Matching Product Discount
   relation_types: Relation Types
   applies_to: Applies To
   editing_relation_type: Editing Relation Type
-  related_products: Related Products
-  add_related_product: Add Related Product
+  related_products: Matching Products
+  add_related_product: Add Matching Product
   name_or_sku: Name or SKU
   manage_relation_types: Manage relation types
   no_relation_types: You need to configure Relation Types before you can use this feature.

spree_related_products.gemspec

@@ -17,8 +17,8 @@ Gem::Specification.new do |s|
 
   s.has_rdoc = true
 
-  s.add_dependency 'spree_core', '~> 1.0.0'
-  s.add_dependency 'spree_promo', '~> 1.0.0'
+  s.add_dependency 'spree_core', '>= 1.0.0'
+  s.add_dependency 'spree_promo', '>= 1.0.0'
 
   s.add_development_dependency 'factory_girl'
   s.add_development_dependency 'rspec-rails',  ' ~> 2.8.0.rc1'