From 258559f9d0d17fc2ab357e884cc4fad5a88cd179 Mon Sep 17 00:00:00 2001
From: Rohan Mitchell <rohan@rohanmitchell.com>
Date: Sun, 1 Jul 2012 10:07:08 +1000
Subject: [PATCH] Update the price on the product details page in real time
 when the variant or the quantity are changed

---
 app/assets/javascripts/store/products.js      | 38 +++++++++++++++++++
 .../spree/products_helper_decorator.rb        |  3 +-
 spec/helpers/products_helper_spec.rb          |  2 +-
 3 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 app/assets/javascripts/store/products.js

diff --git a/app/assets/javascripts/store/products.js b/app/assets/javascripts/store/products.js
new file mode 100644
index 0000000000..ccf5293bf4
--- /dev/null
+++ b/app/assets/javascripts/store/products.js
@@ -0,0 +1,38 @@
+/**
+ * Update the price on the product details page in real time when the variant or the quantity are changed.
+ **/
+
+$(document).ready(function() {
+  // Product page with variant choice
+  $("#product-variants input[type='radio']").change(products_update_price_with_variant);
+  $("#quantity").change(products_update_price_with_variant);
+  $("#quantity").change();
+
+  // Product page with master price only
+  $(".add-to-cart input.title:not(#quantity)").change(products_update_price_without_variant).change();
+});
+
+
+function products_update_price_with_variant() {
+  var variant_price = $("#product-variants input[type='radio']:checked").parent().find("span.price").html();
+  variant_price = variant_price.substr(2, variant_price.length-3);
+
+  var quantity = $("#quantity").val();
+
+  $("#product-price span.price").html("$"+(parseFloat(variant_price) * parseInt(quantity)).toFixed(2));
+}
+
+
+function products_update_price_without_variant() {
+  var master_price = $("#product-price span.price").data('master-price');
+  if(master_price == null) {
+    // Store off the master price
+    master_price = $("#product-price span.price").html();
+    master_price = master_price.substr(1, master_price.length-2);
+    $("#product-price span.price").data('master-price', master_price);
+  }
+
+  var quantity = $(this).val();
+
+  $("#product-price span.price").html("$"+(parseFloat(master_price)*parseInt(quantity)).toFixed(2));
+}
diff --git a/app/helpers/spree/products_helper_decorator.rb b/app/helpers/spree/products_helper_decorator.rb
index 7c17b71a36..8c7b7fbe54 100644
--- a/app/helpers/spree/products_helper_decorator.rb
+++ b/app/helpers/spree/products_helper_decorator.rb
@@ -1,8 +1,7 @@
 module Spree
   ProductsHelper.class_eval do
-    # Return the price of the variant, or nil if it is identical to the master price
+    # Return the price of the variant
     def variant_price_diff(variant)
-      return nil if variant.price == variant.product.price
       "(#{number_to_currency variant.price})"
     end
   end
diff --git a/spec/helpers/products_helper_spec.rb b/spec/helpers/products_helper_spec.rb
index bc55cc208d..a6e16bab55 100644
--- a/spec/helpers/products_helper_spec.rb
+++ b/spec/helpers/products_helper_spec.rb
@@ -11,7 +11,7 @@ module Spree
 
     it "displays variant price differences as absolute, not relative values" do
       variant = make_variant_stub(10.00, 10.00)
-      subject.variant_price_diff(variant).should be_nil
+      subject.variant_price_diff(variant).should == "($10.00)"
 
       variant = make_variant_stub(10.00, 15.55)
       subject.variant_price_diff(variant).should == "($15.55)"