Changed the Hpricot search method

- If multiple values, returns them as a comma-separated string
- Returns nil if no value found

lib/amazon_product.rb

@@ -3,9 +3,10 @@
 class AmazonProduct < ActiveRecord::Base
 #  belongs_to :amazonable, :polymorphic => true
 
-  def hdoc(key)
+  def hdoc(key, separator = ', ')
     @doc ||= Hpricot.XML(xml)
-    @doc.at(key).inner_html
+    values = (@doc/key).collect {|e| e.inner_html } * separator
+    values unless values.blank?
   end
 
   def get(key)

test/acts_as_amazon_product_test.rb

@@ -105,6 +105,10 @@ def test_find_with_multiple
       assert_equal("Mike Clark", @book_ror.amazon.author)
     end
 
+    def test_returns_nil_if_attribute_not_found
+      assert_equal(nil, @book_ror.amazon.get('contributor'))
+    end
+
     def test_update
       assert_not_nil(@book_perl.amazon)
       isbn = @book_perl.amazon.isbn
@@ -115,6 +119,7 @@ def test_update
 
     def test_product_with_all_defaults
       assert_not_nil(@movie_dh.amazon)
-      assert_equal 'Bruce Willis', @movie_dh.amazon.get('itemattributes/actor')
+      assert_equal 'Bruce Willis, Timothy Olyphant, Justin Long, Maggie Q, Cliff Curtis',
+        @movie_dh.amazon.get('itemattributes/actor')
     end
 end