Subclasses support

lib/active_resource/base.rb

@@ -998,12 +998,15 @@ def instantiate_collection(collection, original_params = {}, prefix_options = {}
         end
 
         def instantiate_record(record, prefix_options = {})
-          new(record, true).tap do |resource|
+          instance_klass = self
+          if defined?(self::SUBCLASSES) && self::SUBCLASSES.include?(record["type"])
+            instance_klass = record["type"].constantize
+          end
+          instance_klass.new(record, true).tap do |resource|
             resource.prefix_options = prefix_options
           end
         end
 
-
         # Accepts a URI and creates the site URI from that.
         def create_site_uri_from(site)
           site.is_a?(URI) ? site.dup : URI.parse(site)

test/fixtures/product.rb

@@ -1,3 +1,4 @@
 class Product < ActiveResource::Base
   self.site = 'http://37s.sunrise.i:3000'
+  SUBCLASSES = ["SubProduct"]
 end

test/fixtures/sub_product.rb

@@ -0,0 +1,2 @@
+class SubProduct < Product
+end

test/singleton_test.rb

@@ -1,6 +1,8 @@
 require 'abstract_unit'
 require 'fixtures/weather'
 require 'fixtures/inventory'
+require 'fixtures/product'
+require 'fixtures/sub_product'
 
 class SingletonTest < ActiveSupport::TestCase
   def setup_weather
@@ -59,6 +61,16 @@ def test_singleton_path_with_parameters
     assert_equal '/products/5/inventory.json?sold=true', path
   end
 
+  def test_subclass_instantiation
+    product  = { :id => 1, :type => "SubProduct" }
+    ActiveResource::HttpMock.respond_to do |mock|
+      mock.get    '/products/1.json', {}, product.to_json
+    end
+    sub_product = Product.find 1
+    assert_not_nil sub_product
+    assert_equal 'SubProduct', sub_product.class.name
+  end
+
   def test_find_singleton
     setup_weather
     weather = Weather.send(:find_singleton, Hash.new)