has_many associations respect nested resources

lib/active_resource/associations.rb

@@ -130,16 +130,22 @@ def defines_belongs_to_finder_method(method_name, association_model, finder_key)
     end
   end
 
+  # Defines the has_many finder method
   def defines_has_many_finder_method(method_name, association_model)
     ivar_name = :"@#{method_name}"
 
+    if method_defined?(method_name)
+      instance_variable_set(ivar_name, nil)
+      remove_method(method_name)
+    end
+
     define_method(method_name) do
       if instance_variable_defined?(ivar_name)
         instance_variable_get(ivar_name)
       elsif attributes.include?(method_name)
         attributes[method_name]
       else
-        instance_variable_set(ivar_name, association_model.find(:all, :params => {:"#{self.class.element_name}_id" => self.id}))
+        instance_variable_set(ivar_name, association_model.find(:all, :from => "#{element_base_path}/#{method_name}.#{association_model.format.extension}"))
       end
     end
   end

lib/active_resource/base.rb

@@ -685,10 +685,35 @@ def prefix(options={}) "#{prefix_call}" end
       #   # => /posts/5/comments/1.json?active=1
       #
       def element_path(id, prefix_options = {}, query_options = nil)
-        check_prefix_options(prefix_options)
-
         prefix_options, query_options = split_options(prefix_options) if query_options.nil?
-        "#{prefix(prefix_options)}#{collection_name}/#{URI.parser.escape id.to_s}.#{format.extension}#{query_string(query_options)}"
+        "#{element_base_path(id, prefix_options)}.#{format.extension}#{query_string(query_options)}"
+      end
+
+      # Gets the element base path for the given ID in +id+. This will never return a format extension or params,
+      # it is useful for building prefix paths. See <tt>element_path</tt> if you need format extensions and params.
+      #
+      # ==== Options
+      # +prefix_options+ - A \hash to add a \prefix to the request for nested URLs (e.g., <tt>:account_id => 19</tt>
+      #                    would yield a URL like <tt>/accounts/19</tt>).
+      #
+      # ==== Examples
+      #   Class Post < ActiveResource::Base
+      #     self.site = "https://37s.sunrise.com/api"
+      #   end
+      #
+      #   Post.element_base_path(1)
+      #   # => /api/posts/1
+      #
+      #   class Comment < ActiveResource::Base
+      #     self.site = "https://37s.sunrise.com/api/posts/:post_id"
+      #   end
+      #
+      #   Comment.element_base_path(1, :post_id => 5)
+      #   # => /api/posts/5/comments/1
+      #
+      def element_base_path(id, prefix_options = {})
+        check_prefix_options(prefix_options)
+        "#{prefix(prefix_options)}#{collection_name}/#{URI.parser.escape id.to_s}"
       end
 
       # Gets the new element path for REST resources.
@@ -1423,6 +1448,10 @@ def id_from_response(response)
       def element_path(options = nil)
         self.class.element_path(to_param, options || prefix_options)
       end
+
+      def element_base_path(options = nil)
+        self.class.element_base_path(to_param, options || prefix_options)
+      end
 
       def new_element_path
         self.class.new_element_path(prefix_options)

test/abstract_unit.rb

@@ -27,8 +27,10 @@ def setup_response
   @people_david = { :people => [ { :person => { :id => 2, :name => 'David' } }] }.to_json
   @addresses = { :addresses => [{ :address => { :id => 1, :street => '12345 Street', :country => 'Australia' } }] }.to_json
   @post  = {:id => 1, :title => 'Hello World', :body => 'Lorem Ipsum'}.to_json
+  @post_two  = {:id => 2, :title => 'Hello World', :body => 'Lorem Ipsum'}.to_json
   @posts = [{:id => 1, :title => 'Hello World', :body => 'Lorem Ipsum'},{:id => 2, :title => 'Second Post', :body => 'Lorem Ipsum'}].to_json
   @comments = [{:id => 1, :post_id => 1, :content => 'Interesting post'},{:id => 2, :post_id => 1, :content => 'I agree'}].to_json
+  @comments_two = [{:id => 3, :post_id => 2, :content => 'Interesting post'},{:id => 4, :post_id => 2, :content => 'I agree'}].to_json
 
   # - deep nested resource -
   # - Luis (Customer)
@@ -148,6 +150,8 @@ def setup_response
     mock.get    "/posts.json",                   {}, @posts
     mock.get    "/posts/1.json",                 {}, @post
     mock.get    "/posts/1/comments.json",        {}, @comments
+    mock.get    "/api/posts/2.json",             {}, @post_two
+    mock.get    "/api/posts/2/comments.json",    {}, @comments_two
     # products
     mock.get '/products/1.json', {}, @product
     mock.get '/products/1/inventory.json', {}, @inventory

test/cases/base_test.rb

@@ -1134,6 +1134,29 @@ def test_parse_resources_with_has_many_makes_get_request_on_nested_route
     end
   end
 
+  def test_parse_resources_with_has_many_infers_association_prefix
+    Post.send(:has_many, :comments)
+    post = Post.find(1)
+    post.comments.each do |comment|
+      assert_kind_of Comment, comment
+    end
+  end
+
+  def test_has_many_honors_prefix
+    c_prefix = Comment.prefix
+    p_prefix = Post.prefix
+    Comment.prefix = "/api/"
+    Post.prefix = "/api/"
+    Post.send(:has_many, :comments)
+    post = Post.find(2)
+    post.comments.each do |comment|
+      assert_kind_of Comment, comment
+    end
+  ensure
+    Comment.prefix = c_prefix
+    Post.prefix = p_prefix
+  end
+
   def test_parse_resource_with_has_one_makes_get_request_on_child_route
     Product.send(:has_one, :inventory)
     product = Product.find(1)