From a157b65fbf4122bea3433d132f89090a9ef7e31c Mon Sep 17 00:00:00 2001
From: Ryan Bates <ryan@railscasts.com>
Date: Fri, 6 Aug 2010 09:35:07 -0700
Subject: [PATCH] adding :instance_name option to load/authorize_resource -
 closes #44

---
 lib/cancan/controller_resource.rb       | 8 ++++++--
 spec/cancan/controller_resource_spec.rb | 9 +++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/lib/cancan/controller_resource.rb b/lib/cancan/controller_resource.rb
index 39502cd..1b8a337 100644
--- a/lib/cancan/controller_resource.rb
+++ b/lib/cancan/controller_resource.rb
@@ -25,7 +25,7 @@ module CanCan
 
     def load_resource
       if !resource_instance && (parent? || member_action?)
-        @controller.instance_variable_set("@#{name}", load_resource_instance)
+        @controller.instance_variable_set("@#{instance_name}", load_resource_instance)
       end
     end
 
@@ -72,7 +72,7 @@ module CanCan
     end
 
     def resource_instance
-      @controller.instance_variable_get("@#{name}")
+      @controller.instance_variable_get("@#{instance_name}")
     end
 
     # The object that methods (such as "find", "new" or "build") are called on.
@@ -94,6 +94,10 @@ module CanCan
       @params[:controller].sub("Controller", "").underscore.split('/').last.singularize
     end
 
+    def instance_name
+      @options[:instance_name] || name
+    end
+
     def collection_actions
       [:index] + [@options[:collection]].flatten
     end
diff --git a/spec/cancan/controller_resource_spec.rb b/spec/cancan/controller_resource_spec.rb
index 1fd670c..6ea5895 100644
--- a/spec/cancan/controller_resource_spec.rb
+++ b/spec/cancan/controller_resource_spec.rb
@@ -179,6 +179,15 @@ describe CanCan::ControllerResource do
     lambda { resource.authorize_resource }.should raise_error(CanCan::AccessDenied)
   end
 
+  it "should load and authorize using custom instance name" do
+    @params.merge!(:action => "show", :id => 123)
+    stub(Ability).find(123) { :some_ability }
+    stub(@controller).authorize!(:show, :some_ability) { raise CanCan::AccessDenied }
+    resource = CanCan::ControllerResource.new(@controller, :instance_name => :custom_ability)
+    lambda { resource.load_and_authorize_resource }.should raise_error(CanCan::AccessDenied)
+    @controller.instance_variable_get(:@custom_ability).should == :some_ability
+  end
+
   it "should raise ImplementationRemoved when adding :name option" do
     lambda {
       CanCan::ControllerResource.new(@controller, :name => :foo)