FormHelper's auto_index should use #to_param instead of #id_before_type_cast. Closes #9994 [mattly]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8033 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* FormHelper's auto_index should use #to_param instead of #id_before_type_cast.  Closes #9994 [mattly]
+
 * Doc typo fixes for ActiveRecordHelper. Closes #9973 [mikong]
 
 * Make example parameters in restful routing docs idiomatic. Closes #9993 [danger]

actionpack/lib/action_view/helpers/form_helper.rb

@@ -415,10 +415,10 @@ module ActionView
         @template_object, @local_binding = template_object, local_binding
         @object = object
         if @object_name.sub!(/\[\]$/,"")
-          if object ||= @template_object.instance_variable_get("@#{Regexp.last_match.pre_match}") and object.respond_to?(:id_before_type_cast)
-            @auto_index = object.id_before_type_cast
+          if object ||= @template_object.instance_variable_get("@#{Regexp.last_match.pre_match}") and object.respond_to?(:to_param)
+            @auto_index = object.to_param
           else
-            raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to id_before_type_cast: #{object.inspect}"
+            raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to to_param: #{object.inspect}"
           end
         end
       end

actionpack/test/template/form_helper_test.rb

@@ -6,7 +6,7 @@ silence_warnings do
     alias_method :title_before_type_cast, :title unless respond_to?(:title_before_type_cast)
     alias_method :body_before_type_cast, :body unless respond_to?(:body_before_type_cast)
     alias_method :author_name_before_type_cast, :author_name unless respond_to?(:author_name_before_type_cast)
-
+    
     def new_record=(boolean)
       @new_record = boolean
     end
@@ -53,6 +53,7 @@ class FormHelperTest < Test::Unit::TestCase
     end
     def @post.id; 123; end
     def @post.id_before_type_cast; 123; end
+    def @post.to_param; '123'; end
 
     @post.title       = "Hello World"
     @post.author_name = ""