From 917cb8ff590ffe4de011b7df50c00a908aee01ba Mon Sep 17 00:00:00 2001
From: Kevin Glowacz <glowacz@gmail.com>
Date: Tue, 3 Jun 2008 15:45:45 -0500
Subject: [PATCH] apply index and auto_index to nested fields for

---
 actionpack/lib/action_view/helpers/form_helper.rb |   24 +++++++++++++++---
 actionpack/test/template/form_helper_test.rb      |   28 +++++++++++++++++++++
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb
index 63a9323..f6619bc 100644
--- a/actionpack/lib/action_view/helpers/form_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_helper.rb
@@ -679,7 +679,7 @@ module ActionView
         end
 
         def sanitized_object_name
-          @sanitized_object_name ||= @object_name.gsub(/[^-a-zA-Z0-9:.]/, "_").sub(/_$/, "")
+          @sanitized_object_name ||= @object_name.gsub(/\]\[|[^-a-zA-Z0-9:.]/, "_").sub(/_$/, "")
         end
 
         def sanitized_method_name
@@ -697,6 +697,13 @@ module ActionView
       def initialize(object_name, object, template, options, proc)
         @object_name, @object, @template, @options, @proc = object_name, object, template, options, proc
         @default_options = @options ? @options.slice(:index) : {}
+        if @object_name.to_s.match(/\[\]$/)
+          if object ||= @template.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 to_param: #{object.inspect}"
+          end
+        end
       end
 
       (field_helpers - %w(label check_box radio_button fields_for)).each do |selector|
@@ -709,16 +716,25 @@ module ActionView
       end
 
       def fields_for(record_or_name_or_array, *args, &block)
+        if options.has_key?(:index)
+          index = "[#{options[:index]}]"
+        elsif defined?(@auto_index)
+          self.object_name = @object_name.to_s.sub(/\[\]$/,"")
+          index = "[#{@auto_index}]"
+        else
+          index = ""
+        end
+
         case record_or_name_or_array
         when String, Symbol
-          name = "#{object_name}[#{record_or_name_or_array}]"
+          name = "#{object_name}#{index}[#{record_or_name_or_array}]"
         when Array
           object = record_or_name_or_array.last
-          name = "#{object_name}[#{ActionController::RecordIdentifier.singular_class_name(object)}]"
+          name = "#{object_name}#{index}[#{ActionController::RecordIdentifier.singular_class_name(object)}]"
           args.unshift(object)
         else
           object = record_or_name_or_array
-          name = "#{object_name}[#{ActionController::RecordIdentifier.singular_class_name(object)}]"
+          name = "#{object_name}#{index}[#{ActionController::RecordIdentifier.singular_class_name(object)}]"
           args.unshift(object)
         end
 
diff --git a/actionpack/test/template/form_helper_test.rb b/actionpack/test/template/form_helper_test.rb
index 39649c3..6afd94e 100644
--- a/actionpack/test/template/form_helper_test.rb
+++ b/actionpack/test/template/form_helper_test.rb
@@ -447,6 +447,34 @@ class FormHelperTest < ActionView::TestCase
     assert_dom_equal expected, output_buffer
   end
 
+  def test_nested_fields_for_with_index
+    form_for(:post, @post, :index => 1) do |f|
+      f.fields_for(:comment, @post) do |c|
+        concat c.text_field(:title)
+      end
+    end
+
+    expected = "<form action='http://www.example.com' method='post'>" +
+               "<input name='post[1][comment][title]' size='30' type='text' id='post_1_comment_title' value='Hello World' />" +
+               "</form>"
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_nested_fields_for_with_auto_index
+    form_for("post[]", @post) do |f|
+      f.fields_for(:comment, @post) do |c|
+        concat c.text_field(:title)
+      end
+    end
+
+    expected = "<form action='http://www.example.com' method='post'>" +
+               "<input name='post[123][comment][title]' size='30' type='text' id='post_123_comment_title' value='Hello World' />" +
+               "</form>"
+
+    assert_dom_equal expected, output_buffer
+  end
+
   def test_fields_for
     fields_for(:post, @post) do |f|
       concat f.text_field(:title)
-- 
1.5.6.1