Introduce the :index option for form_for and fields_for to simplify multi-model forms (see http://railscasts.com/episodes/75). Closes #9883.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8786 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 96 insertions, 11 deletions

diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 4ae2cb1cd3..ec983f3ab7 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Introduce the :index option for form_for and fields_for to simplify multi-model forms (see http://railscasts.com/episodes/75).  #9883 [rmm5t]
+
 * Introduce map.resources :cards, :as => 'tarjetas' to use a custom resource name in the URL: cards_path == '/tarjetas'.  #10578 [blj]
 
 * TestSession supports indifferent access.  #7372 [tamc, Arsen7, mhackett, julik, jean.helou]
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb
index d2835a2438..4d1e913fe3 100644
--- a/actionpack/lib/action_view/helpers/form_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_helper.rb
@@ -66,6 +66,9 @@ module ActionView
     #
     #   <input type="text" id="person_1_name" name="person[1][name]" value="<%= @person.name %>" />
     #
+    # An <tt>index</tt> option may also be passed to <tt>form_for</tt> and <tt>fields_for</tt>.  This automatically applies
+    # the <tt>index</tt> to all the nested fields.
+    #
     # There are also methods for helping to build form tags in link:classes/ActionView/Helpers/FormOptionsHelper.html,
     # link:classes/ActionView/Helpers/DateHelper.html, and link:classes/ActionView/Helpers/ActiveRecordHelper.html
     module FormHelper
@@ -644,12 +647,13 @@ 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) : {}
       end
 
       (field_helpers - %w(label check_box radio_button fields_for)).each do |selector|
         src = <<-end_src
           def #{selector}(method, options = {})
-            @template.send(#{selector.inspect}, @object_name, method, options.merge(:object => @object))
+            @template.send(#{selector.inspect}, @object_name, method, objectify_options(options))
           end
         end_src
         class_eval src, __FILE__, __LINE__
@@ -668,20 +672,20 @@ module ActionView
           name = "#{object_name}[#{ActionController::RecordIdentifier.singular_class_name(object)}]"
           args.unshift(object)
         end
-        
+
         @template.fields_for(name, *args, &block)
       end
 
       def label(method, text = nil, options = {})
-        @template.label(@object_name, method, text, options.merge(:object => @object))
+        @template.label(@object_name, method, text, objectify_options(options))
       end
 
       def check_box(method, options = {}, checked_value = "1", unchecked_value = "0")
-        @template.check_box(@object_name, method, options.merge(:object => @object), checked_value, unchecked_value)
+        @template.check_box(@object_name, method, objectify_options(options), checked_value, unchecked_value)
       end
 
       def radio_button(method, tag_value, options = {})
-        @template.radio_button(@object_name, method, tag_value, options.merge(:object => @object))
+        @template.radio_button(@object_name, method, tag_value, objectify_options(options))
       end
 
       def error_message_on(method, prepend_text = "", append_text = "", css_class = "formError")
@@ -689,12 +693,17 @@ module ActionView
       end
 
       def error_messages(options = {})
-        @template.error_messages_for(@object_name, options.merge(:object => @object))
+        @template.error_messages_for(@object_name, objectify_options(options))
       end
 
       def submit(value = "Save changes", options = {})
         @template.submit_tag(value, options.reverse_merge(:id => "#{object_name}_submit"))
       end
+
+      private
+        def objectify_options(options)
+          @default_options.merge(options.merge(:object => @object))
+        end
     end
   end
 
diff --git a/actionpack/test/controller/new_render_test.rb b/actionpack/test/controller/new_render_test.rb
index 4a9b0e9ddf..d3f5ccf4aa 100644
--- a/actionpack/test/controller/new_render_test.rb
+++ b/actionpack/test/controller/new_render_test.rb
@@ -136,11 +136,11 @@ class NewRenderTestController < ActionController::Base
   end
 
   def partial_with_form_builder
-    render :partial => ActionView::Helpers::FormBuilder.new(:post, nil, @template, nil, Proc.new {})
+    render :partial => ActionView::Helpers::FormBuilder.new(:post, nil, @template, {}, Proc.new {})
   end
-  
+
   def partial_with_form_builder_subclass
-    render :partial => LabellingFormBuilder.new(:post, nil, @template, nil, Proc.new {})
+    render :partial => LabellingFormBuilder.new(:post, nil, @template, {}, Proc.new {})
   end
 
   def partial_collection
diff --git a/actionpack/test/template/form_helper_test.rb b/actionpack/test/template/form_helper_test.rb
index a3dff7ec52..b788a9e2f9 100644
--- a/actionpack/test/template/form_helper_test.rb
+++ b/actionpack/test/template/form_helper_test.rb
@@ -363,14 +363,14 @@ class FormHelperTest < Test::Unit::TestCase
 
   def test_form_for_with_index
     _erbout = ''
-    
+
     form_for("post[]", @post) do |f|
       _erbout.concat f.label(:title)
       _erbout.concat f.text_field(:title)
       _erbout.concat f.text_area(:body)
       _erbout.concat f.check_box(:secret)
     end
-    
+
     expected = 
       "<form action='http://www.example.com' method='post'>" +
       "<label for=\"post_123_title\">Title</label>" +
@@ -383,6 +383,26 @@ class FormHelperTest < Test::Unit::TestCase
     assert_dom_equal expected, _erbout
   end
 
+  def test_form_for_with_nil_index_option_override
+    _erbout = ''
+
+    form_for("post[]", @post, :index => nil) do |f|
+      _erbout.concat f.text_field(:title)
+      _erbout.concat f.text_area(:body)
+      _erbout.concat f.check_box(:secret)
+    end
+
+    expected =
+      "<form action='http://www.example.com' method='post'>" +
+      "<input name='post[][title]' size='30' type='text' id='post__title' value='Hello World' />" +
+      "<textarea name='post[][body]' id='post__body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
+      "<input name='post[][secret]' checked='checked' type='checkbox' id='post__secret' value='1' />" +
+      "<input name='post[][secret]' type='hidden' value='0' />" +
+      "</form>"
+
+    assert_dom_equal expected, _erbout
+  end
+
   def test_nested_fields_for
     _erbout = ''
     form_for(:post, @post) do |f|
@@ -416,6 +436,60 @@ class FormHelperTest < Test::Unit::TestCase
     assert_dom_equal expected, _erbout
   end
 
+  def test_fields_for_with_index
+    _erbout = ''
+
+    fields_for("post[]", @post) do |f|
+      _erbout.concat f.text_field(:title)
+      _erbout.concat f.text_area(:body)
+      _erbout.concat f.check_box(:secret)
+    end
+
+    expected =
+      "<input name='post[123][title]' size='30' type='text' id='post_123_title' value='Hello World' />" +
+      "<textarea name='post[123][body]' id='post_123_body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
+      "<input name='post[123][secret]' checked='checked' type='checkbox' id='post_123_secret' value='1' />" +
+      "<input name='post[123][secret]' type='hidden' value='0' />"
+
+    assert_dom_equal expected, _erbout
+  end
+
+  def test_fields_for_with_nil_index_option_override
+    _erbout = ''
+
+    fields_for("post[]", @post, :index => nil) do |f|
+      _erbout.concat f.text_field(:title)
+      _erbout.concat f.text_area(:body)
+      _erbout.concat f.check_box(:secret)
+    end
+
+    expected =
+      "<input name='post[][title]' size='30' type='text' id='post__title' value='Hello World' />" +
+      "<textarea name='post[][body]' id='post__body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
+      "<input name='post[][secret]' checked='checked' type='checkbox' id='post__secret' value='1' />" +
+      "<input name='post[][secret]' type='hidden' value='0' />"
+
+    assert_dom_equal expected, _erbout
+  end
+
+  def test_fields_for_with_index_option_override
+    _erbout = ''
+
+    fields_for("post[]", @post, :index => "abc") do |f|
+      _erbout.concat f.text_field(:title)
+      _erbout.concat f.text_area(:body)
+      _erbout.concat f.check_box(:secret)
+    end
+
+    expected =
+      "<input name='post[abc][title]' size='30' type='text' id='post_abc_title' value='Hello World' />" +
+      "<textarea name='post[abc][body]' id='post_abc_body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
+      "<input name='post[abc][secret]' checked='checked' type='checkbox' id='post_abc_secret' value='1' />" +
+      "<input name='post[abc][secret]' type='hidden' value='0' />"
+
+    assert_dom_equal expected, _erbout
+  end
+
   def test_fields_for_without_object
     _erbout = ''
     fields_for(:post) do |f|