ruby - Rails 3 - Routing error when submitting forms using nested resources -

i'm new rails , i'm having lot of trouble getting nested resource/models work. i'm getting routing error whenever try submit form.

no route matches {:action=>"show", :controller=>"tests", :test_suite_id=>#<test id: 8, name: "1", test_type: "1", result_type: "1", input: "1", created_at: "2012-06-29 07:01:11", updated_at: "2012-06-29 07:01:11", date: "1", test_suite_id: 4>} 

can explain me why there occurrences of test_suite_id in exception output , why action "show" instead of "index"? when submit form, want go index /test_suites/:test_suite_id/tests.

below relevant code:

routes.rb

  resources :test_suites     resources :tests   end 

tests_controller.rb

class testscontroller < applicationcontroller     # /tests     # /tests.json     def index          @testsuite = testsuite.find(params[:test_suite_id])         @tests = @testsuite.tests          respond_to |format|             format.html # index.html.erb             format.json { render json: @tests }         end     end      # /tests/1     # /tests/1.json     def show         @testsuite = testsuite.find(params[:test_suite_id])         @test = @testsuite.tests.find(params[:id])          respond_to |format|             format.html # show.html.erb             format.json { render json: @test }         end     end      # /tests/new     # /tests/new.json     def new         @testsuite = testsuite.find(params[:test_suite_id])         @test = @testsuite.tests.build          #@test = test.new         @test.build_hardware         @test.build_software          respond_to |format|             format.html # new.html.erb             format.json { render json: @test }         end     end      # /tests/1/edit     def edit         @test = test.find(params[:id])     end      # post /tests     # post /tests.json     def create          @testsuite = testsuite.find(params[:test_suite_id])         @test = @testsuite.tests.build(params[:test])          respond_to |format|             if @test.save                 flash[:notice] = "test added succesfully"                 format.html { redirect_to [:test_suite, @test], notice: 'test created.' }                 format.json { render json: @test, status: :created, location: @test }                 else                 format.html { render action: "new" }                 format.json { render json: @test.errors, status: :unprocessable_entity }             end         end     end end 

_form.html.erb

<%= form_for([:test_suite, @test], :action => "index") |f| %>   <% if @test.errors.any? %>     <div id="error_explanation">       <h2><%= pluralize(@test.errors.count, "error") %> prohibited test being saved:</h2>        <ul>       <% @test.errors.full_messages.each |msg| %>         <li><%= msg %></li>       <% end %>       </ul>     </div>   <% end %>   <br />   <h2>test information</h2>    <div class="field">     <%= f.label :name %><br />     <%= f.text_field :name %>   </div>   <div class="field">     <%= f.label :test_type %><br />     <%= f.text_field :test_type %>   </div>   <div class="field">     <%= f.label :result_type %><br />     <%= f.text_field :result_type %>   </div>   <div class="field">     <%= f.label :date %><br />     <%= f.text_field :date %>   </div>   <div class="field">     <%= f.label :input %><br />     <%= f.text_area :input %>   </div>     <% end %>   </div>     <div class="actions">     <%= f.submit %>   </div> <% end %> 

rake routes:

     test_suite_new    /test_suite/new(.:format)                            test_suite#new     test_suite_tests    /test_suites/:test_suite_id/tests(.:format)          tests#index                      post   /test_suites/:test_suite_id/tests(.:format)          tests#create  new_test_suite_test    /test_suites/:test_suite_id/tests/new(.:format)      tests#new edit_test_suite_test    /test_suites/:test_suite_id/tests/:id/edit(.:format) tests#edit      test_suite_test    /test_suites/:test_suite_id/tests/:id(.:format)      tests#show                      put    /test_suites/:test_suite_id/tests/:id(.:format)      tests#update                      delete /test_suites/:test_suite_id/tests/:id(.:format)      tests#destroy          test_suites    /test_suites(.:format)                               test_suites#index                      post   /test_suites(.:format)                               test_suites#create       new_test_suite    /test_suites/new(.:format)                           test_suites#new      edit_test_suite    /test_suites/:id/edit(.:format)                      test_suites#edit           test_suite    /test_suites/:id(.:format)                           test_suites#show                      put    /test_suites/:id(.:format)                           test_suites#update                      delete /test_suites/:id(.:format)                           test_suites#destroy                 root        /                                                    home#index 

the error caused dis-congruity of these 2 lines:

resources :test_suites do

<%= form_for([:test_suite, @test], :action => "index") |f| %>

the use of resources (as opposed resource) implies collection (as opposed singular resource). resources nested within not belong collection, though, must belong specific member in collection.

in form_for([:test_suite, @test]) saying want form belongs singular resource called "test_suite".

you either need change parent resource singular, or pass in specific test_suite instance (ie: form_for([@a_test_suite_instance, @test])).