Problem with @story = Story.find(params[:story_id]) in rails 3

I have an app that I have recently upgraded to rails 3

In my comments controller I have

def creat开发者_C百科e
  @cuser = @current_user   
  @story = Story.find(params[:story_id]) 
  @story.comments.create(:user_id => @cuser.login,:body => params[:comment][:body])
  respond_to do |format|
    format.html { story_path}
    format.js
  end
end

In story.rb I have has_many :comments In comment.rb I have belongs_to :story

When I try to create a comment I get a

Couldn't find Story without an ID

This used to work. Any ideas why it doesn't any more ? What else could be affecting it? Could it be a routing issue?

Your form definition should look like this:

<%= form_for [@story, Comment.new] do |form| %> 
  <div id="body"> 
    <%= form.text_field :body %> 
  </div> <% form.hidden_field :user_id, :value => @current_user.login %> 
  <p>
    <%= submit_tag 'Comment' %>
  </p> 
<% end %>

Your form uses POST /comments instead of POST /stories/:story_id/comments action. It should have thrown an exception about a missing POST /comments route, that's why I wasn't sure about my solution. But your routes have the comments resources for some reason. So it knows how to create the URL, but it doesn't know it should include the /stories/:story_id part.

Another thing here is you pass current_user with the form. It's bad since anyone who knows how to use firebug or any other web-master tools can change this field to, say, your login and post comments as if it were you. You should assign the user field in your create action of the controller.

And one more. I really can't see why you would need all this routes. If it was my app, routes would look something like this:

Telling_tales::Application.routes.draw do 

  resource :session 
  resource :stories #really can't see why you need a singular route here 
  resource :user 
  resources :users do
    get 'register' => 'create', :on => :collection #maps to 'users#create'
  end

  resources :stories do 
    resources :comments
    collection do
      get ':login' => 'show' #it seems illogical to place this route under `stories` namespace 
                            #if you wanted to display stories of one particular user, you'd better make it `/users/:user_id/stories`
      get 'search'
  end
  root :to => 'stories#index' 
end

Take a look at this and this guides.

I assume you have the following route-configuration:

resources :stories do
  resources :comments
end

If that's the case, you have to use params[:story_id].

@story = Story.find(params[:story_id]) 

yes, it can be a routing issue. You have probably spotted that the routing dsl has changed, and I guess you are messing around with it. Looks like you used to have a route something like

`map.resources :stories

and you have (maybe) replaced that with something like

    resources :stories do 
      resources :comments do
        collection  do
          post :create
        end 
      end  
    end

I'm only guessing , but I think this would give the sort of error you are seeing - you need a route like

resources :stories do
  resources :comments
end

which will automatically generate the create route, or if you want to specify it more precisely

resources :stories do
  resources :comments do
    member do
      post :create
    end
  end
end