Rails undefined variable @assets -

i following tutorial

error @asset variable using in _form.html.erb , index.html.erb not working .it saying first argument in form cannot contain nil or empty .but when replace :asset_path starts working
[assets_controller]

class assetscontroller < applicationcontroller    before_filter :authenticate_user!  #authenticate users before methods called      def index      @assets = current_user.assets         end      def new     @asset = current_user.assets.new   end    def create      @asset = current_user.assets.new(user_assets)     end     private     def user_assets          params.require(:asset).permit(:user_id, :uploaded_file)     end  end 

[assets/_form.html.erb]

<%= form_for @assets, :html => {:multipart => true} |f| %>    <%= f.error_messages %>       <p>          <%= f.label :uploaded_file, "file" %><br />          <%= f.file_field :uploaded_file %>        </p>    <p><%= f.submit "upload" %></p>  <% end %> 

[index.html.erb]

  <% title "assets" %>      <table>        <tr>          <th>uploaded files</th>        </tr>         <% asset in @assets %>           <tr>            <td><%= link_to asset.uploaded_file_file_name, asset.uploaded_file.url %></td>            <td><%= link_to "show", asset %></td>            <td><%= link_to "edit", edit_asset_path(asset) %></td>            <td><%= link_to "destroy", asset, :confirm => 'are sure?', :method => :delete %></td>          </tr>        <% end %>      </table>      <p><%= link_to "new asset", new_asset_path %></p> 

[rake routes]

new_user_session    /users/sign_in(.:format)       devise/sessions#new             user_session post   /users/sign_in(.:format)       devise/sessions#create     destroy_user_session    /users/sign_out(.:format)      devise/sessions#destroy            user_password post   /users/password(.:format)      devise/passwords#create        new_user_password    /users/password/new(.:format)  devise/passwords#new       edit_user_password    /users/password/edit(.:format) devise/passwords#edit                          patch  /users/password(.:format)      devise/passwords#update                          put    /users/password(.:format)      devise/passwords#update cancel_user_registration    /users/cancel(.:format)        devise/registrations#cancel        user_registration post   /users(.:format)               devise/registrations#create    new_user_registration    /users/sign_up(.:format)       devise/registrations#new   edit_user_registration    /users/edit(.:format)          devise/registrations#edit                          patch  /users(.:format)               devise/registrations#update                          put    /users(.:format)               devise/registrations#update                          delete /users(.:format)               devise/registrations#destroy                     root    /                              homes#index                   assets    /assets(.:format)              assets#index                          post   /assets(.:format)              assets#create                new_asset    /assets/new(.:format)          assets#new               edit_asset    /assets/:id/edit(.:format)     assets#edit                    asset    /assets/:id(.:format)          assets#show                          patch  /assets/:id(.:format)          assets#update                          put    /assets/:id(.:format)          assets#update                          delete /assets/:id(.:format)          assets#destroy 

#assets/_form.html.erb <%= form_for @asset, :html => {:multipart => true} |f| %>  

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if use form_for, have pass valid object type. typically, done variable (as above), can symbol.

the form_for method infers other form attributes (path etc) initial value, hence need have initial value it.

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the issue have new method, you've declared @asset, yet using @assets in form_for. standard undeclared / nil variable problem unfortunately.