ruby on rails - Couldn't find [Model] without an ID - rails4 -

i new rails , have problem have been finding challenging overcome.

goal:

• i have models advert & form
• advert has_many forms | form belongs_to advert
• i trying display list of forms under advert
• i have managed display number of forms under advert , made link
• in image example, have (job) advert "software engineer" has 2 forms (applications) presented link
• i want user click on link (the figure) , directed page displays forms under advert

• currently when click link (under applications) directed path forms_path displays form per form controller instructs

could 1 advise me how can code index method in forms controller display not created forms forms under specific advert

advert_controller.rb

class advertscontroller < applicationcontroller   respond_to :html, :xml, :json   before_action :set_advert, only: [:show, :edit, :update, :destroy]    def index     @userr = userr.find(params[:userr_id])     @adverts = @userr.adverts.order("created_at desc")     respond_with(@adverts)   end end 

views/ adverts / index.html

<table>   <thead>     <tr>       <th>title</th>       <th>applications</th>       <th colspan="3"></th>     </tr>   </thead>    <tbody>     <% @adverts.each |advert| %>       <tr>         <td><%= link_to advert.title, userr_advert_path(advert.userr, advert) %></td>         <td><%= link_to advert.forms.count, forms_path %></td>       </tr>     <% end %>   </tbody> </table> <br>  <%= link_to 'add new advert', new_userr_advert_path(current_userr) %> 

form_controller.rb

class formscontroller < applicationcontroller   respond_to :html, :xml, :json   before_action :set_form, only: [:show, :edit, :update, :destroy]    def index     @forms = form.all     respond_with(@forms)   end end 

routes.rb

rails.application.routes.draw   resources :forms   devise_for :userrs   resources :userrs     resources :adverts   end end 

in rails console - managed display forms under advert:

2.1.2 :308 >   advert = advert.first   advert load (4.4ms)  select  "adverts".* "adverts"   order "adverts"."id" asc limit 1  => #<advert id: 51, title: "software engineer", content: "lorem ipsum dolor sit amet ac dapibus", category_jobtype_id: 67, category_positiontype_id: 81, salarystart: 1200, salaryend: 2000, category_country_id: 45, city: "accra", town: "tesano estates", postcode: "1206", category_editorialapproval_id: 34, category_applicationrequest_id: 34, created_at: "2015-05-21 21:05:09", updated_at: "2015-05-21 21:05:09", userr_id: 16, category_advert_id: 58>  2.1.2 :309 >  2.1.2 :310 >    2.1.2 :311 >   advert.forms   form load (0.2ms)  select "forms".* "forms"  "forms"."advert_id" = ?  [["advert_id", 51]]  => #<activerecord::associations::collectionproxy [#<form id: 4, firstname: "akunorbea", lastname: "artloe", number: 2089587999, email: "akunorbea@gmail.com", currentjob: "developer", currentemployer: "global reach", category_country_id: 2, advert_id: 51, userj_id: 3, workhere: false, created_at: "2015-05-29 09:09:33", updated_at: "2015-05-29 09:09:33">, #<form id: 6, firstname: "curtis", lastname: "lewis", number: 208958, email: "curtis@gmail.com", currentjob: "security", currentemployer: "megan fox", category_country_id: 2, advert_id: 51, userj_id: 4, workhere: false, created_at: "2015-05-29 17:14:41", updated_at: "2015-05-29 17:14:41">]>  2.1.2 :312 > 

so in form_controller.rb index action typed below got error

class formscontroller < applicationcontroller   respond_to :html, :xml, :json   before_action :set_form, only: [:show, :edit, :update, :destroy]    def index     @advert = advert.find(params[:id])     @forms = @advert.forms     respond_with(@forms)   end end 

views/forms/index.html.erb

<h1>listing forms</h1>  <table>   <thead>     <tr>       <th>firstname</th>       <th>lastname</th>       <th>number</th>       <th>email</th>       <th colspan="3"></th>     </tr>   </thead>    <tbody>     <% @forms.each |form| %>       <tr>         <td><%= form.firstname %></td>         <td><%= form.lastname %></td>         <td><%= form.number %></td>         <td><%= form.email %></td>       </tr>     <% end %>   </tbody> </table>  <br> 

in routes.rb

resources :userrs   resources :adverts     resources :forms, only: [:index]   end end 

in views/adverts/index.html.erb

<td><%= link_to advert.forms.count, userr_advert_forms_path(@userr, advert) %></td> 

in forms_controller.rb

def index   @advert = advert.find(params[:advert_id])   @forms = advert.forms end