CODEWITHSUNDEEP
ruby-on-railsassociations
Avir94
Avir94

Reputation: 919

Rails: creating belongs_to associative class after parent has been created

In my app, the user fills out a form and creates the parent class - Cost

Later, I want the user to be able to go back in to add the associative class - Cost Dependencies.

So the user gets navigated to /costs/3/cost_dependencies/new

When I try to reference @cost in my view, I get a nil class error, So I added @cost=Cost.find(param[:id]) to access it in my controller.

Now I'm getting a Couldn't find Cost with id= error

It's just blank.

Upvotes: 0

Views: 28

Answers (1)

infused
infused

Reputation: 24337

Assuming you have set up nested routes like:

resources :costs do
  resources :cost_dependencies
end

Then the cost id will be available as params[:cost_id], which you can confirm by running rake routes. You should see something like the following:

              cost_cost_dependencies GET      /costs/:cost_id/cost_dependencies(.:format)                                        cost_dependencies#index
                                     POST     /costs/:cost_id/cost_dependencies(.:format)                                        cost_dependencies#create
            new_cost_cost_dependency GET      /costs/:cost_id/cost_dependencies/new(.:format)                                    cost_dependencies#new
           edit_cost_cost_dependency GET      /costs/:cost_id/cost_dependencies/:id/edit(.:format)                               cost_dependencies#edit
                cost_cost_dependency GET      /costs/:cost_id/cost_dependencies/:id(.:format)                                    cost_dependencies#show
                                     PATCH    /costs/:cost_id/cost_dependencies/:id(.:format)                                    cost_dependencies#update
                                     PUT      /costs/:cost_id/cost_dependencies/:id(.:format)                                    cost_dependencies#update
                                     DELETE   /costs/:cost_id/cost_dependencies/:id(.:format)                                    cost_dependencies#destroy
                               costs GET      /costs(.:format)                                                                   costs#index
                                     POST     /costs(.:format)                                                                   costs#create
                            new_cost GET      /costs/new(.:format)                                                               costs#new
                           edit_cost GET      /costs/:id/edit(.:format)                                                          costs#edit
                                cost GET      /costs/:id(.:format)                                                               costs#show
                                     PATCH    /costs/:id(.:format)                                                               costs#update
                                     PUT      /costs/:id(.:format)                                                               costs#update
                                     DELETE   /costs/:id(.:format)                                                               costs#destroy

So, in your controller use the following:

@cost = Cost.find(param[:cost_id])

Upvotes: 1

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