Rails was designed to help reduce the complexity of routing by introducing a built-in shallow routing option
Here’s an example of how shallow routing would work by design according to the Rails Guide.
resources :articles do resources :comments, only: [:index, :new, :create] end resources :comments, only: [:show, :edit, :update, :destroy]
There is a short hand for this in Rails and it looks like this:
resources :articles, shallow: true do resources :comments resources :quotes resources :drafts end
This results in all of the sub-resources to be shallow based on this configuration
My initial reaction for leveraging the shallow routing was to limit all interactions with the form to the sub-resource and all the view only actions to route at the parent level. However, Rails has figured all of this out for us already. Check out this link on StackOverflow for details.
The general gist is that the first object in the array you pass the form builder is
nil, Rails will POST to the second object only. In the example above, you wouldn’t set the @article object in your comments controller edit action. If you need access to the article object, you would access it through @comment