Empty (but working) show method on controller generated via scaffolding?

Question

How is that the show method on a controller class generated via rails generate scaffold xxx empty / contains no code? Where is the code for showing individual records via URL e.g. /my_rails_app:3000/xxx/1 stored?

The method should, at the very least, looks like this IMO:

class ProductController
  # GET /students/1
  # GET /students/1.json
  def show
    @item = Product.find(params[:id])
    render @item
  end
end

but instead it is completely empty:

class ProductController
  # GET /students/1
  # GET /students/1.json
  def show

  end
end

Answer 1

If you are using rails 4 then there should have some before action method which is doing the magic for you please check in the respective controller.

It should be like before_action :set_product, :only => [:show, :edit, :update, :destroy]