Rails JSON Rest API: Getting Child Class from Parent via API Call

Question

I have two API controllers in my Rails app for a RESTful setup:

• StoresController (has many products)
• ProductsController (has one store)

How can I write the API so that

http://localhost:3000/api/v1/stores/37/products

returns only the products for that store(in this case store #37)? I think I'm missing a route and controller method to make that happen.

Routes

    namespace :api, defaults: {format: 'json'} do
      namespace :v1 do
        resources :stores
        resources :licenses
      end
    end

API Controllers

APIController:

    module Api
      module V1
        class ApiController < ApplicationController
          respond_to :json
          before_filter :restrict_access

          private

          def restrict_access
            api_app = ApiApp.find_by_access_token(params[:access_token])
            head :unauthorized unless api_app
          end
        end
      end
    end

StoresController:

  module Api
    module V1
      class StoresController < ApiController

        def index
          respond_with Store.all
        end

        def show
          respond_with Store.find_by_id(params[:id])
        end
      end
    end
  end

ProductsController:

    module Api
      module V1
        class ProductsController < ApiController
          def index
            respond_with Product.all
          end

          def show
            respond_with Product.find_by_id(params[:id])
          end
        end
      end
    end

Thanks for any insight.

Answer 1

You want nested resources in your routes:

resources :stores do
  resources :products
end

So you have those routes:

GET        /stores/:id
GET/POST   /stores/:store_id/products
PUT/DELETE /stores/:store_id/products/:id

You'll may also want shallow routes, to avoid deeply nested resources:

resources :stores, shallow:true do
  resources :products
end

So you have those routes:

GET        /stores/:id
GET/POST   /stores/:store_id/products
PUT/DELETE /products/:id

Once you have the routes, you may just first load the parent store, and use the products association:

@store = Store.find(params[:store_id])
@products = store.products