如何使用RABL为嵌套资源建模？

Question

I want to setup a nested route in my Rails project as illustrated here:

# config/routes.rb
DemoApp::Application.routes.draw do
  namespace :api, defaults: {format: :json} do
    namespace :v1 do
      resources :places, only: [:index]
      resources :users do
        resource :places
      end
    end
  end
  devise_for :users, controllers: { sessions: "sessions" }
  ActiveAdmin.routes(self)
end

I use RABL templates to render JSON contents. It might be that I misunderstand the purpose of child elements in RABL. As far as I understand they will not lead me to a RESTful path as show below. On the other hand please tell me if RABL does not support nested resources.

How can I output JSON for a nested route such as ... ? How can I write a RABL template which matches the route users/:id/places ?

http://localhost:3000/api/v1/users/13/places.json

I do not want to display the user information. It should not be possible to retrieve user data via the following paths:

http://localhost:3000/api/v1/users/13.json
http://localhost:3000/api/v1/users.json

In the project I use CanCan 1.6.9. and Devise 2.2.3.

Answer 1

I've implemented something similar using before filters in the controller.

class Api::PlacesController < ApplicationController
before_filter :find_user

def index
    if @user 
        @places = @user.places
    else
        ...    
    end
end

private

def find_user
    @user = User.find(params[:user_id]) if params[:user_id]
end

Then in api/places/index.json.rabl

collection @places
attributes :id, :name, etc