Rails api 控制器不从父类继承方法

Question

Doing API for my first Rails project. I have base class ApiController for all the APIs:

module Api
  class ApiController < ::ApplicationController
    respond_to :json
    skip_before_action :verify_authenticity_token

    def index
      @collection = resource_class.all
      render json: @collection.as_json(as_json_collection)
    end

    private

    def resource_class
      raise NotImplementedError
    end

    def as_json_collection
      {}
    end

  end
end

And I have child class UsersController:

module Api
  class UsersController < ApiController

    private

    def resource_class
      User
    end

    def resource_params
      params.require(:user).permit(:name, :email)
    end
  end
end

My routes:

namespace :api do
    resources :users
end

Then I'm going to my_app/api/users I have error:

The action 'index' could not be found for Api::UsersController

But then I changing UsersController writing it's own index class, everything works fine and I'm having all my Users in JSON format. I've alrady tried to comment all private marks in both classes, but that doesn't help. I don't want to write an API for every entity in my project and I'd like to avoid this problem in future.

Answer 1

I got it to work with this:

module Api
  class ApiController < ::ApplicationController

    def index
      respond_to do |format|
        format.json { render json: '"abc"' }
      end
    end
  end
end

module Api
  class UsersController < ApiController
  end
end

The URL was http://localhost:3000/api/users.json

So for you I suggest:

module Api
  class ApiController < ::ApplicationController

    def index
      respond_to do |format|
        format.json do
          @collection = resource_class.all
          render json: @collection.as_json(as_json_collection)
        end
      end
    end
  end
end

module Api
  class UsersController < ApiController
    def resource_class
      User
    end

    def resource_params
      params.require(:user).permit(:name, :email)
    end
  end
end

Answer 2

Its supposed to be like this:

  class Api::ApiController < ApplicationController

and do not forget to remove extra end , end of the file!

#sample
- api(folder)
-- api_controller.rb   (Api::ApiController < ApplicationController)
-- users_controller.rb (Api::UsersController < Api::ApiController)

application_controller.rb

Answer 3

You need to read this my friend: rails routes

When you do this:

namespace :api do
    resources :users
end

rails creates CRUD routes automatically which means that my_app/api/users will translate to: .../users#index .

Do this to see your routes created by rails:

rails routes and for specific word (eg user): rails routes | grep user rails routes | grep user

Seeing is believing ;)