Rails Best API design to get all of a record associated with a certain user

Question

This is mostly an api design question. I have a Rails api which has routes for Users and routes for Schools. I would like to make a single call from my front end application to the api with a param of UserId which returns all of the schools associated with that user.

What is the best way to do that? Should I create a new route in UsersController called user-schools? Or a new route in SchoolsController called schools-user? Or create an entirely new controller called user-schools? Thanks for any guidance!

PS: Getting the records from ActiveRecord in the controller is not the problem. The problem is how to best design this api.

Answer 1

The RESTful way to define this would be through a nested route:

GET /users/:user_id/schools

The same basic design principles apply here for API and "classic" applications.

You can define this by nesting the calls to the resources macro:

resources :users do
  resources :schools, only: [:index]
end

This will route /users/:user_id/schools to SchoolsController#index. While you can "sniff" for the user_id param:

class SchoolsController
  # GET /schools
  # GET /users/1/schools
  def index
    schools = if params[:user_id].present?
      user = User.find(params[:user_id])
      user.schools 
    else
      School.all
    end
    render json: schools
  end
end

A cleaner design is to use a seperate controller for the nested context:

resources :users do
  resources :schools, only: [:index], module: :users
end

module Users
  class SchoolsController < ApplicationController
    # GET /users/1/schools
    def index
      user = User.find(params[:user_id])
      render json: user.schools
    end
  end
end

This controller only does a single job. You could also name it UserSchoolsController but splitting your controllers into folders (and namespaces) makes it easier to organize them.