# Gemfile
gem 'jsonite'

# todo_presenter.rb
class TodoPresenter < Jsonite
  property :description
end

# user_presenter.rb
require 'todo_presenter'

class UserPresenter < Jsonite
  property :id
  property :email

  embed :todos, with: TodoPresenter

  link do |context|
    context.user_url self
  end
end

# users_presenter.rb
require 'user_presenter'

class UsersPresenter < Jsonite
  property :count

  embed :users, with: UserPresenter do |context|
    self
  end
end

# users_controller.rb
require 'users_presenter'
require 'user_presenter'

class UsersController < ApplicationController
  def index
    users = User.all
    render json: UsersPresenter.new(users, context: self)
  end
  # {
  #   "count": 12,
  #   "_embedded": {
  #     "users": [
  #       # ...
  #     ]
  #   }
  # }

  def show
    user = User.find params[:id]
    render json: UserPresenter.new(user, context: self)
  end
  # {
  #   "id": "8oljbpyjetu8",
  #   "email": "[email protected]",
  #   "_embedded": {
  #     "todos": [
  #       {
  #         "description": "Buy milk"
  #       }
  #     ]
  #   },
  #   "_links": {
  #     "self":{
  #       "href": "http://example.com/users/8oljbpyjetu8"
  #     }
  #   }
  # }
end