gistfile1.txt

class UsersController < ApplicationController

  def create
    respond User::Create do |user, format|
      format.json { render status: :created, json: user.to_json }
    end
  end
end

class User < ActiveRecord::Base
  has_secure_password
  class Create < Trailblazer::Operation
    include CRUD, Responder, Representer

    model User, :create

    contract do
      property :email
      property :password
      property :password_confirmation

      validates :email, presence: true, uniqueness: true
      validates :password, length: { minimum: 20 }
    end

    def process(params)
      validate(params) { contract.save }
    end

    class JSON < self
      contract do
        property :id
        property :email
      end

      representer do
        property :id
        property :email
      end
    end

    builds do |params|
      JSON if params[:format] == :json
    end
  end
end