Services Objects: Moving Behavior from Controllers http://goo.gl/jtjDw

order_service.rb

module OrderService
  def self.create(listener, user, order_attrs)
    Order.new(order_attrs.merge(user: current_user))
    if order.save
      transaction = PaymentProcessor.create_payment(order)
      listener.order_creation_succeeded(order, transaction)
    else
      listener.order_creation_failed(order)
    end
  end
end

orders_controller.rb

class OrdersController < ApplicationController
  respond_to :html, :json

  def create
    order_attrs = sanitize_attributes(params[:order])
    OrderService.create(self, current_user, order_attrs)
  end

  def order_creation_succeeded(order, transaction)
    flash[:notice] = "Transaction Id: #{transaction}"
    respond_with(order) do |format|
      format.html { redirect_to order_path(order) }
      format.json { render status: 200, json: order, serializer: OrderSerializer }
    end
  end

  def order_creation_failed(order)
    @order = order
    respond_with(@order) do |format|
      format.html { render 'new' }
      format.json { render status: 422, json: order, serializer: OrderSerializer }
    end
  end
end