Rails Shopping Cart - not adding to current order - ruby-on-rails

Question

Rails noob here.
I'm building a basic shopping cart and it was working perfectly before. Without changing any code (I git reset --hard to my prev commit where it was working) it broke. (?!?) Here's the breakdown:
Github Repo: https://github.com/christinecha/michaka
Creates a product. ✓
Adds Product ID to a new Order Item. ✓
Adds Order Item to an Order. ✓
--
Possible Issues
! - New Orders keep being created as you create Order Items = cart is always empty.
! - Cart is not connecting to the right Order ID
! - New sessions are being triggered = new Orders = problem
--
ORDER ITEMS CONTROLLER
class OrderItemsController < ApplicationController
def create
#order = current_order
#order_item = #order.order_items.new(order_item_params)
#order.save
session[:order_id] = #order.id
end
def update
#order = current_order
#order_item = #order.order_items.find(params[:id])
#order_item.update_attributes(order_item_params)
#order_items = #order.order_items
end
def destroy
#order = current_order
#order_item = #order.order_items.find(params[:id])
#order_item.destroy
#order_items = #order.order_items
end
private
def order_item_params
params.require(:order_item).permit(:quantity, :product_id)
end
end
SESSION_STORE.RB
Rails.application.config.session_store :cookie_store, key: '_bead-project_session'
ORDER MODEL
class Order < ActiveRecord::Base
belongs_to :order_status
has_many :order_items
before_create :set_order_status
before_save :update_subtotal
def subtotal
order_items.collect { |oi| oi.valid? ? (oi.quantity * oi.unit_price) : 0 }.sum
end
def subtotal_cents
subtotal * 100
end
private
def set_order_status
self.order_status_id = 1
end
def update_subtotal
self[:subtotal] = subtotal
end
end
APPLICATION CONTROLLER
class ApplicationController < ActionController::Base
protect_from_forgery with: :exception
helper_method :current_order
def current_order
if !session[:order_id].nil?
Order.find(session[:order_id])
else
Order.new
end
end
end

Answer 1

It looks like ProductsController#create is called twice, once with format html and once as json.
I think you're submitting some of your data via ajax but still doing a post request from the form. However your controller, in it's format.html response is redirecting before all of the javascript actions have completed.
Since you only save #order and set the session from OrderItemsController#create which is called by js after your initial ajax().success, it is incomplete when the redirect is received.
What I think happens on click:
ajax post request AND regular form post
ajax success -> submit #order_item_product_id form
redirected by original form post response
I would suggest either redesigning the submit process to submit through regular form post or entirely through js. For example you could disable post from the form and change OrderItemsController#create to finally redirect (via js) render :js => "window.location.href = '/cart';"