No Token Passed PayPal Express Checkout in Rails 5

Question

I'm putting together a basic shopping cart with PayPal Express Checkout functionality. Everything appears to be working until I click on the checkout button, then I get a blank page that says "no token passed". In the server logs it appears that no token is being created but I'm not sure why. I think that this is most likely a problem with the creation of the express checkout token but I'm really not sure what I'm doing wrong. Here is what the server log looks like:

Started GET "/express_checkout" for 10.240.0.204 at 2017-05-27 16:54:43 +0000
Cannot render console from 10.240.0.204! Allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255
Processing by OrdersController#express_checkout as HTML
  Order Load (0.1ms)  SELECT  "orders".* FROM "orders" WHERE "orders"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
  OrderItem Load (0.1ms)  SELECT "order_items".* FROM "order_items" WHERE "order_items"."order_id" = ?  [["order_id", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."active" = ? AND "products"."id" = ? LIMIT ?  [["active", true], ["id", 1], ["LIMIT", 1]]
Redirected to https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=
Completed 302 Found in 615ms (ActiveRecord: 0.5ms)

Here is my Order.rb:

class Order < ApplicationRecord
  has_many :order_items
  before_save :update_subtotal

  def subtotal
    order_items.collect { |oi| oi.valid? ? (oi.quantity * oi.unit_price) : 0 }.sum
  end

  def purchase
    response = EXPRESS_GATEWAY.purchase(order.total, express_purchase_options)
    order.update_attribute(:purchased_at, Time.now) if response.success?
    response.success?
  end

  def express_token=(token)
      self[:express_token]=token
      if new_record? && !token.blank?
        details = EXPRESS_GATEWAY.details_for(token)
        self.express_payer_id = details.payer_id
      end
  end 

private

  def update_subtotal
    self[:subtotal] = subtotal
  end

  def express_purchase_options
    {
      :ip => ip,
      :token => express_token,
      :payer_id => express_payer_id
    }
  end
end

My orders_controller.rb:

class OrdersController < ApplicationController

    def express_checkout
        @order = current_order
        response = EXPRESS_GATEWAY.setup_purchase(@order.subtotal,
        ip: request.remote_ip,
        return_url: 'carts/show',
        cancel_return_url: 'carts/cancel',
        currency: "USD",
        allow_guest_checkout: true,
        items: [{name: "Order", description: "Order description", quantity: "1", amount: @order.subtotal}]
    )
        redirect_to EXPRESS_GATEWAY.redirect_url_for(response.token)
    end

def new
    @order = Order.new(:express_token => params[:token])
end

def create
    @order = current_order.create!(order_params)
    @order.ip = request.remote_ip
    if @order.save
        if @order.purchase
            redirect_to order_url(@order)
        else
            render :action => "failure"
        end
    else
        render :action => 'new'
    end
end

private
def order_params
  params.require(:order).permit(:subtotal, :total, :ip, :express_token, :express_payer_id)
end
end

My application_controller.rb:

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  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(order_params)
    end
  end

end

The Active Merchant code in my development.rb:

config.after_initialize do
ActiveMerchant::Billing::Base.mode = :test
paypal_options = {
  login: "merchant_api1.christianorourke.com",
  password: ************,
  signature: ***************************
}
::EXPRESS_GATEWAY = ActiveMerchant::Billing::PaypalExpressGateway.new(paypal_options)
  end

My Routes file:

Rails.application.routes.draw do

  root "products#index"
  resources :products, only: [:index]
  resource :cart, only: [:show]
  resources :order_items, only: [:create, :update, :destroy]
  get 'express_checkout', to: 'orders#express_checkout'
  resources :orders do 
    collection do
      post 'express_checkout'
    end
  end
end

Answer 1

I just found this link it explains how to configure

paypal-express

https://github.com/nov/paypal-express/wiki

paypal_options = {
  no_shipping: true, # if you want to disable shipping information
  allow_note: false, # if you want to disable notes
  pay_on_paypal: true # if you don't plan on showing your own confirmation step
}

request = Paypal::Express::Request.new(
  :username   => SET_YOUR_OWN,
  :password   => SET_YOUR_OWN,
  :signature  => SET_YOUR_OWN
)
payment_request = Paypal::Payment::Request.new(
  :currency_code => :JPY,   # if nil, PayPal use USD as default
  :description   => FOO,    # item description
  :quantity      => 1,      # item quantity
  :amount        => 1.00,   # item value
  :custom_fields => {
    CARTBORDERCOLOR: "C00000",
    LOGOIMG: "https://example.com/logo.png"
  }
)
response = request.setup(
  payment_request,
  YOUR_SUCCESS_CALLBACK_URL,
  YOUR_CANCEL_CALLBACK_URL,
  paypal_options  # Optional
)
response.redirect_uri

Then you have the ActiveMerchant cofiguration and you can find guides hear:

https://duckduckgo.com/?q=rails+paypal+active+merchant+gem&atb=v52-6_b&ia=qa

How to integrate Paypal with Ruby on Rails

https://spin.atomicobject.com/2011/10/24/integrating-paypal-express-with-rails-3-1-part-1/