Rails將對象傳遞給模塊目錄paypal-sdk-merchant中的類

Question

我遵循http://www.tommyblue.it/2013/07/03/paypal-express-checkout-with-ruby-on-rails-and-paypal-sdk-merchant上的指南；並且，當我嘗試將訂單傳遞給paypal_interface，我得到一個nil對象。

def show
   @order = Order.find(params[:id]) 
   @paypal = PaypalInterface.new(@order) 
   @paypal.express_checkout 
   if @paypal.express_checkout_response.success?
   @paypal_url = @paypal.api.express_checkout_url(@paypal.express_checkout_response)
  else
   # manage error
  end
end

編輯以包括整個文件

paypal_interface.rb

require 'paypal-sdk-merchant'

class PaypalInterface
  attr_reader :api, :express_checkout_response

  PAYPAL_RETURN_URL = Rails.application.routes.url_helpers.paid_orders_url(host: HOST_WO_HTTP)
  PAYPAL_CANCEL_URL = Rails.application.routes.url_helpers.revoked_orders_url(host: HOST_WO_HTTP)
  PAYPAL_NOTIFY_URL = Rails.application.routes.url_helpers.ipn_orders_url(host: HOST_WO_HTTP)

 def initialize(order)
    @api = PayPal::SDK::Merchant::API.new
    @order = order
end

  @set_express_checkout = @api.build_set_express_checkout({
      SetExpressCheckoutRequestDetails: {
        ReturnURL: PAYPAL_RETURN_URL,
        CancelURL: PAYPAL_CANCEL_URL,
       PaymentDetails: [{
          NotifyURL: PAYPAL_NOTIFY_URL,
          OrderTotal: {
            currencyID: "EUR",
           value: @order.total
          },
          ItemTotal: {
            currencyID: "EUR",
           value: @order.total
          },
          ShippingTotal: {
           currencyID: "EUR",
           value: "0"
         },
         TaxTotal: {
           currencyID: "EUR",
           value: "0"
         },
          PaymentDetailsItem: [{
            Name: @order.code,
            Quantity: 1,
            Amount: {
             currencyID: "EUR",
              value: @order.total
            },
            ItemCategory: "Physical"
          }],
          PaymentAction: "Sale"
        }]
      }
        })
# Make API call & get response
    @express_checkout_response = @api.set_express_checkout(@set_express_checkout)

    # Access Response
    if @express_checkout_response.success?
      @order.set_payment_token(@express_checkout_response.Token)
    else
      @express_checkout_response.Errors
    end


def do_express_checkout
    @do_express_checkout_payment = @api.build_do_express_checkout_payment({
      DoExpressCheckoutPaymentRequestDetails: {
        PaymentAction: "Sale",
        Token: @order.payment_token,
        PayerID: @order.payerID,
        PaymentDetails: [{
          OrderTotal: {
            currencyID: "EUR",
            value: @order.total
          },
          NotifyURL: PAYPAL_NOTIFY_URL
        }]
      }
    })

    # Make API call & get response
    @do_express_checkout_payment_response = @api.do_express_checkout_payment(@do_express_checkout_payment)

    # Access Response
    if @do_express_checkout_payment_response.success?
      details = @do_express_checkout_payment_response.DoExpressCheckoutPaymentResponseDetails
     @order.set_payment_details(prepare_express_checkout_response(details))
    else
      errors = @do_express_checkout_payment_response.Errors # => Array
      @order.save_payment_errors errors
    end
  end
    end

該類在/ lib / modules中，並且在加載時，實例變量為nil

從2014年1月7日01:33:46 -0600開始為127.0.0.1的GET“ / orders / 1”，由OrdersController＃show處理為HTML參數：{“ id” =>“ 1”}訂單加載（0.2ms）在“訂單”中選擇“訂單”。*在“訂單”中。“ id” =？ LIMIT 1 [[“ id”，“ 1”]]在18毫秒內完成500個內部服務器錯誤

NoMethodError（ total' for nil:NilClass): lib/modules/paypal_interface.rb:25:in未定義方法total' for nil:NilClass): lib/modules/paypal_interface.rb:25:in in'lib / modules / paypal_interface.rb：3：in <top (required)>' app/controllers/orders_controller.rb:17:in表演中

schema.rb

ActiveRecord::Schema.define(:version => 20140107060318) do

  create_table "orders", :force => true do |t|
   t.text     "code"
   t.text     "total"
   t.text     "payerID"
   t.text     "payment_token"
   t.datetime "created_at",    :null => false
   t.datetime "updated_at",    :null => false
  end

end

我將10的值加載到表單中；並且，我嘗試將total字段更改為：decimal無效，但是由於對象沒有從訂單控制器傳遞到模塊，現在我被卡住了。

Answer 1

如果PaypalInterface中的@question為nil，則Order.find(params[:id])可能找不到任何內容。 在show方法中：

@order = Order.find(params[:id]) 

@order為零？ 您可以嘗試：

def show
   if @order = Order.find(params[:id])
     [...]
   else
     # Can't find order
   end
end

我使用Pry調試此類錯誤，只需要“ pry”，然后將bind.pry放在要停止代碼並打開控制台的位置即可。 一個例子是：

def show
   @order = Order.find(params[:id])
   require 'pry'
   binding.pry # Go to the console and start debugging @order
   [...]
end

PS。 您所指示的paypal_interface.rb只是該文件的一部分？ 因為該代碼似乎是錯誤的。