ruby-on-rails - Rails 将对象传递给模块目录 paypal-sdk-merchant 中的类

Question

我正在按照 http://www.tommyblue.it/2013/07/03/paypal-express-checkout-with-ruby-on-rails-and-paypal-sdk-merchant 上的指南进行操作;并且，当我尝试将订单传递给 paypal_interface 时，我得到一个 nil 对象。

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

编辑以包含整个文件

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

该类在/lib/modules 中，加载时实例变量为nil

在 2014-01-07 01:33:46 -0600 开始为 127.0.0.1 获取“/orders/1”由 OrdersController 处理#show as HTML 参数:{“id”=>“1”} 订单加载 (0.2ms) SELECT "orders".* FROM "orders"WHERE "orders"."id"= ?限制 1 [["id", "1"]]在 18 毫秒内完成 500 个内部服务器错误

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

架构.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

我将值 10 加载到表单中；并且，我尝试将总字段更改为 :decimal 但无济于事，但现在我被卡住了，因为对象没有从订单 Controller 传递到模块。

Answer 1

如果 PaypalInterface 中的 @question 为 nil，可能 Order.find(params[:id]) 没有找到。在显示方法中:

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

@order 为零？你可以试试:

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

我使用 Pry 来调试此类错误，只需要“pry”然后将 binding.pry 放在您要停止代码并打开控制台的位置。一个例子是:

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

附言。您指定的 paypal_interface.rb 只是该文件的一部分？因为该代码似乎是错误的。