Rails：未定义方法“total_price”对于 nil:NilClass

发布于 2024-11-06 21:34:39 字数 1700 浏览 0 评论 0原文

我正在使用 Rails 3.0.4 构建一个音乐会门票销售应用程序，主要使用敏捷 Web 开发教程 (http://pragprog.com/titles/rails3/agile-web-development-with-rails) 并尝试合并Ryan Bate 的订单购买方法（http://railscasts.com/episodes/146-paypal-express-checkout）。一切都适用于orders_controller.rb中的以下内容：

def create
  @order = Order.new(params[:order])
  @order.add_line_items_from_cart(current_cart)
  @order.ip_address = request.remote_ip 

  respond_to do |format|
    if @order.save
  Notifier.order_received(@order).deliver
  format.html { redirect_to(calendar_url, :notice => 'Thank you for your order.') }
      format.xml  { render :xml => @order, :status => :created, :location => @order }
  Cart.destroy(session[:cart_id])
  session[:cart_id] = nil
else
  format.html { render :action => "new" }
      format.xml  { render :xml => @order.errors, :status => :unprocessable_entity }
end
  end

但是当我将“&&@order.purchase”添加到条件子句时，order.rb模型如下：

class Order < ActiveRecord::Base
  #...
  belongs_to :cart
  #...

  def price_in_cents
    (cart.total_price*100).round
  end

  def purchase
    response = GATEWAY.purchase(price_in_cents, credit_card, purchase_options)
    cart.update_attribute(:purchased_at, Time.now) if response.success?
    response.success?
  end
  #...
end

我收到一个“未定义的方法‘total_price’为零： NilClass”错误。我可以通过添加到订单“create”方法来解决这个问题

@order = current_cart.build_order(params[:order])

，但这会以某种方式阻止相关订单信息（在本例中为“@order.line_items”）在电子邮件文本中呈现，从而弄乱了“order_received”通知。

“cart”对象在途中的某个地方被设置为 nil，但是

Cart.destroy(session[:cart_id])

从订单“create”方法中删除并不能解决问题。

有人知道这个菜鸟的线索吗？

原文

I'm building a concert ticket sales application with Rails 3.0.4, working primarily with the Agile Web Development tutorial (http://pragprog.com/titles/rails3/agile-web-development-with-rails) and trying to incorporate Ryan Bate's order purchase method (http://railscasts.com/episodes/146-paypal-express-checkout). Everything works with the following in orders_controller.rb:

def create
  @order = Order.new(params[:order])
  @order.add_line_items_from_cart(current_cart)
  @order.ip_address = request.remote_ip 

  respond_to do |format|
    if @order.save
  Notifier.order_received(@order).deliver
  format.html { redirect_to(calendar_url, :notice => 'Thank you for your order.') }
      format.xml  { render :xml => @order, :status => :created, :location => @order }
  Cart.destroy(session[:cart_id])
  session[:cart_id] = nil
else
  format.html { render :action => "new" }
      format.xml  { render :xml => @order.errors, :status => :unprocessable_entity }
end
  end

But when I add "&& @order.purchase" to the conditional clause, with the order.rb model as follows:

class Order < ActiveRecord::Base
  #...
  belongs_to :cart
  #...

  def price_in_cents
    (cart.total_price*100).round
  end

  def purchase
    response = GATEWAY.purchase(price_in_cents, credit_card, purchase_options)
    cart.update_attribute(:purchased_at, Time.now) if response.success?
    response.success?
  end
  #...
end

I receive an "undefined method `total_price' for nil:NilClass" error. I can get around this by adding

@order = current_cart.build_order(params[:order])

to the orders "create" method, but this messes up the "order_received" notification by somehow preventing the pertinent order information (in this case "@order.line_items") from rendering in the e-mail text.

The "cart" object is being set to nil somewhere along the way, but removing