Ruby on rails 邮件发送无记录

我运行的任务，以取消一个网站，以获得一些音乐会的日期

我的任务是查找/更新音乐会（日期和城市），并将其记录在数据库中。我可以在rails控制台中找到它们，也可以在索引和显示视图中显示它们。 顺便说一句，它似乎没有通过ConcertController中的create方法（我尝试了binding.pry）

任务运行后，如果发现新记录，我希望收到电子邮件警报。当我收到电子邮件时，它不完整：

concert\u mailer/new\u dates.html.erb

<p>The boys are playing at <%= @concert.city %> on <%= @concert.date %></p>
#returns The boys are playing at on 

<p>The boys are playing at <%= @concert.inspect %> </p>

#returns: The boys are playing at <Concert id: 1, date: nil, city: nil, created_at: "2017-12-05 20:32:09", updated_at: "2017-12-05 20:32:09"> 

class Concert < ApplicationRecord
   after_create :send_notification

   def send_notification
    ConcertMailer.new_dates(self).deliver_now
   end
end

class ConcertMailer < ApplicationMailer

  default from: "concert@mountain-men.fr"

  def new_dates(concert)
    @concert = concert

    mail( to:   "email@exemple.com",
         subject:  "The boys are back in town"
        )
  end
end

concert.rb

<p>The boys are playing at <%= @concert.city %> on <%= @concert.date %></p>
#returns The boys are playing at on 

<p>The boys are playing at <%= @concert.inspect %> </p>

#returns: The boys are playing at <Concert id: 1, date: nil, city: nil, created_at: "2017-12-05 20:32:09", updated_at: "2017-12-05 20:32:09"> 

class Concert < ApplicationRecord
   after_create :send_notification

   def send_notification
    ConcertMailer.new_dates(self).deliver_now
   end
end

class ConcertMailer < ApplicationMailer

  default from: "concert@mountain-men.fr"

  def new_dates(concert)
    @concert = concert

    mail( to:   "email@exemple.com",
         subject:  "The boys are back in town"
        )
  end
end

class Concert

concert\u mailer.rb

<p>The boys are playing at <%= @concert.city %> on <%= @concert.date %></p>
#returns The boys are playing at on 

<p>The boys are playing at <%= @concert.inspect %> </p>

#returns: The boys are playing at <Concert id: 1, date: nil, city: nil, created_at: "2017-12-05 20:32:09", updated_at: "2017-12-05 20:32:09"> 

class Concert < ApplicationRecord
   after_create :send_notification

   def send_notification
    ConcertMailer.new_dates(self).deliver_now
   end
end

class ConcertMailer < ApplicationMailer

  default from: "concert@mountain-men.fr"

  def new_dates(concert)
    @concert = concert

    mail( to:   "email@exemple.com",
         subject:  "The boys are back in town"
        )
  end
end

class-ConcertMailer

在用数据更新

Concert

对象之前，将调用用于触发电子邮件的创建后回调。在保存

Concert

对象之前，请尝试向字段中添加值，而不是创建空对象

大概是这样的：

data.each do |concert|
  c = Concert.new
  c.date = concert[0]
  c.city = concert[1]
  c.save
end

或者这个：

data.each do |concert| 
  Concert.create(date: concert[0], city: concert[1]) 
end 

这样，您将在触发\u create回调后的

之前保存值