Ruby 在 Rails 上：Sidekiq：实例变量@organisation 在邮件布局中不可用

Question

我已经使用 sidekiq 和 redis-server 在后台发送电子邮件..
问题：用sync方式发送邮件没问题。 IE。在 applicants_controller.rb

UserMailer.notify_applicant_assignment(current_assigned_user.id, applicant, workflow_step).deliver

但是，当我使用 delay 方法发送电子邮件时，即

在applicants_controller.rb

UserMailer.delay.notify_applicant_assignment(current_assigned_user.id, applicant, workflow_step)

我在 /layouts/user_mailer.html.erb:17:

中收到以下错误 undefined method 'background_color' for nil:NilClass

里面的代码mailers/user_mailer.rb

class UserMailer < ActionMailer::Base
  include Sidekiq::Worker
  default from: CommonConstants::DO_NOT_REPLY_ADDRESS
  layout 'user_mailer'
    def notify_applicant_assignment(user_id, applicant_id, workflow_step_id)
       @user = User.find(user_id)
       @organization = @user.organization
       @applicant = Applicant.find(applicant_id)
       @url = root_url + 'applicants/' + @applicant.id.to_s
       @workflow_step = WorkflowStep.find(workflow_step_id)
       mail(to: @user.email, subject: 'Applicant Assigned.')
    end
end

里面的代码layouts/user_mailer.html.erb

<body style="background:#f4f4f4;">
<table width="100%" bgcolor="<%= @organization.background_color %>" cellpadding="0" cellspacing="0">
  <tr>
    <td>
      <table align="center" width="730" cellpadding="0" cellspacing="0" >

sidekiq 控制台出错

2015-03-24T08:58:14Z 5595 TID-cjors WARN: {"retry"=>true, "queue"=>"default", "class"=>"Sidekiq::Extensions::DelayedMailer", "args"=>["---\n- !ruby/class 'UserMailer'\n- :notify_applicant_assignment\n- - 4\n  - '9'\n  - '9'\n"], "jid"=>"4421abf04e7e6864c7ee9fd8", "enqueued_at"=>1427187124.323067, "error_message"=>"undefined method `background_color' for nil:NilClass", "error_class"=>"ActionView::Template::Error", "failed_at"=>1427187124.3466575, "retry_count"=>4, "retried_at"=>1427187494.9246943}
2015-03-24T08:58:14Z 5595 TID-cjors WARN: undefined method `background_color' for nil:NilClass
2015-03-24T08:58:14Z 5595 TID-cjors WARN: /home/leapfrog/projects/ATS/app/views/layouts/user_mailer.html.erb:17:in `_app_views_layouts_user_mailer_html_erb__235114594899105140_70586860'
/home/leapfrog/.rvm/gems/ruby-2.1.1/gems/actionpack-4.0.4/lib/action_view/template.rb:143:in `block in render'
/home/leapfrog/.rvm/gems/ruby-2.1.1/gems/activesupport-4.0.4/lib/active_support/notifications.rb:161:in `instrument'
/home/leapfrog/.rvm/gems/ruby-2.1.1/gems/actionpack-4.0.4/lib/action_view/template.rb:141:in `render'
/home/leapfrog/.rvm/gems/ruby-2.1.1/gems/actionpack-4.0.4/lib/action_view/renderer/template_renderer.rb:61:in `render_with_layout'
/

Answer 1

延迟扩展的工作方式很可能与您预期的不同。它们与常规异步作业不同。

在the documentation中明确指出：

I strongly recommend avoiding delaying methods on instances. This stores object state in Redis which can get out of date, causing stale data problems.

如果延迟扩展存储未呈现的模板和邮件参数（主题、收件人、发件人等）而不是为过时的实例调用方法本身，我不会感到惊讶。

此外，请注意 notify_applicant_assignment 未定义为 class 方法（它看起来像实例方法），尽管 Sidekiq documentation 声明延迟应应用于 class 方法。

Any class method can be delayed via the same methods as above:

我建议将 notify_applicant_assignment 设为 class 方法并重试（注意 def self.notify_applicant_assignment 与 [=15 中的 self =]).

class UserMailer < ActionMailer::Base
  include Sidekiq::Worker
  default from: CommonConstants::DO_NOT_REPLY_ADDRESS
  layout 'user_mailer'
    def self.notify_applicant_assignment(user_id, applicant_id, workflow_step_id)
       @user = User.find(user_id)
       @organization = @user.organization
       @applicant = Applicant.find(applicant_id)
       @url = root_url + 'applicants/' + @applicant.id.to_s
       @workflow_step = WorkflowStep.find(workflow_step_id)
       mail(to: @user.email, subject: 'Applicant Assigned.')
    end
end

或者，我还建议在 applicants_controller.rb 中使用标准异步引擎：

UserMailer.notify_applicant_assignment_async(current_assigned_user.id, applicant, workflow_step)

请告诉我进展如何，如果还有需要，我可以再研究一下。

祝你好运！

Ruby 在 Rails 上：Sidekiq：实例变量@organisation 在邮件布局中不可用

Ruby On Rails : Sidekiq : Instance variable @organisation not available in mailer-layout

ruby-on-rails

ruby

redis

sidekiq