Rails 中的 Delayed_job 失败

Question

I am just beginning to look into using the delayed_job gem.

To test it, I added "delayed" to the welcome email function and changed that call from

    UserMailer.welcome_email(self).deliver

to

UserMailer.delay.welcome_email(self)

This is called inside the User model after_create. I see an entry show up in the delayed_job table after the function executes. Now when I run "rake jobs:work" on command line the task starts but gives errors as below

[Worker(host:Sanjay-PC pid:7008)] Starting job worker
[Worker(host:Sanjay-PC pid:7008)] Class#welcome_email failed with NoMethodError: undefined method `welcome_email' for #<Class:0x4871d60> - 0 failed attempts
[Worker(host:Sanjay-PC pid:7008)] 1 jobs processed at 0.0939 j/s, 1 failed ...

Thinking that if I changed the welcome_email method declaration to a Class method as

 def self.welcome_email(user)

(added self. in front) that might help. But then when I run rake jobs:work I get the following error

rake aborted!
undefined method `welcome_email' for class `UserMailer'
C:/Ruby192/lib/ruby/gems/1.9.1/gems/activesupport-3.0.5/lib/active_support/core_ext/module/aliasing.rb:31:in `alias_method'
C:/Ruby192/lib/ruby/gems/1.9.1/gems/activesupport-3.0.5/lib/active_support/core_ext/module/aliasing.rb:31:in `alias_method_chain'
C:/Ruby192/lib/ruby/gems/1.9.1/gems/delayed_job-2.1.4/lib/delayed/message_sending.rb:50:in `handle_asynchronously'
c:/mgn/mgn-r3/app/mailers/user_mailer.rb:10:in `<class:UserMailer>'
c:/mgn/mgn-r3/app/mailers/user_mailer.rb:1:in `<top (required)>'
C:/Ruby192/lib/ruby/gems/1.9.1/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:454:in `load'
<Stack truncated>

It seems to now know the class as UserMailer but it somehow doesn't see the class method welcome_email.

I am on Rails 3.0.5, Ruby 1.9.2p180 and the installed delayed_job gem is 2.1.4 - on Windows

Can't seem to find any related answers anywhere.

Thanks for your thoughts.

-S

Adding UserMailer code per @pjammer's request

class UserMailer < ActionMailer::Base
  default :from => "from@example.com"

  def welcome_email(user)
    @user = user
    @url  = "http://example.com/login"
    mail(:to => user.email,
         :subject => "Welcome to My Awesome Site")
  end
end

Answer 1

Just use this

UserMailer.delay.welcome_email(self).deliver

instead of

UserMailer.welcome_email(self).delay.deliver

Answer 2

My solution was to redefine function at the handler class (for you it's UserMailer class)

def self.taguri
  'tag:ruby.yaml.org,2002:class'
end

It's a hack and I'll try to find a better solution but now it works for me.

(Rails 3.0.9, Ruby 1.9.2-p290, delayed_job 2.1.4)

Answer 3

https://groups.google.com/forum/?fromgroups=#!topic/delayed_job/_gvIcbXrOaE solved my handles_asynchronously error for class methods.

As per Brandon Keeper in the link above, the code is the following:

class ClassName
  class << self
    def foo
    end
    handle_asynchronously :foo
  end
end

then use ClassName.delay.foo