Delayed_job什麼都不做：TypeError：無法將nil轉換爲字符串

Question

從「https://github.com/collectiveidea/delayed_job」關注delayed_job。我可否知道爲什麼我的delayed_job什麼都不做？我跑了 「耙作業：工作」 的廣告了這些錯誤

錯誤：

Company#update_count_without_delay failed with TypeError: can't convert nil into String - 2 failed attempts 

完成：

1. 增加了 「寶石 'delayed_job_active_record'」 到的Gemfile
2. 在控制檯：「軌道生成delayed_job：active_record「
3. In console：」rake db：migrate「

我跟着這個指令：

If a method should always be run in the background, you can call #handle_asynchronously after the method declaration: 

class Device 
    def deliver 
    # long running method 
    end 
    handle_asynchronously :deliver 
end 

device = Device.new 
device.deliver 

型號：

require 'json' 
require 'net/http' 
require 'rubygems' 
require 'delayed_job' 

class Company < ActiveRecord::Base 
before_save :validate_fbid 

scope :toplikes, order("count desc").limit(20) 

attr_accessible :desc, :fbid, :name, :url, :count 

url_regex = /^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/ 


validates :name, :presence => true 

validates :url,  :presence => true, 
       :format  => { :with => url_regex }, 
       :uniqueness => { :case_sensitive => false } 
validates :fbid, :presence => true 
validates :desc, :presence => true 

def update_count 
    uri = URI("http://graph.facebook.com/" + fbid) 
    data = Net::HTTP.get(uri) 
    self.count = JSON.parse(data)['likes'] 
end 

handle_asynchronously :update_count  
end 

控制器：

def create 
    company = Company.new(params[:company]) 

    if company.save 
     @message = "New company created." 
     company.update_count 
     redirect_to root_path 
    else 
     @message = "Company create attempt failed. Please try again." 
     redirect_to new_path 
    end    
    end 

1. 補充說： 「需要 '的delayed_job'」 在模型上
2. 重啓我的服務器

Answer 1

您的Company#update_count錯誤。它應該是：

def update_count 
    uri = URI("http://graph.facebook.com/" + fbid) 
    data = Net::HTTP.get(uri) 
    # here you should use your local variable that you set in previous line 
    # instead of unset instance variable: 
    update_attribute(:count, JSON.parse(data)['count']) 
end