在spawn_threadpool中使用Eventmachine gem - > block

Question

按照本教程（http://arfon.org/twitter-streaming-with-eventmachine-and-dynamodb）嘗試啓動Amazon監聽環境。接收特定的推文並將它們添加到一個Dynamo數據庫（通過一個新線程）。

require 'aws-sdk' 
require 'eventmachine' 
require 'tweetstream' 

AWS_ACCESS_KEY = 'HERE IT IS' 
AWS_SECRET_KEY = 'YES HERE' 


dynamo_db = AWS::DynamoDB.new(:access_key_id => AWS_ACCESS_KEY, :secret_access_key => AWS_SECRET_KEY) 

table = dynamo_db.tables['tweets'] 
table.load_schema 

TweetStream.configure do |config| 
    config.username = 'geezlouis' 
    config.password = 'password' 
    config.auth_method = :basic 
end 

EM.run{ 
    client = TweetStream::Client.new 

    def write_to_dynamo(status) 
    EM.defer do 
     tweet_hash = {:user_id => status.user.id, 
        :created_at => status.created_at, 
        :id => status.id, 
        :screen_name => status.user.screen_name} 

     begin 
     table.items.create(tweet_hash) 
     rescue Exception => e 
     puts e.message 
     puts e.backtrace.inspect 
     end 
    end 
    end 

    client.track("Romney", "Gingrich") do |status| 
    write_to_dynamo(status) 
    end 
} 

未定義的局部變量或方法'表「主：對象

["tweets.rb:31:in `block in write_to_dynamo'", "/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:1060:in 

call'", "/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:1060:in 塊spawn_threadpool」」使用EventMachine的時候產卵線程我碰到下面的一切工作但罰款]

Answer 1

表是一個局部變量，所以你不能從方法範圍中得到它。

你想以下幾點：

require 'aws-sdk' 
require 'eventmachine' 
require 'tweetstream' 

AWS_ACCESS_KEY = 'HERE IT IS' 
AWS_SECRET_KEY = 'YES HERE' 


dynamo_db = AWS::DynamoDB.new(:access_key_id => AWS_ACCESS_KEY, :secret_access_key => AWS_SECRET_KEY) 

table = dynamo_db.tables['tweets'] 
table.load_schema 

TweetStream.configure do |config| 
    config.username = 'geezlouis' 
    config.password = 'password' 
    config.auth_method = :basic 
end 

EM.run{ 
    client = TweetStream::Client.new 

    def write_to_dynamo(status, table) 
    EM.defer do 
     tweet_hash = {:user_id => status.user.id, 
        :created_at => status.created_at, 
        :id => status.id, 
        :screen_name => status.user.screen_name} 

     begin 
     table.items.create(tweet_hash) 
     rescue Exception => e 
     puts e.message 
     puts e.backtrace.inspect 
     end 
    end 
    end 

    client.track("Romney", "Gingrich") do |status| 
    write_to_dynamo(status, table) 
    end 
} 

您也可能會希望停止捕獲「異常」，而是趕上「StandardError的」，否則你將無法例如CTRL + C程序。