在MongoDB中使用tweetstream存储推文失败，错误如下

Question

我刚刚开始学习ruby和mongodb的概念。这就是我尝试运行的脚本

require 'rubygems'
require 'tweetstream'
require 'mongo'

TweetStream.configure do |config|
  config.consumer_key = '<key>'
  config.consumer_secret = '<secret>'
  config.oauth_token = '<token>'
  config.oauth_token_secret = '<token_secret'
  config.auth_method = :oauth
end

connection = Mongo::Connection.new

db = connection.db("tweetsDB")

tweets = db.collection("tweets")

client = TweetStream::Client.new

client.on_error do |message|
  puts message
end

client.follow(<user_id>,<user_id>) do |status|
        id = tweets.insert(status, :safe => true)
end

注意:对于这篇文章，我已经删除了上面脚本中的所有静态私有值。

Mongo、bson、bson_ext版本- 1.7.0

错误消息

NoMethodError: undefined method `has_key?' for #<Twitter::Tweet:0x7f21cd14cf08>
    /var/lib/gems/1.8/gems/bson-1.7.0/lib/bson/types/object_id.rb:93:in `create_pk'
    /var/lib/gems/1.8/gems/mongo-1.7.0/lib/mongo/collection.rb:360:in `insert'
    /var/lib/gems/1.8/gems/mongo-1.7.0/lib/mongo/collection.rb:360:in `collect!'
    /var/lib/gems/1.8/gems/mongo-1.7.0/lib/mongo/collection.rb:360:in `insert'
    tracker.rb:28
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:525:in `call'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:525:in `invoke_callback'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:533:in `yield_message_to'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:471:in `respond_to'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:411:in `connect'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:296:in `call'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:296:in `invoke_callback'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:143:in `handle_stream'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:193:in `on_body'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:192:in `each'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:192:in `on_body'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:74:in `<<'
    /var/lib/gems/1.8/gems/em-twitter-0.2.1/lib/em-twitter/connection.rb:74:in `receive_data'
    /var/lib/gems/1.8/gems/eventmachine-1.0.0/lib/eventmachine.rb:187:in `run_machine'
    /var/lib/gems/1.8/gems/eventmachine-1.0.0/lib/eventmachine.rb:187:in `run'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:385:in `start'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:128:in `filter'
    /var/lib/gems/1.8/gems/tweetstream-2.3.0/lib/tweetstream/client.rb:106:in `follow'
    tracker.rb:27

Answer 1

如果您想盲目地将所有内容都转储到MongoDB中，那么只需执行以下操作：

client.follow(<user_id>,<user_id>) do |status|
  data = status.to_hash
  id = tweets.insert(data)
end

如果你想变得更有选择性，那么你可以试着这样做：

# only add the following fields to the database
ONLY = %w{created_at text geo coordinate id_str}

client.follow(<user_id>,<user_id>) do |status|
  data = status.to_hash.select{|k,v| ONLY.include?(k.to_s)}
  id = tweets.insert(data)
end

或者：

# add everything except the following fields to the database
EXCEPT = %w{entities}

client.follow(<user_id>,<user_id>) do |status|
  data = status.to_hash.reject{|k,v| EXCEPT.include?(k.to_s)}
  id = tweets.insert(data)
end

Answer 2

从docs来看，Client.follow只返回一个通用的ruby对象。您必须从对象中提取相关字段，并将它们提取到json (或者，更明智的做法是mongoid对象)中，以发送到数据库。

Answer 3

has_key？是Hash超类中可用的方法。它试图做的是制作一个json字符串来传递给Mongo。除了你在传递一个字符串，has_key？不是String类的一部分。只需将其转换为哈希，您就应该可以运行了。

client.follow(<user_id>,<user_id>) do |status|
    id = tweets.insert({:status => status.text}, :safe => true)
end