Question

I was wondering if anyone can help me understanding the Ruby code below? I’m pretty new to Ruby programming and having trouble understanding the meaning of each functions.

When I run this with my twitter username and password as parameter, I get a stream of twitter feed samples. What do I need to do with this code to only display the hashtags?

I’m trying to gather the hashtags every 30 seconds, then sort from least to most occurrences of the hashtags.

Not looking for solutions, but for ideas. Thanks!

require 'eventmachine'
require 'em-http'
require 'json'

usage = "#{$0} <user> <password>"
abort usage unless user = ARGV.shift
abort usage unless password = ARGV.shift

url = 'https://stream.twitter.com/1/statuses/sample.json'

def handle_tweet(tweet)
  return unless tweet['text']
  puts "#{tweet['user']['screen_name']}: #{tweet['text']}"
end

EventMachine.run do
  http = EventMachine::HttpRequest.new(url).get :head => { 'Authorization' => [ user, password ] }

  buffer = ""

  http.stream do |chunk|
    buffer += chunk
    while line = buffer.slice!(/.+\r?\n/)
      handle_tweet JSON.parse(line)
    end
  end
end

Answer 1

puts "#{tweet['user']['screen_name']}: #{tweet['text']}"

That line shows you a user name followed by the content of the tweet.

Let’s take a step back for a sec.

Hash tags appear inside the tweet’s content–this means they’re inside tweet[‘text’]. A hash tag always takes the form of a # followed by a bunch of non-space characters. That’s really easy to grab with a regex. Ruby’s core API facilitates that via String#scan. Example:

"twitter is short #foo yawn #bar".scan(/\#\w+/) # => ["#foo", "#bar"]

What you want is something like this:

def handle_tweet(tweet)
  return unless tweet['text']
  # puts "#{tweet['user']['screen_name']}: #{tweet['text']}" # OLD
  puts tweet['text'].scan(/\#\w+/).to_s
end

tweet[‘text’].scan(/#\w+/) is an array of strings. You can do whatever you want with that array. Supposing you’re new to Ruby and want to print the hash tags to the console, here’s a brief note about printing arrays with puts:

puts array      # => "#foo\n#bar"
puts array.to_s # => '["#foo", "#bar"]'