Log the homepage position of a Reddit post.

redditShot.js

var page = require("webpage").create(),
    url = 'http://reddit.com?limit=100';

page.open(url, function (status) {
  page.onUrlChanged = function(targetUrl) {
    console.log('New URL: ' + targetUrl);
    phantom.exit();
  };

  page.onCallback = function(msg) {
    page.render((new Date()).getTime()+'-reddit.jpg');
    phantom.exit();
  };

  page.viewportSize = {
    width: 1280,
    height: 720
  };

  if (status !== 'success') {
      console.log('Unable to load the address!');
      phantom.exit();
  } else {
    page.evaluate(function () {
      setTimeout(function () {
        window.callPhantom();
      }, 15000);
    });
  }
});

redditTrack.rb

require 'open-uri'
require 'json'

FINDER_BLOCK  = ->(c){c['data']['url'] == "https://youtu.be/mvK0UzFNw1Q"}
LIMIT         = 100

@cleanPos = 0
@pos      = 0

while true
  begin
    posts = JSON.parse(open("http://www.reddit.com/.json?limit=#{LIMIT}").read)['data']['children']

    newCleanPos = posts.reject{|c|c['data']['over_18']}.find_index(&FINDER_BLOCK) + 1
    newPos      = posts.find_index(&FINDER_BLOCK) + 1

    if (newPos != @pos) || (newCleanPos != @cleanPos)
      @cleanPos = newCleanPos
      @pos      = newPos

      str = "#{Time.now}: Video now at #{@pos} (#{@cleanPos} clean)"

      open('redditLog.txt', 'a'){|f| f << str}
      puts str
      
      # Take a screenshot for posterity
      `phantomjs redditShot.js`
      
    end
    
    # Be nice to Reddit
    sleep 2.5

  rescue
  end
end