What it's supposed to look like

gistfile1.rb

require 'rubygems'
require 'nokogiri'
require 'open-uri'
require 'net/http'

class NokoLinkSet < Nokogiri::XML::NodeSet
  # Create new LinkSet object from the url and the selector
  def initialize(url, selector)
    if not ( url.nil? and selector.nil? )
      @raw_html = open(url)
      @elements = Nokogiri::HTML(@raw_html).css(selector)
    else
      raise ArgumentException, 'Need to supply URL and Selector to initialize LinkSet Object'
    end
  end

  # Validate and clean those elements that do not correspond to given subject
  # Tutorialspoint links that pertain to the subject contain the subject name
  # Eg: www.tutorialspoint.com/java/sometut.htm
  def clean(subject)
    # Filter out anything that is not course material
    @elements = @elements.map{ |@element| @element if @element['href'].include?(subject) }

    # Get rid of nils at the end of the Array
    while @elements[-1].nil?
      @elements.pop
    end
  end
# Get the count of relevant links
@link_count = @elements.length
end