Example refactoring using Introduce Explaining Variable

before.rb

  def convert_to_media(link)
    if URI.split(link)[5].end_with? 'png', 'gif', 'jpeg'
      "<img src=\"#{link}\" />"
    elsif URI.split(link)[2].include?("youtube") && URI.split(link)[7] && URI.split(link)[7].include?('v=')
      video_id = URI.split(link)[7][2..-1]
      "<iframe width=\"560\" height=\"315\" src=\"http://www.youtube.com/embed/#{video_id}\" frameborder=\"0\" allowfullscreen></iframe>"
    elsif URI.split(link)[2].include? "youtu.be"
      video_id = URI.split(link)[5].gsub('/', '')
      "<iframe width=\"560\" height=\"315\" src=\"http://www.youtube.com/embed/#{video_id}\" frameborder=\"0\" allowfullscreen></iframe>"
    else
      "<a href=\"#{link}\">#{link}</a>"
    end
  end

introduce_explaining_variable.rb

  def convert_to_media(link)
    url_components = URI.split(link)
    host = url_components[2]
    path = url_components[5]
    query = url_components[7]

    if path.end_with? 'png', 'gif', 'jpeg'
      "<img src=\"#{link}\" />"
    elsif host.include?("youtube") && query && query.include?('v=')
      video_id = query[2..-1]
      "<iframe width=\"560\" height=\"315\" src=\"http://www.youtube.com/embed/#{video_id}\" frameborder=\"0\" allowfullscreen></iframe>"
    elsif host.include? "youtu.be"
      video_id = path.gsub('/', '')
      "<iframe width=\"560\" height=\"315\" src=\"http://www.youtube.com/embed/#{video_id}\" frameborder=\"0\" allowfullscreen></iframe>"
    else
      "<a href=\"#{link}\">#{link}</a>"
    end
  end