Get youtube links from a web site

youtubelinks.rb

#!/usr/bin/env ruby
require 'open-uri'
require 'kconv'
require 'nokogiri'
require 'json'

class Youtubelinks
    def videoid(id)
        url = "https://gdata.youtube.com/feeds/api/videos/#{id}?v=2&alt=json"
        begin
            JSON.parse(open(url).read)        
        rescue OpenURI::HTTPError => e
            p e
            nil
        rescue => e
            p e
            nil
        end
    end

    def extract(url)
        res = {}
        begin
            doc = Nokogiri::HTML(open(url.strip, "r:binary").read.toutf8)

            res[:url] = url.strip
            res[:title] = (doc/:title).text
            res[:videoids] = []

            patterns = [
                [:embed, [
                    [:src, /v\/([-\w]+)/]
                    ]
                ],
                [:iframe, [
                    [:src, /youtube.com\/embed\/([-\w]+)/]
                    ]
                ],
                [:a, [
                    [:href, /youtube.com\/watch\?v=([-\w]+)/],
                    [:href, /youtu\.be\/([-\w]+)/]]
                ]
            ]

            patterns.each do |tag, attrs|
                (doc/tag).each do |elem|
                    attrs.each do |attr, pat|
                        elem[attr] =~ pat
                        if $1
                            res[:videoids] << $1
                        end
                    end
                end
            end

            res[:videoids].uniq!
        rescue => err
            p err
            res = nil
        end
        return res
    end
    
end


@yt = Youtubelinks.new
yt = @yt.extract("http://matome.naver.jp/odai/2135486241817549301")
videoid = yt[:videoids][0]
p @yt.videoid(videoid)