flickr.rb

来自「用ruby on rails写的一个博客程序,还不错..ruby on rail」· RB 代码 · 共 90 行

require 'open-uri'
require 'time'
require 'rexml/document'

# Example:
#
# flickr = Flickr.new('http://www.flickr.com/services/feeds/photos_public.gne?id=40235412@N00&format=rss_200')
# flickr.pics.each do |pic|
#   puts "#{pic.title} @ #{pic.link} updated at #{pic.date}"
# end
#
class FlickrAggregation
  include REXML

  def choose(num)
    return pics unless pics.size > num
    bag = []
    set = pics.dup
    num.times {|x| bag << set.delete_at(rand(set.size))}
    bag
  end

  attr_accessor :url, :pics, :link, :title, :description

  # This object holds given information of a picture
  class Picture
    attr_accessor :link, :title, :date, :description

    def to_s
      title
    end

    def date=(value)
      @date = Time.parse(value)
    end

    def image
      description.scan( /(http:\/\/(farm1|farm2|static|photos).*?\.jpg)/ ).first.first 
    end
    def thumb
      image.gsub( /\_m\./, '_t.' )
    end
    def square
      image.gsub( /\_m\./, '_s.' )
    end
  end

  # Pass the url to the RSS feed you would like to keep tabs on
  # by default this will request the rss from the server right away and
  # fill the tasks array
  def initialize(url, refresh = true)
    self.pics  = []
    self.url    = url
    self.refresh if refresh
  end

  # This method lets you refresh the tasks int the tasks array
  # useful if you keep the object cached in memory and
  def refresh
    open(@url) do |http|
      parse(http.read)
    end
  end

private

  def parse(body)

    xml = Document.new(body)

    self.pics        = []
    self.link         = XPath.match(xml, "//channel/link/text()").to_s
    self.title        = XPath.match(xml, "//channel/title/text()").to_s
    self.description  = XPath.match(xml, "//channel/description/text()").to_s

    XPath.each(xml, "//item/") do |elem|

      picture = Picture.new
      picture.title       = XPath.match(elem, "title/text()").to_s
      picture.date        = XPath.match(elem, "pubDate/text()").to_s
      picture.link        = XPath.match(elem, "link/text()").to_s
      picture.description = XPath.match(elem, "description/text()").to_s

      pics << picture
    end
  end
end