mothr_flickr.rb

# MothrFlickr, a small and light wrapper for talking to Flickr's API

require 'json'
require 'net/http'

module MothrFlickr
  #put your API Key in config/mothr_flickr.yml

  module Responsable
    def base_path
      @base_path ||= "/services/rest/?api_key=#{MothrFlickr.api_key}"
    end

    def hashed_response(method, params={})
      JSON.parse(
        rest_response(method, params.merge(:format => "json")).body[14..-2]
      )
    end

    def rest_response(method, params={})
      Net::HTTP.get_response("api.flickr.com",
        "#{base_path}&method=#{method}&#{params.to_param}")
    end
  end

  class Photo
    include Responsable

    SIZES = {
      :thumb => 't',
      :square => 's',
      :small => 'm'
    }

    attr_accessor :id, :secret, :server

    def initialize(photo_hash)
      self.id, self.secret, self.server = photo_hash['id'],
                                          photo_hash['secret'],
                                          photo_hash['server']
    end

    def url(size=:thumb)
      "http://farm4.static.flickr.com/#{server}/#{id}_#{secret}_#{SIZES[size]}.jpg"
    end
  end

  class Photoset
    include Responsable
    attr_accessor :id, :secret, :server, :title, :description, :photos

    def initialize(id)
      self.id = id
    end

    def get_photos
      photoset = hashed_response("flickr.photosets.getPhotos", :photoset_id => id)['photoset']
      photoset['photo'].map { |photo| Photo.new(photo) }
    end

    def photos
      @photos ||= get_photos
    end

    def photo_urls(size=:square)
      photos.map { |photo| photo.url(size) }
    end

  end

  class User
    include Responsable
    attr_accessor :nsid, :username

    def initialize(username)
      self.username = username
    end

    def get_photosets
      photosets = hashed_response("flickr.photosets.getList", :user_id => nsid)['photosets']
      photosets['photoset'].map { |photoset| Photoset.new(photoset['id']) }
    end

    def nsid
      @nsid ||= lookup(username)['user']['id']
    end

    def photosets
      @photosets ||= get_photosets
    end

    private

      def lookup(username)
        hashed_response("flickr.urls.lookupUser",
                        :url => "http://www.flickr.com/people/#{username}")
      end

  end

    def self.api_key
      @api_key ||= YAML.load_file("#{RAILS_ROOT}/config/mothr_flickr.yml")['api_key']
    end

    Hash.class_eval do
      def to_param
        self.map{ |k,v| "#{k}=#{v}" }.join("&")
      end
    end unless Object.const_defined?(:Rails)

end