Fetch full Atom feed from Google Reader

example.rb

require './reader'
reader = Reader.new '[email protected]', PASSWORD

# fetch only unread items
feed = reader.fetch_all(FEED_URL, true) do |entry|
  # something with each entry
end

puts feed

Gemfile

source 'https://rubygems.org'

gem 'curb'
gem 'nokogiri'
gem 'addressable'

reader.rb

require 'curb'
require 'nokogiri'
require 'addressable/uri'
require 'addressable/template'

class Reader
  LoginUrl = Addressable::URI.parse('https://www.google.com/accounts/ClientLogin')
  FeedUrl  = Addressable::Template.new 'https://www.google.com/reader/atom/feed/{feed}?n={n}&c={c}&ck={ck}'
  Params   = { :n => 1000, :client => 'ruby', :xt => 'user/-/state/com.google/read' }

  attr_reader :curl

  def initialize(email, password)
    @email, @password = email, password
  end
  
  class Error < StandardError
    attr_accessor :curl
  end
  
  def login
    login_url = LoginUrl.dup
    login_url.query_values = {
      :Email => @email, :Passwd => @password,
      :service => 'reader', :source => 'ruby',
      :continue => 'https://www.google.com/'
    }

    @curl_login = Curl::Easy.new(login_url)
    @curl_login.perform
    
    auth_data = @curl_login.body_str.split("\n").inject({}) { |hash, line|
      key, value = line.split('=')
      hash[key] = value
      hash
    }

    @curl = Curl::Easy.new do |c|
      c.headers['Authorization'] = "GoogleLogin auth=#{auth_data['Auth']}"
    end
    @curl.encoding = 'gzip,deflate'
  end
  
  def fetch_all(feed_url, unread = false, &block)
    continuation = nil
    timestamp = Time.now
    main = nil

    begin
      doc = fetch(feed_url, unread, timestamp, continuation)
      doc.at_xpath('//gr:continuation').tap { |el| continuation = el && el.text }
      entries = doc.xpath('//xmlns:entry')

      if main.nil?
        main = doc
      else
        parent = main.at_xpath('./xmlns:feed')
        entries.each { |entry| parent.add_child entry }
      end

      entries.each(&block) if block_given?
    end while continuation
    
    main
  end
  
  def fetch(feed_url, unread = false, timestamp = Time.now, continuation = nil)
    params = Params.merge :ck => timestamp.utc.to_i, :feed => feed_url.to_s
    params[:c] = continuation if continuation
    params.delete(:xt) unless unread

    login
    @curl.url = FeedUrl.expand(params)
    perform_request
    Nokogiri::XML @curl.body_str, nil, 'utf-8'
  end
  
  def perform_request
    p @curl.url.to_s
    @curl.perform
    unless @curl.response_code == 200
      raise @curl.header_str
    end
    @curl
  end
end