amazon_search.rb

#!/usr/bin/env ruby -Ku

require 'net/http'; Net::HTTP.version_1_2
require 'rexml/document'

module Atok_plugin
  AWS_ACCESS_KEY_ID = '0123456789ABCDEFGHIJ'      # あなたの「AWS Access Key ID」に置き換えてください。

  def run_process(request)
    doc = REXML::Document.new(fetch_amazon(request['composition_string']))

    candidates = doc.elements.to_a('/ItemSearchResponse/Items/Item').map do |item|
      candidate = {'hyoki' => '',
                   'comment' => '',
                   'alternative' => '',
                   'alternative_type' => 'url_jump_string'}

      candidate['alternative'] << item.elements['DetailPageURL'].text

      creators = []
      item.elements.each('ItemAttributes/*') do |item_attribute|
        case item_attribute.name
        when 'Title'; candidate['hyoki'] << item_attribute.text
        when 'ListPrice'; candidate['comment'] << item_attribute.elements['FormattedPrice'].text
        when 'Creator'; creators << "(#{item_attribute.elements['@Role'].value})#{item_attribute.text}"
        end
      end
      candidate['comment'] << ('\\n' << creators.join('\\n')) unless creators.empty?

      candidate
    end

    {'candidate' => candidates}
  rescue TimeoutError => evar
    nil
  rescue => evar
    nil
  end

  private
  def fetch_amazon(keywords)
    url = 'http://ecs.amazonaws.jp/onca/xml?Service=AWSECommerceService&Version=2008-10-07' <<
          "&AWSAccessKeyId=#{AWS_ACCESS_KEY_ID}" <<
          "&Operation=ItemSearch" <<
          "&SearchIndex=Blended" <<
          "&ResponseGroup=ItemAttributes" <<
          "&Keywords=#{URI.encode(keywords)}"
    http_response = Net::HTTP.get_response(URI.parse(url))
    unless http_response.is_a?(Net::HTTPOK)
      raise 'Invalid http response.'
    else
      http_response.body
    end
  end
end