sync / async API with rack-client

rack-client-em-http.rb

require 'rack/client'
require 'yajl'
require 'pp'

require 'eventmachine'
require 'em-synchrony'
require 'em-synchrony/em-http'

module Rack
  module Client
    class Defaults
      include Rack::Client::DualBand

      def initialize(app)
        @app = app
      end

      def sync_call(env)
        env['QUERY_STRING'] += '&appkey=demo'
        response  = Response.new(*@app.call(env))

        response.finish
      end

      def async_call(env, &b)
        env['QUERY_STRING'] += '&appkey=demo'

        @app.call(env) do |response_parts|
          response  = Response.new(*response_parts)
          yield response.finish
        end
      end
    end
  end
end

url = "http://api.postrank.com/v2/feed/info?id=igvita.com"

EM.synchrony do
  client = Rack::Client.new do
    use Rack::Client::Defaults
    run Rack::Client::Handler::EmHttp
  end

  # async request
  client.get url do |resp|
    pp Yajl::Parser.parse(resp.body)
  end

  sleep(1)

  # fibered sync request via em-synchrony
  pp client.get url

  EM.stop
end