XMLRPC

xml_rpc.rb

# config/environment.rb => require 'xmlrpc/client'

#XMLRPC::Config.const_set(:ENABLE_NIL_CREATE, true)
XMLRPC::Config.const_set(:ENABLE_NIL_PARSER, true) unless XMLRPC::Config.const_defined?(:ENABLE_NIL_PARSER)

module XmlRpc
  class Api
    class << self
      
      def method_missing(method, *args)
        call(method, *args)
      end

      def call(method, *args)
        client = XMLRPC::Client.new_from_uri(@host, nil, 90)
        begin
          return client.call(@prefix ? "#{@prefix}.#{method}" : method, *args)
        rescue Errno::ECONNREFUSED => e
          raise BadGateway.new
        rescue XMLRPC::FaultException => e
          # e.faultCode
          raise
        ensure
          begin
            client.instance_variable_get(:@http).finish
          rescue
          end
        end
      end
      
      def site(host, prefix = nil)
        @host = host
        @prefix = prefix != :default ? prefix : self.to_s.underscore.gsub(/_api$/, '')
      end
      
    end
  end
end

# app/apis/backend_api.rb

"""
class BackendApi < XmlRpc::Api

  site("127.0.0.1:8080")
  
  class << self
    # override the remote method ping to shout louder
    def ping
      super.upcase
    end

    # no need to define the remote method echo
  end

end


BackendApi.echo => "echo"
BackendApi.ping => "PONG"
"""