gistfile1.py

# Shamelessly stolen from the Twisted site

from twisted.internet import protocol, reactor, defer
from twisted.protocols.basic import LineReceiver
from twisted.internet.endpoints import TCP4ServerEndpoint

import json


class JsonEchoServer(LineReceiver):

    """
    Implements the server-side mechanisms
    """
    def __init__(self, *args):
        # LineReceiver.__init__(self, *args)
        self.acks = {}
        self.msgid = 0
    
    def connectionMade(self):
        print "Connected!"
        msg = {"from": "server", 
               "message": "connected", 
               "id": self.msgid}
        self.sendLine(json.dumps(msg))
        self.acks[self.msgid] = msg
        self.msgid += 1


    def lineReceived(self, line):
        """Receives a line from our remote"""
        print "Line!"
        m = None
        try:
            m = json.loads(line)
        except json.JSONDecodeError as e:
            self.sendLine(json.dumps(
                {
                    "from": "server",
                    "message": "json parse error {error}".format(e)}
                ))
            print "received non-json-decodable string"
            return

        self.sendLine(json.dumps({"acknowledge": m["id"]}))
        self.sendLine(json.dumps(
                { "from": "EchoServer", "message": "%s said '%s'" % ( m["from"], m["message"] ) }
            )
        )

        # if "message" in m:
        #     self.sendLine(json.dumps(
        #         { "from": "EchoServer", "message": "%s said '%s'" % ( m["from"], m["message"] ) }
        #     ))
        # elif "acknowledge" in m:
        #     if m["acknowledge"] not in self.acks:
        #         self.sendLine(
        #             json.dumps({"from": "EchoServer", "message": "invalid ID to ack" }))
        #     del self.acks[m["acknowledge"]]
        #     print "{id} acknowledged".format(id=m["acknowledge"])

        

class EchoFactory(protocol.Factory):
    def buildProtocol