server chat improved example

# 2013-04-29 johnpfeiffer - use telnet client
from twisted.internet.protocol import Factory
from twisted.protocols.basic import LineReceiver
from twisted.internet import reactor

class Chat( LineReceiver ):

    def __init__( self, users ):
        self.users = users
        self.name = None
        self.state = "GETNAME"

    def connectionMade( self ):
        self.sendLine( "What's your name?" )

    def connectionLost( self, reason ):
        if self.users.has_key( self.name ):
            del self.users[ self.name ]

    def lineReceived( self, line ):
        if self.state == "GETNAME":
            self.handle_GETNAME( line )
        else:
            self.handle_CHAT( line )

    def handle_GETNAME( self, name ):
        if self.users.has_key( name ):
            self.sendLine( "Name taken, please choose another." )
            return
        self.sendLine( "Welcome, %s!" % (name,) )
        self.name = name
        self.users[ name ] = self
        self.state = "CHAT"

    def handle_CHAT(self, message):
        message = "<%s> %s" % ( self.name, message )
        print "received", repr( message )       # better to log this in an async, maybe use Application with twistd
        for name, protocol in self.users.iteritems():
            if protocol != self:
                protocol.sendLine( message )


class ChatFactory( Factory ):

    def __init__( self ):
        self.users = dict() # maps user names to Chat instances

    def buildProtocol( self, addr ):
        return Chat( self.users )


reactor.listenTCP( 8123, ChatFactory() )
reactor.run()