Twisted/wxPython Problem...

[PeterG]

Hi,

I am relatively new to Python, and am learning it as part of a
university
module...

Im currently undertaking a project to create an IM server and IM gui
client.

I have a very basic server, and a basic gui client.  I can get my
client to
connect to my server, but cant get it to disconnect or send messages to
the
server.

I am getting the following error when I click on the 'Disconnect'
button -
AttributeError: 'NoneType' object has no attribute 'loseConnection'

I have attached the code for both the server and the client below this.

I am using the Twisted and wxPython packages, and as previously stated
am
fairly new to Python so would appreciate any help anyone can offer.

Thanks,

Peter

server.py
------------
from twisted.internet import reactor
from twisted.internet.protocol import Factory
from twisted.protocols.basic import LineReceiver

factory = Factory()
#this is a list
factory.transports = []
#this is a dictionary
userNicknames = {}

class SimpleLogger(LineReceiver):

    def connectionMade(self):
	self.factory.transports.append(self.transport)
	userNicknames[self.transport.client] = ''
        #write to the client
	self.transport.write("Welcome to Chris & Pete's chat server!\r\n")
	self.transport.write("Please enter your nickname:\r\n")
	#prints on the server screen
	print 'got connection from', self.transport.client

    def connectionLost(self, reason):
        who = str(userNicknames.get(self.transport.client)) + '
Disconnected' + '\r\n'
        print who
        userNicknames[self.transport.client] = ''
	for transport in self.factory.transports:
	    transport.write(who)


    def lineReceived(self, line):
        #if the users nickname in the dictionary (userNicknames) is
blank, create a
        #value in the dictionary with the line just received.
        #if the user already has a nickname then it must be a message
they are writing.
        #So instead print out the message
        if userNicknames.get(self.transport.client) == '':
            #if the username is already in the dictionary someone is
            #already using it so ask for another one.
            if line in userNicknames.values():
                self.transport.write('That nickname is already in use,
please use another:')
            else:
                userNicknames[self.transport.client] = line
                #print userNicknames.items()
                message = userNicknames.get(self.transport.client) + '
has joined\r\n'
                for transport in self.factory.transports:
                    transport.write(message)

        else:
            message = userNicknames.get(self.transport.client) + ': ' +
line + '\r\n'
            for transport in self.factory.transports:
                transport.write(message)

factory.protocol = SimpleLogger

reactor.listenTCP(1234, factory)
reactor.run()


client.py
----------
from wxPython.wx import *
import wx
from twisted.internet import wxreactor
wxreactor.install()
from twisted.internet import reactor
from twisted.internet.protocol import Protocol, ClientCreator

class imApp(wxApp, Protocol):

    def buildMe(self):
        frame = wx.Frame(None, title="IM Client", size=(800, 550))

        bkg = wx.Panel(frame)

        global ipAdd
        global portNo
        global messages
        global newMsg

        ipAddLab = wx.StaticText(bkg, -1, 'IP Address: ')
        ipAdd = wx.TextCtrl(bkg)
        ipAdd.SetToolTipString('Please enter the server IP address
here.')
        spacer1 = wx.StaticText(bkg, -1, '                  ')
        portNoLab = wx.StaticText(bkg, -1, 'Port No: ')
        portNo = wx.TextCtrl(bkg)
        portNo.SetToolTipString('Please enter the port number the
server is using here.')
        spacer2 = wx.StaticText(bkg, -1, '                  ')
        connectButton = wx.Button(bkg, label='Connect')
        connectButton.SetToolTipString('Click this button to connect to
the server.')
        connectButton.Bind(wx.EVT_BUTTON, self.connectMe)
        disconnectButton = wx.Button(bkg, label='Disconnect')
        disconnectButton.SetToolTipString('Click this button to
disconnect from the server.')
        disconnectButton.Bind(wx.EVT_BUTTON, self.disconnectMe)
        messages = wx.TextCtrl(bkg, style=(wx.TE_MULTILINE |
wx.HSCROLL))
        newMsg = wx.TextCtrl(bkg)
        sendButton = wx.Button(bkg, label='Send')
        sendButton.SetToolTipString('Click this button to send a
message to the server.')
        sendButton.Bind(wx.EVT_BUTTON, self.sendMe)

        hbox1 = wx.BoxSizer()

        hbox1.Add(ipAddLab, proportion=0, flag=wx.EXPAND)
        hbox1.Add(ipAdd, proportion=0, flag=wx.EXPAND)
        hbox1.Add(spacer1, proportion=0, flag=wx.EXPAND)
        hbox1.Add(portNoLab, proportion=0, flag=wx.EXPAND)
        hbox1.Add(portNo, proportion=0, flag=wx.EXPAND)
        hbox1.Add(spacer2, proportion=0, flag=wx.EXPAND)
        hbox1.Add(connectButton, proportion=0, flag=wx.LEFT, border=5)
        hbox1.Add(disconnectButton, proportion=0, flag=wx.LEFT,
border=5)

        hbox2 = wx.BoxSizer()
        hbox2.Add(newMsg, proportion=1, flag=wx.EXPAND | wx.LEFT |
wx.LEFT | wx.LEFT, border=5)
        hbox2.Add(sendButton, proportion=0, flag=wx.LEFT, border=5)

        vbox = wx.BoxSizer(wx.VERTICAL)
        vbox.Add(hbox1, proportion=0, flag=wx.EXPAND | wx.ALL,
border=5)
        vbox.Add(messages, proportion=1, flag=wx.EXPAND | wx.LEFT |
wx.LEFT | wx.LEFT, border=5)
        vbox.Add(hbox2, proportion=1, flag=wx.EXPAND | wx.ALL,
border=5)

        bkg.SetSizer(vbox)

        ipAdd.WriteText('localhost')
        portNo.WriteText('1234')
        frame.Show(true)
        return true

    def sendMe(self, e):
        msg = newMsg.GetValue() + '\n'
        messages.WriteText(msg)
        newMsg.SetValue('')

    def disconnectMe(self, e):
        messages.WriteText('Disconnecting from server...\n')
        self.transport.loseConnection()

    def connectMe(self, e):
        messages.WriteText('Connecting to server...\n')
        c = ClientCreator(reactor, imApp)
        ip = str(ipAdd.GetValue())
        port = int(portNo.GetValue())
        c.connectTCP(ip, port)

def mainProg():
    app = imApp(0)
    app.buildMe()
    reactor.registerWxApp(app)
    reactor.run()

if __name__ == '__main__':
    mainProg()