app.py

from gevent import monkey
monkey.patch_all()

from flask import Flask, render_template, session, request
from flask.ext.socketio import SocketIO, emit, disconnect

app = Flask(__name__)
app.debug = True
app.config['SECRET_KEY'] = 'secret!'
socketio = SocketIO(app)

usernames = {}
number_of_users = 0


@app.route('/')
def index():
	return render_template('index.html')


# When the client emits 'connection', this listens and executes
@socketio.on('connection', namespace='/chat')
def user_connected():
	print 'User connected'


# When the client emits 'new message', this listens and executes
@socketio.on('new message', namespace='/chat')
def new_message(data):
	emit('new message', 
		{ 'username' : session['username'],
	 	'message': data }, broadcast=True )


# When client emits 'add user' this listens and executes
@socketio.on('add user', namespace='/chat')
def add_user(data):
	global usernames
	global number_of_users

	session['username'] = data
	usernames[data] = session['username']

	number_of_users += 1;

	emit('login', { 'numUsers' : number_of_users })
	emit('user joined', { 'username' : session['username'], 'numUsers': number_of_users }, broadcast=True)


@socketio.on('typing', namespace='/chat')
def typing_response():
	try:
		emit('typing', { 'username' : session['username'] }, broadcast=True )
	except:
		pass


@socketio.on('stop typing', namespace='/chat')
def stop_typing():
	try:
		emit('stop typing', { 'username' : session['username'] }, broadcast = True)
	except:
		pass


@socketio.on('disconnect', namespace='/chat')
def disconnect():
	global usernames
	global number_of_users

	
	try:
		del usernames[session['username']]
		number_of_users -= 1
		emit('user left', { 'username' : session['username'], 'numUsers' : number_of_users}, broadcast=True)

	except:
		pass



if __name__ == '__main__':
    socketio.run(app, host='0.0.0.0')