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POpython Socket.IO client for sending broadcast messages to TornadIO2 server
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copied!<p>I am building a realtime web application. <strong>I want to be able to send broadcast messages from the server-side implementation of my python application.</strong></p> <p>Here is the setup:</p> <ul> <li><strong><a href="http://socket.io/" rel="noreferrer">socketio.js</a></strong> on the client-side</li> <li><strong><a href="https://github.com/mrjoes/tornadio2" rel="noreferrer">TornadIO2</a></strong> server as Socket.IO server</li> <li><strong>python</strong> on the server-side (<strong><a href="https://www.djangoproject.com/" rel="noreferrer">Django</a></strong> framework)</li> </ul> <p>I can succesfully send socket.io messages from the client to the server. The server handles these and can send a response. In the following i will describe how i did that.</p> <h2>Current Setup and Code</h2> <p>First, we need to define a Connection which handles socket.io events:</p> <pre><code>class BaseConnection(tornadio2.SocketConnection): def on_message(self, message): pass # will be run if client uses socket.emit('connect', username) @event def connect(self, username): # send answer to client which will be handled by socket.on('log', function) self.emit('log', 'hello ' + username) </code></pre> <p>Starting the server is done by a Django management custom method:</p> <pre><code>class Command(BaseCommand): args = '' help = 'Starts the TornadIO2 server for handling socket.io connections' def handle(self, *args, **kwargs): autoreload.main(self.run, args, kwargs) def run(self, *args, **kwargs): port = settings.SOCKETIO_PORT router = tornadio2.TornadioRouter(BaseConnection) application = tornado.web.Application( router.urls, socket_io_port = port ) print 'Starting socket.io server on port %s' % port server = SocketServer(application) </code></pre> <p>Very well, the server runs now. Let's add the client code:</p> <pre><code><script type="text/javascript"> var sio = io.connect('localhost:9000'); sio.on('connect', function(data) { console.log('connected'); sio.emit('connect', '{{ user.username }}'); }); sio.on('log', function(data) { console.log("log: " + data); }); </script> </code></pre> <p>Obviously, <code>{{ user.username }}</code> will be replaced by the username of the currently logged in user, in this example the username is "alp".</p> <p>Now, every time the page gets refreshed, the console output is:</p> <pre><code>connected log: hello alp </code></pre> <p>Therefore, invoking messages and sending responses works. <em>But now comes the tricky part.</em></p> <h2>Problems</h2> <p>The response "hello alp" is sent only to the invoker of the socket.io message. I want to broadcast a message to all connected clients, so that they can be informed in realtime if a new user joins the party (for example in a chat application).</p> <p>So, here are my questions:</p> <ol> <li><p>How can i send a broadcast message to all connected clients?</p></li> <li><p>How can i send a broadcast message to multiple connected clients that are subscribed on a specific channel?</p></li> <li><p>How can i send a broadcast message anywhere in my python code (outside of the <code>BaseConnection</code> class)? Would this require some sort of Socket.IO client for python or is this builtin with TornadIO2?</p></li> </ol> <p>All these broadcasts should be done in a reliable way, so i guess websockets are the best choice. But i am open to all good solutions.</p>

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