Authors of SocketTornad.IO project:
There's already library which already implements Socket.IO integration using Tornado framework - SocketTornad.IO, but it was not finished, has several known bugs and not very well structured.
TornadIO is different from SocketTornad.IO library in following aspects:
- Simpler internal design, easier to maintain/extend
- No external dependencies (except of the Tornado itself and simplejson on python < 2.6)
- Properly handles on_open/on_close events for polling transports
- Proper Socket.IO protocol parser
- Proper unicode support
- Actively maintained
In order to start working with the TornadIO library, you need to know some basic concepts on how Tornado works. If you don't, please read Tornado tutorial, which can be found here.
If you're familiar with Tornado, do following to add support for Socket.IO to your application:
1. Derive from tornadio.SocketConnection class and override on_message method (on_open/on_close are optional):
class MyConnection(tornadio.SocketConnection): def on_message(self, message): pass
2. Create handler object that will handle all socket.io transport related functionality:
MyRouter = tornadio.get_router(MyConnection)
3. Add your handler routes to the Tornado application:
application = tornado.web.Application( [MyRouter.route()], socket_io_port = 8000)
- Start your application
- You have your socket.io server running at port 8000. Simple, right?
SocketConnection class implements three overridable methods:
on_opencalled when new client connection was established.
on_messagecalled when message was received from the client. If client sent JSON object, it will be automatically decoded into appropriate Python data structures.
on_closecalled when client connection was closed (due to network error or timeout)
send() method which is used to send data to this client. Input parameter
can be one of the:
- String/unicode string - sent as is (though with utf-8 encoding)
- Arbitrary python object - encoded as JSON string automatically
- List of python objects/strings - encoded as series of the socket.io messages using one of the rules above.
You can configure your handler by passing settings to the
get_router function as a
- enabled_protocols: This is a
listof the socket.io protocols the server will respond requests for. Possibilities are:
- websocket: HTML5 WebSocket transport
- flashsocket: Flash emulated websocket transport. Requires Flash policy server running on port 843.
- xhr-multipart: Works with two connections - long GET connection with multipart transfer encoding to receive updates from the server and separate POST requests to send data from the client.
- xhr-polling: Long polling AJAX request to read data from the server and POST requests to send data to the server. If message is available, it will be sent through open GET connection (which is then closed) or queued on the server otherwise.
- jsonp-polling: Similar to the xhr-polling, but pushes data through the JSONp.
- htmlfile: IE only. Creates HTMLFile control which reads data from the server through one persistent connection. POST requests are used to send data back to the server.
- session_check_interval: Specifies how often TornadIO will check session container for expired session objects. In seconds.
- session_expiry: Specifies session expiration interval, in seconds. For polling transports it is actually maximum time allowed between GET requests to consider virtual connection closed.
- heartbeat_interval: Heartbeat interval for persistent transports. Specifies how often heartbeat events should be sent from the server to the clients.
- xhr_polling_timeout: Timeout for long running XHR connection for xhr-polling transport, in seconds. If no data was available during this time, connection will be closed on server side to avoid client-side timeouts.
Best Way: SocketServer
We provide customized version (shamelessly borrowed from the SocketTornad.IO library) of the HttpServer, which simplifies start of the your TornadIO server.
To start it, do following (assuming you created application object before):
if __name__ == "__main__": socketio_server = SocketServer(application)
There is a chatroom example application from the SocketTornad.IO library, contributed by
swanson. It is in the
Simple ping/pong example to measure network performance. It is in the
Simple ping/pong example with chat-like interface with selectable transports. It is in the