Client

Built-in

ws4py comes with various client implementation but they roughly share the same aspects when your application needs one.

An example is better than any word so let’s have a look at a basic client:

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from ws4py.client.threadedclient import WebSocketClient

class DummyClient(WebSocketClient):
    def opened(self):
        def data_provider():
            for i in range(1, 200, 25):
                yield "#" * i

        self.send(data_provider())

        for i in range(0, 200, 25):
            print i
            self.send("*" * i)

    def closed(self, code, reason):
        print "Closed down", code, reason

    def received_message(self, m):
        print "=> %d %s" % (len(m), str(m))
        if len(str(m)) == 175:
            self.close(reason='Bye bye')

if __name__ == '__main__':
    try:
        ws = DummyClient('ws://localhost:9000/', protocols=['http-only', 'chat'])
        ws.connect()
    except KeyboardInterrupt:
        ws.close()

This example demonstrates how to implement a client, here based on a thread-model, that is able to send and receive messages from a connected endpoint at ws://localhost:9000/.

In this snippet, when the handshake is successful, the opened() method is called and within this method we immediatly send to the server a bunch of messages. First we demonstrate how you can use a generator to do so, then we simply send strings.

Assuming the server echoes messages as they arrive, the received_message(message) method will print out the messages returned by the server and simply closes the connection once it receives the last sent messages , which length is 175.

Finally the closed(code, reason=None) method is called with the code and reason given by the server.

Tornado

If you are using a Tornado backend you may use the Tornado client that ws4py provides as follow:

from ws4py.client.tornadoclient import WebSocketClient

The previous example runs exactly in the same way.

gevent

If you are using a gevent backend you may use the gevent client that ws4py provides as follow:

from ws4py.client.geventclient import WebSocketClient

The previous example runs exactly in the same way.

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