A wampy Client

If you’re working from a Python shell or script you can connect to a Router as follows.

1. Router is running on localhost, port 8080, start and stop manually.

from wampy.peers import Client

client = Client()
client.start()  # connects to the Router & establishes a WAMP Session
# send some WAMP messages here
client.stop()  # ends Session, disconnects from Router

2. Router is running on localhost, port 8080, context-manage the Session

from wampy.peers import Client

with Client() as client:
    # send some WAMP messages here

# on exit, the Session and connection are gracefully closed

3. Router is on example.com, port 8080, context-managed client again

from wampy.peers import Client

with Client(url="ws://example.com:8080") as client:
    # send some WAMP messages here

# exits as normal

Under the hood wampy creates an instance of a Router representaion because a Session is a managed conversation between two Peers - a Client and a Router. Because wampy treats a Session like this, there is actually also a fourth method of connection, as you can create the Router instance yourself and pass this into a Client directly. This is bascically only useful for test and CI environments, or local setups during development, or for fun. See the wampy tests for examples and the wampy wrapper around the Crossbar.io Router.

Sending a Message

When a wampy client starts up it will send the HELLO message for you and begin a Session. Once you have the Session you can construct and send a WAMP message yourself, if you so choose. But wampy has the publish and rpc APIs so you don’t have to.

But if you did want to do it yourself, here’s an example how to...

Given a Crossbar.io server running on localhost on port 8080, a realm of “realm1”, and a remote procedure “foobar”, send a CALL message with wampy as follows:

In [1]: from wampy.peers.clients import Client

In [2]: from wampy.messages.call import Call

In [3]: client = Client()

In [4]: message = Call(procedure="foobar", args=(), kwargs={})

In [5]: with client:
            client.send_message(message)

This example assumes a Router running on localhost and a second Peer attached over the same realm who hjas registered the callee “foobar”

Note that in the example, as you leave the context managed function call, the client will send a GOODBYE message and your Session will end.

wampy does not want you to waste time constructing messages by hand, so the above can be replaced with:

In [1]: from wampy.peers.clients import Client

In [2]: client = Client()

In [5]: with client:
            client.rpc.foobar(*args, **kwargs)

Under the hood, wampy has the RpcProxy object that implements the rpc API.